Changeset 349 for palm/trunk/DOC
- Timestamp:
- Jul 8, 2009 11:18:02 AM (16 years ago)
- Location:
- palm/trunk/DOC/app
- Files:
-
- 2 edited
-
chapter_3.8.html (modified) (2 diffs)
-
chapter_4.1.html (modified) (1 diff)
Legend:
- Unmodified
- Added
- Removed
-
TabularUnified palm/trunk/DOC/app/chapter_3.8.html ¶
r344 r349 21 21 <H3 STYLE="line-height: 100%">3.8 Coupled model runs</H3> 22 22 <P STYLE="line-height: 100%">Starting from version 3.4 PALM allows 23 coupled atmosphere-ocean model runs. By analogy with the modular 24 structure of PALM, <B>mrun</B> starts the coupled model as two 23 coupled atmosphere-ocean model runs. If MPI-2 support is available, <B>mrun</B> starts the coupled model as two 25 24 concurrent executables, the atmosphere version and the ocean 26 version of PALM.</P>25 version in analogy with the modular structure of PALM.</P> 27 26 <P STYLE="line-height: 100%">Currently, the coupler is at an 28 27 experimental stage using either a MPI2 (more flexible) or a MPI1 … … 45 44 configuration file. Otherwise, PALM will use a coupling via MPI1. To 46 45 start a coupled model run, this must be requested with the <B>mrun</B> 47 option <TT><FONT SIZE=2>-Y â#1 #2â</FONT></TT> <TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>,48 where </ FONT></FONT></TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#1</FONT></FONT></TT><TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>49 is the number of processors for the atmospheric and </FONT></FONT></TT>< TT><FONT FACE="Andale Mono"><FONT SIZE=2>#2</FONT></FONT></TT><TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>46 option <TT><FONT SIZE=2>-Y â#1 #2â</FONT></TT>, 47 where </TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#1</FONT></FONT></TT> 48 is the number of processors for the atmospheric and </FONT></FONT></TT><FONT FACE="Andale Mono"><FONT SIZE=2>#2</FONT></FONT></TT> 50 49 the number of processors for the oceanic version of PALM (Please note 51 that currently only one-to-one topologies are supported and </FONT></FONT></TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#1</FONT></FONT></TT> <TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>52 must be equal to </FONT></FONT></TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#2</FONT></FONT></TT>< TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>).53 </FONT></FONT></TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3> Thi</FONT></FONT>s50 that currently only one-to-one topologies are supported and </FONT></FONT></TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#1</FONT></FONT></TT> 51 must be equal to </FONT></FONT></TT><TT><FONT FACE="Andale Mono"><FONT SIZE=2>#2</FONT></FONT></TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3>). 52 </FONT></FONT></TT><FONT FACE="Times New Roman, serif"><FONT SIZE=3></FONT></FONT>This 54 53 tells <B>mrun</B> to start two PALM executables. Coupled runs are 55 54 only possible in parallel mode, which means that the <B>mrun</B> -
TabularUnified palm/trunk/DOC/app/chapter_4.1.html ¶
r344 r349 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> 2 <HTML> 3 <HEAD> 4 <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=utf-8"> 5 <TITLE>PALM chapter 4.1</TITLE> 6 <META NAME="GENERATOR" CONTENT="OpenOffice.org 3.0 (Unix)"> 7 <META NAME="CREATED" CONTENT="0;0"> 8 <META NAME="CHANGED" CONTENT="20090624;16094200"> 9 </HEAD> 10 <BODY LANG="en-US" DIR="LTR"> 11 <H3><A NAME="chapter4.1"></A>4.1 Initialization parameters</H3> 12 <P STYLE="margin-bottom: 0in"><BR> 13 </P> 14 <TABLE WIDTH=1643 BORDER=1 CELLPADDING=2 CELLSPACING=3> 15 <COL WIDTH=126> 16 <COL WIDTH=45> 17 <COL WIDTH=159> 18 <COL WIDTH=1280> 19 <TR> 20 <TD WIDTH=126> 21 <P><FONT SIZE=4><B>Parameter name</B></FONT></P> 22 </TD> 23 <TD WIDTH=45> 24 <P><FONT SIZE=4><B>Type</B></FONT></P> 25 </TD> 26 <TD WIDTH=159> 27 <P><FONT SIZE=4><B>Default</B></FONT> <BR><FONT SIZE=4><B>value</B></FONT></P> 28 </TD> 29 <TD WIDTH=1280> 30 <P><FONT SIZE=4><B>Explanation</B></FONT></P> 31 </TD> 32 </TR> 33 <TR> 34 <TD WIDTH=126> 35 <P><A NAME="adjust_mixing_length"></A><B>adjust_mixing_length</B></P> 36 </TD> 37 <TD WIDTH=45> 38 <P>L</P> 39 </TD> 40 <TD WIDTH=159> 41 <P><I>.F.</I></P> 42 </TD> 43 <TD WIDTH=1280> 44 <P STYLE="font-style: normal">Near-surface adjustment of the 45 mixing length to the Prandtl-layer law. 46 </P> 47 <P>Usually the mixing length in LES models l<SUB>LES</SUB> depends 48 (as in PALM) on the grid size and is possibly restricted further 49 in case of stable stratification and near the lower wall (see 50 parameter <A HREF="#wall_adjustment">wall_adjustment</A>). With 51 <B>adjust_mixing_length</B> = <I>.T.</I> the Prandtl' mixing 52 length l<SUB>PR</SUB> = kappa * z/phi is calculated and the mixing 53 length actually used in the model is set l = MIN (l<SUB>LES</SUB>, 54 l<SUB>PR</SUB>). This usually gives a decrease of the mixing 55 length at the bottom boundary and considers the fact that eddy 56 sizes decrease in the vicinity of the wall. 57 </P> 58 <P STYLE="font-style: normal"><B>Warning:</B> So far, there is no 59 good experience with <B>adjust_mixing_length</B> = <I>.T.</I> ! 60 </P> 61 <P>With <B>adjust_mixing_length</B> = <I>.T.</I> and the 62 Prandtl-layer being switched on (see <A HREF="#prandtl_layer">prandtl_layer</A>) 63 <I>'(u*)** 2+neumann'</I> should always be set as the lower 64 boundary condition for the TKE (see <A HREF="#bc_e_b">bc_e_b</A>), 65 otherwise the near-surface value of the TKE is not in agreement 66 with the Prandtl-layer law (Prandtl-layer law and 67 Prandtl-Kolmogorov-Ansatz should provide the same value for K<SUB>m</SUB>). 68 A warning is given, if this is not the case.</P> 69 </TD> 70 </TR> 71 <TR> 72 <TD WIDTH=126> 73 <P><A NAME="alpha_surface"></A><B>alpha_surface</B></P> 74 </TD> 75 <TD WIDTH=45> 76 <P>R</P> 77 </TD> 78 <TD WIDTH=159> 79 <P><I>0.0</I></P> 80 </TD> 81 <TD WIDTH=1280> 82 <P STYLE="font-style: normal">Inclination of the model domain with 83 respect to the horizontal (in degrees). 84 </P> 85 <P STYLE="font-style: normal">By means of <B>alpha_surface</B> the 86 model domain can be inclined in x-direction with respect to the 87 horizontal. In this way flows over inclined surfaces (e.g. 88 drainage flows, gravity flows) can be simulated. In case of 89 <B>alpha_surface </B>/= <I>0</I> the buoyancy term appears both in 90 the equation of motion of the u-component and of the w-component.</P> 91 <P><SPAN STYLE="font-style: normal">An inclination is only 92 possible in case of cyclic horizontal boundary conditions along x 93 AND y (see <A HREF="#bc_lr">bc_lr</A> and <A HREF="#bc_ns">bc_ns</A>) 94 and <A HREF="#topography">topography</A> = </SPAN><I>'flat'</I><SPAN STYLE="font-style: normal">. 95 </SPAN> 96 </P> 97 <P>Runs with inclined surface still require additional 98 user-defined code as well as modifications to the default code. 99 Please ask the <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/PALM_group.html#0">PALM 100 developer group</A>.</P> 101 </TD> 102 </TR> 103 <TR> 104 <TD WIDTH=126> 105 <P><A NAME="bc_e_b"></A><B>bc_e_b</B></P> 106 </TD> 107 <TD WIDTH=45> 108 <P>C * 20</P> 109 </TD> 110 <TD WIDTH=159> 111 <P><I>'neumann'</I></P> 112 </TD> 113 <TD WIDTH=1280> 114 <P STYLE="font-style: normal">Bottom boundary condition of the 115 TKE. 116 </P> 117 <P><B>bc_e_b</B> may be set to <I>'neumann'</I> or <I>'(u*) 118 ** 2+neumann'</I>. <B>bc_e_b</B> = <I>'neumann'</I> yields to 119 e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is 120 calculated via the prognostic TKE equation. Choice of 121 <I>'(u*)**2+neumann'</I> also yields to e(k=0)=e(k=1), but the TKE 122 at the Prandtl-layer top (k=1) is calculated diagnostically by 123 e(k=1)=(us/0.1)**2. However, this is only allowed if a 124 Prandtl-layer is used (<A HREF="#prandtl_layer">prandtl_layer</A>). 125 If this is not the case, a warning is given and <B>bc_e_b</B> is 126 reset to <I>'neumann'</I>. 127 </P> 128 <P STYLE="font-style: normal">At the top boundary a Neumann 129 boundary condition is generally used: (e(nz+1) = e(nz)).</P> 130 </TD> 131 </TR> 132 <TR> 133 <TD WIDTH=126> 134 <P><A NAME="bc_lr"></A><B>bc_lr</B></P> 135 </TD> 136 <TD WIDTH=45> 137 <P>C * 20</P> 138 </TD> 139 <TD WIDTH=159> 140 <P><I>'cyclic'</I></P> 141 </TD> 142 <TD WIDTH=1280> 143 <P>Boundary condition along x (for all quantities).<BR><BR>By 144 default, a cyclic boundary condition is used along x.<BR><BR><B>bc_lr</B> 145 may also be assigned the values <I>'dirichlet/radiation'</I> 146 (inflow from left, outflow to the right) or <I>'radiation/dirichlet'</I> 147 (inflow from right, outflow to the left). This requires the 148 multi-grid method to be used for solving the Poisson equation for 149 perturbation pressure (see <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</A>) 150 and it also requires cyclic boundary conditions along y 151 (see <A HREF="#bc_ns">bc_ns</A>).<BR><BR>In case of these 152 non-cyclic lateral boundaries, a Dirichlet condition is used at 153 the inflow for all quantities (initial vertical profiles - see 154 <A HREF="#initializing_actions">initializing_actions</A> - are 155 fixed during the run) except u, to which a Neumann (zero gradient) 156 condition is applied. At the outflow, a radiation condition is 157 used for all velocity components, while a Neumann (zero gradient) 158 condition is used for the scalars. For perturbation pressure 159 Neumann (zero gradient) conditions are assumed both at the inflow 160 and at the outflow.<BR><BR>When using non-cyclic lateral 161 boundaries, a filter is applied to the velocity field in the 162 vicinity of the outflow in order to suppress any reflections of 163 outgoing disturbances (see <A HREF="#km_damp_max">km_damp_max</A> 164 and <A HREF="#outflow_damping_width">outflow_damping_width</A>).<BR><BR>In 165 order to maintain a turbulent state of the flow, it may be 166 neccessary to continuously impose perturbations on the horizontal 167 velocity field in the vicinity of the inflow throughout the whole 168 run. This can be switched on using <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#create_disturbances">create_disturbances</A>. 169 The horizontal range to which these perturbations are applied is 170 controlled by the parameters <A HREF="#inflow_disturbance_begin">inflow_disturbance_begin</A> 171 and <A HREF="#inflow_disturbance_end">inflow_disturbance_end</A>. 172 The vertical range and the perturbation amplitude are given by 173 <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_b</A>, 174 <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_t</A>, 175 and <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_amplitude</A>. 176 The time interval at which perturbations are to be imposed is set 177 by <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#dt_disturb">dt_disturb</A>.<BR><BR>In 178 case of non-cyclic horizontal boundaries <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#call_psolver_at_all_substeps">call_psolver 179 at_all_substeps</A> = .T. should be used.<BR><BR><B>Note:</B><BR>Using 180 non-cyclic lateral boundaries requires very sensitive adjustments 181 of the inflow (vertical profiles) and the bottom boundary 182 conditions, e.g. a surface heating should not be applied near the 183 inflow boundary because this may significantly disturb the inflow. 184 Please check the model results very carefully.</P> 185 </TD> 186 </TR> 187 <TR> 188 <TD WIDTH=126> 189 <P><A NAME="bc_ns"></A><B>bc_ns</B></P> 190 </TD> 191 <TD WIDTH=45> 192 <P>C * 20</P> 193 </TD> 194 <TD WIDTH=159> 195 <P><I>'cyclic'</I></P> 196 </TD> 197 <TD WIDTH=1280> 198 <P>Boundary condition along y (for all quantities).<BR><BR>By 199 default, a cyclic boundary condition is used along y.<BR><BR><B>bc_ns</B> 200 may also be assigned the values <I>'dirichlet/radiation'</I> 201 (inflow from rear ("north"), outflow to the front 202 ("south")) or <I>'radiation/dirichlet'</I> (inflow from 203 front ("south"), outflow to the rear ("north")). 204 This requires the multi-grid method to be used for solving the 205 Poisson equation for perturbation pressure (see <A HREF="chapter_4.2.html#psolver">psolver</A>) 206 and it also requires cyclic boundary conditions along x 207 (see<BR><A HREF="#bc_lr">bc_lr</A>).<BR><BR>In case of these 208 non-cyclic lateral boundaries, a Dirichlet condition is used at 209 the inflow for all quantities (initial vertical profiles - see 210 <A HREF="#initializing_actions">initializing_actions</A> - are 211 fixed during the run) except u, to which a Neumann (zero gradient) 212 condition is applied. At the outflow, a radiation condition is 213 used for all velocity components, while a Neumann (zero gradient) 214 condition is used for the scalars. For perturbation pressure 215 Neumann (zero gradient) conditions are assumed both at the inflow 216 and at the outflow.<BR><BR>For further details regarding 217 non-cyclic lateral boundary conditions see <A HREF="#bc_lr">bc_lr</A>.</P> 218 </TD> 219 </TR> 220 <TR> 221 <TD WIDTH=126> 222 <P><A NAME="bc_p_b"></A><B>bc_p_b</B></P> 223 </TD> 224 <TD WIDTH=45> 225 <P>C * 20</P> 226 </TD> 227 <TD WIDTH=159> 228 <P><I>'neumann'</I></P> 229 </TD> 230 <TD WIDTH=1280> 231 <P STYLE="font-style: normal">Bottom boundary condition of the 232 perturbation pressure. 233 </P> 234 <P>Allowed values are <I>'dirichlet'</I>, <I>'neumann'</I> and 235 <I>'neumann+inhomo'</I>. <I>'dirichlet'</I> sets 236 p(k=0)=0.0, <I>'neumann'</I> sets p(k=0)=p(k=1). 237 <I>'neumann+inhomo'</I> corresponds to an extended Neumann 238 boundary condition where heat flux or temperature inhomogeneities 239 near the surface (pt(k=1)) are additionally regarded (see 240 Shen and LeClerc (1995, Q.J.R. Meteorol. Soc., 1209)). This 241 condition is only permitted with the Prandtl-layer switched on 242 (<A HREF="#prandtl_layer">prandtl_layer</A>), otherwise the run is 243 terminated. 244 </P> 245 <P>Since at the bottom boundary of the model the vertical velocity 246 disappears (w(k=0) = 0.0), the consistent Neumann condition 247 (<I>'neumann'</I> or <I>'neumann+inhomo'</I>) dp/dz = 0 should be 248 used, which leaves the vertical component w unchanged when the 249 pressure solver is applied. Simultaneous use of the Neumann 250 boundary conditions both at the bottom and at the top boundary 251 (<A HREF="#bc_p_t">bc_p_t</A>) usually yields no consistent 252 solution for the perturbation pressure and should be avoided.</P> 253 </TD> 254 </TR> 255 <TR> 256 <TD WIDTH=126> 257 <P><A NAME="bc_p_t"></A><B>bc_p_t</B></P> 258 </TD> 259 <TD WIDTH=45> 260 <P>C * 20</P> 261 </TD> 262 <TD WIDTH=159> 263 <P><I>'dirichlet'</I></P> 264 </TD> 265 <TD WIDTH=1280> 266 <P STYLE="font-style: normal">Top boundary condition of the 267 perturbation pressure. 268 </P> 269 <P STYLE="font-style: normal">Allowed values are <I>'dirichlet'</I> 270 (p(k=nz+1)= 0.0) or <I>'neumann'</I> (p(k=nz+1)=p(k=nz)). 271 </P> 272 <P>Simultaneous use of Neumann boundary conditions both at the top 273 and bottom boundary (<A HREF="#bc_p_b">bc_p_b</A>) usually yields 274 no consistent solution for the perturbation pressure and should be 275 avoided. Since at the bottom boundary the Neumann condition 276 is a good choice (see <A HREF="#bc_p_b">bc_p_b</A>), a Dirichlet 277 condition should be set at the top boundary.</P> 278 </TD> 279 </TR> 280 <TR> 281 <TD WIDTH=126> 282 <P><A NAME="bc_pt_b"></A><B>bc_pt_b</B></P> 283 </TD> 284 <TD WIDTH=45> 285 <P>C*20</P> 286 </TD> 287 <TD WIDTH=159> 288 <P><I>'dirichlet'</I></P> 289 </TD> 290 <TD WIDTH=1280> 291 <P STYLE="font-style: normal">Bottom boundary condition of the 292 potential temperature. 293 </P> 294 <P>Allowed values are <I>'dirichlet'</I> (pt(k=0) = const. = 295 <A HREF="#pt_surface">pt_surface</A> + <A HREF="#pt_surface_initial_change">pt_surface_initial_change</A>; 296 the user may change this value during the run using user-defined 297 code) and <I>'neumann'</I> (pt(k=0)=pt(k=1)). <BR>When a 298 constant surface sensible heat flux is used (<A HREF="#surface_heatflux">surface_heatflux</A>), 299 <B>bc_pt_b</B> = <I>'neumann'</I> must be used, because otherwise 300 the resolved scale may contribute to the surface flux so that a 301 constant value cannot be guaranteed.</P> 302 <P>In the <A HREF="chapter_3.8.html">coupled</A> atmosphere 303 executable, <A HREF="chapter_4.2.html#bc_pt_b">bc_pt_b</A> is 304 internally set and does not need to be prescribed.</P> 305 </TD> 306 </TR> 307 <TR> 308 <TD WIDTH=126> 309 <P><A NAME="pc_pt_t"></A><B>bc_pt_t</B></P> 310 </TD> 311 <TD WIDTH=45> 312 <P>C * 20</P> 313 </TD> 314 <TD WIDTH=159> 315 <P><I>'initial_ gradient'</I></P> 316 </TD> 317 <TD WIDTH=1280> 318 <P STYLE="font-style: normal">Top boundary condition of the 319 potential temperature. 320 </P> 321 <P>Allowed are the values <I>'dirichlet' </I>(pt(k=nz+1) does not 322 change during the run), <I>'neumann'</I> (pt(k=nz+1)=pt(k=nz)), 323 and <I>'initial_gradient'</I>. With the 324 'initial_gradient'-condition the value of the temperature gradient 325 at the top is calculated from the initial temperature profile (see 326 <A HREF="#pt_surface">pt_surface</A>, <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A>) 327 by bc_pt_t_val = (pt_init(k=nz+1) - pt_init(k=nz)) / 328 dzu(nz+1).<BR>Using this value (assumed constant during the run) 329 the temperature boundary values are calculated as 330 </P> 331 <UL> 332 <P STYLE="font-style: normal">pt(k=nz+1) = pt(k=nz) + bc_pt_t_val 333 * dzu(nz+1)</P> 334 </UL> 335 <P><SPAN STYLE="font-style: normal">(up to k=nz the prognostic 336 equation for the temperature is solved).<BR>When a constant 337 sensible heat flux is used at the top boundary (<A HREF="#top_heatflux">top_heatflux</A>), 338 </SPAN><SPAN STYLE="font-style: normal"><B>bc_pt_t</B></SPAN> <SPAN STYLE="font-style: normal">= 339 </SPAN><I>'neumann'</I> <SPAN STYLE="font-style: normal">must be 340 used, because otherwise the resolved scale may contribute to the 341 top flux so that a constant value cannot be guaranteed.</SPAN></P> 342 </TD> 343 </TR> 344 <TR> 345 <TD WIDTH=126> 346 <P><A NAME="bc_q_b"></A><B>bc_q_b</B></P> 347 </TD> 348 <TD WIDTH=45> 349 <P>C * 20</P> 350 </TD> 351 <TD WIDTH=159> 352 <P><I>'dirichlet'</I></P> 353 </TD> 354 <TD WIDTH=1280> 355 <P STYLE="font-style: normal">Bottom boundary condition of the 356 specific humidity / total water content. 357 </P> 358 <P>Allowed values are <I>'dirichlet'</I> (q(k=0) = const. = 359 <A HREF="#q_surface">q_surface</A> + <A HREF="#q_surface_initial_change">q_surface_initial_change</A>; 360 the user may change this value during the run using user-defined 361 code) and <I>'neumann'</I> (q(k=0)=q(k=1)). <BR>When a 362 constant surface latent heat flux is used (<A HREF="#surface_waterflux">surface_waterflux</A>), 363 <B>bc_q_b</B> = <I>'neumann'</I> must be used, because otherwise 364 the resolved scale may contribute to the surface flux so that a 365 constant value cannot be guaranteed.</P> 366 </TD> 367 </TR> 368 <TR> 369 <TD WIDTH=126> 370 <P><A NAME="bc_q_t"></A><B>bc_q_t</B></P> 371 </TD> 372 <TD WIDTH=45> 373 <P><I>C * 20</I></P> 374 </TD> 375 <TD WIDTH=159> 376 <P><I>'neumann'</I></P> 377 </TD> 378 <TD WIDTH=1280> 379 <P STYLE="font-style: normal">Top boundary condition of the 380 specific humidity / total water content. 381 </P> 382 <P>Allowed are the values <I>'dirichlet'</I> (q(k=nz) and 383 q(k=nz+1) do not change during the run) and <I>'neumann'</I>. With 384 the Neumann boundary condition the value of the humidity gradient 385 at the top is calculated from the initial humidity profile (see 386 <A HREF="#q_surface">q_surface</A>, <A HREF="#q_vertical_gradient">q_vertical_gradient</A>) 387 by: bc_q_t_val = ( q_init(k=nz) - q_init(k=nz-1)) / dzu(nz).<BR>Using 388 this value (assumed constant during the run) the humidity boundary 389 values are calculated as 390 </P> 391 <UL> 392 <P STYLE="font-style: normal">q(k=nz+1) =q(k=nz) + bc_q_t_val * 393 dzu(nz+1)</P> 394 </UL> 395 <P STYLE="font-style: normal">(up tp k=nz the prognostic equation 396 for q is solved). 397 </P> 398 </TD> 399 </TR> 400 <TR> 401 <TD WIDTH=126> 402 <P><A NAME="bc_s_b"></A><B>bc_s_b</B></P> 403 </TD> 404 <TD WIDTH=45> 405 <P>C * 20</P> 406 </TD> 407 <TD WIDTH=159> 408 <P><I>'dirichlet'</I></P> 409 </TD> 410 <TD WIDTH=1280> 411 <P STYLE="font-style: normal">Bottom boundary condition of the 412 scalar concentration. 413 </P> 414 <P>Allowed values are <I>'dirichlet'</I> (s(k=0) = const. = 415 <A HREF="#s_surface">s_surface</A> + <A HREF="#s_surface_initial_change">s_surface_initial_change</A>; 416 the user may change this value during the run using user-defined 417 code) and <I>'neumann'</I> (s(k=0) = s(k=1)). <BR>When a 418 constant surface concentration flux is used (<A HREF="#surface_scalarflux">surface_scalarflux</A>), 419 <B>bc_s_b</B> = <I>'neumann'</I> must be used, because otherwise 420 the resolved scale may contribute to the surface flux so that a 421 constant value cannot be guaranteed.</P> 422 </TD> 423 </TR> 424 <TR> 425 <TD WIDTH=126> 426 <P><A NAME="bc_s_t"></A><B>bc_s_t</B></P> 427 </TD> 428 <TD WIDTH=45> 429 <P>C * 20</P> 430 </TD> 431 <TD WIDTH=159> 432 <P><I>'neumann'</I></P> 433 </TD> 434 <TD WIDTH=1280> 435 <P STYLE="font-style: normal">Top boundary condition of the scalar 436 concentration. 437 </P> 438 <P>Allowed are the values <I>'dirichlet'</I> (s(k=nz) and 439 s(k=nz+1) do not change during the run) and <I>'neumann'</I>. With 440 the Neumann boundary condition the value of the scalar 441 concentration gradient at the top is calculated from the initial 442 scalar concentration profile (see <A HREF="#s_surface">s_surface</A>, 443 <A HREF="#s_vertical_gradient">s_vertical_gradient</A>) by: 444 bc_s_t_val = (s_init(k=nz) - s_init(k=nz-1)) / dzu(nz).<BR>Using 445 this value (assumed constant during the run) the concentration 446 boundary values are calculated as 447 </P> 448 <UL> 449 <P STYLE="font-style: normal">s(k=nz+1) = s(k=nz) + bc_s_t_val * 450 dzu(nz+1)</P> 451 </UL> 452 <P STYLE="font-style: normal">(up to k=nz the prognostic equation 453 for the scalar concentration is solved).</P> 454 </TD> 455 </TR> 456 <TR> 457 <TD WIDTH=126> 458 <P><A NAME="bc_sa_t"></A><B>bc_sa_t</B></P> 459 </TD> 460 <TD WIDTH=45> 461 <P>C * 20</P> 462 </TD> 463 <TD WIDTH=159> 464 <P><I>'neumann'</I></P> 465 </TD> 466 <TD WIDTH=1280> 467 <P STYLE="font-style: normal">Top boundary condition of the 468 salinity. 469 </P> 470 <P>This parameter only comes into effect for ocean runs (see 471 parameter <A HREF="#ocean">ocean</A>).</P> 472 <P><SPAN STYLE="font-style: normal">Allowed are the values 473 </SPAN><I>'dirichlet' </I><SPAN STYLE="font-style: normal">(sa(k=nz+1) 474 does not change during the run) and </SPAN><I>'neumann'</I> 475 <SPAN STYLE="font-style: normal">(sa(k=nz+1)=sa(k=nz)). <BR><BR>When 476 a constant salinity flux is used at the top boundary 477 (<A HREF="#top_salinityflux">top_salinityflux</A>), </SPAN><SPAN STYLE="font-style: normal"><B>bc_sa_t</B></SPAN> 478 <SPAN STYLE="font-style: normal">= </SPAN><I>'neumann'</I> <SPAN STYLE="font-style: normal">must 479 be used, because otherwise the resolved scale may contribute to 480 the top flux so that a constant value cannot be guaranteed.</SPAN></P> 481 </TD> 482 </TR> 483 <TR> 484 <TD WIDTH=126> 485 <P><A NAME="bc_uv_b"></A><B>bc_uv_b</B></P> 486 </TD> 487 <TD WIDTH=45> 488 <P>C * 20</P> 489 </TD> 490 <TD WIDTH=159> 491 <P><I>'dirichlet'</I></P> 492 </TD> 493 <TD WIDTH=1280> 494 <P STYLE="font-style: normal">Bottom boundary condition of the 495 horizontal velocity components u and v. 496 </P> 497 <P>Allowed values are <I>'dirichlet' </I>and <I>'neumann'</I>. 498 <B>bc_uv_b</B> = <I>'dirichlet'</I> yields the no-slip condition 499 with u=v=0 at the bottom. Due to the staggered grid u(k=0) and 500 v(k=0) are located at z = - 0,5 * <A HREF="#dz">dz</A> (below the 501 bottom), while u(k=1) and v(k=1) are located at z = +0,5 * dz. 502 u=v=0 at the bottom is guaranteed using mirror boundary 503 condition: 504 </P> 505 <UL> 506 <P STYLE="font-style: normal">u(k=0) = - u(k=1) and v(k=0) = - 507 v(k=1)</P> 508 </UL> 509 <P><SPAN STYLE="font-style: normal">The Neumann boundary condition 510 yields the free-slip condition with u(k=0) = u(k=1) and v(k=0) = 511 v(k=1). With Prandtl - layer switched on (see <A HREF="#prandtl_layer">prandtl_layer</A>), 512 the free-slip condition is not allowed (otherwise the run will be 513 terminated)</SPAN><FONT COLOR="#000000"><SPAN STYLE="font-style: normal">.</SPAN></FONT></P> 514 </TD> 515 </TR> 516 <TR> 517 <TD WIDTH=126> 518 <P><A NAME="bc_uv_t"></A><B>bc_uv_t</B></P> 519 </TD> 520 <TD WIDTH=45> 521 <P>C * 20</P> 522 </TD> 523 <TD WIDTH=159> 524 <P><I>'dirichlet'</I></P> 525 </TD> 526 <TD WIDTH=1280> 527 <P STYLE="font-style: normal">Top boundary condition of the 528 horizontal velocity components u and v. 529 </P> 530 <P>Allowed values are <I>'dirichlet'</I>, <I>'dirichlet_0'</I> and 531 <I>'neumann'</I>. The Dirichlet condition yields u(k=nz+1) = 532 ug(nz+1) and v(k=nz+1) = vg(nz+1), Neumann condition yields the 533 free-slip condition with u(k=nz+1) = u(k=nz) and v(k=nz+1) = 534 v(k=nz) (up to k=nz the prognostic equations for the velocities 535 are solved). The special condition <I>'dirichlet_0'</I> can 536 be used for channel flow, it yields the no-slip condition 537 u(k=nz+1) = ug(nz+1) = 0 and v(k=nz+1) = vg(nz+1) = 0.</P> 538 <P>In the <A HREF="chapter_3.8.html">coupled</A> ocean executable, 539 <A HREF="chapter_4.2.html#bc_uv_t">bc_uv_t</A> is internally 540 set ('neumann') and does not need to be prescribed.</P> 541 </TD> 542 </TR> 543 <TR> 544 <TD WIDTH=126> 545 <P><A NAME="bottom_salinityflux"></A><B>bottom_salinityflux</B></P> 546 </TD> 547 <TD WIDTH=45> 548 <P>R</P> 549 </TD> 550 <TD WIDTH=159> 551 <P><I>0.0</I></P> 552 </TD> 553 <TD WIDTH=1280> 554 <P>Kinematic salinity flux near the surface (in psu m/s). </P> 555 <P>This parameter only comes into effect for ocean runs (see 556 parameter <A HREF="#ocean">ocean</A>). 557 </P> 558 <P>The respective salinity flux value is used as bottom 559 (horizontally homogeneous) boundary condition for the salinity 560 equation. This additionally requires that a Neumann condition must 561 be used for the salinity, which is currently the only available 562 condition.</P> 563 </TD> 564 </TR> 565 <TR> 566 <TD WIDTH=126> 567 <P><A NAME="building_height"></A><B>building_height</B></P> 568 </TD> 569 <TD WIDTH=45> 570 <P>R</P> 571 </TD> 572 <TD WIDTH=159> 573 <P><I>50.0</I></P> 574 </TD> 575 <TD WIDTH=1280> 576 <P>Height of a single building in m.<BR><BR><B>building_height</B> 577 must be less than the height of the model domain. This parameter 578 requires the use of <A HREF="#topography">topography</A> = 579 <I>'single_building'</I>.</P> 580 </TD> 581 </TR> 582 <TR> 583 <TD WIDTH=126> 584 <P><A NAME="building_length_x"></A><B>building_length_x</B></P> 585 </TD> 586 <TD WIDTH=45> 587 <P>R</P> 588 </TD> 589 <TD WIDTH=159> 590 <P><I>50.0</I></P> 591 </TD> 592 <TD WIDTH=1280> 593 <P>Width of a single building in m.<BR><BR>Currently, 594 <B>building_length_x</B> must be at least <I>3 * <A HREF="#dx">dx</A></I> 595 and no more than <I>( <A HREF="#nx">nx</A></I> <I>- 1 ) * <A HREF="#dx">dx</A> 596 - <A HREF="#building_wall_left">building_wall_left</A></I>. This 597 parameter requires the use of <A HREF="#topography">topography</A> 598 = <I>'single_building'</I>.</P> 599 </TD> 600 </TR> 601 <TR> 602 <TD WIDTH=126> 603 <P><A NAME="building_length_y"></A><B>building_length_y</B></P> 604 </TD> 605 <TD WIDTH=45> 606 <P>R</P> 607 </TD> 608 <TD WIDTH=159> 609 <P><I>50.0</I></P> 610 </TD> 611 <TD WIDTH=1280> 612 <P>Depth of a single building in m.<BR><BR>Currently, 613 <B>building_length_y</B> must be at least <I>3 * <A HREF="#dy">dy</A></I> 614 and no more than <I>( <A HREF="#ny">ny</A></I> <I>- 1 ) </I> 615 <I>* <A HREF="#dy">dy</A></I> <I>- <A HREF="#building_wall_south">building_wall_south</A></I>. 616 This parameter requires the use of <A HREF="#topography">topography</A> 617 = <I>'single_building'</I>.</P> 618 </TD> 619 </TR> 620 <TR> 621 <TD WIDTH=126> 622 <P><A NAME="building_wall_left"></A><B>building_wall_left</B></P> 623 </TD> 624 <TD WIDTH=45> 625 <P>R</P> 626 </TD> 627 <TD WIDTH=159> 628 <P><I>building centered in x-direction</I></P> 629 </TD> 630 <TD WIDTH=1280> 631 <P>x-coordinate of the left building wall (distance between the 632 left building wall and the left border of the model domain) in 633 m.<BR><BR>Currently, <B>building_wall_left</B> must be at least <I>1 634 * <A HREF="#dx">dx</A></I> and less than <I>( <A HREF="#nx">nx</A> 635 - 1 ) * <A HREF="#dx">dx</A> - <A HREF="#building_length_x">building_length_x</A></I>. 636 This parameter requires the use of <A HREF="#topography">topography</A> 637 = <I>'single_building'</I>.<BR><BR>The default 638 value <B>building_wall_left</B> = <I>( ( <A HREF="#nx">nx</A> + 639 1 ) * <A HREF="#dx">dx</A> - <A HREF="#building_length_x">building_length_x</A> 640 ) / 2</I> centers the building in x-direction. <FONT COLOR="#000000">Due 641 to the staggered grid the building will be displaced by -0.5 <A HREF="#dx">dx</A> 642 in x-direction and -0.5 <A HREF="#dy">dy</A> in y-direction.</FONT> 643 </P> 644 </TD> 645 </TR> 646 <TR> 647 <TD WIDTH=126> 648 <P><A NAME="building_wall_south"></A><B>building_wall_south</B></P> 649 </TD> 650 <TD WIDTH=45> 651 <P>R</P> 652 </TD> 653 <TD WIDTH=159> 654 <P><I>building centered in y-direction</I></P> 655 </TD> 656 <TD WIDTH=1280> 657 <P>y-coordinate of the South building wall (distance between the 658 South building wall and the South border of the model domain) in 659 m.<BR><BR>Currently, <B>building_wall_south</B> must be at least <I>1 660 * <A HREF="#dy">dy</A></I> and less than <I>( <A HREF="#ny">ny</A> 661 - 1 ) * <A HREF="#dy">dy</A> - <A HREF="#building_length_y">building_length_y</A></I>. 662 This parameter requires the use of <A HREF="#topography">topography</A> 663 = <I>'single_building'</I>.<BR><BR>The default 664 value <B>building_wall_south</B> = <I>( ( <A HREF="#ny">ny</A> + 665 1 ) * <A HREF="#dy">dy</A> - <A HREF="#building_length_y">building_length_y</A> 666 ) / 2</I> centers the building in y-direction. <FONT COLOR="#000000">Due 667 to the staggered grid the building will be displaced by -0.5 <A HREF="#dx">dx</A> 668 in x-direction and -0.5 <A HREF="#dy">dy</A> in y-direction.</FONT> 669 </P> 670 </TD> 671 </TR> 672 <TR> 673 <TD WIDTH=126> 674 <P><A NAME="canopy_mode"></A><B>canopy_mode</B></P> 675 </TD> 676 <TD WIDTH=45> 677 <P>C * 20</P> 678 </TD> 679 <TD WIDTH=159> 680 <P><I>'block'</I></P> 681 </TD> 682 <TD WIDTH=1280> 683 <P>Canopy mode.<BR><BR><FONT COLOR="#000000">Besides using the 684 default value, that will create a horizontally homogeneous plant 685 canopy that extends over the total horizontal extension of the 686 model domain, the user may add code to the user interface 687 subroutine <A HREF="chapter_3.5.1.html#user_init_plant_canopy">user_init_plant_canopy</A> 688 to allow further canopy modes. <BR><BR>The setting of 689 <A HREF="#canopy_mode">canopy_mode</A> becomes only active, 690 if <A HREF="#plant_canopy">plant_canopy</A> has been set </FONT><FONT COLOR="#000000"><I>.T.</I></FONT><FONT COLOR="#000000"> 691 and a non-zero <A HREF="#drag_coefficient">drag_coefficient</A> 692 has been defined.</FONT></P> 693 </TD> 694 </TR> 695 <TR> 696 <TD WIDTH=126> 697 <P><A NAME="canyon_height"></A><B>canyon_height</B></P> 698 </TD> 699 <TD WIDTH=45> 700 <P>R</P> 701 </TD> 702 <TD WIDTH=159> 703 <P><I>50.0</I></P> 704 </TD> 705 <TD WIDTH=1280> 706 <P>Street canyon height in m.<BR><BR><B>canyon_height</B> must be 707 less than the height of the model domain. This parameter 708 requires <A HREF="#topography">topography</A> = 709 <I>'single_street_canyon'</I>.</P> 710 </TD> 711 </TR> 712 <TR> 713 <TD WIDTH=126> 714 <P><A NAME="canyon_width_x"></A><B>canyon_width_x</B></P> 715 </TD> 716 <TD WIDTH=45> 717 <P>R</P> 718 </TD> 719 <TD WIDTH=159> 720 <P><I>9999999.9</I></P> 721 </TD> 722 <TD WIDTH=1280> 723 <P>Street canyon width in x-direction in m.<BR><BR>Currently, 724 <B>canyon_width_x</B> must be at least <I>3 * <A HREF="#dx">dx</A></I> 725 and no more than <I>( <A HREF="#nx">nx</A></I> <I>- 1 ) * <A HREF="#dx">dx</A> 726 - <A HREF="#canyon_wall_left">canyon_wall_left</A></I>. This 727 parameter requires <A HREF="#topography">topography</A> = 728 <I>'single_street_canyon'</I>. A non-default value implies a 729 canyon orientation in y-direction.</P> 730 </TD> 731 </TR> 732 <TR> 733 <TD WIDTH=126> 734 <P><A NAME="canyon_width_y"></A><B>canyon_width_y</B></P> 735 </TD> 736 <TD WIDTH=45> 737 <P>R</P> 738 </TD> 739 <TD WIDTH=159> 740 <P><I>9999999.9</I></P> 741 </TD> 742 <TD WIDTH=1280> 743 <P>Street canyon width in y-direction in m.<BR><BR>Currently, 744 <B>canyon_width_y</B> must be at least <I>3 * <A HREF="#dy">dy</A></I> 745 and no more than <I>( <A HREF="#ny">ny</A></I> <I>- 1 ) </I> 746 <I>* <A HREF="#dy">dy</A></I> <I>- <A HREF="#canyon_wall_south">canyon_wall_south</A></I>. 747 This parameter requires <A HREF="#topography">topography</A> 748 = <I>'single_street_canyon</I>. A non-default value implies a 749 canyon orientation in x-direction.</P> 750 </TD> 751 </TR> 752 <TR> 753 <TD WIDTH=126> 754 <P><A NAME="canyon_wall_left"></A><B>canyon_wall_left</B></P> 755 </TD> 756 <TD WIDTH=45> 757 <P>R</P> 758 </TD> 759 <TD WIDTH=159> 760 <P><I>canyon centered in x-direction</I></P> 761 </TD> 762 <TD WIDTH=1280> 763 <P>x-coordinate of the left canyon wall (distance between the left 764 canyon wall and the left border of the model domain) in 765 m.<BR><BR>Currently, <B>canyon_wall_left</B> must be at least <I>1 766 * <A HREF="#dx">dx</A></I> and less than <I>( <A HREF="#nx">nx</A> 767 - 1 ) * <A HREF="#dx">dx</A> - <A HREF="#canyon_width_x">canyon_width_x</A></I>. 768 This parameter requires <A HREF="#topography">topography</A> 769 = <I>'single_street_canyon'</I>.<BR><BR>The default value 770 <B>canyon_wall_left</B> = <I>( ( <A HREF="#nx">nx</A> + 1 ) * 771 <A HREF="#dx">dx</A> - <A HREF="#canyon_width_x">canyon_width_x</A> 772 ) / 2</I> centers the canyon in x-direction.</P> 773 </TD> 774 </TR> 775 <TR> 776 <TD WIDTH=126> 777 <P><A NAME="canyon_wall_south"></A><B>canyon_wall_south</B></P> 778 </TD> 779 <TD WIDTH=45> 780 <P>R</P> 781 </TD> 782 <TD WIDTH=159> 783 <P><I>canyon centered in y-direction</I></P> 784 </TD> 785 <TD WIDTH=1280> 786 <P>y-coordinate of the South canyon wall (distance between the 787 South canyon wall and the South border of the model domain) in 788 m.<BR><BR>Currently, <B>canyon_wall_south</B> must be at least <I>1 789 * <A HREF="#dy">dy</A></I> and less than <I>( <A HREF="#ny">ny</A> 790 - 1 ) * <A HREF="#dy">dy</A> - <A HREF="#canyon_width_y">canyon_width_y</A></I>. 791 This parameter requires <A HREF="#topography">topography</A> 792 = <I>'single_street_canyon'</I>.<BR><BR>The default value 793 <B>canyon_wall_south</B> = <I>( ( <A HREF="#ny">ny</A> + 1 ) 794 * <A HREF="#dy">dy</A> - <A HREF="#canyon_width_y">canyon_wid</A><A HREF="#canyon_width_y">th_y</A> 795 ) / 2</I> centers the canyon in y-direction.</P> 796 </TD> 797 </TR> 798 <TR> 799 <TD WIDTH=126> 800 <P><A NAME="cloud_droplets"></A><B>cloud_droplets</B></P> 801 </TD> 802 <TD WIDTH=45> 803 <P>L</P> 804 </TD> 805 <TD WIDTH=159> 806 <P><I>.F.</I></P> 807 </TD> 808 <TD WIDTH=1280> 809 <P>Parameter to switch on usage of cloud droplets.<BR><BR>Cloud 810 droplets require to use particles (i.e. the NAMELIST group 811 <FONT FACE="Courier New, Courier, monospace">particles_par</FONT> 812 has to be included in the parameter file). Then each particle is a 813 representative for a certain number of droplets. The droplet 814 features (number of droplets, initial radius, etc.) can be steered 815 with the respective particle parameters (see e.g. <A HREF="#chapter_4.2.html#radius">radius</A>). 816 The real number of initial droplets in a grid cell is equal to the 817 initial number of droplets (defined by the particle source 818 parameters <FONT FACE="Thorndale, serif"><SPAN LANG="en-GB"><A HREF="chapter_4.2.html#pst">pst</A>, 819 <A HREF="chapter_4.2.html#psl">psl</A>, <A HREF="chapter_4.2.html#psr">psr</A>, 820 <A HREF="chapter_4.2.html#pss">pss</A>, <A HREF="chapter_4.2.html#psn">psn</A>, 821 <A HREF="chapter_4.2.html#psb">psb</A>, <A HREF="chapter_4.2.html#pdx">pdx</A>, 822 <A HREF="chapter_4.2.html#pdy">pdy</A></SPAN></FONT> <FONT FACE="Thorndale, serif"><SPAN LANG="en-GB">and 823 <A HREF="chapter_4.2.html#pdz">pdz</A></SPAN></FONT>) times the 824 <A HREF="#initial_weighting_factor">initial_weighting_factor</A>.<BR><BR>In 825 case of using cloud droplets, the default condensation scheme in 826 PALM cannot be used, i.e. <A HREF="#cloud_physics">cloud_physics</A> 827 must be set <I>.F.</I>.</P> 828 </TD> 829 </TR> 830 <TR> 831 <TD WIDTH=126> 832 <P><A NAME="cloud_physics"></A><B>cloud_physics</B></P> 833 </TD> 834 <TD WIDTH=45> 835 <P>L</P> 836 </TD> 837 <TD WIDTH=159> 838 <P><I>.F.</I></P> 839 </TD> 840 <TD WIDTH=1280> 841 <P>Parameter to switch on the condensation scheme. 842 </P> 843 <P>For <B>cloud_physics =</B> <I>.TRUE.</I>, equations for the 844 liquid water content and the liquid water potential 845 temperature are solved instead of those for specific humidity and 846 potential temperature. Note that a grid volume is assumed to be 847 either completely saturated or completely unsaturated 848 (0%-or-100%-scheme). A simple precipitation scheme can 849 additionally be switched on with parameter <A HREF="#precipitation">precipitation</A>. 850 Also cloud-top cooling by longwave radiation can be utilized (see 851 <A HREF="#radiation">radiation</A>)<BR><B><BR>cloud_physics =</B> 852 <I>.TRUE. </I>requires <A HREF="#humidity">humidity</A> = 853 <I>.TRUE.</I> .<BR>Detailed information about the condensation 854 scheme is given in the description of the <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM-1/Dokumentationen/Cloud_physics/wolken.pdf">cloud 855 physics module</A> (pdf-file, only in German).<BR><BR>This 856 condensation scheme is not allowed if cloud droplets are simulated 857 explicitly (see <A HREF="#cloud_droplets">cloud_droplets</A>).</P> 858 </TD> 859 </TR> 860 <TR> 861 <TD WIDTH=126> 862 <P><A NAME="conserve_volume_flow"></A><B>conserve_volume_flow</B></P> 863 </TD> 864 <TD WIDTH=45> 865 <P>L</P> 866 </TD> 867 <TD WIDTH=159> 868 <P><I>.F.</I></P> 869 </TD> 870 <TD WIDTH=1280> 871 <P>Conservation of volume flow in x- and 872 y-direction.<BR><BR><B>conserve_volume_flow</B> = <I>.T.</I> 873 guarantees that the volume flow through the xz- and 874 yz-cross-sections of the total model domain remains constant 875 throughout the run depending on the chosen 876 <A HREF="#conserve_volume_flow_mode">conserve_volume_flow_mode</A>.<BR><BR>Note 877 that <B>conserve_volume_flow</B> = <I>.T.</I> requires 878 <A HREF="#dp_external">dp_external</A> = <I>.F.</I> .</P> 879 </TD> 880 </TR> 881 <TR> 882 <TD WIDTH=126> 883 <P><A NAME="conserve_volume_flow_mode"></A><B>conserve_volume_flow_mode</B></P> 884 </TD> 885 <TD WIDTH=45> 886 <P>C * 16</P> 887 </TD> 888 <TD WIDTH=159> 889 <P><I>'default'</I></P> 890 </TD> 891 <TD WIDTH=1280> 892 <P>Modus of volume flow conservation.<BR><BR>The following values 893 are allowed:</P> 894 <P STYLE="font-style: normal"><I>'default'</I> 895 </P> 896 <UL> 897 <P>Per default, PALM uses <I>'initial_profiles'</I> for 898 cyclic lateral boundary conditions (<A HREF="#bc_lr">bc_lr</A> = 899 <I>'cyclic'</I> and <A HREF="#bc_ns">bc_ns</A> = <I>'cyclic'</I>) 900 and <I>'inflow_profile'</I> for non-cyclic lateral boundary 901 conditions (<A HREF="#bc_lr">bc_lr</A> /= <I>'cyclic'</I> or 902 <A HREF="#bc_ns">bc_ns</A> /= <I>'cyclic'</I>).</P> 903 </UL> 904 <P><I>'initial_profiles' </I> 905 </P> 906 <UL> 907 <P>The target volume flow is calculated at t=0 from the 908 initial profiles of u and v. This setting is only allowed 909 for cyclic lateral boundary conditions (<A HREF="#bc_lr">bc_lr</A> 910 = <I>'cyclic'</I> and <A HREF="#bc_ns">bc_ns</A> = <I>'cyclic'</I>).</P> 911 </UL> 912 <P STYLE="font-style: normal"><I>'inflow_profile'</I> 913 </P> 914 <UL> 915 <P>The target volume flow is calculated at every 916 timestep from the inflow profile of u or v, respectively. 917 This setting is only allowed for non-cyclic lateral 918 boundary conditions (<A HREF="#bc_lr">bc_lr</A> /= <I>'cyclic'</I> 919 or <A HREF="#bc_ns">bc_ns</A> /= <I>'cyclic'</I>).</P> 920 </UL> 921 <P><I>'bulk_velocity' </I> 922 </P> 923 <UL> 924 <P>The target volume flow is calculated from a predefined bulk 925 velocity (see <A HREF="#u_bulk">u_bulk</A> and <A HREF="#v_bulk">v_bulk</A>). 926 This setting is only allowed for cyclic lateral boundary 927 conditions (<A HREF="#bc_lr">bc_lr</A> = <I>'cyclic'</I> and 928 <A HREF="#bc_ns">bc_ns</A> = <I>'cyclic'</I>).</P> 929 </UL> 930 <P>Note that <B>conserve_volume_flow_mode</B> only comes into 931 effect if <A HREF="#conserve_volume_flow">conserve_volume_flow</A> 932 = <I>.T. .</I> 933 </P> 934 </TD> 935 </TR> 936 <TR> 937 <TD WIDTH=126> 938 <P><A NAME="coupling_start_time"></A><B>coupling_start_time</B></P> 939 </TD> 940 <TD WIDTH=45> 941 <P>R</P> 942 </TD> 943 <TD WIDTH=159> 944 <P><I>0.0</I></P> 945 </TD> 946 <TD WIDTH=1280> 947 <P>Simulation time of precursor run.</P> 948 <P>Sets the time period a precursor run shall run uncoupled. This 949 parameter is used to set up the precursor run control for 950 atmosphere-ocean-<A HREF="chapter_3.8.html">coupled runs</A>. It 951 has to be set individually to the atmospheric / oceanic precursor 952 run. The time in the data output will show negative values during 953 the precursor run. See <A HREF="../misc/precursor_run_control.pdf">documentation</A> 954 for further information.</P> 955 </TD> 956 </TR> 957 <TR> 958 <TD WIDTH=126> 959 <P><A NAME="cthf"></A><B>cthf</B></P> 960 </TD> 961 <TD WIDTH=45> 962 <P>R</P> 963 </TD> 964 <TD WIDTH=159> 965 <P><I>0.0</I></P> 966 </TD> 967 <TD WIDTH=1280> 968 <P>Average heat flux that is prescribed at the top of the plant 969 canopy.<BR><BR>If <A HREF="#plant_canopy">plant_canopy</A> is set 970 <I>.T.</I>, the user can prescribe a heat flux at the top of the 971 plant canopy.<BR>It is assumed that solar radiation penetrates the 972 canopy and warms the foliage which, in turn, warms the air in 973 contact with it. <BR>Note: Instead of using the value prescribed 974 by <A HREF="#surface_heatflux">surface_heatflux</A>, the near 975 surface heat flux is determined from an exponential function that 976 is dependent on the cumulative leaf_area_index (Shaw and Schumann 977 (1992, Boundary Layer Meteorol., 61, 47-64)).</P> 978 </TD> 979 </TR> 980 <TR> 981 <TD WIDTH=126> 982 <P><A NAME="cut_spline_overshoot"></A><B>cut_spline_overshoot</B></P> 983 </TD> 984 <TD WIDTH=45> 985 <P>L</P> 986 </TD> 987 <TD WIDTH=159> 988 <P><I>.T.</I></P> 989 </TD> 990 <TD WIDTH=1280> 991 <P>Cuts off of so-called overshoots, which can occur with the 992 upstream-spline scheme. 993 </P> 994 <P><FONT COLOR="#000000">The cubic splines tend to overshoot in 995 case of discontinuous changes of variables between neighbouring 996 grid points.</FONT><FONT COLOR="#ff0000"> </FONT><FONT COLOR="#000000">This 997 may lead to errors in calculating the advection tendency.</FONT> 998 Choice of <B>cut_spline_overshoot</B> = <I>.TRUE.</I> (switched on 999 by default) allows variable values not to exceed an interval 1000 defined by the respective adjacent grid points. This interval can 1001 be adjusted seperately for every prognostic variable (see 1002 initialization parameters <A HREF="#overshoot_limit_e">overshoot_limit_e</A>, 1003 <A HREF="#overshoot_limit_pt">overshoot_limit_pt</A>, 1004 <A HREF="#overshoot_limit_u">overshoot_limit_u</A>, etc.). This 1005 might be necessary in case that the default interval has a 1006 non-tolerable effect on the model results. 1007 </P> 1008 <P>Overshoots may also be removed using the parameters 1009 <A HREF="#ups_limit_e">ups_limit_e</A>, <A HREF="#ups_limit_pt">ups_limit_pt</A>, 1010 etc. as well as by applying a long-filter (see 1011 <A HREF="#long_filter_factor">long_filter_factor</A>).</P> 1012 </TD> 1013 </TR> 1014 <TR> 1015 <TD WIDTH=126> 1016 <P><A NAME="damp_level_1d"></A><B>damp_level_1d</B></P> 1017 </TD> 1018 <TD WIDTH=45> 1019 <P>R</P> 1020 </TD> 1021 <TD WIDTH=159> 1022 <P><I>zu(nz+1)</I></P> 1023 </TD> 1024 <TD WIDTH=1280> 1025 <P>Height where the damping layer begins in the 1d-model (in m). 1026 </P> 1027 <P>This parameter is used to switch on a damping layer for the 1028 1d-model, which is generally needed for the damping of inertia 1029 oscillations. Damping is done by gradually increasing the value of 1030 the eddy diffusivities about 10% per vertical grid level (starting 1031 with the value at the height given by <B>damp_level_1d</B>, or 1032 possibly from the next grid pint above), i.e. K<SUB>m</SUB>(k+1) = 1033 1.1 * K<SUB>m</SUB>(k). The values of K<SUB>m</SUB> are limited to 1034 10 m**2/s at maximum. <BR>This parameter only comes into 1035 effect if the 1d-model is switched on for the initialization of 1036 the 3d-model using <A HREF="#initializing_actions">initializing_actions</A> 1037 = <I>'set_1d-model_profiles'</I>. 1038 </P> 1039 </TD> 1040 </TR> 1041 <TR> 1042 <TD WIDTH=126> 1043 <P><A NAME="dissipation_1d"></A><B>dissipation_1d</B></P> 1044 </TD> 1045 <TD WIDTH=45> 1046 <P>C*20</P> 1047 </TD> 1048 <TD WIDTH=159> 1049 <P><I>'as_in_3d_</I><BR><I>model'</I></P> 1050 </TD> 1051 <TD WIDTH=1280> 1052 <P>Calculation method for the energy dissipation term in the TKE 1053 equation of the 1d-model.<BR><BR>By default the dissipation is 1054 calculated as in the 3d-model using diss = (0.19 + 0.74 * l / 1055 l_grid) * e**1.5 / l.<BR><BR>Setting <B>dissipation_1d</B> = 1056 <I>'detering'</I> forces the dissipation to be calculated as diss 1057 = 0.064 * e**1.5 / l.</P> 1058 </TD> 1059 </TR> 1060 <TR> 1061 <TD WIDTH=126> 1062 <P><A NAME="dp_external"></A><B>dp_external</B></P> 1063 </TD> 1064 <TD WIDTH=45> 1065 <P>L</P> 1066 </TD> 1067 <TD WIDTH=159> 1068 <P><I>.F.</I></P> 1069 </TD> 1070 <TD WIDTH=1280> 1071 <P>External pressure gradient switch.<BR><BR>This parameter is 1072 used to switch on/off an external pressure gradient as driving 1073 force. The external pressure gradient is controlled by the 1074 parameters <A HREF="#dp_smooth">dp_smooth</A>, <A HREF="#dp_level_b">dp_level_b</A> 1075 and <A HREF="#dpdxy">dpdxy</A>.<BR><BR>Note that <B>dp_external</B> 1076 = <I>.T.</I> requires <A HREF="#conserve_volume_flow">conserve_volume_flow</A> 1077 = <I>.F. </I>It is normally recommended to disable the Coriolis 1078 force by setting <A HREF="l#omega">omega</A> = 0.0.</P> 1079 </TD> 1080 </TR> 1081 <TR> 1082 <TD WIDTH=126> 1083 <P><A NAME="dp_smooth"></A><B>dp_smooth</B></P> 1084 </TD> 1085 <TD WIDTH=45> 1086 <P>L</P> 1087 </TD> 1088 <TD WIDTH=159> 1089 <P><I>.F.</I></P> 1090 </TD> 1091 <TD WIDTH=1280> 1092 <P>Vertically smooth the external pressure gradient using a 1093 sinusoidal smoothing function.<BR><BR>This parameter only applies 1094 if <A HREF="#dp_external">dp_external</A> = <I>.T. </I>. It is 1095 useful in combination with <A HREF="#dp_level_b">dp_level_b</A> 1096 >> 0 to generate a non-accelerated boundary layer well 1097 below <A HREF="#dp_level_b">dp_level_b</A>.</P> 1098 </TD> 1099 </TR> 1100 <TR> 1101 <TD WIDTH=126> 1102 <P><A NAME="dp_level_b"></A><B>dp_level_b</B></P> 1103 </TD> 1104 <TD WIDTH=45> 1105 <P>R</P> 1106 </TD> 1107 <TD WIDTH=159> 1108 <P><I>0.0</I></P> 1109 </TD> 1110 <TD WIDTH=1280> 1111 <P><FONT SIZE=3>Lower limit of the vertical range for which the 1112 external pressure gradient is applied (</FONT>in <FONT SIZE=3>m).</FONT><BR><BR>This 1113 parameter only applies if <A HREF="#dp_external">dp_external</A> = 1114 <I>.T. </I><SPAN LANG="en-GB">It must hold the condition zu(0) <= 1115 </SPAN><SPAN LANG="en-GB"><B>dp_level_b</B></SPAN> <SPAN LANG="en-GB"><= 1116 zu(<A HREF="#nz">nz</A>). </SPAN>It can be used in 1117 combination with <A HREF="#dp_smooth">dp_smooth</A> = <I>.T.</I> 1118 to generate a non-accelerated boundary layer well below <B>dp_level_b</B> 1119 if <B>dp_level_b</B> >> 0.<BR><BR>Note that there is no 1120 upper limit of the vertical range because the external pressure 1121 gradient is always applied up to the top of the model domain.</P> 1122 </TD> 1123 </TR> 1124 <TR> 1125 <TD WIDTH=126> 1126 <P><A NAME="dpdxy"></A><B>dpdxy</B></P> 1127 </TD> 1128 <TD WIDTH=45> 1129 <P>R(2)</P> 1130 </TD> 1131 <TD WIDTH=159> 1132 <P><I>2 * 0.0</I></P> 1133 </TD> 1134 <TD WIDTH=1280> 1135 <P>Values of the external pressure gradient applied in x- and 1136 y-direction, respectively (in Pa/m).<BR><BR>This parameter only 1137 applies if <A HREF="#dp_external">dp_external</A> = <I>.T. </I>It 1138 sets the pressure gradient values. Negative values mean an 1139 acceleration, positive values mean deceleration. For example, 1140 <B>dpdxy</B> = -0.0002, 0.0, drives the flow in positive 1141 x-direction, 1142 </P> 1143 </TD> 1144 </TR> 1145 <TR> 1146 <TD WIDTH=126> 1147 <P><A NAME="drag_coefficient"></A><B>drag_coefficient</B></P> 1148 </TD> 1149 <TD WIDTH=45> 1150 <P>R</P> 1151 </TD> 1152 <TD WIDTH=159> 1153 <P><I>0.0</I></P> 1154 </TD> 1155 <TD WIDTH=1280> 1156 <P>Drag coefficient used in the plant canopy model.<BR><BR>This 1157 parameter has to be non-zero, if the parameter <A HREF="#plant_canopy">plant_canopy</A> 1158 is set <I>.T.</I>.</P> 1159 </TD> 1160 </TR> 1161 <TR> 1162 <TD WIDTH=126> 1163 <P><A NAME="dt"></A><B>dt</B></P> 1164 </TD> 1165 <TD WIDTH=45> 1166 <P>R</P> 1167 </TD> 1168 <TD WIDTH=159> 1169 <P><I>variable</I></P> 1170 </TD> 1171 <TD WIDTH=1280> 1172 <P>Time step for the 3d-model (in s). 1173 </P> 1174 <P>By default, (i.e. if a Runge-Kutta scheme is used, see 1175 <A HREF="#timestep_scheme">timestep_scheme</A>) the value of the 1176 time step is calculating after each time step (following the time 1177 step criteria) and used for the next step.</P> 1178 <P>If the user assigns <B>dt</B> a value, then the time step is 1179 fixed to this value throughout the whole run (whether it fulfills 1180 the time step criteria or not). However, changes are allowed for 1181 restart runs, because <B>dt</B> can also be used as a <A HREF="chapter_4.2.html#dt_laufparameter">run 1182 parameter</A>. 1183 </P> 1184 <P>In case that the calculated time step meets the condition</P> 1185 <UL> 1186 <P><B>dt</B> < 0.00001 * <A HREF="chapter_4.2.html#dt_max">dt_max</A> 1187 (with dt_max = 20.0)</P> 1188 </UL> 1189 <P>the simulation will be aborted. Such situations usually arise 1190 in case of any numerical problem / instability which causes a 1191 non-realistic increase of the wind speed. 1192 </P> 1193 <P>A small time step due to a large mean horizontal windspeed 1194 speed may be enlarged by using a coordinate transformation (see 1195 <A HREF="#galilei_transformation">galilei_transformation</A>), in 1196 order to spare CPU time.</P> 1197 <P>If the leapfrog timestep scheme is used (see <A HREF="#timestep_scheme">timestep_scheme</A>) 1198 a temporary time step value dt_new is calculated first, with 1199 dt_new = <A HREF="chapter_4.2.html#fcl_factor">cfl_factor</A> * 1200 dt_crit where dt_crit is the maximum timestep allowed by the CFL 1201 and diffusion condition. Next it is examined whether dt_new 1202 exceeds or falls below the value of the previous timestep by at 1203 least +5 % / -2%. If it is smaller, <B>dt</B> = dt_new is 1204 immediately used for the next timestep. If it is larger, then <B>dt 1205 </B>= 1.02 * dt_prev (previous timestep) is used as the new 1206 timestep, however the time step is only increased if the last 1207 change of the time step is dated back at least 30 iterations. If 1208 dt_new is located in the interval mentioned above, then dt does 1209 not change at all. By doing so, permanent time step changes as 1210 well as large sudden changes (increases) in the time step are 1211 avoided.</P> 1212 </TD> 1213 </TR> 1214 <TR> 1215 <TD WIDTH=126> 1216 <P><A NAME="dt_pr_1d"></A><B>dt_pr_1d</B></P> 1217 </TD> 1218 <TD WIDTH=45> 1219 <P>R</P> 1220 </TD> 1221 <TD WIDTH=159> 1222 <P><I>9999999.9</I></P> 1223 </TD> 1224 <TD WIDTH=1280> 1225 <P>Temporal interval of vertical profile output of the 1D-model 1226 (in s). 1227 </P> 1228 <P>Data are written in ASCII format to file <A HREF="chapter_3.4.html#LIST_PROFIL_1D">LIST_PROFIL_1D</A>. 1229 This parameter is only in effect if the 1d-model has been switched 1230 on for the initialization of the 3d-model with 1231 <A HREF="#initializing_actions">initializing_actions</A> = 1232 <I>'set_1d-model_profiles'</I>.</P> 1233 </TD> 1234 </TR> 1235 <TR> 1236 <TD WIDTH=126> 1237 <P><A NAME="dt_run_control_1d"></A><B>dt_run_control_1d</B></P> 1238 </TD> 1239 <TD WIDTH=45> 1240 <P>R</P> 1241 </TD> 1242 <TD WIDTH=159> 1243 <P><I>60.0</I></P> 1244 </TD> 1245 <TD WIDTH=1280> 1246 <P>Temporal interval of runtime control output of the 1d-model (in 1247 s). 1248 </P> 1249 <P>Data are written in ASCII format to file <A HREF="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</A>. 1250 This parameter is only in effect if the 1d-model is switched on 1251 for the initialization of the 3d-model with <A HREF="#initializing_actions">initializing_actions</A> 1252 = <I>'set_1d-model_profiles'</I>.</P> 1253 </TD> 1254 </TR> 1255 <TR> 1256 <TD WIDTH=126> 1257 <P><A NAME="dx"></A><B>dx</B></P> 1258 </TD> 1259 <TD WIDTH=45> 1260 <P>R</P> 1261 </TD> 1262 <TD WIDTH=159> 1263 <P><I>1.0</I></P> 1264 </TD> 1265 <TD WIDTH=1280> 1266 <P>Horizontal grid spacing along the x-direction (in m). 1267 </P> 1268 <P>Along x-direction only a constant grid spacing is allowed.</P> 1269 <P>For <A HREF="chapter_3.8.html">coupled runs</A> this parameter 1270 must be equal in both parameter files <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN</FONT></A> 1271 and <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A>.</P> 1272 </TD> 1273 </TR> 1274 <TR> 1275 <TD WIDTH=126> 1276 <P><A NAME="dy"></A><B>dy</B></P> 1277 </TD> 1278 <TD WIDTH=45> 1279 <P>R</P> 1280 </TD> 1281 <TD WIDTH=159> 1282 <P><I>1.0</I></P> 1283 </TD> 1284 <TD WIDTH=1280> 1285 <P>Horizontal grid spacing along the y-direction (in m). 1286 </P> 1287 <P>Along y-direction only a constant grid spacing is allowed.</P> 1288 <P>For <A HREF="chapter_3.8.html">coupled runs</A> this parameter 1289 must be equal in both parameter files <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN</FONT></A> 1290 and <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A>.</P> 1291 </TD> 1292 </TR> 1293 <TR> 1294 <TD WIDTH=126> 1295 <P><A NAME="dz"></A><B>dz</B></P> 1296 </TD> 1297 <TD WIDTH=45> 1298 <P>R</P> 1299 </TD> 1300 <TD WIDTH=159> 1301 <P><BR> 1302 </P> 1303 </TD> 1304 <TD WIDTH=1280> 1305 <P>Vertical grid spacing (in m). 1306 </P> 1307 <P>This parameter must be assigned by the user, because no default 1308 value is given.</P> 1309 <P>By default, the model uses constant grid spacing along 1310 z-direction, but it can be stretched using the parameters 1311 <A HREF="#dz_stretch_level">dz_stretch_level</A> and 1312 <A HREF="#dz_stretch_factor">dz_stretch_factor</A>. In case of 1313 stretching, a maximum allowed grid spacing can be given by <A HREF="#dz_max">dz_max</A>.</P> 1314 <P>Assuming a constant <B>dz</B>, the scalar levels (zu) are 1315 calculated directly by: 1316 </P> 1317 <UL> 1318 <P>zu(0) = - dz * 0.5 <BR>zu(1) = dz * 0.5</P> 1319 </UL> 1320 <P>The w-levels lie half between them: 1321 </P> 1322 <UL> 1323 <P>zw(k) = ( zu(k) + zu(k+1) ) * 0.5</P> 1324 </UL> 1325 </TD> 1326 </TR> 1327 <TR> 1328 <TD WIDTH=126> 1329 <P><A NAME="dz_max"></A><B>dz_max</B></P> 1330 </TD> 1331 <TD WIDTH=45> 1332 <P>R</P> 1333 </TD> 1334 <TD WIDTH=159> 1335 <P><I>9999999.9</I></P> 1336 </TD> 1337 <TD WIDTH=1280> 1338 <P>Allowed maximum vertical grid spacing (in m).<BR><BR>If the 1339 vertical grid is stretched (see <A HREF="#dz_stretch_factor">dz_stretch_factor</A> 1340 and <A HREF="#dz_stretch_level">dz_stretch_level</A>), <B>dz_max</B> 1341 can be used to limit the vertical grid spacing.</P> 1342 </TD> 1343 </TR> 1344 <TR> 1345 <TD WIDTH=126> 1346 <P><A NAME="dz_stretch_factor"></A><B>dz_stretch_factor</B></P> 1347 </TD> 1348 <TD WIDTH=45> 1349 <P>R</P> 1350 </TD> 1351 <TD WIDTH=159> 1352 <P><I>1.08</I></P> 1353 </TD> 1354 <TD WIDTH=1280> 1355 <P>Stretch factor for a vertically stretched grid (see 1356 <A HREF="#dz_stretch_level">dz_stretch_level</A>). 1357 </P> 1358 <P>The stretch factor should not exceed a value of approx. 1.10 - 1359 1.12, otherwise the discretization errors due to the stretched 1360 grid not negligible any more. (refer Kalnay de Rivas)</P> 1361 </TD> 1362 </TR> 1363 <TR> 1364 <TD WIDTH=126> 1365 <P><A NAME="dz_stretch_level"></A><B>dz_stretch_level</B></P> 1366 </TD> 1367 <TD WIDTH=45> 1368 <P>R</P> 1369 </TD> 1370 <TD WIDTH=159> 1371 <P><I>100000.0</I></P> 1372 </TD> 1373 <TD WIDTH=1280> 1374 <P>Height level above/below which the grid is to be stretched 1375 vertically (in m). 1376 </P> 1377 <P>For <A HREF="#ocean">ocean</A> = .F., <B>dz_stretch_level </B>is 1378 the height level (in m) <B>above </B>which the grid is to be 1379 stretched vertically. The vertical grid spacings <A HREF="#dz">dz</A> 1380 above this level are calculated as 1381 </P> 1382 <UL> 1383 <P><B>dz</B>(k+1) = <B>dz</B>(k) * <A HREF="#dz_stretch_factor">dz_stretch_factor</A></P> 1384 </UL> 1385 <P>and used as spacings for the scalar levels (zu). The w-levels 1386 are then defined as: 1387 </P> 1388 <UL> 1389 <P>zw(k) = ( zu(k) + zu(k+1) ) * 0.5. 1390 </P> 1391 </UL> 1392 <P>For <A HREF="#ocean">ocean</A> = .T., <B>dz_stretch_level </B>is 1393 the height level (in m, negative) <B>below</B> which the grid is 1394 to be stretched vertically. The vertical grid spacings <A HREF="#dz">dz</A> 1395 below this level are calculated correspondingly as 1396 </P> 1397 <UL> 1398 <P><B>dz</B>(k-1) = <B>dz</B>(k) * <A HREF="#dz_stretch_factor">dz_stretch_factor</A>.</P> 1399 </UL> 1400 </TD> 1401 </TR> 1402 <TR> 1403 <TD WIDTH=126> 1404 <P><A NAME="e_init"></A><B>e_init</B></P> 1405 </TD> 1406 <TD WIDTH=45> 1407 <P>R</P> 1408 </TD> 1409 <TD WIDTH=159> 1410 <P><I>0.0</I></P> 1411 </TD> 1412 <TD WIDTH=1280> 1413 <P>Initial subgrid-scale TKE in m<SUP>2</SUP>s<SUP>-2</SUP>.<BR><BR>This 1414 option prescribes an initial subgrid-scale TKE from which the 1415 initial diffusion coefficients K<SUB>m</SUB> and K<SUB>h</SUB> 1416 will be calculated if <B>e_init</B> is positive. This option only 1417 has an effect if <A HREF="#km_constant">km_constant</A> is 1418 not set.</P> 1419 </TD> 1420 </TR> 1421 <TR> 1422 <TD WIDTH=126> 1423 <P><A NAME="e_min"></A><B>e_min</B></P> 1424 </TD> 1425 <TD WIDTH=45> 1426 <P>R</P> 1427 </TD> 1428 <TD WIDTH=159> 1429 <P><I>0.0</I></P> 1430 </TD> 1431 <TD WIDTH=1280> 1432 <P>Minimum subgrid-scale TKE in m<SUP>2</SUP>s<SUP>-2</SUP>.<BR><BR>This 1433 option adds artificial viscosity to the flow by ensuring that 1434 the subgrid-scale TKE does not fall below the minimum threshold 1435 <B>e_min</B>.</P> 1436 </TD> 1437 </TR> 1438 <TR> 1439 <TD WIDTH=126> 1440 <P><A NAME="end_time_1d"></A><B>end_time_1d</B></P> 1441 </TD> 1442 <TD WIDTH=45> 1443 <P>R</P> 1444 </TD> 1445 <TD WIDTH=159> 1446 <P><I>864000.0</I></P> 1447 </TD> 1448 <TD WIDTH=1280> 1449 <P>Time to be simulated for the 1d-model (in s). 1450 </P> 1451 <P>The default value corresponds to a simulated time of 10 days. 1452 Usually, after such a period the inertia oscillations have 1453 completely decayed and the solution of the 1d-model can be 1454 regarded as stationary (see <A HREF="#damp_level_1d">damp_level_1d</A>). 1455 This parameter is only in effect if the 1d-model is switched on 1456 for the initialization of the 3d-model with <A HREF="#initializing_actions">initializing_actions</A> 1457 = <I>'set_1d-model_profiles'</I>.</P> 1458 </TD> 1459 </TR> 1460 <TR> 1461 <TD WIDTH=126> 1462 <P><A NAME="fft_method"></A><B>fft_method</B></P> 1463 </TD> 1464 <TD WIDTH=45> 1465 <P>C * 20</P> 1466 </TD> 1467 <TD WIDTH=159> 1468 <P><I>'system-</I><BR><I>specific'</I></P> 1469 </TD> 1470 <TD WIDTH=1280> 1471 <P>FFT-method to be used.</P> 1472 <P><BR>The fast fourier transformation (FFT) is used for solving 1473 the perturbation pressure equation with a direct method (see 1474 <A HREF="chapter_4.2.html#psolver">psolver</A>) and for 1475 calculating power spectra (see optional software packages, section 1476 <A HREF="chapter_4.2.html#spectra_package">4.2</A>).</P> 1477 <P><BR>By default, system-specific, optimized routines from 1478 external vendor libraries are used. However, these are available 1479 only on certain computers and there are more or less severe 1480 restrictions concerning the number of gridpoints to be used with 1481 them.</P> 1482 <P>There are two other PALM internal methods available on every 1483 machine (their respective source code is part of the PALM source 1484 code):</P> 1485 <P>1.: The <B>Temperton</B>-method from Clive Temperton (ECWMF) 1486 which is computationally very fast and switched on with <B>fft_method</B> 1487 = <I>'temperton-algorithm'</I>. The number of horizontal 1488 gridpoints (nx+1, ny+1) to be used with this method must be 1489 composed of prime factors 2, 3 and 5.</P> 1490 <P>2.: The <B>Singleton</B>-method which is very slow but has no 1491 restrictions concerning the number of gridpoints to be used with, 1492 switched on with <B>fft_method</B> = <I>'singleton-algorithm'</I>. 1493 </P> 1494 </TD> 1495 </TR> 1496 <TR> 1497 <TD WIDTH=126> 1498 <P><A NAME="galilei_transformation"></A><B>galilei_transformation</B></P> 1499 </TD> 1500 <TD WIDTH=45> 1501 <P>L</P> 1502 </TD> 1503 <TD WIDTH=159> 1504 <P><I>.F.</I></P> 1505 </TD> 1506 <TD WIDTH=1280> 1507 <P>Application of a Galilei-transformation to the coordinate 1508 system of the model.</P> 1509 <P>With <B>galilei_transformation</B> = <I>.T.,</I> a so-called 1510 Galilei-transformation is switched on which ensures that the 1511 coordinate system of the model is moved along with the 1512 geostrophical wind. Alternatively, the model domain can be moved 1513 along with the averaged horizontal wind (see 1514 <A HREF="#use_ug_for_galilei_tr">use_ug_for_galilei_tr</A>, this 1515 can and will naturally change in time). With this method, 1516 numerical inaccuracies of the Piascek - Williams - scheme 1517 (concerns in particular the momentum advection) are minimized. 1518 Beyond that, in the majority of cases the lower relative 1519 velocities in the moved system permit a larger time step (<A HREF="#dt">dt</A>). 1520 Switching the transformation on is only worthwhile if the 1521 geostrophical wind (ug, vg) and the averaged horizontal wind 1522 clearly deviate from the value 0. In each case, the distance the 1523 coordinate system has been moved is written to the file 1524 <A HREF="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</A>. 1525 </P> 1526 <P>Non-cyclic lateral boundary conditions (see <A HREF="#bc_lr">bc_lr</A> 1527 and <A HREF="#bc_ns">bc_ns</A>), the specification of a gestrophic 1528 wind that is not constant with height as well as e.g. stationary 1529 inhomogeneities at the bottom boundary do not allow the use of 1530 this transformation.</P> 1531 </TD> 1532 </TR> 1533 <TR> 1534 <TD WIDTH=126> 1535 <P><A NAME="grid_matching"></A><B>grid_matching</B></P> 1536 </TD> 1537 <TD WIDTH=45> 1538 <P>C * 6</P> 1539 </TD> 1540 <TD WIDTH=159> 1541 <P><I>'strict'</I></P> 1542 </TD> 1543 <TD WIDTH=1280> 1544 <P>Variable to adjust the subdomain sizes in parallel runs.<BR><BR>For 1545 <B>grid_matching</B> = <I>'strict'</I>, the subdomains are forced 1546 to have an identical size on all processors. In this case the 1547 processor numbers in the respective directions of the virtual 1548 processor net must fulfill certain divisor conditions concerning 1549 the grid point numbers in the three directions (see <A HREF="#nx">nx</A>, 1550 <A HREF="#ny">ny</A> and <A HREF="#nz">nz</A>). Advantage of this 1551 method is that all PEs bear the same computational load.<BR><BR>There 1552 is no such restriction by default, because then smaller subdomains 1553 are allowed on those processors which form the right and/or north 1554 boundary of the virtual processor grid. On all other processors 1555 the subdomains are of same size. Whether smaller subdomains are 1556 actually used, depends on the number of processors and the grid 1557 point numbers used. Information about the respective settings are 1558 given in file <A HREF="../../../../../../raasch/public_html/PALM_group/home/raasch/public_html/PALM_group/doc/app/chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</A>.<BR><BR>When 1559 using a multi-grid method for solving the Poisson equation (see 1560 <A HREF="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</A>) 1561 only <B>grid_matching</B> = <I>'strict'</I> is allowed.<BR><BR><B>Note:</B><BR>In 1562 some cases for small processor numbers there may be a very bad 1563 load balancing among the processors which may reduce the 1564 performance of the code.</P> 1565 </TD> 1566 </TR> 1567 <TR> 1568 <TD WIDTH=126> 1569 <P><A NAME="humidity"></A><B>humidity</B></P> 1570 </TD> 1571 <TD WIDTH=45> 1572 <P>L</P> 1573 </TD> 1574 <TD WIDTH=159> 1575 <P><I>.F.</I></P> 1576 </TD> 1577 <TD WIDTH=1280> 1578 <P>Parameter to switch on the prognostic equation for specific 1579 humidity q.</P> 1580 <P>The initial vertical profile of q can be set via parameters 1581 <A HREF="#q_surface">q_surface</A>, <A HREF="#q_vertical_gradient">q_vertical_gradient</A> 1582 and <A HREF="#q_vertical_gradient_level">q_vertical_gradient_level</A>. 1583 Boundary conditions can be set via <A HREF="#q_surface_initial_change">q_surface_initial_change</A> 1584 and <A HREF="#surface_waterflux">surface_waterflux</A>.</P> 1585 <P>If the condensation scheme is switched on (<A HREF="#cloud_physics">cloud_physics</A> 1586 = .TRUE.), q becomes the total liquid water content (sum of 1587 specific humidity and liquid water content).</P> 1588 </TD> 1589 </TR> 1590 <TR> 1591 <TD WIDTH=126> 1592 <P><A NAME="inflow_damping_height"></A><B>inflow_damping_height</B></P> 1593 </TD> 1594 <TD WIDTH=45> 1595 <P>R</P> 1596 </TD> 1597 <TD WIDTH=159> 1598 <P><I>from precursor run</I></P> 1599 </TD> 1600 <TD WIDTH=1280> 1601 <P>Height below which the turbulence signal is used for turbulence 1602 recycling (in m).<BR><BR>In case of a turbulent inflow (see 1603 <A HREF="#turbulent_inflow">turbulent_inflow</A>), this parameter 1604 defines the vertical thickness of the turbulent layer up to which 1605 the turbulence extracted at the recycling plane (see 1606 <A HREF="#recycling_width">recycling_width</A>) shall be imposed 1607 to the inflow. Above this level the turbulence signal is linearly 1608 damped to zero. The transition range within which the signal falls 1609 to zero is given by the parameter <A HREF="#inflow_damping_width">inflow_damping_width</A>.<BR><BR>By 1610 default, this height is set as the height of the convective 1611 boundary layer as calculated from a precursor run. See <A HREF="chapter_3.9.html">chapter 1612 3.9</A> about proper settings for getting this CBL height from a 1613 precursor run. 1614 </P> 1615 </TD> 1616 </TR> 1617 <TR> 1618 <TD WIDTH=126> 1619 <P><A NAME="inflow_damping_width"></A><B>inflow_damping_width</B></P> 1620 </TD> 1621 <TD WIDTH=45> 1622 <P>R</P> 1623 </TD> 1624 <TD WIDTH=159> 1625 <P><I>0.1 * <A HREF="#inflow_damping_height">inflow_damping</A></I><A HREF="#inflow_damping_height"><BR><I>_height</I></A></P> 1626 </TD> 1627 <TD WIDTH=1280> 1628 <P>Transition range within which the turbulance signal is damped 1629 to zero (in m).<BR><BR>See <A HREF="#inflow_damping_height">inflow_damping_height</A> 1630 for explanation.</P> 1631 </TD> 1632 </TR> 1633 <TR> 1634 <TD WIDTH=126> 1635 <P><A NAME="inflow_disturbance_begin"></A><B>inflow_disturbance_<BR>begin</B></P> 1636 </TD> 1637 <TD WIDTH=45> 1638 <P>I</P> 1639 </TD> 1640 <TD WIDTH=159> 1641 <P><I>MIN(10,</I><BR><I>nx/2 or ny/2)</I></P> 1642 </TD> 1643 <TD WIDTH=1280> 1644 <P>Lower limit of the horizontal range for which random 1645 perturbations are to be imposed on the horizontal velocity field 1646 (gridpoints).<BR><BR>If non-cyclic lateral boundary conditions are 1647 used (see <A HREF="#bc_lr">bc_lr</A> or <A HREF="#bc_ns">bc_ns</A>), 1648 this parameter gives the gridpoint number (counted horizontally 1649 from the inflow) from which on perturbations are imposed on 1650 the horizontal velocity field. Perturbations must be switched on 1651 with parameter <A HREF="chapter_4.2.html#create_disturbances">create_disturbances</A>.</P> 1652 </TD> 1653 </TR> 1654 <TR> 1655 <TD WIDTH=126> 1656 <P><A NAME="inflow_disturbance_end"></A><B>inflow_disturbance_<BR>end</B></P> 1657 </TD> 1658 <TD WIDTH=45> 1659 <P>I</P> 1660 </TD> 1661 <TD WIDTH=159> 1662 <P><I>MIN(100,</I><BR><I>3/4*nx or</I><BR><I>3/4*ny)</I></P> 1663 </TD> 1664 <TD WIDTH=1280> 1665 <P>Upper limit of the horizontal range for which random 1666 perturbations are to be imposed on the horizontal velocity field 1667 (gridpoints).<BR><BR>If non-cyclic lateral boundary conditions are 1668 used (see <A HREF="#bc_lr">bc_lr</A> or <A HREF="#bc_ns">bc_ns</A>), 1669 this parameter gives the gridpoint number (counted horizontally 1670 from the inflow) unto which perturbations are imposed on the 1671 horizontal velocity field. Perturbations must be switched on with 1672 parameter <A HREF="chapter_4.2.html#create_disturbances">create_disturbances</A>.</P> 1673 </TD> 1674 </TR> 1675 <TR> 1676 <TD WIDTH=126> 1677 <P><A NAME="initializing_actions"></A><B>initializing_actions</B></P> 1678 </TD> 1679 <TD WIDTH=45> 1680 <P>C * 100</P> 1681 </TD> 1682 <TD WIDTH=159> 1683 <P><BR> 1684 </P> 1685 </TD> 1686 <TD WIDTH=1280> 1687 <P STYLE="font-style: normal">Initialization actions to be carried 1688 out. 1689 </P> 1690 <P STYLE="font-style: normal">This parameter does not have a 1691 default value and therefore must be assigned with each model run. 1692 For restart runs <B>initializing_actions</B> = <I>'read_restart_data'</I> 1693 must be set. For the initial run of a job chain the following 1694 values are allowed: 1695 </P> 1696 <P STYLE="font-style: normal"><I>'set_constant_profiles'</I> 1697 </P> 1698 <UL> 1699 <P>A horizontal wind profile consisting of linear sections (see 1700 <A HREF="#ug_surface">ug_surface</A>, <A HREF="#ug_vertical_gradient">ug_vertical_gradient</A>, 1701 <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A> 1702 and <A HREF="#vg_surface">vg_surface</A>, <A HREF="#vg_vertical_gradient">vg_vertical_gradient</A>, 1703 <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A>, 1704 respectively) as well as a vertical temperature (humidity) 1705 profile consisting of linear sections (see <A HREF="#pt_surface">pt_surface</A>, 1706 <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A>, 1707 <A HREF="#q_surface">q_surface</A> and <A HREF="#q_vertical_gradient">q_vertical_gradient</A>) 1708 are assumed as initial profiles. The subgrid-scale TKE is set to 1709 0 but K<SUB>m</SUB> and K<SUB>h</SUB> are set to very small 1710 values because otherwise no TKE would be generated.</P> 1711 </UL> 1712 <P><I>'set_1d-model_profiles' </I> 1713 </P> 1714 <UL> 1715 <P>The arrays of the 3d-model are initialized with the 1716 (stationary) solution of the 1d-model. These are the variables e, 1717 kh, km, u, v and with Prandtl layer switched on rif, us, usws, 1718 vsws. The temperature (humidity) profile consisting of linear 1719 sections is set as for 'set_constant_profiles' and assumed as 1720 constant in time within the 1d-model. For steering of the 1721 1d-model a set of parameters with suffix "_1d" (e.g. 1722 <A HREF="#end_time_1d">end_time_1d</A>, <A HREF="#damp_level_1d">damp_level_1d</A>) 1723 is available.</P> 1724 </UL> 1725 <P><I>'by_user'</I></P> 1726 <P STYLE="margin-left: 0.42in">The initialization of the arrays of 1727 the 3d-model is under complete control of the user and has to be 1728 done in routine <A HREF="chapter_3.5.1.html#user_init_3d_model">user_init_3d_model</A> 1729 of the user-interface.</P> 1730 <P><I>'initialize_vortex'</I> 1731 </P> 1732 <P STYLE="margin-left: 0.42in">The initial velocity field of the 1733 3d-model corresponds to a Rankine-vortex with vertical axis. This 1734 setting may be used to test advection schemes. Free-slip boundary 1735 conditions for u and v (see <A HREF="#bc_uv_b">bc_uv_b</A>, 1736 <A HREF="#bc_uv_t">bc_uv_t</A>) are necessary. In order not to 1737 distort the vortex, an initial horizontal wind profile constant 1738 with height is necessary (to be set by <B>initializing_actions</B> 1739 = <I>'set_constant_profiles'</I>) and some other conditions have 1740 to be met (neutral stratification, diffusion must be switched off, 1741 see <A HREF="#km_constant">km_constant</A>). The center of the 1742 vortex is located at jc = (nx+1)/2. It extends from k = 0 to k = 1743 nz+1. Its radius is 8 * <A HREF="#dx">dx</A> and the exponentially 1744 decaying part ranges to 32 * <A HREF="#dx">dx</A> (see 1745 init_rankine.f90). 1746 </P> 1747 <P><I>'initialize_ptanom'</I> 1748 </P> 1749 <UL> 1750 <P>A 2d-Gauss-like shape disturbance (x,y) is added to the 1751 initial temperature field with radius 10.0 * <A HREF="#dx">dx</A> 1752 and center at jc = (nx+1)/2. This may be used for tests of scalar 1753 advection schemes (see <A HREF="#scalar_advec">scalar_advec</A>). 1754 Such tests require a horizontal wind profile constant with hight 1755 and diffusion switched off (see <I>'initialize_vortex'</I>). 1756 Additionally, the buoyancy term must be switched of in the 1757 equation of motion for w (this requires the user to comment 1758 out the call of <FONT FACE="monospace">buoyancy</FONT> in the 1759 source code of <FONT FACE="monospace">prognostic_equations.f90</FONT>).</P> 1760 </UL> 1761 <P><I>'cyclic_fill'</I></P> 1762 <P STYLE="margin-left: 0.42in"><SPAN STYLE="font-style: normal">Here, 1763 3d-data from a precursor run are read by the initial (main) run. 1764 The precursor run is allowed to have a smaller domain along x and 1765 y compared with the main run. Also, different numbers of 1766 processors can be used for these two runs. Limitations are that 1767 the precursor run must use cyclic horizontal boundary conditions 1768 and that the number of vertical grid points, <A HREF="#nz">nz</A>, 1769 must be same for the precursor run and the main run. If the total 1770 domain of the main run is larger than that of the precursor run, 1771 the domain is filled by cyclic repetition of the (cyclic) 1772 precursor data. This initialization method is recommended if a 1773 turbulent inflow is used (see <A HREF="#turbulent_inflow">turbulent_inflow</A>). 1774 3d-data must be made available to the run by activating an 1775 appropriate file connection statement for local file BININ. See 1776 <A HREF="chapter_3.9.html">chapter 3.9</A> for more details, where 1777 usage of a turbulent inflow is explained. </SPAN> 1778 </P> 1779 <P STYLE="font-style: normal">Values may be combined, e.g. 1780 <B>initializing_actions</B> = <I>'set_constant_profiles 1781 initialize_vortex'</I>, but the values of <I>'set_constant_profiles'</I>, 1782 <I>'set_1d-model_profiles'</I> , and <I>'by_user'</I> must not be 1783 given at the same time.</P> 1784 </TD> 1785 </TR> 1786 <TR> 1787 <TD WIDTH=126> 1788 <P><A NAME="km_constant"></A><B>km_constant</B></P> 1789 </TD> 1790 <TD WIDTH=45> 1791 <P>R</P> 1792 </TD> 1793 <TD WIDTH=159> 1794 <P><I>variable<BR>(computed from TKE)</I></P> 1795 </TD> 1796 <TD WIDTH=1280> 1797 <P>Constant eddy diffusivities are used (laminar simulations). 1798 </P> 1799 <P>If this parameter is specified, both in the 1d and in the 1800 3d-model constant values for the eddy diffusivities are used in 1801 space and time with K<SUB>m</SUB> = <B>km_constant</B> and K<SUB>h</SUB> 1802 = K<SUB>m</SUB> / <A HREF="chapter_4.2.html#prandtl_number">prandtl_number</A>. 1803 The prognostic equation for the subgrid-scale TKE is switched off. 1804 Constant eddy diffusivities are only allowed with the Prandtl 1805 layer (<A HREF="#prandtl_layer">prandtl_layer</A>) switched off.</P> 1806 </TD> 1807 </TR> 1808 <TR> 1809 <TD WIDTH=126> 1810 <P><A NAME="km_damp_max"></A><B>km_damp_max</B></P> 1811 </TD> 1812 <TD WIDTH=45> 1813 <P>R</P> 1814 </TD> 1815 <TD WIDTH=159> 1816 <P><I>0.5*(dx or dy)</I></P> 1817 </TD> 1818 <TD WIDTH=1280> 1819 <P>Maximum diffusivity used for filtering the velocity field in 1820 the vicinity of the outflow (in m<SUP>2</SUP>/s).<BR><BR>When 1821 using non-cyclic lateral boundaries (see <A HREF="#bc_lr">bc_lr</A> 1822 or <A HREF="#bc_ns">bc_ns</A>), a smoothing has to be applied to 1823 the velocity field in the vicinity of the outflow in order to 1824 suppress any reflections of outgoing disturbances. Smoothing is 1825 done by increasing the eddy diffusivity along the horizontal 1826 direction which is perpendicular to the outflow boundary. Only 1827 velocity components parallel to the outflow boundary are filtered 1828 (e.g. v and w, if the outflow is along x). Damping is applied from 1829 the bottom to the top of the domain.<BR><BR>The horizontal range 1830 of the smoothing is controlled by <A HREF="#outflow_damping_width">outflow_damping_width</A> 1831 which defines the number of gridpoints (counted from the outflow 1832 boundary) from where on the smoothing is applied. Starting from 1833 that point, the eddy diffusivity is linearly increased (from zero 1834 to its maximum value given by <B>km_damp_max</B>) until half of 1835 the damping range width, from where it remains constant up to the 1836 outflow boundary. If at a certain grid point the eddy diffusivity 1837 calculated from the flow field is larger than as described above, 1838 it is used instead.<BR><BR>The default value of <B>km_damp_max</B> 1839 has been empirically proven to be sufficient.</P> 1840 </TD> 1841 </TR> 1842 <TR> 1843 <TD WIDTH=126> 1844 <P><A NAME="lad_surface"></A><B>lad_surface</B></P> 1845 </TD> 1846 <TD WIDTH=45> 1847 <P>R</P> 1848 </TD> 1849 <TD WIDTH=159> 1850 <P><I>0.0</I></P> 1851 </TD> 1852 <TD WIDTH=1280> 1853 <P>Surface value of the leaf area density (in m<SUP>2</SUP>/m<SUP>3</SUP>).<BR><BR>This 1854 parameter assigns the value of the leaf area density <B>lad</B> at 1855 the surface (k=0)<B>.</B> Starting from this value, the leaf area 1856 density profile is constructed with <A HREF="#lad_vertical_gradient">lad_vertical_gradient</A> 1857 and <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level 1858 </A>.</P> 1859 </TD> 1860 </TR> 1861 <TR> 1862 <TD WIDTH=126> 1863 <P><A NAME="lad_vertical_gradient"></A><B>lad_vertical_gradient</B></P> 1864 </TD> 1865 <TD WIDTH=45> 1866 <P>R (10)</P> 1867 </TD> 1868 <TD WIDTH=159> 1869 <P><I>10 * 0.0</I></P> 1870 </TD> 1871 <TD WIDTH=1280> 1872 <P>Gradient(s) of the leaf area density (in m<SUP>2</SUP>/m<SUP>4</SUP>).</P> 1873 <P>This leaf area density gradient holds starting from the height 1874 level defined by <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level</A> 1875 (precisely: for all uv levels k where zu(k) > 1876 lad_vertical_gradient_level, lad(k) is set: lad(k) = lad(k-1) + 1877 dzu(k) * <B>lad_vertical_gradient</B>) up to the level defined by 1878 <A HREF="#pch_index">pch_index</A>. Above that level lad(k) will 1879 automatically set to 0.0. A total of 10 different gradients for 11 1880 height intervals (10 intervals if <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level</A>(1) 1881 = <I>0.0</I>) can be assigned. The leaf area density at the 1882 surface is assigned via <A HREF="#lad_surface">lad_surface</A>. 1883 </P> 1884 </TD> 1885 </TR> 1886 <TR> 1887 <TD WIDTH=126> 1888 <P><A NAME="lad_vertical_gradient_level"></A><B>lad_vertical_gradient_level</B></P> 1889 </TD> 1890 <TD WIDTH=45> 1891 <P>R (10)</P> 1892 </TD> 1893 <TD WIDTH=159> 1894 <P><I>10 * 0.0</I></P> 1895 </TD> 1896 <TD WIDTH=1280> 1897 <P>Height level from which on the gradient of the leaf area 1898 density defined by <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level</A> 1899 is effective (in m).<BR><BR>The height levels have to be assigned 1900 in ascending order. The default values result in a leaf area 1901 density that is constant with height uup to the top of the plant 1902 canopy layer defined by <A HREF="#pch_index">pch_index</A>. For 1903 the piecewise construction of temperature profiles see 1904 <A HREF="#lad_vertical_gradient">lad_vertical_gradient</A>.</P> 1905 </TD> 1906 </TR> 1907 <TR> 1908 <TD WIDTH=126> 1909 <P><A NAME="leaf_surface_concentration"></A><B>leaf_surface_concentration</B></P> 1910 </TD> 1911 <TD WIDTH=45> 1912 <P>R</P> 1913 </TD> 1914 <TD WIDTH=159> 1915 <P><I>0.0</I></P> 1916 </TD> 1917 <TD WIDTH=1280> 1918 <P>Concentration of a passive scalar at the surface of a leaf (in 1919 K m/s).<BR><BR>This parameter is only of importance in cases in 1920 that both, <A HREF="#plant_canopy">plant_canopy</A> and 1921 <A HREF="#passive_scalar">passive_scalar</A>, are set <I>.T.</I>. 1922 The value of the concentration of a passive scalar at the surface 1923 of a leaf is required for the parametrisation of the sources and 1924 sinks of scalar concentration due to the canopy.</P> 1925 </TD> 1926 </TR> 1927 <TR> 1928 <TD WIDTH=126> 1929 <P><A NAME="long_filter_factor"></A><B>long_filter_factor</B></P> 1930 </TD> 1931 <TD WIDTH=45> 1932 <P>R</P> 1933 </TD> 1934 <TD WIDTH=159> 1935 <P><I>0.0</I></P> 1936 </TD> 1937 <TD WIDTH=1280> 1938 <P>Filter factor for the so-called Long-filter.</P> 1939 <P><BR>This filter very efficiently eliminates 2-delta-waves 1940 sometimes cauesed by the upstream-spline scheme (see Mahrer and 1941 Pielke, 1978: Mon. Wea. Rev., 106, 818-830). It works in all three 1942 directions in space. A value of <B>long_filter_factor</B> = <I>0.01</I> 1943 sufficiently removes the small-scale waves without affecting the 1944 longer waves.</P> 1945 <P>By default, the filter is switched off (= <I>0.0</I>). It is 1946 exclusively applied to the tendencies calculated by the 1947 upstream-spline scheme (see <A HREF="#momentum_advec">momentum_advec</A> 1948 and <A HREF="#scalar_advec">scalar_advec</A>), not to the 1949 prognostic variables themselves. At the bottom and top boundary of 1950 the model domain the filter effect for vertical 2-delta-waves is 1951 reduced. There, the amplitude of these waves is only reduced by 1952 approx. 50%, otherwise by nearly 100%. <BR>Filter factors 1953 with values > <I>0.01</I> also reduce the amplitudes of waves 1954 with wavelengths longer than 2-delta (see the paper by Mahrer and 1955 Pielke, quoted above). 1956 </P> 1957 </TD> 1958 </TR> 1959 <TR> 1960 <TD WIDTH=126> 1961 <P><A NAME="loop_optimization"></A><B>loop_optimization</B></P> 1962 </TD> 1963 <TD WIDTH=45> 1964 <P>C*16</P> 1965 </TD> 1966 <TD WIDTH=159> 1967 <P><I>see right</I></P> 1968 </TD> 1969 <TD WIDTH=1280> 1970 <P>Method used to optimize loops for solving the prognostic 1971 equations .<BR><BR>By default, the optimization method depends on 1972 the host on which PALM is running. On machines with vector-type 1973 CPUs, single 3d-loops are used to calculate each tendency term of 1974 each prognostic equation, while on all other machines, all 1975 prognostic equations are solved within one big loop over the two 1976 horizontal indices <FONT FACE="Courier New, Courier, monospace">i 1977 </FONT>and <FONT FACE="Courier New, Courier, monospace">j </FONT>(giving 1978 a good cache uitilization).<BR><BR>The default behaviour can be 1979 changed by setting either <B>loop_optimization</B> = <I>'vector'</I> 1980 or <B>loop_optimization</B> = <I>'cache'</I>.</P> 1981 </TD> 1982 </TR> 1983 <TR> 1984 <TD WIDTH=126> 1985 <P><A NAME="mixing_length_1d"></A><B>mixing_length_1d</B></P> 1986 </TD> 1987 <TD WIDTH=45> 1988 <P>C*20</P> 1989 </TD> 1990 <TD WIDTH=159> 1991 <P><I>'as_in_3d_</I><BR><I>model'</I></P> 1992 </TD> 1993 <TD WIDTH=1280> 1994 <P>Mixing length used in the 1d-model.<BR><BR>By default the 1995 mixing length is calculated as in the 3d-model (i.e. it depends on 1996 the grid spacing).<BR><BR>By setting <B>mixing_length_1d</B> = 1997 <I>'blackadar'</I>, the so-called Blackadar mixing length is used 1998 (l = kappa * z / ( 1 + kappa * z / lambda ) with the limiting 1999 value lambda = 2.7E-4 * u_g / f).</P> 2000 </TD> 2001 </TR> 2002 <TR> 2003 <TD WIDTH=126> 2004 <P><A NAME="momentum_advec"></A><B>momentum_advec</B></P> 2005 </TD> 2006 <TD WIDTH=45> 2007 <P>C * 10</P> 2008 </TD> 2009 <TD WIDTH=159> 2010 <P><I>'pw-scheme'</I></P> 2011 </TD> 2012 <TD WIDTH=1280> 2013 <P>Advection scheme to be used for the momentum equations.<BR><BR>The 2014 user can choose between the following schemes:<BR> <BR><BR><I>'pw-scheme'</I></P> 2015 <P STYLE="margin-left: 0.42in">The scheme of Piascek and Williams 2016 (1970, J. Comp. Phys., 6, 392-405) with central differences in the 2017 form C3 is used.<BR>If intermediate Euler-timesteps are carried 2018 out in case of <A HREF="#timestep_scheme">timestep_scheme</A> = 2019 <I>'leapfrog+euler'</I> the advection scheme is - for the 2020 Euler-timestep - automatically switched to an upstream-scheme.</P> 2021 <P><I>'ups-scheme'</I></P> 2022 <P STYLE="margin-left: 0.42in">The upstream-spline scheme is used 2023 (see Mahrer and Pielke, 1978: Mon. Wea. Rev., 106, 818-830). In 2024 opposite to the Piascek-Williams scheme, this is characterized by 2025 much better numerical features (less numerical diffusion, better 2026 preservation of flow structures, e.g. vortices), but 2027 computationally it is much more expensive. In addition, the use of 2028 the Euler-timestep scheme is mandatory (<A HREF="#timestep_scheme">timestep_scheme</A> 2029 = <I>'euler'</I>), i.e. the timestep accuracy is only of first 2030 order. For this reason the advection of scalar variables (see 2031 <A HREF="#scalar_advec">scalar_advec</A>) should then also be 2032 carried out with the upstream-spline scheme, because otherwise the 2033 scalar variables would be subject to large numerical diffusion due 2034 to the upstream scheme. 2035 </P> 2036 <P STYLE="margin-left: 0.42in">Since the cubic splines used tend 2037 to overshoot under certain circumstances, this effect must be 2038 adjusted by suitable filtering and smoothing (see 2039 <A HREF="#cut_spline_overshoot">cut_spline_overshoot</A>, 2040 <A HREF="#long_filter_factor">long_filter_factor</A>, 2041 <A HREF="#ups_limit_pt">ups_limit_pt</A>, <A HREF="#ups_limit_u">ups_limit_u</A>, 2042 <A HREF="#ups_limit_v">ups_limit_v</A>, <A HREF="#ups_limit_w">ups_limit_w</A>). 2043 This is always neccessary for runs with stable stratification, 2044 even if this stratification appears only in parts of the model 2045 domain.</P> 2046 <P STYLE="margin-left: 0.42in">With stable stratification the 2047 upstream-spline scheme also produces gravity waves with large 2048 amplitude, which must be suitably damped (see 2049 <A HREF="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</A>).<BR><BR><B>Important: 2050 </B>The upstream-spline scheme is not implemented for 2051 humidity and passive scalars (see <A HREF="#humidity">humidity</A> 2052 and <A HREF="#passive_scalar">passive_scalar</A>) and requires the 2053 use of a 2d-domain-decomposition. The last conditions severely 2054 restricts code optimization on several machines leading to very 2055 long execution times! The scheme is also not allowed for 2056 non-cyclic lateral boundary conditions (see <A HREF="#bc_lr">bc_lr</A> 2057 and <A HREF="#bc_ns">bc_ns</A>).</P> 2058 </TD> 2059 </TR> 2060 <TR> 2061 <TD WIDTH=126> 2062 <P><A NAME="netcdf_precision"></A><B>netcdf_precision</B></P> 2063 </TD> 2064 <TD WIDTH=45> 2065 <P>C*20<BR>(10)</P> 2066 </TD> 2067 <TD WIDTH=159> 2068 <P><I>single preci-</I><BR><I>sion for all</I><BR><I>output 2069 quan-</I><BR><I>tities</I></P> 2070 </TD> 2071 <TD WIDTH=1280> 2072 <P>Defines the accuracy of the NetCDF output.<BR><BR>By default, 2073 all NetCDF output data (see <A HREF="chapter_4.2.html#data_output_format">data_output_format</A>) 2074 have single precision (4 byte) accuracy. Double precision (8 2075 byte) can be choosen alternatively.<BR>Accuracy for the different 2076 output data (cross sections, 3d-volume data, spectra, etc.) can be 2077 set independently.<BR><I>'<out>_NF90_REAL4'</I> (single 2078 precision) or <I>'<out>_NF90_REAL8'</I> (double precision) 2079 are the two principally allowed values for <B>netcdf_precision</B>, 2080 where the string <I>'<out>' </I>can be chosen out of the 2081 following list:</P> 2082 <TABLE BORDER=1 CELLPADDING=2 CELLSPACING=2> 2083 <TR> 2084 <TD> 2085 <P><I>'xy'</I></P> 2086 </TD> 2087 <TD> 2088 <P>horizontal cross section</P> 2089 </TD> 2090 </TR> 2091 <TR> 2092 <TD> 2093 <P><I>'xz'</I></P> 2094 </TD> 2095 <TD> 2096 <P>vertical (xz) cross section</P> 2097 </TD> 2098 </TR> 2099 <TR> 2100 <TD> 2101 <P><I>'yz'</I></P> 2102 </TD> 2103 <TD> 2104 <P>vertical (yz) cross section</P> 2105 </TD> 2106 </TR> 2107 <TR> 2108 <TD> 2109 <P><I>'2d'</I></P> 2110 </TD> 2111 <TD> 2112 <P>all cross sections</P> 2113 </TD> 2114 </TR> 2115 <TR> 2116 <TD> 2117 <P><I>'3d'</I></P> 2118 </TD> 2119 <TD> 2120 <P>volume data</P> 2121 </TD> 2122 </TR> 2123 <TR> 2124 <TD> 2125 <P><I>'pr'</I></P> 2126 </TD> 2127 <TD> 2128 <P>vertical profiles</P> 2129 </TD> 2130 </TR> 2131 <TR> 2132 <TD> 2133 <P><I>'ts'</I></P> 2134 </TD> 2135 <TD> 2136 <P>time series, particle time series</P> 2137 </TD> 2138 </TR> 2139 <TR> 2140 <TD> 2141 <P><I>'sp'</I></P> 2142 </TD> 2143 <TD> 2144 <P>spectra</P> 2145 </TD> 2146 </TR> 2147 <TR> 2148 <TD> 2149 <P><I>'prt'</I></P> 2150 </TD> 2151 <TD> 2152 <P>particles</P> 2153 </TD> 2154 </TR> 2155 <TR> 2156 <TD> 2157 <P><I>'all'</I></P> 2158 </TD> 2159 <TD> 2160 <P>all output quantities</P> 2161 </TD> 2162 </TR> 2163 </TABLE> 2164 <P><BR><B>Example:</B><BR>If all cross section data and the 2165 particle data shall be output in double precision and all other 2166 quantities in single precision, then <B>netcdf_precision</B> = 2167 <I>'2d_NF90_REAL8'</I>, <I>'prt_NF90_REAL8'</I> has to be 2168 assigned.</P> 2169 </TD> 2170 </TR> 2171 <TR> 2172 <TD WIDTH=126> 2173 <P><A NAME="nsor_ini"></A><B>nsor_ini</B></P> 2174 </TD> 2175 <TD WIDTH=45> 2176 <P>I</P> 2177 </TD> 2178 <TD WIDTH=159> 2179 <P><I>100</I></P> 2180 </TD> 2181 <TD WIDTH=1280> 2182 <P>Initial number of iterations with the SOR algorithm. 2183 </P> 2184 <P>This parameter is only effective if the SOR algorithm was 2185 selected as the pressure solver scheme (<A HREF="chapter_4.2.html#psolver">psolver</A> 2186 = <I>'sor'</I>) and specifies the number of initial iterations of 2187 the SOR scheme (at t = 0). The number of subsequent iterations at 2188 the following timesteps is determined with the parameter <A HREF="#nsor">nsor</A>. 2189 Usually <B>nsor</B> < <B>nsor_ini</B>, since in each case 2190 subsequent calls to <A HREF="chapter_4.2.html#psolver">psolver</A> 2191 use the solution of the previous call as initial value. Suitable 2192 test runs should determine whether sufficient convergence of the 2193 solution is obtained with the default value and if necessary the 2194 value of <B>nsor_ini</B> should be changed.</P> 2195 </TD> 2196 </TR> 2197 <TR> 2198 <TD WIDTH=126> 2199 <P><A NAME="nx"></A><B>nx</B></P> 2200 </TD> 2201 <TD WIDTH=45> 2202 <P>I</P> 2203 </TD> 2204 <TD WIDTH=159> 2205 <P><BR><BR> 2206 </P> 2207 </TD> 2208 <TD WIDTH=1280> 2209 <P>Number of grid points in x-direction. 2210 </P> 2211 <P>A value for this parameter must be assigned. Since the lower 2212 array bound in PALM starts with i = 0, the actual number of grid 2213 points is equal to <B>nx+1</B>. In case of cyclic boundary 2214 conditions along x, the domain size is (<B>nx+1</B>)* <A HREF="#dx">dx</A>.</P> 2215 <P>For parallel runs, in case of <A HREF="#grid_matching">grid_matching</A> 2216 = <I>'strict'</I>, <B>nx+1</B> must be an integral multiple of the 2217 processor numbers (see <A HREF="#npex">npex</A> and <A HREF="#npey">npey</A>) 2218 along x- as well as along y-direction (due to data transposition 2219 restrictions).</P> 2220 <P>For <A HREF="chapter_3.8.html">coupled runs</A> this parameter 2221 must be equal in both parameter files <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN</FONT></A> 2222 and <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A>.</P> 2223 </TD> 2224 </TR> 2225 <TR> 2226 <TD WIDTH=126> 2227 <P><A NAME="ny"></A><B>ny</B></P> 2228 </TD> 2229 <TD WIDTH=45> 2230 <P>I</P> 2231 </TD> 2232 <TD WIDTH=159> 2233 <P><BR><BR> 2234 </P> 2235 </TD> 2236 <TD WIDTH=1280> 2237 <P>Number of grid points in y-direction. 2238 </P> 2239 <P>A value for this parameter must be assigned. Since the lower 2240 array bound in PALM starts with j = 0, the actual number of grid 2241 points is equal to <B>ny+1</B>. In case of cyclic boundary 2242 conditions along y, the domain size is (<B>ny+1</B>) * <A HREF="#dy">dy</A>.</P> 2243 <P>For parallel runs, in case of <A HREF="#grid_matching">grid_matching</A> 2244 = <I>'strict'</I>, <B>ny+1</B> must be an integral multiple of the 2245 processor numbers (see <A HREF="#npex">npex</A> and <A HREF="#npey">npey</A>) 2246 along y- as well as along x-direction (due to data transposition 2247 restrictions).</P> 2248 <P>For <A HREF="chapter_3.8.html">coupled runs</A> this parameter 2249 must be equal in both parameter files <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN</FONT></A> 2250 and <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A>.</P> 2251 </TD> 2252 </TR> 2253 <TR> 2254 <TD WIDTH=126> 2255 <P><A NAME="nz"></A><B>nz</B></P> 2256 </TD> 2257 <TD WIDTH=45> 2258 <P>I</P> 2259 </TD> 2260 <TD WIDTH=159> 2261 <P><BR><BR> 2262 </P> 2263 </TD> 2264 <TD WIDTH=1280> 2265 <P>Number of grid points in z-direction. 2266 </P> 2267 <P>A value for this parameter must be assigned. Since the lower 2268 array bound in PALM starts with k = 0 and since one additional 2269 grid point is added at the top boundary (k = <B>nz+1</B>), the 2270 actual number of grid points is <B>nz+2</B>. However, the 2271 prognostic equations are only solved up to <B>nz</B> (u, v) or up 2272 to <B>nz-1</B> (w, scalar quantities). The top boundary for u and 2273 v is at k = <B>nz+1</B> (u, v) while at k = <B>nz</B> for all 2274 other quantities. 2275 </P> 2276 <P>For parallel runs, in case of <A HREF="#grid_matching">grid_matching</A> 2277 = <I>'strict'</I>, <B>nz</B> must be an integral multiple of the 2278 number of processors in x-direction (due to data transposition 2279 restrictions).</P> 2280 </TD> 2281 </TR> 2282 <TR> 2283 <TD WIDTH=126> 2284 <P><A NAME="ocean"></A><B>ocean</B></P> 2285 </TD> 2286 <TD WIDTH=45> 2287 <P>L</P> 2288 </TD> 2289 <TD WIDTH=159> 2290 <P><I>.F.</I></P> 2291 </TD> 2292 <TD WIDTH=1280> 2293 <P>Parameter to switch on ocean runs.<BR><BR>By default PALM 2294 is configured to simulate atmospheric flows. However, 2295 starting from version 3.3, <B>ocean</B> = <I>.T.</I> 2296 allows simulation of ocean turbulent flows. Setting this 2297 switch has several effects:</P> 2298 <UL> 2299 <LI><P STYLE="margin-bottom: 0in">An additional prognostic 2300 equation for salinity is solved. 2301 </P> 2302 <LI><P STYLE="margin-bottom: 0in">Potential temperature in 2303 buoyancy and stability-related terms is replaced by potential 2304 density. 2305 </P> 2306 <LI><P STYLE="margin-bottom: 0in">Potential density is calculated 2307 from the equation of state for seawater after each timestep, 2308 using the algorithm proposed by Jackett et al. (2006, J. Atmos. 2309 Oceanic Technol., <B>23</B>, 1709-1728).<BR>So far, only the 2310 initial hydrostatic pressure is entered into this equation. 2311 </P> 2312 <LI><P STYLE="margin-bottom: 0in">z=0 (sea surface) is assumed at 2313 the model top (vertical grid index <FONT FACE="Courier New, Courier, monospace">k=nzt</FONT> 2314 on the w-grid), with negative values of z indicating the depth. 2315 </P> 2316 <LI><P STYLE="margin-bottom: 0in">Initial profiles are 2317 constructed (e.g. from <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A> 2318 / <A HREF="#pt_vertical_gradient_level">pt_vertical_gradient_level</A>) 2319 starting from the sea surface, using surface values given by 2320 <A HREF="#pt_surface">pt_surface</A>, <A HREF="#sa_surface">sa_surface</A>, 2321 <A HREF="#ug_surface">ug_surface</A>, and <A HREF="#vg_surface">vg_surface</A>. 2322 </P> 2323 <LI><P STYLE="margin-bottom: 0in">Zero salinity flux is used as 2324 default boundary condition at the bottom of the sea. 2325 </P> 2326 <LI><P>If switched on, random perturbations are by default 2327 imposed to the upper model domain from zu(nzt*2/3) to zu(nzt-3). 2328 </P> 2329 </UL> 2330 <P><BR>Relevant parameters to be exclusively used for steering 2331 ocean runs are <A HREF="#bc_sa_t">bc_sa_t</A>, 2332 <A HREF="#bottom_salinityflux">bottom_salinityflux</A>, 2333 <A HREF="#sa_surface">sa_surface</A>, <A HREF="#sa_vertical_gradient">sa_vertical_gradient</A>, 2334 <A HREF="#sa_vertical_gradient_level">sa_vertical_gradient_level</A>, 2335 and <A HREF="#top_salinityflux">top_salinityflux</A>.<BR><BR>Section 2336 <A HREF="chapter_4.2.2.html">4.4.2</A> gives an example for 2337 appropriate settings of these and other parameters neccessary for 2338 ocean runs.<BR><BR><B>ocean</B> = <I>.T.</I> does not allow 2339 settings of <A HREF="#timestep_scheme">timestep_scheme</A> = 2340 <I>'leapfrog'</I> or <I>'leapfrog+euler'</I> as well as 2341 <A HREF="#scalar_advec">scalar_advec</A> = <I>'ups-scheme'</I>.</P> 2342 </TD> 2343 </TR> 2344 <TR> 2345 <TD WIDTH=126> 2346 <P><A NAME="omega"></A><B>omega</B></P> 2347 </TD> 2348 <TD WIDTH=45> 2349 <P>R</P> 2350 </TD> 2351 <TD WIDTH=159> 2352 <P><I>7.29212E-5</I></P> 2353 </TD> 2354 <TD WIDTH=1280> 2355 <P>Angular velocity of the rotating system (in rad s<SUP>-1</SUP>). 2356 </P> 2357 <P>The angular velocity of the earth is set by default. The values 2358 of the Coriolis parameters are calculated as: 2359 </P> 2360 <UL> 2361 <P>f = 2.0 * <B>omega</B> * sin(<A HREF="#phi">phi</A>) <BR>f* 2362 = 2.0 * <B>omega</B> * cos(<A HREF="#phi">phi</A>)</P> 2363 </UL> 2364 </TD> 2365 </TR> 2366 <TR> 2367 <TD WIDTH=126> 2368 <P><A NAME="outflow_damping_width"></A><B>outflow_damping_width</B></P> 2369 </TD> 2370 <TD WIDTH=45> 2371 <P>I</P> 2372 </TD> 2373 <TD WIDTH=159> 2374 <P><I>MIN(20, nx/2</I> or <I>ny/2)</I></P> 2375 </TD> 2376 <TD WIDTH=1280> 2377 <P>Width of the damping range in the vicinity of the outflow 2378 (gridpoints).<BR><BR>When using non-cyclic lateral boundaries (see 2379 <A HREF="#bc_lr">bc_lr</A> or <A HREF="#bc_ns">bc_ns</A>), a 2380 smoothing has to be applied to the velocity field in the vicinity 2381 of the outflow in order to suppress any reflections of outgoing 2382 disturbances. This parameter controlls the horizontal range to 2383 which the smoothing is applied. The range is given in gridpoints 2384 counted from the respective outflow boundary. For further details 2385 about the smoothing see parameter <A HREF="#km_damp_max">km_damp_max</A>, 2386 which defines the magnitude of the damping.</P> 2387 </TD> 2388 </TR> 2389 <TR> 2390 <TD WIDTH=126> 2391 <P><A NAME="overshoot_limit_e"></A><B>overshoot_limit_e</B></P> 2392 </TD> 2393 <TD WIDTH=45> 2394 <P>R</P> 2395 </TD> 2396 <TD WIDTH=159> 2397 <P><I>0.0</I></P> 2398 </TD> 2399 <TD WIDTH=1280> 2400 <P>Allowed limit for the overshooting of subgrid-scale TKE in case 2401 that the upstream-spline scheme is switched on (in m<SUP>2</SUP>/s<SUP>2</SUP>). 2402 </P> 2403 <P>By deafult, if cut-off of overshoots is switched on for the 2404 upstream-spline scheme (see <A HREF="#cut_spline_overshoot">cut_spline_overshoot</A>), 2405 no overshoots are permitted at all. If <B>overshoot_limit_e</B> is 2406 given a non-zero value, overshoots with the respective amplitude 2407 (both upward and downward) are allowed. 2408 </P> 2409 <P>Only positive values are allowed for <B>overshoot_limit_e</B>.</P> 2410 </TD> 2411 </TR> 2412 <TR> 2413 <TD WIDTH=126> 2414 <P><A NAME="overshoot_limit_pt"></A><B>overshoot_limit_pt</B></P> 2415 </TD> 2416 <TD WIDTH=45> 2417 <P>R</P> 2418 </TD> 2419 <TD WIDTH=159> 2420 <P><I>0.0</I></P> 2421 </TD> 2422 <TD WIDTH=1280> 2423 <P>Allowed limit for the overshooting of potential temperature in 2424 case that the upstream-spline scheme is switched on (in K). 2425 </P> 2426 <P>For further information see <A HREF="#overshoot_limit_e">overshoot_limit_e</A>. 2427 </P> 2428 <P>Only positive values are allowed for <B>overshoot_limit_pt</B>.</P> 2429 </TD> 2430 </TR> 2431 <TR> 2432 <TD WIDTH=126> 2433 <P><A NAME="overshoot_limit_u"></A><B>overshoot_limit_u</B></P> 2434 </TD> 2435 <TD WIDTH=45> 2436 <P>R</P> 2437 </TD> 2438 <TD WIDTH=159> 2439 <P><I>0.0</I></P> 2440 </TD> 2441 <TD WIDTH=1280> 2442 <P>Allowed limit for the overshooting of the u-component of 2443 velocity in case that the upstream-spline scheme is switched on 2444 (in m/s). 2445 </P> 2446 <P>For further information see <A HREF="#overshoot_limit_e">overshoot_limit_e</A>. 2447 </P> 2448 <P>Only positive values are allowed for <B>overshoot_limit_u</B>.</P> 2449 </TD> 2450 </TR> 2451 <TR> 2452 <TD WIDTH=126> 2453 <P><A NAME="overshoot_limit_v"></A><B>overshoot_limit_v</B></P> 2454 </TD> 2455 <TD WIDTH=45> 2456 <P>R</P> 2457 </TD> 2458 <TD WIDTH=159> 2459 <P><I>0.0</I></P> 2460 </TD> 2461 <TD WIDTH=1280> 2462 <P>Allowed limit for the overshooting of the v-component of 2463 velocity in case that the upstream-spline scheme is switched on 2464 (in m/s). 2465 </P> 2466 <P>For further information see <A HREF="#overshoot_limit_e">overshoot_limit_e</A>. 2467 </P> 2468 <P>Only positive values are allowed for <B>overshoot_limit_v</B>.</P> 2469 </TD> 2470 </TR> 2471 <TR> 2472 <TD WIDTH=126> 2473 <P><A NAME="overshoot_limit_w"></A><B>overshoot_limit_w</B></P> 2474 </TD> 2475 <TD WIDTH=45> 2476 <P>R</P> 2477 </TD> 2478 <TD WIDTH=159> 2479 <P><I>0.0</I></P> 2480 </TD> 2481 <TD WIDTH=1280> 2482 <P>Allowed limit for the overshooting of the w-component of 2483 velocity in case that the upstream-spline scheme is switched on 2484 (in m/s). 2485 </P> 2486 <P>For further information see <A HREF="#overshoot_limit_e">overshoot_limit_e</A>. 2487 </P> 2488 <P>Only positive values are permitted for <B>overshoot_limit_w</B>.</P> 2489 </TD> 2490 </TR> 2491 <TR> 2492 <TD WIDTH=126> 2493 <P><A NAME="passive_scalar"></A><B>passive_scalar</B></P> 2494 </TD> 2495 <TD WIDTH=45> 2496 <P>L</P> 2497 </TD> 2498 <TD WIDTH=159> 2499 <P><I>.F.</I></P> 2500 </TD> 2501 <TD WIDTH=1280> 2502 <P>Parameter to switch on the prognostic equation for a passive 2503 scalar. 2504 </P> 2505 <P>The initial vertical profile of s can be set via parameters 2506 <A HREF="#s_surface">s_surface</A>, <A HREF="#s_vertical_gradient">s_vertical_gradient</A> 2507 and <A HREF="#s_vertical_gradient_level">s_vertical_gradient_level</A>. 2508 Boundary conditions can be set via <A HREF="#s_surface_initial_change">s_surface_initial_change</A> 2509 and <A HREF="#surface_scalarflux">surface_scalarflux</A>. 2510 </P> 2511 <P><B>Note:</B> <BR>With <B>passive_scalar</B> switched on, the 2512 simultaneous use of humidity (see <A HREF="#humidity">humidity</A>) 2513 is impossible.</P> 2514 </TD> 2515 </TR> 2516 <TR> 2517 <TD WIDTH=126> 2518 <P><A NAME="pch_index"></A><B>pch_index</B></P> 2519 </TD> 2520 <TD WIDTH=45> 2521 <P>I</P> 2522 </TD> 2523 <TD WIDTH=159> 2524 <P><I>0</I></P> 2525 </TD> 2526 <TD WIDTH=1280> 2527 <P>Grid point index (scalar) of the upper boundary of the plant 2528 canopy layer.<BR><BR>Above <B>pch_index</B> the arrays of leaf 2529 area density and drag_coeffient are automatically set to zero in 2530 case of <A HREF="#plant_canopy">plant_canopy</A> = .T.. Up to 2531 <B>pch_index</B> a leaf area density profile can be prescribed by 2532 using the parameters <A HREF="#lad_surface">lad_surface</A>, 2533 <A HREF="#lad_vertical_gradient">lad_vertical_gradient</A> and 2534 <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level</A>.</P> 2535 </TD> 2536 </TR> 2537 <TR> 2538 <TD WIDTH=126> 2539 <P><A NAME="phi"></A><B>phi</B></P> 2540 </TD> 2541 <TD WIDTH=45> 2542 <P>R</P> 2543 </TD> 2544 <TD WIDTH=159> 2545 <P><I>55.0</I></P> 2546 </TD> 2547 <TD WIDTH=1280> 2548 <P>Geographical latitude (in degrees). 2549 </P> 2550 <P>The value of this parameter determines the value of the 2551 Coriolis parameters f and f*, provided that the angular velocity 2552 (see <A HREF="#omega">omega</A>) is non-zero.</P> 2553 </TD> 2554 </TR> 2555 <TR> 2556 <TD WIDTH=126> 2557 <P><A NAME="plant_canopy"></A><B>plant_canopy</B></P> 2558 </TD> 2559 <TD WIDTH=45> 2560 <P>L</P> 2561 </TD> 2562 <TD WIDTH=159> 2563 <P><I>.F.</I></P> 2564 </TD> 2565 <TD WIDTH=1280> 2566 <P>Switch for the plant_canopy_model.<BR><BR>If <B>plant_canopy</B> 2567 is set <I>.T.</I>, the plant canopy model of Watanabe (2004, BLM 2568 112, 307-341) is used. <BR>The impact of a plant canopy on a 2569 turbulent flow is considered by an additional drag term in the 2570 momentum equations and an additional sink term in the prognostic 2571 equation for the subgrid-scale TKE. These additional terms are 2572 dependent on the leaf drag coefficient (see <A HREF="#drag_coefficient">drag_coefficient</A>) 2573 and the leaf area density (see <A HREF="#lad_surface">lad_surface</A>, 2574 <A HREF="#lad_vertical_gradient">lad_vertical_gradient</A>, 2575 <A HREF="#lad_vertical_gradient_level">lad_vertical_gradient_level</A>). 2576 The top boundary of the plant canopy is determined by the 2577 parameter <A HREF="#pch_index">pch_index</A>. For all heights 2578 equal to or larger than zw(k=<B>pch_index</B>) the leaf area 2579 density is 0 (i.e. there is no canopy at these heights!). <BR>By 2580 default, a horizontally homogeneous plant canopy is prescribed, 2581 if <B>plant_canopy</B> is set <I>.T.</I>. However, the user 2582 can define other types of plant canopies (see <A HREF="#canopy_mode">canopy_mode</A>).<BR><BR>If 2583 <B>plant_canopy</B> and <B>passive_scalar</B> are set <I>.T.</I>, 2584 the canopy acts as an additional source or sink, respectively, of 2585 scalar concentration. The source/sink strength is dependent on the 2586 scalar concentration at the leaf surface, which is generally 2587 constant with time in PALM and which can be specified by 2588 specifying the parameter <A HREF="#leaf_surface_concentration">leaf_surface_concentration</A>. 2589 <BR><BR>Additional heating of the air by the plant canopy is taken 2590 into account, when the default value of the parameter <A HREF="#cthf">cthf</A> 2591 is altered in the parameter file. In that case the value of 2592 <A HREF="#surface_heatflux">surface_heatflux</A> specified in the 2593 parameter file is not used in the model. Instead the near-surface 2594 heat flux is derived from an expontial function that is dependent 2595 on the cumulative leaf area index. <BR><BR><B>plant_canopy</B> = 2596 <I>.T. </I>is only allowed together with a non-zero 2597 <A HREF="#drag_coefficient">drag_coefficient</A>.</P> 2598 </TD> 2599 </TR> 2600 <TR> 2601 <TD WIDTH=126> 2602 <P><A NAME="prandtl_layer"></A><B>prandtl_layer</B></P> 2603 </TD> 2604 <TD WIDTH=45> 2605 <P>L</P> 2606 </TD> 2607 <TD WIDTH=159> 2608 <P><I>.T.</I></P> 2609 </TD> 2610 <TD WIDTH=1280> 2611 <P>Parameter to switch on a Prandtl layer. 2612 </P> 2613 <P>By default, a Prandtl layer is switched on at the bottom 2614 boundary between z = 0 and z = 0.5 * <A HREF="#dz">dz</A> (the 2615 first computational grid point above ground for u, v and the 2616 scalar quantities). In this case, at the bottom boundary, 2617 free-slip conditions for u and v (see <A HREF="#bc_uv_b">bc_uv_b</A>) 2618 are not allowed. Likewise, laminar simulations with constant eddy 2619 diffusivities (<A HREF="#km_constant">km_constant</A>) are 2620 forbidden. 2621 </P> 2622 <P>With Prandtl-layer switched off, the TKE boundary condition 2623 <A HREF="#bc_e_b">bc_e_b</A> = '<I>(u*)**2+neumann'</I> must not 2624 be used and is automatically changed to <I>'neumann'</I> if 2625 necessary. Also, the pressure boundary condition <A HREF="#bc_p_b">bc_p_b</A> 2626 = <I>'neumann+inhomo'</I> is not allowed. 2627 </P> 2628 <P>The roughness length is declared via the parameter 2629 <A HREF="#roughness_length">roughness_length</A>.</P> 2630 </TD> 2631 </TR> 2632 <TR> 2633 <TD WIDTH=126> 2634 <P><A NAME="precipitation"></A><B>precipitation</B></P> 2635 </TD> 2636 <TD WIDTH=45> 2637 <P>L</P> 2638 </TD> 2639 <TD WIDTH=159> 2640 <P><I>.F.</I></P> 2641 </TD> 2642 <TD WIDTH=1280> 2643 <P>Parameter to switch on the precipitation scheme.</P> 2644 <P>For precipitation processes PALM uses a simplified Kessler 2645 scheme. This scheme only considers the so-called autoconversion, 2646 that means the generation of rain water by coagulation of cloud 2647 drops among themselves. Precipitation begins and is immediately 2648 removed from the flow as soon as the liquid water content exceeds 2649 the critical value of 0.5 g/kg.</P> 2650 <P>The precipitation rate and amount can be output by assigning 2651 the runtime parameter <A HREF="chapter_4.2.html#data_output">data_output</A> 2652 = <I>'prr*'</I> or <I>'pra*'</I>, respectively. The time interval 2653 on which the precipitation amount is defined can be controlled via 2654 runtime parameter <A HREF="chapter_4.2.html#precipitation_amount_interval">precipitation_amount_interval</A>.</P> 2655 </TD> 2656 </TR> 2657 <TR> 2658 <TD WIDTH=126> 2659 <P><A NAME="pt_reference"></A><B>pt_reference</B></P> 2660 </TD> 2661 <TD WIDTH=45> 2662 <P>R</P> 2663 </TD> 2664 <TD WIDTH=159> 2665 <P><I>use horizontal average as refrence</I></P> 2666 </TD> 2667 <TD WIDTH=1280> 2668 <P>Reference temperature to be used in all buoyancy terms (in 2669 K).<BR><BR>By default, the instantaneous horizontal average over 2670 the total model domain is used.<BR><BR><B>Attention:</B><BR>In 2671 case of ocean runs (see <A HREF="#ocean">ocean</A>), always a 2672 reference temperature is used in the buoyancy terms with a default 2673 value of <B>pt_reference</B> = <A HREF="#pt_surface">pt_surface</A>.</P> 2674 </TD> 2675 </TR> 2676 <TR> 2677 <TD WIDTH=126> 2678 <P><A NAME="pt_surface"></A><B>pt_surface</B></P> 2679 </TD> 2680 <TD WIDTH=45> 2681 <P>R</P> 2682 </TD> 2683 <TD WIDTH=159> 2684 <P><I>300.0</I></P> 2685 </TD> 2686 <TD WIDTH=1280> 2687 <P>Surface potential temperature (in K). 2688 </P> 2689 <P>This parameter assigns the value of the potential temperature 2690 <B>pt</B> at the surface (k=0)<B>.</B> Starting from this value, 2691 the initial vertical temperature profile is constructed with 2692 <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A> and 2693 <A HREF="#pt_vertical_gradient_level">pt_vertical_gradient_level </A>. 2694 This profile is also used for the 1d-model as a stationary 2695 profile.</P> 2696 <P><B>Attention:</B><BR>In case of ocean runs (see <A HREF="#ocean">ocean</A>), 2697 this parameter gives the temperature value at the sea surface, 2698 which is at k=nzt. The profile is then constructed from the 2699 surface down to the bottom of the model.</P> 2700 </TD> 2701 </TR> 2702 <TR> 2703 <TD WIDTH=126> 2704 <P><A NAME="pt_surface_initial_change"></A><B>pt_surface_initial</B> 2705 <BR><B>_change</B></P> 2706 </TD> 2707 <TD WIDTH=45> 2708 <P>R</P> 2709 </TD> 2710 <TD WIDTH=159> 2711 <P><I>0.0</I></P> 2712 </TD> 2713 <TD WIDTH=1280> 2714 <P>Change in surface temperature to be made at the beginning of 2715 the 3d run (in K). 2716 </P> 2717 <P>If <B>pt_surface_initial_change</B> is set to a non-zero value, 2718 the near surface sensible heat flux is not allowed to be given 2719 simultaneously (see <A HREF="#surface_heatflux">surface_heatflux</A>).</P> 2720 </TD> 2721 </TR> 2722 <TR> 2723 <TD WIDTH=126> 2724 <P><A NAME="pt_vertical_gradient"></A><B>pt_vertical_gradient</B></P> 2725 </TD> 2726 <TD WIDTH=45> 2727 <P>R (10)</P> 2728 </TD> 2729 <TD WIDTH=159> 2730 <P><I>10 * 0.0</I></P> 2731 </TD> 2732 <TD WIDTH=1280> 2733 <P>Temperature gradient(s) of the initial temperature profile (in 2734 K / 100 m). 2735 </P> 2736 <P>This temperature gradient holds starting from the height 2737 level defined by <A HREF="#pt_vertical_gradient_level">pt_vertical_gradient_level</A> 2738 (precisely: for all uv levels k where zu(k) > 2739 pt_vertical_gradient_level, pt_init(k) is set: pt_init(k) = 2740 pt_init(k-1) + dzu(k) * <B>pt_vertical_gradient</B>) up to the top 2741 boundary or up to the next height level defined by 2742 <A HREF="#pt_vertical_gradient_level">pt_vertical_gradient_level</A>. 2743 A total of 10 different gradients for 11 height intervals (10 2744 intervals if <A HREF="#pt_vertical_gradient_level">pt_vertical_gradient_level</A>(1) 2745 = <I>0.0</I>) can be assigned. The surface temperature is assigned 2746 via <A HREF="#pt_surface">pt_surface</A>. 2747 </P> 2748 <P>Example: 2749 </P> 2750 <UL> 2751 <P><B>pt_vertical_gradient</B> = <I>1.0</I>, <I>0.5</I>, 2752 <BR><B>pt_vertical_gradient_level</B> = <I>500.0</I>, <I>1000.0</I>,</P> 2753 </UL> 2754 <P>That defines the temperature profile to be neutrally stratified 2755 up to z = 500.0 m with a temperature given by <A HREF="#pt_surface">pt_surface</A>. 2756 For 500.0 m < z <= 1000.0 m the temperature gradient is 1.0 2757 K / 100 m and for z > 1000.0 m up to the top boundary it is 0.5 2758 K / 100 m (it is assumed that the assigned height levels 2759 correspond with uv levels).</P> 2760 <P><B>Attention:</B><BR>In case of ocean runs (see <A HREF="#ocean">ocean</A>), 2761 the profile is constructed like described above, but starting from 2762 the sea surface (k=nzt) down to the bottom boundary of the model. 2763 Height levels have then to be given as negative values, e.g. 2764 <B>pt_vertical_gradient_level</B> = <I>-500.0</I>, <I>-1000.0</I>.</P> 2765 </TD> 2766 </TR> 2767 <TR> 2768 <TD WIDTH=126> 2769 <P><A NAME="pt_vertical_gradient_level"></A><B>pt_vertical_gradient</B> 2770 <BR><B>_level</B></P> 2771 </TD> 2772 <TD WIDTH=45> 2773 <P>R (10)</P> 2774 </TD> 2775 <TD WIDTH=159> 2776 <P><I>10 *</I> <I>0.0</I></P> 2777 </TD> 2778 <TD WIDTH=1280> 2779 <P>Height level from which on the temperature gradient defined by 2780 <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A> is 2781 effective (in m). 2782 </P> 2783 <P>The height levels have to be assigned in ascending order. The 2784 default values result in a neutral stratification regardless of 2785 the values of <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A> 2786 (unless the top boundary of the model is higher than 100000.0 m). 2787 For the piecewise construction of temperature profiles see 2788 <A HREF="#pt_vertical_gradient">pt_vertical_gradient</A>.</P> 2789 <P><B>Attention:</B><BR>In case of ocean runs (see <A HREF="#ocean">ocean</A>), 2790 the (negative) height levels have to be assigned in descending 2791 order. 2792 </P> 2793 </TD> 2794 </TR> 2795 <TR> 2796 <TD WIDTH=126> 2797 <P><A NAME="q_surface"></A><B>q_surface</B></P> 2798 </TD> 2799 <TD WIDTH=45> 2800 <P>R</P> 2801 </TD> 2802 <TD WIDTH=159> 2803 <P><I>0.0</I></P> 2804 </TD> 2805 <TD WIDTH=1280> 2806 <P>Surface specific humidity / total water content (kg/kg). 2807 </P> 2808 <P>This parameter assigns the value of the specific humidity q at 2809 the surface (k=0). Starting from this value, the initial 2810 humidity profile is constructed with <A HREF="#q_vertical_gradient">q_vertical_gradient</A> 2811 and <A HREF="#q_vertical_gradient_level">q_vertical_gradient_level</A>. 2812 This profile is also used for the 1d-model as a stationary 2813 profile.</P> 2814 </TD> 2815 </TR> 2816 <TR> 2817 <TD WIDTH=126> 2818 <P><A NAME="q_surface_initial_change"></A><B>q_surface_initial</B> 2819 <BR><B>_change</B></P> 2820 </TD> 2821 <TD WIDTH=45> 2822 <P>R</P> 2823 </TD> 2824 <TD WIDTH=159> 2825 <P><I>0.0</I></P> 2826 </TD> 2827 <TD WIDTH=1280> 2828 <P>Change in surface specific humidity / total water content to be 2829 made at the beginning of the 3d run (kg/kg). 2830 </P> 2831 <P>If <B>q_surface_initial_change</B> is set to a non-zero value 2832 the near surface latent heat flux (water flux) is not allowed to 2833 be given simultaneously (see <A HREF="#surface_waterflux">surface_waterflux</A>).</P> 2834 </TD> 2835 </TR> 2836 <TR> 2837 <TD WIDTH=126> 2838 <P><A NAME="q_vertical_gradient"></A><B>q_vertical_gradient</B></P> 2839 </TD> 2840 <TD WIDTH=45> 2841 <P>R (10)</P> 2842 </TD> 2843 <TD WIDTH=159> 2844 <P><I>10 * 0.0</I></P> 2845 </TD> 2846 <TD WIDTH=1280> 2847 <P>Humidity gradient(s) of the initial humidity profile (in 1/100 2848 m). 2849 </P> 2850 <P>This humidity gradient holds starting from the height level 2851 defined by <A HREF="#q_vertical_gradient_level">q_vertical_gradient_level</A> 2852 (precisely: for all uv levels k, where zu(k) > 2853 q_vertical_gradient_level, q_init(k) is set: q_init(k) = 2854 q_init(k-1) + dzu(k) * <B>q_vertical_gradient</B>) up to the top 2855 boundary or up to the next height level defined by 2856 <A HREF="#q_vertical_gradient_level">q_vertical_gradient_level</A>. 2857 A total of 10 different gradients for 11 height intervals (10 2858 intervals if <A HREF="#q_vertical_gradient_level">q_vertical_gradient_level</A>(1) 2859 = <I>0.0</I>) can be asigned. The surface humidity is assigned via 2860 <A HREF="#q_surface">q_surface</A>. 2861 </P> 2862 <P>Example: 2863 </P> 2864 <UL> 2865 <P><B>q_vertical_gradient</B> = <I>0.001</I>, <I>0.0005</I>, 2866 <BR><B>q_vertical_gradient_level</B> = <I>500.0</I>, <I>1000.0</I>,</P> 2867 </UL> 2868 <P>That defines the humidity to be constant with height up to z = 2869 500.0 m with a value given by <A HREF="#q_surface">q_surface</A>. 2870 For 500.0 m < z <= 1000.0 m the humidity gradient is 0.001 / 2871 100 m and for z > 1000.0 m up to the top boundary it is 0.0005 2872 / 100 m (it is assumed that the assigned height levels correspond 2873 with uv levels). 2874 </P> 2875 </TD> 2876 </TR> 2877 <TR> 2878 <TD WIDTH=126> 2879 <P><A NAME="q_vertical_gradient_level"></A><B>q_vertical_gradient</B> 2880 <BR><B>_level</B></P> 2881 </TD> 2882 <TD WIDTH=45> 2883 <P>R (10)</P> 2884 </TD> 2885 <TD WIDTH=159> 2886 <P><I>10 *</I> <I>0.0</I></P> 2887 </TD> 2888 <TD WIDTH=1280> 2889 <P>Height level from which on the humidity gradient defined by 2890 <A HREF="#q_vertical_gradient">q_vertical_gradient</A> is 2891 effective (in m). 2892 </P> 2893 <P>The height levels are to be assigned in ascending order. The 2894 default values result in a humidity constant with height 2895 regardless of the values of <A HREF="#q_vertical_gradient">q_vertical_gradient</A> 2896 (unless the top boundary of the model is higher than 100000.0 m). 2897 For the piecewise construction of humidity profiles see 2898 <A HREF="#q_vertical_gradient">q_vertical_gradient</A>.</P> 2899 </TD> 2900 </TR> 2901 <TR> 2902 <TD WIDTH=126> 2903 <P><A NAME="radiation"></A><B>radiation</B></P> 2904 </TD> 2905 <TD WIDTH=45> 2906 <P>L</P> 2907 </TD> 2908 <TD WIDTH=159> 2909 <P><I>.F.</I></P> 2910 </TD> 2911 <TD WIDTH=1280> 2912 <P>Parameter to switch on longwave radiation cooling at 2913 cloud-tops. 2914 </P> 2915 <P>Long-wave radiation processes are parameterized by the 2916 effective emissivity, which considers only the absorption and 2917 emission of long-wave radiation at cloud droplets. The radiation 2918 scheme can be used only with <A HREF="#cloud_physics">cloud_physics</A> 2919 = .TRUE. .</P> 2920 </TD> 2921 </TR> 2922 <TR> 2923 <TD WIDTH=126> 2924 <P><A NAME="random_generator"></A><B>random_generator</B></P> 2925 </TD> 2926 <TD WIDTH=45> 2927 <P>C * 20</P> 2928 </TD> 2929 <TD WIDTH=159> 2930 <P><I>'numerical</I><BR><I>recipes'</I></P> 2931 </TD> 2932 <TD WIDTH=1280> 2933 <P>Random number generator to be used for creating uniformly 2934 distributed random numbers. 2935 </P> 2936 <P>It is used if random perturbations are to be imposed on the 2937 velocity field or on the surface heat flux field (see 2938 <A HREF="chapter_4.2.html#create_disturbances">create_disturbances</A> 2939 and <A HREF="chapter_4.2.html#random_heatflux">random_heatflux</A>). 2940 By default, the "Numerical Recipes" random number 2941 generator is used. This one provides exactly the same order of 2942 random numbers on all different machines and should be used in 2943 particular for comparison runs.<BR><BR>Besides, a system-specific 2944 generator is available ( <B>random_generator</B> = 2945 <I>'system-specific')</I> which should particularly be used for 2946 runs on vector parallel computers (NEC), because the default 2947 generator cannot be vectorized and therefore significantly drops 2948 down the code performance on these machines.</P> 2949 <P><B>Note:</B><BR>Results from two otherwise identical model runs 2950 will not be comparable one-to-one if they used different random 2951 number generators.</P> 2952 </TD> 2953 </TR> 2954 <TR> 2955 <TD WIDTH=126> 2956 <P><A NAME="random_heatflux"></A><B>random_heatflux</B></P> 2957 </TD> 2958 <TD WIDTH=45> 2959 <P>L</P> 2960 </TD> 2961 <TD WIDTH=159> 2962 <P><I>.F.</I></P> 2963 </TD> 2964 <TD WIDTH=1280> 2965 <P>Parameter to impose random perturbations on the internal 2966 two-dimensional near surface heat flux field <I>shf</I>. 2967 </P> 2968 <P>If a near surface heat flux is used as bottom boundary 2969 condition (see <A HREF="#surface_heatflux">surface_heatflux</A>), 2970 it is by default assumed to be horizontally homogeneous. Random 2971 perturbations can be imposed on the internal two-dimensional heat 2972 flux field <I>shf</I> by assigning <B>random_heatflux</B> = <I>.T.</I>. 2973 The disturbed heat flux field is calculated by multiplying the 2974 values at each mesh point with a normally distributed random 2975 number with a mean value and standard deviation of 1. This is 2976 repeated after every timestep.<BR><BR>In case of a non-flat 2977 <A HREF="#topography">topography</A>, assigning 2978 <B>random_heatflux</B> = <I>.T.</I> imposes random perturbations 2979 on the combined heat flux field <I>shf</I> composed of 2980 <A HREF="#surface_heatflux">surface_heatflux</A> at the bottom 2981 surface and <A HREF="#wall_heatflux">wall_heatflux(0)</A> at the 2982 topography top face.</P> 2983 </TD> 2984 </TR> 2985 <TR> 2986 <TD WIDTH=126> 2987 <P><A NAME="recycling_width"></A><B>recycling_width</B></P> 2988 </TD> 2989 <TD WIDTH=45> 2990 <P>R</P> 2991 </TD> 2992 <TD WIDTH=159> 2993 <P><I>0.1 * <A HREF="#nx">nx</A> * <A HREF="#dx">dx</A></I></P> 2994 </TD> 2995 <TD WIDTH=1280> 2996 <P>Distance of the recycling plane from the inflow boundary (in 2997 m).<BR><BR>This parameter sets the horizontal extension (along the 2998 direction of the main flow) of the so-called recycling domain 2999 which is used to generate a turbulent inflow (see 3000 <A HREF="#turbulent_inflow">turbulent_inflow</A>). <B>recycling_width</B> 3001 must be larger than the grid spacing (dx) and smaller than the 3002 length of the total domain (nx * dx).</P> 3003 </TD> 3004 </TR> 3005 <TR> 3006 <TD WIDTH=126> 3007 <P><A NAME="rif_max"></A><B>rif_max</B></P> 3008 </TD> 3009 <TD WIDTH=45> 3010 <P>R</P> 3011 </TD> 3012 <TD WIDTH=159> 3013 <P><I>1.0</I></P> 3014 </TD> 3015 <TD WIDTH=1280> 3016 <P>Upper limit of the flux-Richardson number. 3017 </P> 3018 <P>With the Prandtl layer switched on (see <A HREF="#prandtl_layer">prandtl_layer</A>), 3019 flux-Richardson numbers (rif) are calculated for z=z<SUB>p</SUB> 3020 (k=1) in the 3d-model (in the 1d model for all heights). Their 3021 values in particular determine the values of the friction velocity 3022 (1d- and 3d-model) and the values of the eddy diffusivity 3023 (1d-model). With small wind velocities at the Prandtl layer top or 3024 small vertical wind shears in the 1d-model, rif can take up 3025 unrealistic large values. They are limited by an upper (<B>rif_max</B>) 3026 and lower limit (see <A HREF="#rif_min">rif_min</A>) for the 3027 flux-Richardson number. The condition <B>rif_max</B> > <B>rif_min</B> 3028 must be met.</P> 3029 </TD> 3030 </TR> 3031 <TR> 3032 <TD WIDTH=126> 3033 <P><A NAME="rif_min"></A><B>rif_min</B></P> 3034 </TD> 3035 <TD WIDTH=45> 3036 <P>R</P> 3037 </TD> 3038 <TD WIDTH=159> 3039 <P><I>- 5.0</I></P> 3040 </TD> 3041 <TD WIDTH=1280> 3042 <P>Lower limit of the flux-Richardson number. 3043 </P> 3044 <P>For further explanations see <A HREF="#rif_max">rif_max</A>. 3045 The condition <B>rif_max</B> > <B>rif_min </B>must be met.</P> 3046 </TD> 3047 </TR> 3048 <TR> 3049 <TD WIDTH=126> 3050 <P><A NAME="roughness_length"></A><B>roughness_length</B></P> 3051 </TD> 3052 <TD WIDTH=45> 3053 <P>R</P> 3054 </TD> 3055 <TD WIDTH=159> 3056 <P><I>0.1</I></P> 3057 </TD> 3058 <TD WIDTH=1280> 3059 <P>Roughness length (in m). 3060 </P> 3061 <P>This parameter is effective only in case that a Prandtl layer 3062 is switched on (see <A HREF="#prandtl_layer">prandtl_layer</A>).</P> 3063 </TD> 3064 </TR> 3065 <TR> 3066 <TD WIDTH=126> 3067 <P><A NAME="sa_surface"></A><B>sa_surface</B></P> 3068 </TD> 3069 <TD WIDTH=45> 3070 <P>R</P> 3071 </TD> 3072 <TD WIDTH=159> 3073 <P><I>35.0</I></P> 3074 </TD> 3075 <TD WIDTH=1280> 3076 <P>Surface salinity (in psu). </P> 3077 <P>This parameter only comes into effect for ocean runs (see 3078 parameter <A HREF="#ocean">ocean</A>). 3079 </P> 3080 <P>This parameter assigns the value of the salinity <B>sa</B> at 3081 the sea surface (k=nzt)<B>.</B> Starting from this value, the 3082 initial vertical salinity profile is constructed from the surface 3083 down to the bottom of the model (k=0) by 3084 using <A HREF="#sa_vertical_gradient">sa_vertical_gradient</A> 3085 and <A HREF="#sa_vertical_gradient_level">sa_vertical_gradient_level 3086 </A>.</P> 3087 </TD> 3088 </TR> 3089 <TR> 3090 <TD WIDTH=126> 3091 <P><A NAME="sa_vertical_gradient"></A><B>sa_vertical_gradient</B></P> 3092 </TD> 3093 <TD WIDTH=45> 3094 <P>R(10)</P> 3095 </TD> 3096 <TD WIDTH=159> 3097 <P><I>10 * 0.0</I></P> 3098 </TD> 3099 <TD WIDTH=1280> 3100 <P>Salinity gradient(s) of the initial salinity profile (in psu / 3101 100 m). 3102 </P> 3103 <P>This parameter only comes into effect for ocean runs (see 3104 parameter <A HREF="#ocean">ocean</A>).</P> 3105 <P>This salinity gradient holds starting from the height 3106 level defined by <A HREF="#sa_vertical_gradient_level">sa_vertical_gradient_level</A> 3107 (precisely: for all uv levels k where zu(k) < 3108 sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) = 3109 sa_init(k+1) - dzu(k+1) * <B>sa_vertical_gradient</B>) down to the 3110 bottom boundary or down to the next height level defined by 3111 <A HREF="#sa_vertical_gradient_level">sa_vertical_gradient_level</A>. 3112 A total of 10 different gradients for 11 height intervals (10 3113 intervals if <A HREF="#sa_vertical_gradient_level">sa_vertical_gradient_level</A>(1) 3114 = <I>0.0</I>) can be assigned. The surface salinity at k=nzt is 3115 assigned via <A HREF="#sa_surface">sa_surface</A>. 3116 </P> 3117 <P>Example: 3118 </P> 3119 <UL> 3120 <P><B>sa_vertical_gradient</B> = <I>1.0</I>, <I>0.5</I>, 3121 <BR><B>sa_vertical_gradient_level</B> = <I>-500.0</I>, -<I>1000.0</I>,</P> 3122 </UL> 3123 <P>That defines the salinity to be constant down to z = -500.0 m 3124 with a salinity given by <A HREF="#sa_surface">sa_surface</A>. For 3125 -500.0 m < z <= -1000.0 m the salinity gradient is 1.0 psu / 3126 100 m and for z < -1000.0 m down to the bottom boundary it is 3127 0.5 psu / 100 m (it is assumed that the assigned height levels 3128 correspond with uv levels).</P> 3129 </TD> 3130 </TR> 3131 <TR> 3132 <TD WIDTH=126> 3133 <P><A NAME="sa_vertical_gradient_level"></A><B>sa_vertical_gradient_level</B></P> 3134 </TD> 3135 <TD WIDTH=45> 3136 <P>R(10)</P> 3137 </TD> 3138 <TD WIDTH=159> 3139 <P><I>10 * 0.0</I></P> 3140 </TD> 3141 <TD WIDTH=1280> 3142 <P>Height level from which on the salinity gradient defined by 3143 <A HREF="#sa_vertical_gradient">sa_vertical_gradient</A> is 3144 effective (in m). 3145 </P> 3146 <P>This parameter only comes into effect for ocean runs (see 3147 parameter <A HREF="#ocean">ocean</A>).</P> 3148 <P>The height levels have to be assigned in descending order. The 3149 default values result in a constant salinity profile regardless of 3150 the values of <A HREF="#sa_vertical_gradient">sa_vertical_gradient</A> 3151 (unless the bottom boundary of the model is lower than -100000.0 3152 m). For the piecewise construction of salinity profiles see 3153 <A HREF="#sa_vertical_gradient">sa_vertical_gradient</A>.</P> 3154 </TD> 3155 </TR> 3156 <TR> 3157 <TD WIDTH=126> 3158 <P><A NAME="scalar_advec"></A><B>scalar_advec</B></P> 3159 </TD> 3160 <TD WIDTH=45> 3161 <P>C * 10</P> 3162 </TD> 3163 <TD WIDTH=159> 3164 <P><I>'pw-scheme'</I></P> 3165 </TD> 3166 <TD WIDTH=1280> 3167 <P>Advection scheme to be used for the scalar quantities. 3168 </P> 3169 <P>The user can choose between the following schemes:</P> 3170 <P><I>'pw-scheme'</I></P> 3171 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">The scheme of 3172 Piascek and Williams (1970, J. Comp. Phys., 6, 392-405) with 3173 central differences in the form C3 is used.<BR>If intermediate 3174 Euler-timesteps are carried out in case of <A HREF="#timestep_scheme">timestep_scheme</A> 3175 = <I>'leapfrog+euler'</I> the advection scheme is - for the 3176 Euler-timestep - automatically switched to an upstream-scheme. 3177 </P> 3178 <P><BR><BR> 3179 </P> 3180 <P><I>'bc-scheme'</I></P> 3181 <P STYLE="margin-left: 0.42in">The Bott scheme modified by Chlond 3182 (1994, Mon. Wea. Rev., 122, 111-125). This is a conservative 3183 monotonous scheme with very small numerical diffusion and 3184 therefore very good conservation of scalar flow features. The 3185 scheme however, is computationally very expensive both because it 3186 is expensive itself and because it does (so far) not allow 3187 specific code optimizations (e.g. cache optimization). Choice of 3188 this scheme forces the Euler timestep scheme to be used for the 3189 scalar quantities. For output of horizontally averaged profiles of 3190 the resolved / total heat flux, <A HREF="chapter_4.2.html#data_output_pr">data_output_pr</A> 3191 = <I>'w*pt*BC'</I> / <I>'wptBC' </I>should be used, instead of the 3192 standard profiles (<I>'w*pt*'</I> and <I>'wpt'</I>) because these 3193 are too inaccurate with this scheme. However, for subdomain 3194 analysis (see <A HREF="#statistic_regions">statistic_regions</A>) 3195 exactly the reverse holds: here <I>'w*pt*BC'</I> and <I>'wptBC'</I> 3196 show very large errors and should not be used.<BR><BR>This scheme 3197 is not allowed for non-cyclic lateral boundary conditions (see 3198 <A HREF="#bc_lr">bc_lr</A> and <A HREF="#bc_ns">bc_ns</A>).</P> 3199 <P><I>'ups-scheme'</I></P> 3200 <P STYLE="margin-left: 0.42in">The upstream-spline-scheme is used 3201 (see Mahrer and Pielke, 1978: Mon. Wea. Rev., 106, 818-830). In 3202 opposite to the Piascek Williams scheme, this is characterized by 3203 much better numerical features (less numerical diffusion, better 3204 preservation of flux structures, e.g. vortices), but 3205 computationally it is much more expensive. In addition, the use of 3206 the Euler-timestep scheme is mandatory (<A HREF="#timestep_scheme">timestep_scheme</A> 3207 = <I>'euler'</I>), i.e. the timestep accuracy is only first order. 3208 For this reason the advection of momentum (see <A HREF="#momentum_advec">momentum_advec</A>) 3209 should then also be carried out with the upstream-spline scheme, 3210 because otherwise the momentum would be subject to large numerical 3211 diffusion due to the upstream scheme. 3212 </P> 3213 <P STYLE="margin-left: 0.42in">Since the cubic splines used tend 3214 to overshoot under certain circumstances, this effect must be 3215 adjusted by suitable filtering and smoothing (see 3216 <A HREF="#cut_spline_overshoot">cut_spline_overshoot</A>, 3217 <A HREF="#long_filter_factor">long_filter_factor</A>, 3218 <A HREF="#ups_limit_pt">ups_limit_pt</A>, <A HREF="#ups_limit_u">ups_limit_u</A>, 3219 <A HREF="#ups_limit_v">ups_limit_v</A>, <A HREF="#ups_limit_w">ups_limit_w</A>). 3220 This is always neccesssary for runs with stable stratification, 3221 even if this stratification appears only in parts of the model 3222 domain. 3223 </P> 3224 <P STYLE="margin-left: 0.42in">With stable stratification the 3225 upstream-upline scheme also produces gravity waves with large 3226 amplitude, which must be suitably damped (see 3227 <A HREF="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</A>).</P> 3228 <P STYLE="margin-left: 0.42in"><B>Important: </B>The 3229 upstream-spline scheme is not implemented for humidity and passive 3230 scalars (see <A HREF="#humidity">humidity</A> and 3231 <A HREF="#passive_scalar">passive_scalar</A>) and requires the use 3232 of a 2d-domain-decomposition. The last conditions severely 3233 restricts code optimization on several machines leading to very 3234 long execution times! This scheme is also not allowed for 3235 non-cyclic lateral boundary conditions (see <A HREF="#bc_lr">bc_lr</A> 3236 and <A HREF="#bc_ns">bc_ns</A>).</P> 3237 <P><BR>A differing advection scheme can be choosed for the 3238 subgrid-scale TKE using parameter <A HREF="#use_upstream_for_tke">use_upstream_for_tke</A>.</P> 3239 </TD> 3240 </TR> 3241 <TR> 3242 <TD WIDTH=126> 3243 <P><A NAME="scalar_exchange_coefficient"></A><B>scalar_exchange_coefficient</B></P> 3244 </TD> 3245 <TD WIDTH=45> 3246 <P>R</P> 3247 </TD> 3248 <TD WIDTH=159> 3249 <P><I>0.0</I></P> 3250 </TD> 3251 <TD WIDTH=1280> 3252 <P>Scalar exchange coefficient for a leaf (dimensionless).<BR><BR>This 3253 parameter is only of importance in cases in that both, 3254 <A HREF="../../../../../DEVELOPER_VERSION/chapter_4.1_adjusted.html#plant_canopy">plant_canopy</A> 3255 and <A HREF="../../../../../DEVELOPER_VERSION/chapter_4.1_adjusted.html#passive_scalar">passive_scalar</A>, 3256 are set <I>.T.</I>. The value of the scalar exchange coefficient 3257 is required for the parametrisation of the sources and sinks of 3258 scalar concentration due to the canopy.</P> 3259 </TD> 3260 </TR> 3261 <TR> 3262 <TD WIDTH=126> 3263 <P><A NAME="statistic_regions"></A><B>statistic_regions</B></P> 3264 </TD> 3265 <TD WIDTH=45> 3266 <P>I</P> 3267 </TD> 3268 <TD WIDTH=159> 3269 <P><I>0</I></P> 3270 </TD> 3271 <TD WIDTH=1280> 3272 <P>Number of additional user-defined subdomains for which 3273 statistical analysis and corresponding output (profiles, time 3274 series) shall be made. 3275 </P> 3276 <P>By default, vertical profiles and other statistical quantities 3277 are calculated as horizontal and/or volume average of the total 3278 model domain. Beyond that, these calculations can also be carried 3279 out for subdomains which can be defined using the field <A HREF="chapter_3.5.3.html">rmask 3280 </A>within the user-defined software (see <A HREF="chapter_3.5.3.html">chapter 3281 3.5.3</A>). The number of these subdomains is determined with the 3282 parameter <B>statistic_regions</B>. Maximum 9 additional 3283 subdomains are allowed. The parameter <A HREF="chapter_4.3.html#region">region</A> 3284 can be used to assigned names (identifier) to these subdomains 3285 which are then used in the headers of the output files and plots.</P> 3286 <P>If the default NetCDF output format is selected (see parameter 3287 <A HREF="chapter_4.2.html#data_output_format">data_output_format</A>), 3288 data for the total domain and all defined subdomains are output to 3289 the same file(s) (<A HREF="chapter_3.4.html#DATA_1D_PR_NETCDF">DATA_1D_PR_NETCDF</A>, 3290 <A HREF="chapter_3.4.html#DATA_1D_TS_NETCDF">DATA_1D_TS_NETCDF</A>). 3291 In case of <B>statistic_regions</B> > <I>0</I>, data on the 3292 file for the different domains can be distinguished by a suffix 3293 which is appended to the quantity names. Suffix 0 means data for 3294 the total domain, suffix 1 means data for subdomain 1, etc.</P> 3295 <P>In case of <B>data_output_format</B> = <I>'profil'</I>, 3296 individual local files for profiles (<A HREF="chapter_3.4.html#PLOT1D_DATA">PLOT1D_DATA</A>) are 3297 created for each subdomain. The individual subdomain files differ 3298 by their name (the number of the respective subdomain is attached, 3299 e.g. PLOT1D_DATA_1). In this case the name of the file with the 3300 data of the total domain is PLOT1D_DATA_0. If no subdomains are 3301 declared (<B>statistic_regions</B> = <I>0</I>), the name 3302 PLOT1D_DATA is used (this must be considered in the respective 3303 file connection statements of the <B>mrun</B> configuration file).</P> 3304 </TD> 3305 </TR> 3306 <TR> 3307 <TD WIDTH=126> 3308 <P><A NAME="surface_heatflux"></A><B>surface_heatflux</B></P> 3309 </TD> 3310 <TD WIDTH=45> 3311 <P>R</P> 3312 </TD> 3313 <TD WIDTH=159> 3314 <P><I>no prescribed<BR>heatflux</I></P> 3315 </TD> 3316 <TD WIDTH=1280> 3317 <P>Kinematic sensible heat flux at the bottom surface (in K m/s). 3318 </P> 3319 <P>If a value is assigned to this parameter, the internal 3320 two-dimensional surface heat flux field <I>shf</I> is initialized 3321 with the value of <B>surface_heatflux</B> as bottom 3322 (horizontally homogeneous) boundary condition for the temperature 3323 equation. This additionally requires that a Neumann condition must 3324 be used for the potential temperature (see <A HREF="#bc_pt_b">bc_pt_b</A>), 3325 because otherwise the resolved scale may contribute to the surface 3326 flux so that a constant value cannot be guaranteed. Also, changes 3327 of the surface temperature (see <A HREF="#pt_surface_initial_change">pt_surface_initial_change</A>) 3328 are not allowed. The parameter <A HREF="#random_heatflux">random_heatflux</A> 3329 can be used to impose random perturbations on the (homogeneous) 3330 surface heat flux field <I>shf</I>. </P> 3331 <P>In case of a non-flat <A HREF="#topography">topography</A>, the 3332 internal two-dimensional surface heat flux field <I>shf</I> 3333 is initialized with the value of <B>surface_heatflux</B> at the 3334 bottom surface and <A HREF="#wall_heatflux">wall_heatflux(0)</A> 3335 at the topography top face. The parameter<A HREF="#random_heatflux"> 3336 random_heatflux</A> can be used to impose random perturbations on 3337 this combined surface heat flux field <I>shf</I>. 3338 </P> 3339 <P>If no surface heat flux is assigned, <I>shf</I> is calculated 3340 at each timestep by u<SUB>*</SUB> * theta<SUB>*</SUB> (of course 3341 only with <A HREF="#prandtl_layer">prandtl_layer</A> switched on). 3342 Here, u<SUB>*</SUB> and theta<SUB>*</SUB> are calculated from the 3343 Prandtl law assuming logarithmic wind and temperature profiles 3344 between k=0 and k=1. In this case a Dirichlet condition (see 3345 <A HREF="#bc_pt_b">bc_pt_b</A>) must be used as bottom boundary 3346 condition for the potential temperature.</P> 3347 <P>See also <A HREF="#top_heatflux">top_heatflux</A>.</P> 3348 </TD> 3349 </TR> 3350 <TR> 3351 <TD WIDTH=126> 3352 <P><A NAME="surface_pressure"></A><B>surface_pressure</B></P> 3353 </TD> 3354 <TD WIDTH=45> 3355 <P>R</P> 3356 </TD> 3357 <TD WIDTH=159> 3358 <P><I>1013.25</I></P> 3359 </TD> 3360 <TD WIDTH=1280> 3361 <P>Atmospheric pressure at the surface (in hPa). 3362 </P> 3363 <P>Starting from this surface value, the vertical pressure profile 3364 is calculated once at the beginning of the run assuming a 3365 neutrally stratified atmosphere. This is needed for converting 3366 between the liquid water potential temperature and the potential 3367 temperature (see <A HREF="#cloud_physics">cloud_physics</A>).</P> 3368 </TD> 3369 </TR> 3370 <TR> 3371 <TD WIDTH=126> 3372 <P><A NAME="surface_scalarflux"></A><B>surface_scalarflux</B></P> 3373 </TD> 3374 <TD WIDTH=45> 3375 <P>R</P> 3376 </TD> 3377 <TD WIDTH=159> 3378 <P><I>0.0</I></P> 3379 </TD> 3380 <TD WIDTH=1280> 3381 <P>Scalar flux at the surface (in kg/(m<SUP>2</SUP> s)). 3382 </P> 3383 <P>If a non-zero value is assigned to this parameter, the 3384 respective scalar flux value is used as bottom (horizontally 3385 homogeneous) boundary condition for the scalar concentration 3386 equation. This additionally requires that a Neumann condition 3387 must be used for the scalar concentration (see <A HREF="#bc_s_b">bc_s_b</A>), 3388 because otherwise the resolved scale may contribute to the surface 3389 flux so that a constant value cannot be guaranteed. Also, changes 3390 of the surface scalar concentration (see <A HREF="#s_surface_initial_change">s_surface_initial_change</A>) 3391 are not allowed. 3392 </P> 3393 <P>If no surface scalar flux is assigned (<B>surface_scalarflux</B> 3394 = <I>0.0</I>), it is calculated at each timestep by u<SUB>*</SUB> 3395 * s<SUB>*</SUB> (of course only with Prandtl layer switched on). 3396 Here, s<SUB>*</SUB> is calculated from the Prandtl law assuming a 3397 logarithmic scalar concentration profile between k=0 and k=1. In 3398 this case a Dirichlet condition (see <A HREF="#bc_s_b">bc_s_b</A>) 3399 must be used as bottom boundary condition for the scalar 3400 concentration.</P> 3401 </TD> 3402 </TR> 3403 <TR> 3404 <TD WIDTH=126> 3405 <P><A NAME="surface_waterflux"></A><B>surface_waterflux</B></P> 3406 </TD> 3407 <TD WIDTH=45> 3408 <P>R</P> 3409 </TD> 3410 <TD WIDTH=159> 3411 <P><I>0.0</I></P> 3412 </TD> 3413 <TD WIDTH=1280> 3414 <P>Kinematic water flux near the surface (in m/s). 3415 </P> 3416 <P>If a non-zero value is assigned to this parameter, the 3417 respective water flux value is used as bottom (horizontally 3418 homogeneous) boundary condition for the humidity equation. This 3419 additionally requires that a Neumann condition must be used for 3420 the specific humidity / total water content (see <A HREF="#bc_q_b">bc_q_b</A>), 3421 because otherwise the resolved scale may contribute to the surface 3422 flux so that a constant value cannot be guaranteed. Also, changes 3423 of the surface humidity (see <A HREF="#q_surface_initial_change">q_surface_initial_change</A>) 3424 are not allowed.</P> 3425 <P>If no surface water flux is assigned (<B>surface_waterflux</B> 3426 = <I>0.0</I>), it is calculated at each timestep by u<SUB>*</SUB> 3427 * q<SUB>*</SUB> (of course only with Prandtl layer switched on). 3428 Here, q<SUB>*</SUB> is calculated from the Prandtl law assuming a 3429 logarithmic temperature profile between k=0 and k=1. In this case 3430 a Dirichlet condition (see <A HREF="#bc_q_b">bc_q_b</A>) must be 3431 used as the bottom boundary condition for the humidity.</P> 3432 </TD> 3433 </TR> 3434 <TR> 3435 <TD WIDTH=126> 3436 <P><A NAME="s_surface"></A><B>s_surface</B></P> 3437 </TD> 3438 <TD WIDTH=45> 3439 <P>R</P> 3440 </TD> 3441 <TD WIDTH=159> 3442 <P><I>0.0</I></P> 3443 </TD> 3444 <TD WIDTH=1280> 3445 <P>Surface value of the passive scalar (in kg/m<SUP>3</SUP>). </P> 3446 <P>This parameter assigns the value of the passive scalar s at the 3447 surface (k=0)<B>.</B> Starting from this value, the initial 3448 vertical scalar concentration profile is constructed with<A HREF="#s_vertical_gradient"> 3449 s_vertical_gradient</A> and <A HREF="#s_vertical_gradient_level">s_vertical_gradient_level</A>.</P> 3450 </TD> 3451 </TR> 3452 <TR> 3453 <TD WIDTH=126> 3454 <P><A NAME="s_surface_initial_change"></A><B>s_surface_initial</B> 3455 <BR><B>_change</B></P> 3456 </TD> 3457 <TD WIDTH=45> 3458 <P>R</P> 3459 </TD> 3460 <TD WIDTH=159> 3461 <P><I>0.0</I></P> 3462 </TD> 3463 <TD WIDTH=1280> 3464 <P>Change in surface scalar concentration to be made at the 3465 beginning of the 3d run (in kg/m<SUP>3</SUP>). 3466 </P> 3467 <P>If <B>s_surface_initial_change</B> is set to a non-zero 3468 value, the near surface scalar flux is not allowed to be given 3469 simultaneously (see <A HREF="#surface_scalarflux">surface_scalarflux</A>).</P> 3470 </TD> 3471 </TR> 3472 <TR> 3473 <TD WIDTH=126> 3474 <P><A NAME="s_vertical_gradient"></A><B>s_vertical_gradient</B></P> 3475 </TD> 3476 <TD WIDTH=45> 3477 <P>R (10)</P> 3478 </TD> 3479 <TD WIDTH=159> 3480 <P><I>10 * 0.0</I></P> 3481 </TD> 3482 <TD WIDTH=1280> 3483 <P>Scalar concentration gradient(s) of the initial scalar 3484 concentration profile (in kg/m<SUP>3 </SUP>/ 100 m). 3485 </P> 3486 <P>The scalar gradient holds starting from the height level 3487 defined by <A HREF="#s_vertical_gradient_level">s_vertical_gradient_level 3488 </A>(precisely: for all uv levels k, where zu(k) > 3489 s_vertical_gradient_level, s_init(k) is set: s_init(k) = 3490 s_init(k-1) + dzu(k) * <B>s_vertical_gradient</B>) up to the top 3491 boundary or up to the next height level defined by 3492 <A HREF="#s_vertical_gradient_level">s_vertical_gradient_level</A>. 3493 A total of 10 different gradients for 11 height intervals (10 3494 intervals if <A HREF="#s_vertical_gradient_level">s_vertical_gradient_level</A>(1) 3495 = <I>0.0</I>) can be assigned. The surface scalar value is 3496 assigned via <A HREF="#s_surface">s_surface</A>.</P> 3497 <P>Example: 3498 </P> 3499 <UL> 3500 <P><B>s_vertical_gradient</B> = <I>0.1</I>, <I>0.05</I>, 3501 <BR><B>s_vertical_gradient_level</B> = <I>500.0</I>, <I>1000.0</I>,</P> 3502 </UL> 3503 <P>That defines the scalar concentration to be constant with 3504 height up to z = 500.0 m with a value given by <A HREF="#s_surface">s_surface</A>. 3505 For 500.0 m < z <= 1000.0 m the scalar gradient is 0.1 kg/m<SUP>3 3506 </SUP>/ 100 m and for z > 1000.0 m up to the top boundary it is 3507 0.05 kg/m<SUP>3 </SUP>/ 100 m (it is assumed that the assigned 3508 height levels correspond with uv levels).</P> 3509 </TD> 3510 </TR> 3511 <TR> 3512 <TD WIDTH=126> 3513 <P><A NAME="s_vertical_gradient_level"></A><B>s_vertical_gradient_</B> 3514 <BR><B>level</B></P> 3515 </TD> 3516 <TD WIDTH=45> 3517 <P>R (10)</P> 3518 </TD> 3519 <TD WIDTH=159> 3520 <P><I>10 *</I> <I>0.0</I></P> 3521 </TD> 3522 <TD WIDTH=1280> 3523 <P>Height level from which on the scalar gradient defined by 3524 <A HREF="#s_vertical_gradient">s_vertical_gradient</A> is 3525 effective (in m). 3526 </P> 3527 <P>The height levels are to be assigned in ascending order. The 3528 default values result in a scalar concentration constant with 3529 height regardless of the values of <A HREF="#s_vertical_gradient">s_vertical_gradient</A> 3530 (unless the top boundary of the model is higher than 100000.0 m). 3531 For the piecewise construction of scalar concentration profiles 3532 see <A HREF="#s_vertical_gradient">s_vertical_gradient</A>.</P> 3533 </TD> 3534 </TR> 3535 <TR> 3536 <TD WIDTH=126> 3537 <P><A NAME="timestep_scheme"></A><B>timestep_scheme</B></P> 3538 </TD> 3539 <TD WIDTH=45> 3540 <P>C * 20</P> 3541 </TD> 3542 <TD WIDTH=159> 3543 <P><I>'runge</I><BR><I>kutta-3'</I></P> 3544 </TD> 3545 <TD WIDTH=1280> 3546 <P>Time step scheme to be used for the integration of the 3547 prognostic variables. 3548 </P> 3549 <P>The user can choose between the following schemes:</P> 3550 <P><I>'runge-kutta-3'</I></P> 3551 <P STYLE="margin-left: 0.42in">Third order Runge-Kutta 3552 scheme.<BR>This scheme requires the use of <A HREF="#momentum_advec">momentum_advec</A> 3553 = <A HREF="#scalar_advec">scalar_advec</A> = '<I>pw-scheme'</I>. 3554 Please refer to the <A HREF="../tec/numerik.heiko/zeitschrittverfahren.pdf">documentation 3555 on PALM's time integration schemes (28p., in German)</A> fur 3556 further details.</P> 3557 <P><I>'runge-kutta-2'</I></P> 3558 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">Second order 3559 Runge-Kutta scheme.<BR>For special features see <B>timestep_scheme</B> 3560 = '<I>runge-kutta-3'</I>.</P> 3561 <P><BR><I>'leapfrog'</I></P> 3562 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">Second order 3563 leapfrog scheme.<BR>Although this scheme requires a constant 3564 timestep (because it is centered in time), is even applied 3565 in case of changes in timestep. Therefore, only small changes of 3566 the timestep are allowed (see <A HREF="#dt">dt</A>). However, an 3567 Euler timestep is always used as the first timestep of an initiali 3568 run. When using the Bott-Chlond scheme for scalar advection (see 3569 <A HREF="#scalar_advec">scalar_advec</A>), the prognostic equation 3570 for potential temperature will be calculated with the Euler 3571 scheme, although the leapfrog scheme is switched on. <BR>The 3572 leapfrog scheme must not be used together with the upstream-spline 3573 scheme for calculating the advection (see <A HREF="#scalar_advec">scalar_advec</A> 3574 = '<I>ups-scheme'</I> and <A HREF="#momentum_advec">momentum_advec</A> 3575 = '<I>ups-scheme'</I>).</P> 3576 <P><BR><I>'leapfrog+euler'</I></P> 3577 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">The leapfrog 3578 scheme is used, but after each change of a timestep an Euler 3579 timestep is carried out. Although this method is theoretically 3580 correct (because the pure leapfrog method does not allow timestep 3581 changes), the divergence of the velocity field (after applying the 3582 pressure solver) may be significantly larger than with <I>'leapfrog'</I>.</P> 3583 <P><BR><I>'euler'</I></P> 3584 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">First order 3585 Euler scheme. <BR>The Euler scheme must be used when 3586 treating the advection terms with the upstream-spline scheme (see 3587 <A HREF="#scalar_advec">scalar_advec</A> = <I>'ups-scheme'</I> and 3588 <A HREF="#momentum_advec">momentum_advec</A> = <I>'ups-scheme'</I>).</P> 3589 <P STYLE="margin-bottom: 0in"><BR><BR>A differing timestep scheme 3590 can be choosed for the subgrid-scale TKE using parameter 3591 <A HREF="#use_upstream_for_tke">use_upstream_for_tke</A>.</P> 3592 </TD> 3593 </TR> 3594 <TR> 3595 <TD WIDTH=126> 3596 <P ALIGN=LEFT><A NAME="topography"></A><B>topography</B></P> 3597 </TD> 3598 <TD WIDTH=45> 3599 <P>C * 40</P> 3600 </TD> 3601 <TD WIDTH=159> 3602 <P><I>'flat'</I></P> 3603 </TD> 3604 <TD WIDTH=1280> 3605 <P>Topography mode. 3606 </P> 3607 <P>The user can choose between the following modes:</P> 3608 <P><I>'flat'</I></P> 3609 <P STYLE="margin-left: 0.42in">Flat surface.</P> 3610 <P><I>'single_building'</I></P> 3611 <P STYLE="margin-left: 0.42in">Flow around a single 3612 rectangular building mounted on a flat surface.<BR>The building 3613 size and location can be specified by the parameters 3614 <A HREF="#building_height">building_height</A>, <A HREF="#building_length_x">building_length_x</A>, 3615 <A HREF="#building_length_y">building_length_y</A>, 3616 <A HREF="#building_wall_left">building_wall_left</A> and 3617 <A HREF="#building_wall_south">building_wall_south</A>.</P> 3618 <P><I>'single_street_canyon'</I></P> 3619 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">Flow over a 3620 single, quasi-2D street canyon of infinite length oriented either 3621 in x- or in y-direction.<BR>The canyon size, orientation and 3622 location can be specified by the parameters <A HREF="#canyon_height">canyon_height</A> 3623 plus <B>either</B> <A HREF="#canyon_width_x">canyon_width_x</A> 3624 and <A HREF="#canyon_wall_left">canyon_wall_left</A> <B>or</B> 3625 <A HREF="#canyon_width_y">canyon_width_y</A> and 3626 <A HREF="#canyon_wall_south">canyon_wall_south</A>.</P> 3627 <P> </P> 3628 <P><I>'read_from_file'</I></P> 3629 <P STYLE="margin-left: 0.42in; margin-bottom: 0in">Flow around 3630 arbitrary topography.<BR>This mode requires the input file 3631 <A HREF="chapter_3.4.html#TOPOGRAPHY_DATA">TOPOGRAPHY_DATA</A><FONT COLOR="#000000">. 3632 This file contains the arbitrary topography height 3633 information in m. These data must exactly match the 3634 horizontal grid.</FONT></P> 3635 <P STYLE="margin-bottom: 0in"><I><BR></I><FONT COLOR="#000000">Alternatively, 3636 the user may add code to the user interface subroutine 3637 <A HREF="chapter_3.5.1.html#user_init_grid">user_init_grid</A> to 3638 allow further topography modes. </FONT>These require to explicitly 3639 set the <A HREF="#topography_grid_convention">topography_grid_convention</A> to 3640 either <I>'cell_edge'</I> or <I>'cell_center'</I>.<BR><FONT COLOR="#000000"><BR>Non-flat 3641 </FONT><FONT COLOR="#000000"><B>topography</B></FONT><FONT COLOR="#000000"> 3642 modes may assign a</FONT> kinematic sensible<FONT COLOR="#000000"> 3643 <A HREF="#wall_heatflux">wall_heatflux</A> at the five topography 3644 faces.</FONT><BR><FONT COLOR="#000000"><BR>All non-flat </FONT><FONT COLOR="#000000"><B>topography</B></FONT><FONT COLOR="#000000"> 3645 modes </FONT>require the use of <A HREF="#momentum_advec">momentum_advec</A> 3646 = <A HREF="#scalar_advec">scalar_advec</A> = '<I>pw-scheme'</I>, 3647 <A HREF="chapter_4.2.html#psolver">psolver</A> /= <I>'sor'</I>, 3648 <A HREF="#alpha_surface">alpha_surface</A> = 3649 0.0, <A HREF="#galilei_transformation">galilei_transformation</A> 3650 = <I>.F.</I>, <A HREF="#cloud_physics">cloud_physics </A> 3651 = <I>.F.</I>, <A HREF="#cloud_droplets">cloud_droplets</A> = 3652 <I>.F.</I>, <A HREF="#humidity">humidity</A> = <I>.F.</I>, 3653 and <A HREF="#prandtl_layer">prandtl_layer</A> = .T..<BR><FONT COLOR="#000000"><BR>Note 3654 that an inclined model domain requires the use of </FONT><FONT COLOR="#000000"><B>topography</B></FONT><FONT COLOR="#000000"> 3655 = </FONT><FONT COLOR="#000000"><I>'flat'</I></FONT><FONT COLOR="#000000"> 3656 and a nonzero </FONT><A HREF="#alpha_surface">alpha_surface</A>.</P> 3657 </TD> 3658 </TR> 3659 <TR> 3660 <TD WIDTH=126> 3661 <P><A NAME="topography_grid_convention"></A><B>topography_grid_</B><BR><B>convention</B></P> 3662 </TD> 3663 <TD WIDTH=45> 3664 <P>C*11</P> 3665 </TD> 3666 <TD WIDTH=159> 3667 <P><I>default depends on value of <A HREF="#topography">topography</A>; 3668 see text for details</I></P> 3669 </TD> 3670 <TD WIDTH=1280> 3671 <P>Convention for defining the topography grid.<BR><BR>Possible 3672 values are</P> 3673 <UL> 3674 <LI><P STYLE="margin-bottom: 0in"><I>'cell_edge': </I>the 3675 distance between cell edges defines the extent of topography. 3676 This setting is normally for <I>generic topographies</I>, i.e. 3677 topographies that are constructed using length parameters. For 3678 example, <A HREF="#topography">topography</A> = <I>'single_building'</I> 3679 is constructed using <A HREF="#building_length_x">building_length_x</A> 3680 and <A HREF="#building_length_y">building_length_y</A>. The 3681 advantage of this setting is that the actual size of generic 3682 topography is independent of the grid size, provided that the 3683 length parameters are an integer multiple of the grid lengths <A HREF="#dx">dx</A> 3684 and <A HREF="#dy">dy</A>. This is convenient for 3685 resolution parameter studies.</P> 3686 <LI><P><I>'cell_center': </I>the number of topography cells 3687 define the extent of topography. This setting is normally for 3688 <I>rastered real topographies</I> derived from digital elevation 3689 models. For example, <A HREF="#topography">topography</A> = 3690 <I>'read_from_file'</I> is constructed using the input file 3691 <A HREF="chapter_3.4.html#TOPOGRAPHY_DATA">TOPOGRAPHY_DATA</A><FONT COLOR="#000000">. </FONT>The 3692 advantage of this setting is that the rastered topography 3693 cells of the input file are directly mapped to topography grid 3694 boxes in PALM. 3695 </P> 3696 </UL> 3697 <P>The example files <CODE><FONT SIZE=4>example_topo_file</FONT></CODE> 3698 and <CODE><FONT SIZE=4>example_building</FONT></CODE> in 3699 <CODE><FONT SIZE=4>trunk/EXAMPLES/</FONT></CODE> illustrate the 3700 difference between both approaches. Both examples simulate a 3701 single building and yield the same results. The former uses a 3702 rastered topography input file with <I>'cell_center'</I> 3703 convention, the latter applies a generic topography with 3704 <I>'cell_edge'</I> convention.<BR><BR>The default value is</P> 3705 <UL> 3706 <LI><P STYLE="margin-bottom: 0in"><I>'cell_edge' </I>if 3707 <A HREF="#topography">topography</A> = <I>'single_building'</I> 3708 or <I>'single_street_canyon'</I>,</P> 3709 <LI><P STYLE="margin-bottom: 0in"><I>'cell_center'</I> if 3710 <A HREF="#topography">topography</A> = <I>'read_from_file'</I>,</P> 3711 <LI><P><I>none (' '</I> ) otherwise, leading to an abort 3712 if <B>topography_grid_convention</B> is not set.</P> 3713 </UL> 3714 <P>This means that 3715 </P> 3716 <UL> 3717 <LI><P STYLE="margin-bottom: 0in">For PALM simulations using a 3718 <I>user-defined topography</I>, the <B>topography_grid_convention</B> 3719 must be explicitly set to either <I>'cell_edge'</I> or 3720 <I>'cell_center'</I>.</P> 3721 <LI><P>For PALM simulations using a <I>standard topography</I> 3722 <I>('single_building'</I>, <I>'single_street_canyon'</I> or 3723 <I>'read_from_file')</I>, it is possible but not required to set 3724 the <B>topography_grid_convention</B> because appropriate 3725 default values apply.</P> 3726 </UL> 3727 </TD> 3728 </TR> 3729 <TR> 3730 <TD WIDTH=126> 3731 <P><A NAME="top_heatflux"></A><B>top_heatflux</B></P> 3732 </TD> 3733 <TD WIDTH=45> 3734 <P>R</P> 3735 </TD> 3736 <TD WIDTH=159> 3737 <P><I>no prescribed<BR>heatflux</I></P> 3738 </TD> 3739 <TD WIDTH=1280> 3740 <P>Kinematic sensible heat flux at the top boundary (in K m/s). 3741 </P> 3742 <P>If a value is assigned to this parameter, the internal 3743 two-dimensional surface heat flux field <FONT FACE="monospace">tswst</FONT> 3744 is initialized with the value of <B>top_heatflux</B> as top 3745 (horizontally homogeneous) boundary condition for the temperature 3746 equation. This additionally requires that a Neumann condition must 3747 be used for the potential temperature (see <A HREF="#bc_pt_t">bc_pt_t</A>), 3748 because otherwise the resolved scale may contribute to the top 3749 flux so that a constant flux value cannot be guaranteed. </P> 3750 <P><B>Note:</B><BR>The application of a top heat flux additionally 3751 requires the setting of initial parameter <A HREF="#use_top_fluxes">use_top_fluxes</A> 3752 = .T.. 3753 </P> 3754 <P>No Prandtl-layer is available at the top boundary so far.</P> 3755 <P>See also <A HREF="#surface_heatflux">surface_heatflux</A>.</P> 3756 </TD> 3757 </TR> 3758 <TR> 3759 <TD WIDTH=126> 3760 <P><A NAME="top_momentumflux_u"></A><B>top_momentumflux_u</B></P> 3761 </TD> 3762 <TD WIDTH=45> 3763 <P>R</P> 3764 </TD> 3765 <TD WIDTH=159> 3766 <P><I>no prescribed momentumflux</I></P> 3767 </TD> 3768 <TD WIDTH=1280> 3769 <P>Momentum flux along x at the top boundary (in m2/s2).</P> 3770 <P>If a value is assigned to this parameter, the internal 3771 two-dimensional u-momentum flux field <FONT FACE="monospace">uswst</FONT> 3772 is initialized with the value of <B>top_momentumflux_u</B> as top 3773 (horizontally homogeneous) boundary condition for the u-momentum 3774 equation.</P> 3775 <P><B>Notes:</B><BR>The application of a top momentum flux 3776 additionally requires the setting of initial parameter 3777 <A HREF="#use_top_fluxes">use_top_fluxes</A> = .T.. Setting of 3778 <B>top_momentumflux_u</B> requires setting of <A HREF="#top_momentumflux_v">top_momentumflux_v</A> 3779 also.</P> 3780 <P>A Neumann condition should be used for the u velocity 3781 component (see <A HREF="#bc_uv_t">bc_uv_t</A>), because otherwise 3782 the resolved scale may contribute to the top flux so that a 3783 constant flux value cannot be guaranteed. </P> 3784 <P>No Prandtl-layer is available at the top boundary so far.</P> 3785 <P>The <A HREF="chapter_3.8.html">coupled</A> ocean parameter 3786 file <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A> 3787 should include dummy REAL value assignments to both 3788 <A HREF="#top_momentumflux_u">top_momentumflux_u</A> 3789 and <A HREF="#top_momentumflux_v">top_momentumflux_v</A> 3790 (e.g. top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to 3791 enable the momentum flux coupling.</P> 3792 </TD> 3793 </TR> 3794 <TR> 3795 <TD WIDTH=126> 3796 <P><A NAME="top_momentumflux_v"></A><B>top_momentumflux_v</B></P> 3797 </TD> 3798 <TD WIDTH=45> 3799 <P>R</P> 3800 </TD> 3801 <TD WIDTH=159> 3802 <P><I>no prescribed momentumflux</I></P> 3803 </TD> 3804 <TD WIDTH=1280> 3805 <P>Momentum flux along y at the top boundary (in m2/s2).</P> 3806 <P>If a value is assigned to this parameter, the internal 3807 two-dimensional v-momentum flux field <FONT FACE="monospace">vswst</FONT> 3808 is initialized with the value of <B>top_momentumflux_v</B> as top 3809 (horizontally homogeneous) boundary condition for the v-momentum 3810 equation.</P> 3811 <P><B>Notes:</B><BR>The application of a top momentum flux 3812 additionally requires the setting of initial parameter 3813 <A HREF="#use_top_fluxes">use_top_fluxes</A> = .T.. Setting of 3814 <B>top_momentumflux_v</B> requires setting of <A HREF="#top_momentumflux_u">top_momentumflux_u</A> 3815 also.</P> 3816 <P>A Neumann condition should be used for the v velocity 3817 component (see <A HREF="#bc_uv_t">bc_uv_t</A>), because otherwise 3818 the resolved scale may contribute to the top flux so that a 3819 constant flux value cannot be guaranteed. </P> 3820 <P>No Prandtl-layer is available at the top boundary so far.</P> 3821 <P>The <A HREF="chapter_3.8.html">coupled</A> ocean parameter 3822 file <A HREF="chapter_3.4.html#PARIN"><FONT SIZE=2>PARIN_O</FONT></A> 3823 should include dummy REAL value assignments to both 3824 <A HREF="#top_momentumflux_u">top_momentumflux_u</A> 3825 and <A HREF="#top_momentumflux_v">top_momentumflux_v</A> 3826 (e.g. top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to 3827 enable the momentum flux coupling.</P> 3828 </TD> 3829 </TR> 3830 <TR> 3831 <TD WIDTH=126> 3832 <P><A NAME="top_salinityflux"></A><B>top_salinityflux</B></P> 3833 </TD> 3834 <TD WIDTH=45> 3835 <P>R</P> 3836 </TD> 3837 <TD WIDTH=159> 3838 <P><I>no prescribed<BR>salinityflux</I></P> 3839 </TD> 3840 <TD WIDTH=1280> 3841 <P>Kinematic salinity flux at the top boundary, i.e. the sea 3842 surface (in psu m/s). 3843 </P> 3844 <P>This parameter only comes into effect for ocean runs (see 3845 parameter <A HREF="#ocean">ocean</A>).</P> 3846 <P>If a value is assigned to this parameter, the internal 3847 two-dimensional surface heat flux field <FONT FACE="monospace">saswst</FONT> 3848 is initialized with the value of <B>top_salinityflux</B> as 3849 top (horizontally homogeneous) boundary condition for the salinity 3850 equation. This additionally requires that a Neumann condition must 3851 be used for the salinity (see <A HREF="#bc_sa_t">bc_sa_t</A>), 3852 because otherwise the resolved scale may contribute to the top 3853 flux so that a constant flux value cannot be guaranteed. </P> 3854 <P><B>Note:</B><BR>The application of a salinity flux at the model 3855 top additionally requires the setting of initial parameter 3856 <A HREF="#use_top_fluxes">use_top_fluxes</A> = .T.. 3857 </P> 3858 <P>See also <A HREF="#bottom_salinityflux">bottom_salinityflux</A>.</P> 3859 </TD> 3860 </TR> 3861 <TR> 3862 <TD WIDTH=126> 3863 <P><A NAME="turbulent_inflow"></A><B>turbulent_inflow</B></P> 3864 </TD> 3865 <TD WIDTH=45> 3866 <P>L</P> 3867 </TD> 3868 <TD WIDTH=159> 3869 <P><I>.F.</I></P> 3870 </TD> 3871 <TD WIDTH=1280> 3872 <P>Generates a turbulent inflow at side boundaries using a 3873 turbulence recycling method.<BR><BR>Turbulent inflow is realized 3874 using the turbulence recycling method from Lund et al. (1998, J. 3875 Comp. Phys., <B>140</B>, 233-258) modified by Kataoka and Mizuno 3876 (2002, Wind and Structures, <B>5</B>, 379-392).<BR><BR>A turbulent 3877 inflow requires Dirichlet conditions at the respective inflow 3878 boundary. <B>So far, a turbulent inflow is realized from the left 3879 (west) side only, i.e. <A HREF="#bc_lr">bc_lr</A></B> <B>=</B> 3880 <I><B>'dirichlet/radiation'</B></I> <B>is required!</B><BR><BR>The 3881 initial (quasi-stationary) turbulence field should be generated by 3882 a precursor run and used by setting <A HREF="#initializing_actions">initializing_actions</A> 3883 = <I>'cyclic_fill'</I>.<BR><BR>The distance of the recycling plane 3884 from the inflow boundary can be set with parameter 3885 <A HREF="#recycling_width">recycling_width</A>. The heigth above 3886 ground above which the turbulence signal is not used for recycling 3887 and the width of the layer within the magnitude of the 3888 turbulence signal is damped from 100% to 0% can be set with 3889 parameters <A HREF="#inflow_damping_height">inflow_damping_height</A> 3890 and <A HREF="#inflow_damping_width">inflow_damping_width</A>.<BR><BR>The 3891 detailed setup for a turbulent inflow is described in <A HREF="chapter_3.9.html">chapter 3892 3.9</A>.</P> 3893 </TD> 3894 </TR> 3895 <TR> 3896 <TD WIDTH=126> 3897 <P><A NAME="u_bulk"></A><B>u_bulk</B></P> 3898 </TD> 3899 <TD WIDTH=45> 3900 <P>R</P> 3901 </TD> 3902 <TD WIDTH=159> 3903 <P><I>0.0</I></P> 3904 </TD> 3905 <TD WIDTH=1280> 3906 <P>u-component of the predefined bulk velocity (in m/s).<BR><BR>This 3907 parameter comes into effect if <A HREF="#conserve_volume_flow">conserve_volume_flow</A> 3908 = <I>.T.</I> and <A HREF="#conserve_volume_flow_mode">conserve_volume_flow_mode</A> 3909 = <I>'bulk_velocity'</I>.</P> 3910 </TD> 3911 </TR> 3912 <TR> 3913 <TD WIDTH=126> 3914 <P><A NAME="ug_surface"></A><B>ug_surface</B></P> 3915 </TD> 3916 <TD WIDTH=45> 3917 <P>R</P> 3918 </TD> 3919 <TD WIDTH=159> 3920 <P><I>0.0</I></P> 3921 </TD> 3922 <TD WIDTH=1280> 3923 <P>u-component of the geostrophic wind at the surface (in 3924 m/s).<BR><BR>This parameter assigns the value of the u-component 3925 of the geostrophic wind (ug) at the surface (k=0). Starting from 3926 this value, the initial vertical profile of the <BR>u-component of 3927 the geostrophic wind is constructed with <A HREF="#ug_vertical_gradient">ug_vertical_gradient</A> 3928 and <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A>. 3929 The profile constructed in that way is used for creating the 3930 initial vertical velocity profile of the 3d-model. Either it is 3931 applied, as it has been specified by the user 3932 (<A HREF="#initializing_actions">initializing_actions</A> = 3933 'set_constant_profiles') or it is used for calculating a 3934 stationary boundary layer wind profile (<A HREF="#initializing_actions">initializing_actions</A> 3935 = 'set_1d-model_profiles'). If ug is constant with height (i.e. 3936 ug(k)=<B>ug_surface</B>) and has a large value, it is 3937 recommended to use a Galilei-transformation of the coordinate 3938 system, if possible (see <A HREF="#galilei_transformation">galilei_transformation</A>), 3939 in order to obtain larger time steps.<BR><BR><B>Attention:</B><BR>In 3940 case of ocean runs (see <A HREF="#ocean">ocean</A>), this 3941 parameter gives the geostrophic velocity value (i.e. the pressure 3942 gradient) at the sea surface, which is at k=nzt. The profile is 3943 then constructed from the surface down to the bottom of the model.</P> 3944 </TD> 3945 </TR> 3946 <TR> 3947 <TD WIDTH=126> 3948 <P><A NAME="ug_vertical_gradient"></A><B>ug_vertical_gradient</B></P> 3949 </TD> 3950 <TD WIDTH=45> 3951 <P>R(10)</P> 3952 </TD> 3953 <TD WIDTH=159> 3954 <P><I>10 * 0.0</I></P> 3955 </TD> 3956 <TD WIDTH=1280> 3957 <P>Gradient(s) of the initial profile of the u-component of 3958 the geostrophic wind (in 1/100s).<BR><BR>The gradient holds 3959 starting from the height level defined by 3960 <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A> 3961 (precisely: for all uv levels k where zu(k) > 3962 <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A>, 3963 ug(k) is set: ug(k) = ug(k-1) + dzu(k) * <B>ug_vertical_gradient</B>) 3964 up to the top boundary or up to the next height level defined by 3965 <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A>. 3966 A total of 10 different gradients for 11 height intervals (10 3967 intervals if <A HREF="#ug_vertical_gradient_level">ug_vertical_gradient_level</A>(1) 3968 = 0.0) can be assigned. The surface geostrophic wind is assigned 3969 by <A HREF="#ug_surface">ug_surface</A>.<BR><BR><B>Attention:</B><BR>In 3970 case of ocean runs (see <A HREF="#ocean">ocean</A>), the profile 3971 is constructed like described above, but starting from the sea 3972 surface (k=nzt) down to the bottom boundary of the model. Height 3973 levels have then to be given as negative values, e.g. 3974 <B>ug_vertical_gradient_level</B> = <I>-500.0</I>, <I>-1000.0</I>.</P> 3975 </TD> 3976 </TR> 3977 <TR> 3978 <TD WIDTH=126> 3979 <P><A NAME="ug_vertical_gradient_level"></A><B>ug_vertical_gradient_level</B></P> 3980 </TD> 3981 <TD WIDTH=45> 3982 <P>R(10)</P> 3983 </TD> 3984 <TD WIDTH=159> 3985 <P><I>10 * 0.0</I></P> 3986 </TD> 3987 <TD WIDTH=1280> 3988 <P>Height level from which on the gradient defined by 3989 <A HREF="#ug_vertical_gradient">ug_vertical_gradient</A> is 3990 effective (in m).<BR><BR>The height levels have to be assigned in 3991 ascending order. For the piecewise construction of a profile of 3992 the u-component of the geostrophic wind component (ug) see 3993 <A HREF="#ug_vertical_gradient">ug_vertical_gradient</A>.<BR><BR><B>Attention:</B><BR>In 3994 case of ocean runs (see <A HREF="#ocean">ocean</A>), the 3995 (negative) height levels have to be assigned in descending order.</P> 3996 </TD> 3997 </TR> 3998 <TR> 3999 <TD WIDTH=126> 4000 <P><A NAME="ups_limit_e"></A><B>ups_limit_e</B></P> 4001 </TD> 4002 <TD WIDTH=45> 4003 <P>R</P> 4004 </TD> 4005 <TD WIDTH=159> 4006 <P><I>0.0</I></P> 4007 </TD> 4008 <TD WIDTH=1280> 4009 <P>Subgrid-scale turbulent kinetic energy difference used as 4010 criterion for applying the upstream scheme when upstream-spline 4011 advection is switched on (in m<SUP>2</SUP>/s<SUP>2</SUP>). 4012 </P> 4013 <P>This variable steers the appropriate treatment of the advection 4014 of the subgrid-scale turbulent kinetic energy in case that the 4015 uptream-spline scheme is used . For further information see 4016 <A HREF="#ups_limit_pt">ups_limit_pt</A>. 4017 </P> 4018 <P>Only positive values are allowed for <B>ups_limit_e</B>. 4019 </P> 4020 </TD> 4021 </TR> 4022 <TR> 4023 <TD WIDTH=126> 4024 <P><A NAME="ups_limit_pt"></A><B>ups_limit_pt</B></P> 4025 </TD> 4026 <TD WIDTH=45> 4027 <P>R</P> 4028 </TD> 4029 <TD WIDTH=159> 4030 <P><I>0.0</I></P> 4031 </TD> 4032 <TD WIDTH=1280> 4033 <P>Temperature difference used as criterion for applying the 4034 upstream scheme when upstream-spline advection is switched 4035 on (in K). 4036 </P> 4037 <P>This criterion is used if the upstream-spline scheme is 4038 switched on (see <A HREF="#scalar_advec">scalar_advec</A>).<BR>If, 4039 for a given gridpoint, the absolute temperature difference with 4040 respect to the upstream grid point is smaller than the value given 4041 for <B>ups_limit_pt</B>, the upstream scheme is used for this 4042 gridpoint (by default, the upstream-spline scheme is always used). 4043 Reason: in case of a very small upstream gradient, the advection 4044 should cause only a very small tendency. However, in such 4045 situations the upstream-spline scheme may give wrong tendencies at 4046 a grid point due to spline overshooting, if simultaneously the 4047 downstream gradient is very large. In such cases it may be more 4048 reasonable to use the upstream scheme. The numerical diffusion 4049 caused by the upstream schme remains small as long as the upstream 4050 gradients are small.</P> 4051 <P>The percentage of grid points for which the upstream scheme is 4052 actually used, can be output as a time series with respect to the 4053 three directions in space with run parameter (see <A HREF="chapter_4.2.html#dt_dots">dt_dots</A>, 4054 the timeseries names in the NetCDF file are <I>'splptx'</I>, 4055 <I>'splpty'</I>, <I>'splptz'</I>). The percentage of gridpoints 4056 should stay below a certain limit, however, it is not possible to 4057 give a general limit, since it depends on the respective flow. 4058 </P> 4059 <P>Only positive values are permitted for <B>ups_limit_pt</B>.</P> 4060 <P>A more effective control of the âovershootsâ can be 4061 achieved with parameter <A HREF="#cut_spline_overshoot">cut_spline_overshoot</A>. 4062 </P> 4063 </TD> 4064 </TR> 4065 <TR> 4066 <TD WIDTH=126> 4067 <P><A NAME="ups_limit_u"></A><B>ups_limit_u</B></P> 4068 </TD> 4069 <TD WIDTH=45> 4070 <P>R</P> 4071 </TD> 4072 <TD WIDTH=159> 4073 <P><I>0.0</I></P> 4074 </TD> 4075 <TD WIDTH=1280> 4076 <P>Velocity difference (u-component) used as criterion for 4077 applying the upstream scheme when upstream-spline advection is 4078 switched on (in m/s). 4079 </P> 4080 <P>This variable steers the appropriate treatment of the advection 4081 of the u-velocity-component in case that the upstream-spline 4082 scheme is used. For further information see <A HREF="#ups_limit_pt">ups_limit_pt</A>. 4083 </P> 4084 <P>Only positive values are permitted for <B>ups_limit_u</B>.</P> 4085 </TD> 4086 </TR> 4087 <TR> 4088 <TD WIDTH=126> 4089 <P><A NAME="ups_limit_v"></A><B>ups_limit_v</B></P> 4090 </TD> 4091 <TD WIDTH=45> 4092 <P>R</P> 4093 </TD> 4094 <TD WIDTH=159> 4095 <P><I>0.0</I></P> 4096 </TD> 4097 <TD WIDTH=1280> 4098 <P>Velocity difference (v-component) used as criterion for 4099 applying the upstream scheme when upstream-spline advection is 4100 switched on (in m/s). 4101 </P> 4102 <P>This variable steers the appropriate treatment of the advection 4103 of the v-velocity-component in case that the upstream-spline 4104 scheme is used. For further information see <A HREF="#ups_limit_pt">ups_limit_pt</A>. 4105 </P> 4106 <P>Only positive values are permitted for <B>ups_limit_v</B>.</P> 4107 </TD> 4108 </TR> 4109 <TR> 4110 <TD WIDTH=126> 4111 <P><A NAME="ups_limit_w"></A><B>ups_limit_w</B></P> 4112 </TD> 4113 <TD WIDTH=45> 4114 <P>R</P> 4115 </TD> 4116 <TD WIDTH=159> 4117 <P><I>0.0</I></P> 4118 </TD> 4119 <TD WIDTH=1280> 4120 <P>Velocity difference (w-component) used as criterion for 4121 applying the upstream scheme when upstream-spline advection is 4122 switched on (in m/s). 4123 </P> 4124 <P>This variable steers the appropriate treatment of the advection 4125 of the w-velocity-component in case that the upstream-spline 4126 scheme is used. For further information see <A HREF="#ups_limit_pt">ups_limit_pt</A>. 4127 </P> 4128 <P>Only positive values are permitted for <B>ups_limit_w</B>.</P> 4129 </TD> 4130 </TR> 4131 <TR> 4132 <TD WIDTH=126> 4133 <P><A NAME="use_surface_fluxes"></A><B>use_surface_fluxes</B></P> 4134 </TD> 4135 <TD WIDTH=45> 4136 <P>L</P> 4137 </TD> 4138 <TD WIDTH=159> 4139 <P><I>.F.</I></P> 4140 </TD> 4141 <TD WIDTH=1280> 4142 <P>Parameter to steer the treatment of the subgrid-scale vertical 4143 fluxes within the diffusion terms at k=1 (bottom boundary).</P> 4144 <P>By default, the near-surface subgrid-scale fluxes are 4145 parameterized (like in the remaining model domain) using the 4146 gradient approach. If <B>use_surface_fluxes</B> = <I>.TRUE.</I>, 4147 the user-assigned surface fluxes are used instead (see 4148 <A HREF="#surface_heatflux">surface_heatflux</A>, 4149 <A HREF="#surface_waterflux">surface_waterflux</A> and 4150 <A HREF="#surface_scalarflux">surface_scalarflux</A>) <B>or</B> 4151 the surface fluxes are calculated via the Prandtl layer relation 4152 (depends on the bottom boundary conditions, see <A HREF="#bc_pt_b">bc_pt_b</A>, 4153 <A HREF="#bc_q_b">bc_q_b</A> and <A HREF="#bc_s_b">bc_s_b</A>).</P> 4154 <P><B>use_surface_fluxes</B> is automatically set <I>.TRUE.</I>, 4155 if a Prandtl layer is used (see <A HREF="#prandtl_layer">prandtl_layer</A>). 4156 </P> 4157 <P>The user may prescribe the surface fluxes at the bottom 4158 boundary without using a Prandtl layer by setting 4159 <B>use_surface_fluxes</B> = <I>.T.</I> and <B>prandtl_layer</B> = 4160 <I>.F.</I>. If , in this case, the momentum flux (u<SUB>*</SUB><SUP>2</SUP>) 4161 should also be prescribed, the user must assign an appropriate 4162 value within the user-defined code.</P> 4163 </TD> 4164 </TR> 4165 <TR> 4166 <TD WIDTH=126> 4167 <P><A NAME="use_top_fluxes"></A><B>use_top_fluxes</B></P> 4168 </TD> 4169 <TD WIDTH=45> 4170 <P>L</P> 4171 </TD> 4172 <TD WIDTH=159> 4173 <P><I>.F.</I></P> 4174 </TD> 4175 <TD WIDTH=1280> 4176 <P>Parameter to steer the treatment of the subgrid-scale vertical 4177 fluxes within the diffusion terms at k=nz (top boundary).</P> 4178 <P>By default, the fluxes at nz are calculated using the gradient 4179 approach. If <B>use_top_fluxes</B> = <I>.TRUE.</I>, the 4180 user-assigned top fluxes are used instead (see <A HREF="#top_heatflux">top_heatflux</A>, 4181 <A HREF="#top_momentumflux_u">top_momentumflux_u</A>, 4182 <A HREF="#top_momentumflux_v">top_momentumflux_v</A>, 4183 <A HREF="#top_salinityflux">top_salinityflux</A>).</P> 4184 <P>Currently, no value for the latent heatflux can be assigned. In 4185 case of <B>use_top_fluxes</B> = <I>.TRUE.</I>, the latent heat 4186 flux at the top will be automatically set to zero.</P> 4187 </TD> 4188 </TR> 4189 <TR> 4190 <TD WIDTH=126> 4191 <P><A NAME="use_ug_for_galilei_tr"></A><B>use_ug_for_galilei_tr</B></P> 4192 </TD> 4193 <TD WIDTH=45> 4194 <P>L</P> 4195 </TD> 4196 <TD WIDTH=159> 4197 <P><I>.T.</I></P> 4198 </TD> 4199 <TD WIDTH=1280> 4200 <P>Switch to determine the translation velocity in case that a 4201 Galilean transformation is used.</P> 4202 <P>In case of a Galilean transformation (see 4203 <A HREF="#galilei_transformation">galilei_transformation</A>), 4204 <B>use_ug_for_galilei_tr</B> = <I>.T.</I> ensures that the 4205 coordinate system is translated with the geostrophic windspeed.</P> 4206 <P>Alternatively, with <B>use_ug_for_galilei_tr</B> = <I>.F</I>., 4207 the geostrophic wind can be replaced as translation speed by the 4208 (volume) averaged velocity. However, in this case the user must be 4209 aware of fast growing gravity waves, so this choice is usually not 4210 recommended!</P> 4211 </TD> 4212 </TR> 4213 <TR VALIGN=TOP> 4214 <TD WIDTH=126> 4215 <P ALIGN=LEFT><A NAME="use_upstream_for_tke"></A><B>use_upstream_for_tke</B></P> 4216 </TD> 4217 <TD WIDTH=45> 4218 <P ALIGN=LEFT>L</P> 4219 </TD> 4220 <TD WIDTH=159> 4221 <P ALIGN=LEFT><I>.F.</I></P> 4222 </TD> 4223 <TD WIDTH=1280> 4224 <P ALIGN=LEFT>Parameter to choose the advection/timestep scheme to 4225 be used for the subgrid-scale TKE.<BR><BR>By default, the 4226 advection scheme and the timestep scheme to be used for the 4227 subgrid-scale TKE are set by the initialization parameters 4228 <A HREF="#scalar_advec">scalar_advec</A> and <A HREF="#timestep_scheme">timestep_scheme</A>, 4229 respectively. <B>use_upstream_for_tke</B> = <I>.T.</I> forces the 4230 Euler-scheme and the upstream-scheme to be used as timestep scheme 4231 and advection scheme, respectively. By these methods, the strong 4232 (artificial) near-surface vertical gradients of the subgrid-scale 4233 TKE are significantly reduced. This is required when subgrid-scale 4234 velocities are used for advection of particles (see particle 4235 package parameter <A HREF="chapter_4.2.html#use_sgs_for_particles">use_sgs_for_particles</A>).</P> 4236 </TD> 4237 </TR> 4238 <TR> 4239 <TD WIDTH=126> 4240 <P><A NAME="v_bulk"></A><B>v_bulk</B></P> 4241 </TD> 4242 <TD WIDTH=45> 4243 <P>R</P> 4244 </TD> 4245 <TD WIDTH=159> 4246 <P><I>0.0</I></P> 4247 </TD> 4248 <TD WIDTH=1280> 4249 <P>v-component of the predefined bulk velocity (in m/s).<BR><BR>This 4250 parameter comes into effect if <A HREF="#conserve_volume_flow">conserve_volume_flow</A> 4251 = <I>.T.</I> and <A HREF="#conserve_volume_flow_mode">conserve_volume_flow_mode</A> 4252 = <I>'bulk_velocity'</I>.</P> 4253 </TD> 4254 </TR> 4255 <TR> 4256 <TD WIDTH=126> 4257 <P><A NAME="vg_surface"></A><B>vg_surface</B></P> 4258 </TD> 4259 <TD WIDTH=45> 4260 <P>R</P> 4261 </TD> 4262 <TD WIDTH=159> 4263 <P><I>0.0</I></P> 4264 </TD> 4265 <TD WIDTH=1280> 4266 <P>v-component of the geostrophic wind at the surface (in 4267 m/s).<BR><BR>This parameter assigns the value of the v-component 4268 of the geostrophic wind (vg) at the surface (k=0). Starting from 4269 this value, the initial vertical profile of the <BR>v-component of 4270 the geostrophic wind is constructed with <A HREF="#vg_vertical_gradient">vg_vertical_gradient</A> 4271 and <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A>. 4272 The profile constructed in that way is used for creating the 4273 initial vertical velocity profile of the 3d-model. Either it is 4274 applied, as it has been specified by the user 4275 (<A HREF="#initializing_actions">initializing_actions</A> = 4276 'set_constant_profiles') or it is used for calculating a 4277 stationary boundary layer wind profile (<A HREF="#initializing_actions">initializing_actions</A> 4278 = 'set_1d-model_profiles'). If vg is constant with height (i.e. 4279 vg(k)=<B>vg_surface</B>) and has a large value, it is 4280 recommended to use a Galilei-transformation of the coordinate 4281 system, if possible (see <A HREF="#galilei_transformation">galilei_transformation</A>), 4282 in order to obtain larger time steps.<BR><BR><B>Attention:</B><BR>In 4283 case of ocean runs (see <A HREF="#ocean">ocean</A>), this 4284 parameter gives the geostrophic velocity value (i.e. the pressure 4285 gradient) at the sea surface, which is at k=nzt. The profile is 4286 then constructed from the surface down to the bottom of the model.</P> 4287 </TD> 4288 </TR> 4289 <TR> 4290 <TD WIDTH=126> 4291 <P><A NAME="vg_vertical_gradient"></A><B>vg_vertical_gradient</B></P> 4292 </TD> 4293 <TD WIDTH=45> 4294 <P>R(10)</P> 4295 </TD> 4296 <TD WIDTH=159> 4297 <P><I>10 * 0.0</I></P> 4298 </TD> 4299 <TD WIDTH=1280> 4300 <P>Gradient(s) of the initial profile of the v-component of 4301 the geostrophic wind (in 1/100s).<BR><BR>The gradient holds 4302 starting from the height level defined by 4303 <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A> 4304 (precisely: for all uv levels k where zu(k) > 4305 <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A>, 4306 vg(k) is set: vg(k) = vg(k-1) + dzu(k) * <B>vg_vertical_gradient</B>) 4307 up to the top boundary or up to the next height level defined by 4308 <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A>. 4309 A total of 10 different gradients for 11 height intervals (10 4310 intervals if <A HREF="#vg_vertical_gradient_level">vg_vertical_gradient_level</A>(1) 4311 = 0.0) can be assigned. The surface geostrophic wind is assigned 4312 by <A HREF="#vg_surface">vg_surface</A>.<BR><BR><B>Attention:</B><BR>In 4313 case of ocean runs (see <A HREF="#ocean">ocean</A>), the profile 4314 is constructed like described above, but starting from the sea 4315 surface (k=nzt) down to the bottom boundary of the model. Height 4316 levels have then to be given as negative values, e.g. 4317 <B>vg_vertical_gradient_level</B> = <I>-500.0</I>, <I>-1000.0</I>.</P> 4318 </TD> 4319 </TR> 4320 <TR> 4321 <TD WIDTH=126> 4322 <P><A NAME="vg_vertical_gradient_level"></A><B>vg_vertical_gradient_level</B></P> 4323 </TD> 4324 <TD WIDTH=45> 4325 <P>R(10)</P> 4326 </TD> 4327 <TD WIDTH=159> 4328 <P><I>10 * 0.0</I></P> 4329 </TD> 4330 <TD WIDTH=1280> 4331 <P>Height level from which on the gradient defined by 4332 <A HREF="#vg_vertical_gradient">vg_vertical_gradient</A> is 4333 effective (in m).<BR><BR>The height levels have to be assigned in 4334 ascending order. For the piecewise construction of a profile of 4335 the v-component of the geostrophic wind component (vg) see 4336 <A HREF="#vg_vertical_gradient">vg_vertical_gradient</A>.<BR><BR><B>Attention:</B><BR>In 4337 case of ocean runs (see <A HREF="#ocean">ocean</A>), the 4338 (negative) height levels have to be assigned in descending order.</P> 4339 </TD> 4340 </TR> 4341 <TR> 4342 <TD WIDTH=126> 4343 <P><A NAME="wall_adjustment"></A><B>wall_adjustment</B></P> 4344 </TD> 4345 <TD WIDTH=45> 4346 <P>L</P> 4347 </TD> 4348 <TD WIDTH=159> 4349 <P><I>.T.</I></P> 4350 </TD> 4351 <TD WIDTH=1280> 4352 <P>Parameter to restrict the mixing length in the vicinity of the 4353 bottom boundary (and near vertical walls of a non-flat 4354 <A HREF="#topography">topography</A>). 4355 </P> 4356 <P>With <B>wall_adjustment</B> = <I>.TRUE., </I>the mixing length 4357 is limited to a maximum of 1.8 * z. This condition typically 4358 affects only the first grid points above the bottom boundary.</P> 4359 <P>In case of a non-flat <A HREF="#topography">topography</A> 4360 the respective horizontal distance from vertical walls is used.</P> 4361 </TD> 4362 </TR> 4363 <TR> 4364 <TD WIDTH=126> 4365 <P><A NAME="wall_heatflux"></A><B>wall_heatflux</B></P> 4366 </TD> 4367 <TD WIDTH=45> 4368 <P>R(5)</P> 4369 </TD> 4370 <TD WIDTH=159> 4371 <P><I>5 * 0.0</I></P> 4372 </TD> 4373 <TD WIDTH=1280> 4374 <P>Prescribed kinematic sensible heat flux in K m/s at the five 4375 topography faces:</P> 4376 <P STYLE="margin-left: 0.42in; margin-bottom: 0in"><B>wall_heatflux(0) 4377 </B>top face<BR><B>wall_heatflux(1) </B>left 4378 face<BR><B>wall_heatflux(2) </B>right 4379 face<BR><B>wall_heatflux(3) </B>south 4380 face<BR><B>wall_heatflux(4) </B>north face</P> 4381 <P STYLE="margin-bottom: 0in"><BR>This parameter applies only in 4382 case of a non-flat <A HREF="#topography">topography</A>. The 4383 parameter <A HREF="#random_heatflux">random_heatflux</A> can be 4384 used to impose random perturbations on the internal 4385 two-dimensional surface heat flux field <I>shf</I> that is 4386 composed of <A HREF="#surface_heatflux">surface_heatflux</A> at 4387 the bottom surface and <B>wall_heatflux(0)</B> at the topography 4388 top face. </P> 4389 </TD> 4390 </TR> 4391 </TABLE> 4392 <P><BR><BR> 4393 </P> 4394 <P STYLE="line-height: 100%"><BR><FONT COLOR="#000080"><A HREF="chapter_4.0.html"><FONT COLOR="#000080"><IMG SRC="left.gif" NAME="Grafik1" ALIGN=BOTTOM WIDTH=32 HEIGHT=32 BORDER=1></FONT></A><A HREF="index.html"><FONT COLOR="#000080"><IMG SRC="up.gif" NAME="Grafik2" ALIGN=BOTTOM WIDTH=32 HEIGHT=32 BORDER=1></FONT></A><A HREF="chapter_4.2.html"><FONT COLOR="#000080"><IMG SRC="right.gif" NAME="Grafik3" ALIGN=BOTTOM WIDTH=32 HEIGHT=32 BORDER=1></FONT></A></FONT></P> 4395 <P STYLE="line-height: 100%"><I>Last change: </I> $Id: 4396 chapter_4.1.html 328 2009-05-28 12:13:56Z letzel $ 4397 </P> 4398 <P><BR><BR> 4399 </P> 4400 </BODY> 4401 </HTML> 1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2 <html><head> 3 4 5 6 7 8 9 10 11 12 13 14 15 16 <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> 17 18 19 20 21 22 23 24 25 26 27 28 29 <title>PALM chapter 4.1</title></head> 30 <body> 31 32 33 34 35 36 37 <h3><a name="chapter4.1"></a>4.1 38 Initialization parameters</h3> 39 40 41 42 43 44 45 46 <br> 47 48 49 50 51 52 53 <table style="text-align: left; width: 100%;" border="1" cellpadding="2" cellspacing="2"> 54 55 56 57 58 59 60 <tbody> 61 62 63 64 65 66 67 68 <tr> 69 70 71 72 73 74 75 <td style="vertical-align: top;"><font size="4"><b>Parameter name</b></font></td> 76 77 78 79 80 81 82 83 <td style="vertical-align: top;"><font size="4"><b>Type</b></font></td> 84 85 86 87 88 89 90 91 <td style="vertical-align: top;"> 92 93 94 95 96 97 98 <p><b><font size="4">Default</font></b> <br> 99 100 101 102 103 104 105 <b><font size="4">value</font></b></p> 106 107 108 109 110 111 112 </td> 113 114 115 116 117 118 119 120 <td style="vertical-align: top;"><font size="4"><b>Explanation</b></font></td> 121 122 123 124 125 126 127 128 </tr> 129 130 131 132 133 134 135 <tr> 136 137 138 139 140 141 142 <td style="vertical-align: top;"> 143 144 145 146 147 148 149 <p><a name="adjust_mixing_length"></a><b>adjust_mixing_length</b></p> 150 151 152 153 154 155 156 157 </td> 158 159 160 161 162 163 164 <td style="vertical-align: top;">L</td> 165 166 167 168 169 170 171 172 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 173 174 175 176 177 178 179 <td style="vertical-align: top;"> 180 181 182 183 184 185 186 <p style="font-style: normal;">Near-surface adjustment of the 187 mixing length to the Prandtl-layer law. </p> 188 189 190 191 192 193 194 195 196 197 198 199 200 201 <p>Usually 202 the mixing length in LES models l<sub>LES</sub> 203 depends (as in PALM) on the grid size and is possibly restricted 204 further in case of stable stratification and near the lower wall (see 205 parameter <a href="#wall_adjustment">wall_adjustment</a>). 206 With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> 207 the Prandtl' mixing length l<sub>PR</sub> = kappa * z/phi 208 is calculated 209 and the mixing length actually used in the model is set l = MIN (l<sub>LES</sub>, 210 l<sub>PR</sub>). This usually gives a decrease of the 211 mixing length at 212 the bottom boundary and considers the fact that eddy sizes 213 decrease in the vicinity of the wall. </p> 214 215 216 217 218 219 220 221 222 223 224 225 226 227 <p style="font-style: normal;"><b>Warning:</b> So 228 far, there is 229 no good experience with <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> ! </p> 230 231 232 233 234 235 236 237 238 239 240 241 242 243 <p>With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> and the 244 Prandtl-layer being 245 switched on (see <a href="#prandtl_layer">prandtl_layer</a>) 246 <span style="font-style: italic;">'(u*)** 2+neumann'</span> 247 should always be set as the lower boundary condition for the TKE (see <a href="#bc_e_b">bc_e_b</a>), 248 otherwise the near-surface value of the TKE is not in agreement with 249 the Prandtl-layer law (Prandtl-layer law and Prandtl-Kolmogorov-Ansatz 250 should provide the same value for K<sub>m</sub>). A warning 251 is given, 252 if this is not the case.</p> 253 254 255 256 257 258 259 </td> 260 261 262 263 264 265 266 </tr> 267 268 269 270 271 272 273 <tr> 274 275 276 277 278 279 280 281 <td style="vertical-align: top;"> 282 283 284 285 286 287 288 <p><a name="alpha_surface"></a><b>alpha_surface</b></p> 289 290 291 292 293 294 295 296 </td> 297 298 299 300 301 302 303 <td style="vertical-align: top;">R<br> 304 305 306 307 308 309 310 </td> 311 312 313 314 315 316 317 318 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br> 319 320 321 322 323 324 325 </td> 326 327 328 329 330 331 332 333 <td style="vertical-align: top;"> 334 335 336 337 338 339 340 <p style="font-style: normal;">Inclination of the model domain 341 with respect to the horizontal (in degrees). </p> 342 343 344 345 346 347 348 349 350 351 352 353 354 355 <p style="font-style: normal;">By means of <b>alpha_surface</b> 356 the model domain can be inclined in x-direction with respect to the 357 horizontal. In this way flows over inclined surfaces (e.g. drainage 358 flows, gravity flows) can be simulated. In case of <b>alpha_surface 359 </b>/= <span style="font-style: italic;">0</span> 360 the buoyancy term 361 appears both in 362 the equation of motion of the u-component and of the w-component.<br> 363 364 365 366 367 368 369 370 </p> 371 372 373 374 375 376 377 378 379 380 381 382 383 384 <p style="font-style: normal;">An inclination 385 is only possible in 386 case of cyclic horizontal boundary conditions along x AND y (see <a href="#bc_lr">bc_lr</a> 387 and <a href="#bc_ns">bc_ns</a>) and <a href="#topography">topography</a> = <span style="font-style: italic;">'flat'</span>. </p> 388 389 390 391 392 393 394 395 396 397 398 399 400 401 <p>Runs with inclined surface still require additional 402 user-defined code as well as modifications to the default code. Please 403 ask the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/PALM_group.html#0">PALM 404 developer group</a>.</p> 405 406 407 408 409 410 411 </td> 412 413 414 415 416 417 418 </tr> 419 420 421 422 423 424 425 426 <tr> 427 428 429 430 431 432 433 <td style="vertical-align: top;"> 434 435 436 437 438 439 440 <p><a name="bc_e_b"></a><b>bc_e_b</b></p> 441 442 443 444 445 446 447 </td> 448 449 450 451 452 453 454 455 <td style="vertical-align: top;">C * 20</td> 456 457 458 459 460 461 462 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td> 463 464 465 466 467 468 469 470 <td style="vertical-align: top;"> 471 472 473 474 475 476 477 <p style="font-style: normal;">Bottom boundary condition of the 478 TKE. </p> 479 480 481 482 483 484 485 486 487 488 489 490 491 492 <p><b>bc_e_b</b> may be 493 set to <span style="font-style: italic;">'neumann'</span> 494 or <span style="font-style: italic;">'(u*) ** 2+neumann'</span>. 495 <b>bc_e_b</b> 496 = <span style="font-style: italic;">'neumann'</span> 497 yields to 498 e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is calculated 499 via the prognostic TKE equation. Choice of <span style="font-style: italic;">'(u*)**2+neumann'</span> 500 also yields to 501 e(k=0)=e(k=1), but the TKE at the Prandtl-layer top (k=1) is calculated 502 diagnostically by e(k=1)=(us/0.1)**2. However, this is only allowed if 503 a Prandtl-layer is used (<a href="#prandtl_layer">prandtl_layer</a>). 504 If this is not the case, a warning is given and <b>bc_e_b</b> 505 is reset 506 to <span style="font-style: italic;">'neumann'</span>. 507 </p> 508 509 510 511 512 513 514 515 516 517 518 519 520 521 <p style="font-style: normal;">At the top 522 boundary a Neumann 523 boundary condition is generally used: (e(nz+1) = e(nz)).</p> 524 525 526 527 528 529 530 </td> 531 532 533 534 535 536 537 538 </tr> 539 540 541 542 543 544 545 <tr> 546 547 548 549 550 551 552 <td style="vertical-align: top;"> 553 554 555 556 557 558 559 <p><a name="bc_lr"></a><b>bc_lr</b></p> 560 561 562 563 564 565 566 567 </td> 568 569 570 571 572 573 574 <td style="vertical-align: top;">C * 20</td> 575 576 577 578 579 580 581 582 <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td> 583 584 585 586 587 588 589 590 <td style="vertical-align: top;">Boundary 591 condition along x (for all quantities).<br> 592 593 594 595 596 597 598 <br> 599 600 601 602 603 604 605 606 By default, a cyclic boundary condition is used along x.<br> 607 608 609 610 611 612 613 <br> 614 615 616 617 618 619 620 621 <span style="font-weight: bold;">bc_lr</span> may 622 also be 623 assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span> 624 (inflow from left, outflow to the right) or <span style="font-style: italic;">'radiation/dirichlet'</span> 625 (inflow from 626 right, outflow to the left). This requires the multi-grid method to be 627 used for solving the Poisson equation for perturbation pressure (see <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</a>) 628 and it also requires cyclic boundary conditions along y (see <a href="#bc_ns">bc_ns</a>).<br> 629 630 631 632 633 634 635 <br> 636 637 638 639 640 641 642 643 In case of these non-cyclic lateral boundaries, a Dirichlet condition 644 is used at the inflow for all quantities (initial vertical profiles - 645 see <a href="#initializing_actions">initializing_actions</a> 646 - are fixed during the run) except u, to which a Neumann (zero 647 gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero 648 gradient) condition is used for the scalars. For perturbation 649 pressure Neumann (zero gradient) conditions are assumed both at the 650 inflow and at the outflow.<br> 651 652 653 654 655 656 657 <br> 658 659 660 661 662 663 664 665 When using non-cyclic lateral boundaries, a filter is applied to the 666 velocity field in the vicinity of the outflow in order to suppress any 667 reflections of outgoing disturbances (see <a href="#km_damp_max">km_damp_max</a> 668 and <a href="#outflow_damping_width">outflow_damping_width</a>).<br> 669 670 671 672 673 674 675 676 <br> 677 678 679 680 681 682 683 684 In order to maintain a turbulent state of the flow, it may be 685 neccessary to continuously impose perturbations on the horizontal 686 velocity field in the vicinity of the inflow throughout the whole run. 687 This can be switched on using <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#create_disturbances">create_disturbances</a>. 688 The horizontal range to which these perturbations are applied is 689 controlled by the parameters <a href="#inflow_disturbance_begin">inflow_disturbance_begin</a> 690 and <a href="#inflow_disturbance_end">inflow_disturbance_end</a>. 691 The vertical range and the perturbation amplitude are given by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_b</a>, 692 <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_t</a>, 693 and <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_amplitude</a>. 694 The time interval at which perturbations are to be imposed is set by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#dt_disturb">dt_disturb</a>.<br> 695 696 697 698 699 700 701 702 <br> 703 704 705 706 707 708 709 710 In case of non-cyclic horizontal boundaries <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#call_psolver_at_all_substeps">call_psolver 711 at_all_substeps</a> = .T. should be used.<br> 712 713 714 715 716 717 718 <br> 719 720 721 722 723 724 725 <span style="font-weight: bold;">Note:</span><br> 726 727 728 729 730 731 732 733 Using non-cyclic lateral boundaries requires very sensitive adjustments 734 of the inflow (vertical profiles) and the bottom boundary conditions, 735 e.g. a surface heating should not be applied near the inflow boundary 736 because this may significantly disturb the inflow. Please check the 737 model results very carefully.</td> 738 739 740 741 742 743 744 </tr> 745 746 747 748 749 750 751 <tr> 752 753 754 755 756 757 758 <td style="vertical-align: top;"> 759 760 761 762 763 764 765 <p><a name="bc_ns"></a><b>bc_ns</b></p> 766 767 768 769 770 771 772 773 </td> 774 775 776 777 778 779 780 <td style="vertical-align: top;">C * 20</td> 781 782 783 784 785 786 787 788 <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td> 789 790 791 792 793 794 795 796 <td style="vertical-align: top;">Boundary 797 condition along y (for all quantities).<br> 798 799 800 801 802 803 804 <br> 805 806 807 808 809 810 811 812 By default, a cyclic boundary condition is used along y.<br> 813 814 815 816 817 818 819 <br> 820 821 822 823 824 825 826 827 <span style="font-weight: bold;">bc_ns</span> may 828 also be 829 assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span> 830 (inflow from rear ("north"), outflow to the front ("south")) or <span style="font-style: italic;">'radiation/dirichlet'</span> 831 (inflow from front ("south"), outflow to the rear ("north")). This 832 requires the multi-grid 833 method to be used for solving the Poisson equation for perturbation 834 pressure (see <a href="chapter_4.2.html#psolver">psolver</a>) 835 and it also requires cyclic boundary conditions along x (see<br> 836 837 838 839 840 841 842 <a href="#bc_lr">bc_lr</a>).<br> 843 844 845 846 847 848 849 <br> 850 851 852 853 854 855 856 857 In case of these non-cyclic lateral boundaries, a Dirichlet condition 858 is used at the inflow for all quantities (initial vertical profiles - 859 see <a href="chapter_4.1.html#initializing_actions">initializing_actions</a> 860 - are fixed during the run) except u, to which a Neumann (zero 861 gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero 862 gradient) condition is used for the scalars. For perturbation 863 pressure Neumann (zero gradient) conditions are assumed both at the 864 inflow and at the outflow.<br> 865 866 867 868 869 870 871 <br> 872 873 874 875 876 877 878 879 For further details regarding non-cyclic lateral boundary conditions 880 see <a href="#bc_lr">bc_lr</a>.</td> 881 882 883 884 885 886 887 </tr> 888 889 890 891 892 893 894 895 <tr> 896 897 898 899 900 901 902 <td style="vertical-align: top;"> 903 904 905 906 907 908 909 <p><a name="bc_p_b"></a><b>bc_p_b</b></p> 910 911 912 913 914 915 916 </td> 917 918 919 920 921 922 923 924 <td style="vertical-align: top;">C * 20</td> 925 926 927 928 929 930 931 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td> 932 933 934 935 936 937 938 939 <td style="vertical-align: top;"> 940 941 942 943 944 945 946 <p style="font-style: normal;">Bottom boundary condition of the 947 perturbation pressure. </p> 948 949 950 951 952 953 954 955 956 957 958 959 960 961 <p>Allowed values 962 are <span style="font-style: italic;">'dirichlet'</span>, 963 <span style="font-style: italic;">'neumann'</span> 964 and <span style="font-style: italic;">'neumann+inhomo'</span>. 965 <span style="font-style: italic;">'dirichlet'</span> 966 sets 967 p(k=0)=0.0, <span style="font-style: italic;">'neumann'</span> 968 sets p(k=0)=p(k=1). <span style="font-style: italic;">'neumann+inhomo'</span> 969 corresponds to an extended Neumann boundary condition where heat flux 970 or temperature inhomogeneities near the 971 surface (pt(k=1)) are additionally regarded (see Shen and 972 LeClerc 973 (1995, Q.J.R. Meteorol. Soc., 974 1209)). This condition is only permitted with the Prandtl-layer 975 switched on (<a href="#prandtl_layer">prandtl_layer</a>), 976 otherwise the run is terminated. </p> 977 978 979 980 981 982 983 984 985 986 987 988 989 990 <p>Since 991 at the bottom boundary of the model the vertical 992 velocity 993 disappears (w(k=0) = 0.0), the consistent Neumann condition (<span style="font-style: italic;">'neumann'</span> or <span style="font-style: italic;">'neumann+inhomo'</span>) 994 dp/dz = 0 should 995 be used, which leaves the vertical component w unchanged when the 996 pressure solver is applied. Simultaneous use of the Neumann boundary 997 conditions both at the bottom and at the top boundary (<a href="#bc_p_t">bc_p_t</a>) 998 usually yields no consistent solution for the perturbation pressure and 999 should be avoided.</p> 1000 1001 1002 1003 1004 1005 1006 </td> 1007 1008 1009 1010 1011 1012 1013 </tr> 1014 1015 1016 1017 1018 1019 1020 <tr> 1021 1022 1023 1024 1025 1026 1027 <td style="vertical-align: top;"> 1028 1029 1030 1031 1032 1033 1034 <p><a name="bc_p_t"></a><b>bc_p_t</b></p> 1035 1036 1037 1038 1039 1040 1041 1042 </td> 1043 1044 1045 1046 1047 1048 1049 <td style="vertical-align: top;">C * 20</td> 1050 1051 1052 1053 1054 1055 1056 1057 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 1058 1059 1060 1061 1062 1063 1064 1065 <td style="vertical-align: top;"> 1066 1067 1068 1069 1070 1071 1072 <p style="font-style: normal;">Top boundary condition of the 1073 perturbation pressure. </p> 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 <p style="font-style: normal;">Allowed values are <span style="font-style: italic;">'dirichlet'</span> 1088 (p(k=nz+1)= 0.0) or <span style="font-style: italic;">'neumann'</span> 1089 (p(k=nz+1)=p(k=nz)). </p> 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 <p>Simultaneous use 1104 of Neumann boundary conditions both at the 1105 top and bottom boundary (<a href="#bc_p_b">bc_p_b</a>) 1106 usually yields no consistent solution for the perturbation pressure and 1107 should be avoided. Since at the bottom boundary the Neumann 1108 condition is a good choice (see <a href="#bc_p_b">bc_p_b</a>), 1109 a Dirichlet condition should be set at the top boundary.</p> 1110 1111 1112 1113 1114 1115 1116 </td> 1117 1118 1119 1120 1121 1122 1123 1124 </tr> 1125 1126 1127 1128 1129 1130 1131 <tr> 1132 1133 1134 1135 1136 1137 1138 <td style="vertical-align: top;"> 1139 1140 1141 1142 1143 1144 1145 <p><a name="bc_pt_b"></a><b>bc_pt_b</b></p> 1146 1147 1148 1149 1150 1151 1152 1153 </td> 1154 1155 1156 1157 1158 1159 1160 <td style="vertical-align: top;">C*20</td> 1161 1162 1163 1164 1165 1166 1167 1168 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 1169 1170 1171 1172 1173 1174 1175 1176 <td style="vertical-align: top;"> 1177 1178 1179 1180 1181 1182 1183 <p style="font-style: normal;">Bottom boundary condition of the 1184 potential temperature. </p> 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 <p>Allowed values 1199 are <span style="font-style: italic;">'dirichlet'</span> 1200 (pt(k=0) = const. = <a href="#pt_surface">pt_surface</a> 1201 + <a href="#pt_surface_initial_change">pt_surface_initial_change</a>; 1202 the user may change this value during the run using user-defined code) 1203 and <span style="font-style: italic;">'neumann'</span> 1204 (pt(k=0)=pt(k=1)). <br> 1205 1206 1207 1208 1209 1210 1211 1212 When a constant surface sensible heat flux is used (<a href="#surface_heatflux">surface_heatflux</a>), <b>bc_pt_b</b> 1213 = <span style="font-style: italic;">'neumann'</span> 1214 must be used, because otherwise the resolved scale may contribute to 1215 the surface flux so that a constant value cannot be guaranteed.</p> 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 <p>In the <a href="chapter_3.8.html">coupled</a> atmosphere executable, <a href="chapter_4.2.html#bc_pt_b">bc_pt_b</a> is internally set and does not need to be prescribed.</p> 1229 1230 1231 1232 1233 1234 1235 1236 </td> 1237 1238 1239 1240 1241 1242 1243 </tr> 1244 1245 1246 1247 1248 1249 1250 <tr> 1251 1252 1253 1254 1255 1256 1257 <td style="vertical-align: top;"> 1258 1259 1260 1261 1262 1263 1264 <p><a name="pc_pt_t"></a><b>bc_pt_t</b></p> 1265 1266 1267 1268 1269 1270 1271 1272 </td> 1273 1274 1275 1276 1277 1278 1279 <td style="vertical-align: top;">C * 20</td> 1280 1281 1282 1283 1284 1285 1286 1287 <td style="vertical-align: top;"><span style="font-style: italic;">'initial_ gradient'</span></td> 1288 1289 1290 1291 1292 1293 1294 1295 <td style="vertical-align: top;"> 1296 1297 1298 1299 1300 1301 1302 <p style="font-style: normal;">Top boundary condition of the 1303 potential temperature. </p> 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 <p>Allowed are the 1318 values <span style="font-style: italic;">'dirichlet' </span>(pt(k=nz+1) 1319 does not change during the run), <span style="font-style: italic;">'neumann'</span> 1320 (pt(k=nz+1)=pt(k=nz)), and <span style="font-style: italic;">'initial_gradient'</span>. 1321 With the 'initial_gradient'-condition the value of the temperature 1322 gradient at the top is 1323 calculated from the initial 1324 temperature profile (see <a href="#pt_surface">pt_surface</a>, 1325 <a href="#pt_vertical_gradient">pt_vertical_gradient</a>) 1326 by bc_pt_t_val = (pt_init(k=nz+1) - 1327 pt_init(k=nz)) / dzu(nz+1).<br> 1328 1329 1330 1331 1332 1333 1334 1335 Using this value (assumed constant during the 1336 run) the temperature boundary values are calculated as </p> 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 <ul> 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 <p style="font-style: normal;">pt(k=nz+1) = 1365 pt(k=nz) + 1366 bc_pt_t_val * dzu(nz+1)</p> 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 </ul> 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 <p style="font-style: normal;">(up to k=nz the prognostic 1395 equation for the temperature is solved).<br> 1396 1397 1398 1399 1400 1401 1402 1403 When a constant sensible heat flux is used at the top boundary (<a href="chapter_4.1.html#top_heatflux">top_heatflux</a>), 1404 <b>bc_pt_t</b> = <span style="font-style: italic;">'neumann'</span> 1405 must be used, because otherwise the resolved scale may contribute to 1406 the top flux so that a constant value cannot be guaranteed.</p> 1407 1408 1409 1410 1411 1412 1413 </td> 1414 1415 1416 1417 1418 1419 1420 1421 </tr> 1422 1423 1424 1425 1426 1427 1428 <tr> 1429 1430 1431 1432 1433 1434 1435 <td style="vertical-align: top;"> 1436 1437 1438 1439 1440 1441 1442 <p><a name="bc_q_b"></a><b>bc_q_b</b></p> 1443 1444 1445 1446 1447 1448 1449 1450 </td> 1451 1452 1453 1454 1455 1456 1457 <td style="vertical-align: top;">C * 20</td> 1458 1459 1460 1461 1462 1463 1464 1465 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 1466 1467 1468 1469 1470 1471 1472 1473 <td style="vertical-align: top;"> 1474 1475 1476 1477 1478 1479 1480 <p style="font-style: normal;">Bottom boundary condition of the 1481 specific humidity / total water content. </p> 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 <p>Allowed 1496 values are <span style="font-style: italic;">'dirichlet'</span> 1497 (q(k=0) = const. = <a href="#q_surface">q_surface</a> 1498 + <a href="#q_surface_initial_change">q_surface_initial_change</a>; 1499 the user may change this value during the run using user-defined code) 1500 and <span style="font-style: italic;">'neumann'</span> 1501 (q(k=0)=q(k=1)). <br> 1502 1503 1504 1505 1506 1507 1508 1509 When a constant surface latent heat flux is used (<a href="#surface_waterflux">surface_waterflux</a>), <b>bc_q_b</b> 1510 = <span style="font-style: italic;">'neumann'</span> 1511 must be used, because otherwise the resolved scale may contribute to 1512 the surface flux so that a constant value cannot be guaranteed.</p> 1513 1514 1515 1516 1517 1518 1519 1520 </td> 1521 1522 1523 1524 1525 1526 1527 </tr> 1528 1529 1530 1531 1532 1533 1534 <tr> 1535 1536 1537 1538 1539 1540 1541 <td style="vertical-align: top;"> 1542 1543 1544 1545 1546 1547 1548 <p><a name="bc_q_t"></a><b>bc_q_t</b></p> 1549 1550 1551 1552 1553 1554 1555 1556 </td> 1557 1558 1559 1560 1561 1562 1563 <td style="vertical-align: top;"><span style="font-style: italic;">C 1564 * 20</span></td> 1565 1566 1567 1568 1569 1570 1571 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td> 1572 1573 1574 1575 1576 1577 1578 1579 <td style="vertical-align: top;"> 1580 1581 1582 1583 1584 1585 1586 <p style="font-style: normal;">Top boundary condition of the 1587 specific humidity / total water content. </p> 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 <p>Allowed 1602 are the values <span style="font-style: italic;">'dirichlet'</span> 1603 (q(k=nz) and q(k=nz+1) do 1604 not change during the run) and <span style="font-style: italic;">'neumann'</span>. 1605 With the Neumann boundary 1606 condition the value of the humidity gradient at the top is calculated 1607 from the 1608 initial humidity profile (see <a href="#q_surface">q_surface</a>, 1609 <a href="#q_vertical_gradient">q_vertical_gradient</a>) 1610 by: bc_q_t_val = ( q_init(k=nz) - q_init(k=nz-1)) / dzu(nz).<br> 1611 1612 1613 1614 1615 1616 1617 1618 Using this value (assumed constant during the run) the humidity 1619 boundary values 1620 are calculated as </p> 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 <ul> 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 <p style="font-style: normal;">q(k=nz+1) =q(k=nz) + 1649 bc_q_t_val * dzu(nz+1)</p> 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 </ul> 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 <p style="font-style: normal;">(up tp k=nz the prognostic 1678 equation for q is solved). </p> 1679 1680 1681 1682 1683 1684 1685 </td> 1686 1687 1688 1689 1690 1691 1692 </tr> 1693 1694 1695 1696 1697 1698 1699 <tr> 1700 1701 1702 1703 1704 1705 1706 1707 <td style="vertical-align: top;"> 1708 1709 1710 1711 1712 1713 1714 <p><a name="bc_s_b"></a><b>bc_s_b</b></p> 1715 1716 1717 1718 1719 1720 1721 </td> 1722 1723 1724 1725 1726 1727 1728 1729 <td style="vertical-align: top;">C * 20</td> 1730 1731 1732 1733 1734 1735 1736 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 1737 1738 1739 1740 1741 1742 1743 1744 <td style="vertical-align: top;"> 1745 1746 1747 1748 1749 1750 1751 <p style="font-style: normal;">Bottom boundary condition of the 1752 scalar concentration. </p> 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 <p>Allowed values 1767 are <span style="font-style: italic;">'dirichlet'</span> 1768 (s(k=0) = const. = <a href="#s_surface">s_surface</a> 1769 + <a href="#s_surface_initial_change">s_surface_initial_change</a>; 1770 the user may change this value during the run using user-defined code) 1771 and <span style="font-style: italic;">'neumann'</span> 1772 (s(k=0) = 1773 s(k=1)). <br> 1774 1775 1776 1777 1778 1779 1780 1781 When a constant surface concentration flux is used (<a href="#surface_scalarflux">surface_scalarflux</a>), <b>bc_s_b</b> 1782 = <span style="font-style: italic;">'neumann'</span> 1783 must be used, because otherwise the resolved scale may contribute to 1784 the surface flux so that a constant value cannot be guaranteed.</p> 1785 1786 1787 1788 1789 1790 1791 1792 </td> 1793 1794 1795 1796 1797 1798 1799 </tr> 1800 1801 1802 1803 1804 1805 1806 <tr> 1807 1808 1809 1810 1811 1812 1813 <td style="vertical-align: top;"> 1814 1815 1816 1817 1818 1819 1820 <p><a name="bc_s_t"></a><b>bc_s_t</b></p> 1821 1822 1823 1824 1825 1826 1827 1828 </td> 1829 1830 1831 1832 1833 1834 1835 <td style="vertical-align: top;">C * 20</td> 1836 1837 1838 1839 1840 1841 1842 1843 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td> 1844 1845 1846 1847 1848 1849 1850 1851 <td style="vertical-align: top;"> 1852 1853 1854 1855 1856 1857 1858 <p style="font-style: normal;">Top boundary condition of the 1859 scalar concentration. </p> 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 <p>Allowed are the 1874 values <span style="font-style: italic;">'dirichlet'</span> 1875 (s(k=nz) and s(k=nz+1) do 1876 not change during the run) and <span style="font-style: italic;">'neumann'</span>. 1877 With the Neumann boundary 1878 condition the value of the scalar concentration gradient at the top is 1879 calculated 1880 from the initial scalar concentration profile (see <a href="#s_surface">s_surface</a>, <a href="#s_vertical_gradient">s_vertical_gradient</a>) 1881 by: bc_s_t_val = (s_init(k=nz) - s_init(k=nz-1)) / dzu(nz).<br> 1882 1883 1884 1885 1886 1887 1888 1889 Using this value (assumed constant during the run) the concentration 1890 boundary values 1891 are calculated as </p> 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 <ul> 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 <p style="font-style: normal;">s(k=nz+1) = s(k=nz) + 1920 bc_s_t_val * dzu(nz+1)</p> 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 </ul> 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 <p style="font-style: normal;">(up to k=nz the prognostic 1949 equation for the scalar concentration is 1950 solved).</p> 1951 1952 1953 1954 1955 1956 1957 </td> 1958 1959 1960 1961 1962 1963 1964 </tr> 1965 1966 1967 1968 1969 1970 1971 <tr> 1972 1973 1974 1975 1976 1977 1978 <td style="vertical-align: top;"><a name="bc_sa_t"></a><span style="font-weight: bold;">bc_sa_t</span></td> 1979 1980 1981 1982 1983 1984 1985 <td style="vertical-align: top;">C * 20</td> 1986 1987 1988 1989 1990 1991 1992 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td> 1993 1994 1995 1996 1997 1998 1999 <td style="vertical-align: top;"> 2000 2001 2002 2003 2004 2005 2006 <p style="font-style: normal;">Top boundary condition of the salinity. </p> 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 <p>This parameter only comes into effect for ocean runs (see parameter <a href="#ocean">ocean</a>).</p> 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 <p style="font-style: normal;">Allowed are the 2034 values <span style="font-style: italic;">'dirichlet' </span>(sa(k=nz+1) 2035 does not change during the run) and <span style="font-style: italic;">'neumann'</span> 2036 (sa(k=nz+1)=sa(k=nz))<span style="font-style: italic;"></span>. <br> 2037 2038 2039 2040 2041 2042 2043 <br> 2044 2045 2046 2047 2048 2049 2050 2051 When a constant salinity flux is used at the top boundary (<a href="chapter_4.1.html#top_salinityflux">top_salinityflux</a>), 2052 <b>bc_sa_t</b> = <span style="font-style: italic;">'neumann'</span> 2053 must be used, because otherwise the resolved scale may contribute to 2054 the top flux so that a constant value cannot be guaranteed.</p> 2055 2056 2057 2058 2059 2060 2061 </td> 2062 2063 2064 2065 2066 2067 2068 </tr> 2069 2070 2071 2072 2073 2074 2075 <tr> 2076 2077 2078 2079 2080 2081 2082 <td style="vertical-align: top;"> 2083 2084 2085 2086 2087 2088 2089 <p><a name="bc_uv_b"></a><b>bc_uv_b</b></p> 2090 2091 2092 2093 2094 2095 2096 2097 </td> 2098 2099 2100 2101 2102 2103 2104 <td style="vertical-align: top;">C * 20</td> 2105 2106 2107 2108 2109 2110 2111 2112 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 2113 2114 2115 2116 2117 2118 2119 2120 <td style="vertical-align: top;"> 2121 2122 2123 2124 2125 2126 2127 <p style="font-style: normal;">Bottom boundary condition of the 2128 horizontal velocity components u and v. </p> 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 <p>Allowed 2143 values are <span style="font-style: italic;">'dirichlet' </span>and 2144 <span style="font-style: italic;">'neumann'</span>. <b>bc_uv_b</b> 2145 = <span style="font-style: italic;">'dirichlet'</span> 2146 yields the 2147 no-slip condition with u=v=0 at the bottom. Due to the staggered grid 2148 u(k=0) and v(k=0) are located at z = - 0,5 * <a href="#dz">dz</a> 2149 (below the bottom), while u(k=1) and v(k=1) are located at z = +0,5 * 2150 dz. u=v=0 at the bottom is guaranteed using mirror boundary 2151 condition: </p> 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 <ul> 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 <p style="font-style: normal;">u(k=0) = - u(k=1) and v(k=0) = - 2180 v(k=1)</p> 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 </ul> 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 <p style="font-style: normal;">The 2209 Neumann boundary condition 2210 yields the free-slip condition with u(k=0) = u(k=1) and v(k=0) = 2211 v(k=1). 2212 With Prandtl - layer switched on (see <a href="#prandtl_layer">prandtl_layer</a>), the free-slip condition is not 2213 allowed (otherwise the run will be terminated)<font color="#000000">.</font></p> 2214 2215 2216 2217 2218 2219 2220 2221 </td> 2222 2223 2224 2225 2226 2227 2228 </tr> 2229 2230 2231 2232 2233 2234 2235 <tr> 2236 2237 2238 2239 2240 2241 2242 <td style="vertical-align: top;"> 2243 2244 2245 2246 2247 2248 2249 <p><a name="bc_uv_t"></a><b>bc_uv_t</b></p> 2250 2251 2252 2253 2254 2255 2256 2257 </td> 2258 2259 2260 2261 2262 2263 2264 <td style="vertical-align: top;">C * 20</td> 2265 2266 2267 2268 2269 2270 2271 2272 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td> 2273 2274 2275 2276 2277 2278 2279 2280 <td style="vertical-align: top;"> 2281 2282 2283 2284 2285 2286 2287 <p style="font-style: normal;">Top boundary condition of the 2288 horizontal velocity components u and v. </p> 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 <p>Allowed 2303 values are <span style="font-style: italic;">'dirichlet'</span>, <span style="font-style: italic;">'dirichlet_0'</span> 2304 and <span style="font-style: italic;">'neumann'</span>. 2305 The 2306 Dirichlet condition yields u(k=nz+1) = ug(nz+1) and v(k=nz+1) = 2307 vg(nz+1), 2308 Neumann condition yields the free-slip condition with u(k=nz+1) = 2309 u(k=nz) and v(k=nz+1) = v(k=nz) (up to k=nz the prognostic equations 2310 for the velocities are solved). The special condition <span style="font-style: italic;">'dirichlet_0'</span> can be used for channel flow, it yields the no-slip condition u(k=nz+1) = ug(nz+1) = 0 and v(k=nz+1) = 2311 vg(nz+1) = 0.</p> 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 <p>In the <a href="chapter_3.8.html">coupled</a> ocean executable, <a href="chapter_4.2.html#bc_uv_t">bc_uv_t</a> is internally set ('neumann') and does not need to be prescribed.</p> 2325 2326 2327 2328 2329 2330 2331 </td> 2332 2333 2334 2335 2336 2337 2338 </tr> 2339 2340 2341 2342 2343 2344 2345 <tr> 2346 2347 2348 2349 2350 2351 2352 <td style="vertical-align: top;"><a name="bottom_salinityflux"></a><span style="font-weight: bold;">bottom_salinityflux</span></td> 2353 2354 2355 2356 2357 2358 2359 <td style="vertical-align: top;">R</td> 2360 2361 2362 2363 2364 2365 2366 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 2367 2368 2369 2370 2371 2372 2373 <td style="vertical-align: top;"> 2374 2375 2376 2377 2378 2379 2380 <p>Kinematic salinity flux near the surface (in psu m/s). </p> 2381 2382 2383 2384 2385 2386 2387 This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>). 2388 2389 2390 2391 2392 2393 2394 <p>The 2395 respective salinity flux value is used 2396 as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann 2397 condition must be used for the salinity, which is currently the only available condition.<br> 2398 2399 2400 2401 2402 2403 2404 </p> 2405 2406 2407 2408 2409 2410 2411 </td> 2412 2413 2414 2415 2416 2417 2418 </tr> 2419 2420 2421 2422 2423 2424 2425 <tr> 2426 2427 2428 2429 2430 2431 2432 2433 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_height"></a>building_height</span></td> 2434 2435 2436 2437 2438 2439 2440 2441 <td style="vertical-align: top;">R</td> 2442 2443 2444 2445 2446 2447 2448 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td> 2449 2450 2451 2452 2453 2454 2455 <td>Height 2456 of a single building in m.<br> 2457 2458 2459 2460 2461 2462 2463 <br> 2464 2465 2466 2467 2468 2469 2470 <span style="font-weight: bold;">building_height</span> must 2471 be less than the height of the model domain. This parameter requires 2472 the use of <a href="#topography">topography</a> 2473 = <span style="font-style: italic;">'single_building'</span>.</td> 2474 2475 2476 2477 2478 2479 2480 2481 </tr> 2482 2483 2484 2485 2486 2487 2488 <tr> 2489 2490 2491 2492 2493 2494 2495 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_x"></a>building_length_x</span></td> 2496 2497 2498 2499 2500 2501 2502 2503 <td style="vertical-align: top;">R</td> 2504 2505 2506 2507 2508 2509 2510 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td> 2511 2512 2513 2514 2515 2516 2517 <td><span style="font-style: italic;"></span>Width of a single 2518 building in m.<br> 2519 2520 2521 2522 2523 2524 2525 <br> 2526 2527 2528 2529 2530 2531 2532 2533 Currently, <span style="font-weight: bold;">building_length_x</span> 2534 must be at least <span style="font-style: italic;">3 2535 * </span><a style="font-style: italic;" href="#dx">dx</a> and no more than <span style="font-style: italic;">( </span><a style="font-style: italic;" href="#nx">nx</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="#dx">dx</a> 2536 </span><span style="font-style: italic;">- <a href="#building_wall_left">building_wall_left</a></span>. 2537 This parameter requires the use of <a href="#topography">topography</a> 2538 = <span style="font-style: italic;">'single_building'</span>.</td> 2539 2540 2541 2542 2543 2544 2545 2546 </tr> 2547 2548 2549 2550 2551 2552 2553 <tr> 2554 2555 2556 2557 2558 2559 2560 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_y"></a>building_length_y</span></td> 2561 2562 2563 2564 2565 2566 2567 2568 <td style="vertical-align: top;">R</td> 2569 2570 2571 2572 2573 2574 2575 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td> 2576 2577 2578 2579 2580 2581 2582 <td>Depth 2583 of a single building in m.<br> 2584 2585 2586 2587 2588 2589 2590 <br> 2591 2592 2593 2594 2595 2596 2597 2598 Currently, <span style="font-weight: bold;">building_length_y</span> 2599 must be at least <span style="font-style: italic;">3 2600 * </span><a style="font-style: italic;" href="#dy">dy</a> and no more than <span style="font-style: italic;">( </span><a style="font-style: italic;" href="#ny">ny</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="#dy">dy</a></span><span style="font-style: italic;"> - <a href="#building_wall_south">building_wall_south</a></span>. This parameter requires 2601 the use of <a href="#topography">topography</a> 2602 = <span style="font-style: italic;">'single_building'</span>.</td> 2603 2604 2605 2606 2607 2608 2609 2610 </tr> 2611 2612 2613 2614 2615 2616 2617 <tr> 2618 2619 2620 2621 2622 2623 2624 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_left"></a>building_wall_left</span></td> 2625 2626 2627 2628 2629 2630 2631 2632 <td style="vertical-align: top;">R</td> 2633 2634 2635 2636 2637 2638 2639 <td style="vertical-align: top;"><span style="font-style: italic;">building centered in x-direction</span></td> 2640 2641 2642 2643 2644 2645 2646 2647 <td>x-coordinate of the left building wall (distance between the 2648 left building wall and the left border of the model domain) in m.<br> 2649 2650 2651 2652 2653 2654 2655 2656 <br> 2657 2658 2659 2660 2661 2662 2663 2664 Currently, <span style="font-weight: bold;">building_wall_left</span> 2665 must be at least <span style="font-style: italic;">1 2666 * </span><a style="font-style: italic;" href="#dx">dx</a> and less than <span style="font-style: italic;">( <a href="#nx">nx</a> 2667 - 1 ) * <a href="#dx">dx</a> - <a href="#building_length_x">building_length_x</a></span>. 2668 This parameter requires the use of <a href="#topography">topography</a> 2669 = <span style="font-style: italic;">'single_building'</span>.<br> 2670 2671 2672 2673 2674 2675 2676 2677 <br> 2678 2679 2680 2681 2682 2683 2684 2685 The default value <span style="font-weight: bold;">building_wall_left</span> 2686 = <span style="font-style: italic;">( ( <a href="#nx">nx</a> + 2687 1 ) * <a href="#dx">dx</a> - <a href="#building_length_x">building_length_x</a> ) / 2</span> 2688 centers the building in x-direction. <font color="#000000">Due to the staggered grid the building will be displaced by -0.5 <a href="chapter_4.1.html#dx">dx</a> in x-direction and -0.5 <a href="chapter_4.1.html#dy">dy</a> in y-direction.</font> </td> 2689 2690 2691 2692 2693 2694 2695 </tr> 2696 2697 2698 2699 2700 2701 2702 <tr> 2703 2704 2705 2706 2707 2708 2709 2710 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_south"></a>building_wall_south</span></td> 2711 2712 2713 2714 2715 2716 2717 2718 <td style="vertical-align: top;">R</td> 2719 2720 2721 2722 2723 2724 2725 <td style="vertical-align: top;"><span style="font-style: italic;"></span><span style="font-style: italic;">building centered in y-direction</span></td> 2726 2727 2728 2729 2730 2731 2732 2733 <td>y-coordinate of the South building wall (distance between the 2734 South building wall and the South border of the model domain) in m.<br> 2735 2736 2737 2738 2739 2740 2741 2742 <br> 2743 2744 2745 2746 2747 2748 2749 2750 Currently, <span style="font-weight: bold;">building_wall_south</span> 2751 must be at least <span style="font-style: italic;">1 2752 * </span><a style="font-style: italic;" href="#dy">dy</a> and less than <span style="font-style: italic;">( <a href="#ny">ny</a> 2753 - 1 ) * <a href="#dy">dy</a> - <a href="#building_length_y">building_length_y</a></span>. 2754 This parameter requires the use of <a href="#topography">topography</a> 2755 = <span style="font-style: italic;">'single_building'</span>.<br> 2756 2757 2758 2759 2760 2761 2762 2763 <br> 2764 2765 2766 2767 2768 2769 2770 2771 The default value <span style="font-weight: bold;">building_wall_south</span> 2772 = <span style="font-style: italic;">( ( <a href="#ny">ny</a> + 2773 1 ) * <a href="#dy">dy</a> - <a href="#building_length_y">building_length_y</a> ) / 2</span> 2774 centers the building in y-direction. <font color="#000000">Due to the staggered grid the building will be displaced by -0.5 <a href="chapter_4.1.html#dx">dx</a> in x-direction and -0.5 <a href="chapter_4.1.html#dy">dy</a> in y-direction.</font> </td> 2775 2776 2777 2778 2779 2780 2781 </tr> 2782 2783 2784 2785 2786 2787 2788 <tr> 2789 2790 <td style="vertical-align: top;"><a name="canopy_mode"></a><span style="font-weight: bold;">canopy_mode</span></td> 2791 2792 <td style="vertical-align: top;">C * 20</td> 2793 2794 <td style="vertical-align: top;"><span style="font-style: italic;">'block'</span></td> 2795 2796 <td style="vertical-align: top;">Canopy mode.<br> 2797 2798 <br> 2799 2800 <font color="#000000"> 2801 Besides using the default value, that will create a horizontally 2802 homogeneous plant canopy that extends over the total horizontal 2803 extension of the model domain, the user may add code to the user 2804 interface subroutine <a href="chapter_3.5.1.html#user_init_plant_canopy">user_init_plant_canopy</a> 2805 to allow further canopy modes. <br> 2806 2807 <br> 2808 2809 The setting of <a href="#canopy_mode">canopy_mode</a> becomes only active, if <a href="#plant_canopy">plant_canopy</a> has been set <span style="font-style: italic;">.T.</span> and a non-zero <a href="#drag_coefficient">drag_coefficient</a> has been defined.</font></td> 2810 2811 </tr> 2812 2813 <tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_height"></a>canyon_height</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">50.0</td><td>Street canyon height 2814 in m.<br> 2815 2816 2817 2818 2819 2820 2821 <br> 2822 2823 2824 2825 2826 2827 2828 <span style="font-weight: bold;">canyon_height</span> must 2829 be less than the height of the model domain. This parameter requires <a href="chapter_4.1.html#topography">topography</a> 2830 = <span style="font-style: italic;">'single_street_canyon'</span>.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_width_x"></a>canyon_width_x</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">9999999.9</td><td>Street canyon width in x-direction in m.<br> 2831 2832 2833 2834 2835 2836 2837 <br> 2838 2839 2840 2841 2842 2843 2844 2845 Currently, <span style="font-weight: bold;">canyon_width_x</span> 2846 must be at least <span style="font-style: italic;">3 2847 * </span><a style="font-style: italic;" href="chapter_4.1.html#dx">dx</a> and no more than <span style="font-style: italic;">( </span><a style="font-style: italic;" href="chapter_4.1.html#nx">nx</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="chapter_4.1.html#dx">dx</a> 2848 </span><span style="font-style: italic;">- <a href="chapter_4.1.html#canyon_wall_left">canyon_wall_left</a></span>. 2849 This parameter requires <a href="chapter_4.1.html#topography">topography</a> 2850 = <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>. A non-default value implies a canyon orientation in y-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_width_y"></a>canyon_width_y</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">9999999.9</td><td>Street canyon width in y-direction in m.<br> 2851 2852 2853 2854 2855 2856 2857 <br> 2858 2859 2860 2861 2862 2863 2864 2865 Currently, <span style="font-weight: bold;">canyon_width_y</span> 2866 must be at least <span style="font-style: italic;">3 2867 * </span><a style="font-style: italic;" href="chapter_4.1.html#dy">dy</a> and no more than <span style="font-style: italic;">( </span><a style="font-style: italic;" href="chapter_4.1.html#ny">ny</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="chapter_4.1.html#dy">dy</a></span><span style="font-style: italic;"> - <a href="chapter_4.1.html#canyon_wall_south">canyon_wall_south</a></span>. This parameter requires <a href="chapter_4.1.html#topography">topography</a> 2868 = <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span>. A non-default value implies a canyon orientation in x-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_wall_left"></a>canyon_wall_left</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;"><span style="font-style: italic;">canyon centered in x-direction</span></td><td>x-coordinate of the left canyon wall (distance between the 2869 left canyon wall and the left border of the model domain) in m.<br> 2870 2871 2872 2873 2874 2875 2876 2877 <br> 2878 2879 2880 2881 2882 2883 2884 2885 Currently, <span style="font-weight: bold;">canyon_wall_left</span> 2886 must be at least <span style="font-style: italic;">1 2887 * </span><a style="font-style: italic;" href="chapter_4.1.html#dx">dx</a> and less than <span style="font-style: italic;">( <a href="chapter_4.1.html#nx">nx</a> 2888 - 1 ) * <a href="chapter_4.1.html#dx">dx</a> - <a href="chapter_4.1.html#canyon_width_x">canyon_width_x</a></span>. 2889 This parameter requires <a href="chapter_4.1.html#topography">topography</a> 2890 = <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>.<br> 2891 2892 2893 2894 2895 2896 2897 2898 <br> 2899 2900 2901 2902 2903 2904 2905 2906 The default value <span style="font-weight: bold;">canyon_wall_left</span> 2907 = <span style="font-style: italic;">( ( <a href="chapter_4.1.html#nx">nx</a> + 2908 1 ) * <a href="chapter_4.1.html#dx">dx</a> - <a href="chapter_4.1.html#canyon_width_x">canyon_width_x</a> ) / 2</span> 2909 centers the canyon in x-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_wall_south"></a>canyon_wall_south</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;"><span style="font-style: italic;">canyon centered in y-direction</span></td><td>y-coordinate of the South canyon wall (distance between the 2910 South canyon wall and the South border of the model domain) in m.<br> 2911 2912 2913 2914 2915 2916 2917 2918 <br> 2919 2920 2921 2922 2923 2924 2925 2926 Currently, <span style="font-weight: bold;">canyon_wall_south</span> 2927 must be at least <span style="font-style: italic;">1 2928 * </span><a style="font-style: italic;" href="chapter_4.1.html#dy">dy</a> and less than <span style="font-style: italic;">( <a href="chapter_4.1.html#ny">ny</a> 2929 - 1 ) * <a href="chapter_4.1.html#dy">dy</a> - <a href="chapter_4.1.html#canyon_width_y">canyon_width_y</a></span>. 2930 This parameter requires <a href="chapter_4.1.html#topography">topography</a> 2931 = <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>.<br> 2932 2933 2934 2935 2936 2937 2938 2939 <br> 2940 2941 2942 2943 2944 2945 2946 2947 The default value <span style="font-weight: bold;">canyon_wall_south</span> 2948 = <span style="font-style: italic;">( ( <a href="chapter_4.1.html#ny">ny</a> + 2949 1 ) * <a href="chapter_4.1.html#dy">dy</a> - </span><a href="chapter_4.1.html#building_length_y"><span style="font-style: italic;"></span></a><a style="font-style: italic;" href="chapter_4.1.html#canyon_width_y">canyon_wid</a><span style="font-style: italic;"><a style="font-style: italic;" href="chapter_4.1.html#canyon_width_y">th_y</a> ) / 2</span> 2950 centers the canyon in y-direction.</td></tr><tr> 2951 2952 2953 2954 2955 2956 2957 2958 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="cloud_droplets"></a>cloud_droplets</span><br> 2959 2960 2961 2962 2963 2964 2965 2966 </td> 2967 2968 2969 2970 2971 2972 2973 <td style="vertical-align: top;">L<br> 2974 2975 2976 2977 2978 2979 2980 </td> 2981 2982 2983 2984 2985 2986 2987 2988 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span><br> 2989 2990 2991 2992 2993 2994 2995 </td> 2996 2997 2998 2999 3000 3001 3002 3003 <td style="vertical-align: top;">Parameter to switch on 3004 usage of cloud droplets.<br> 3005 3006 3007 3008 3009 3010 3011 <br> 3012 3013 3014 3015 3016 3017 3018 3019 <span style="font-weight: bold;"></span><span style="font-family: monospace;"></span> 3020 3021 3022 3023 3024 Cloud droplets require to use particles (i.e. the NAMELIST group <span style="font-family: Courier New,Courier,monospace;">particles_par</span> has to be included in the parameter file<span style="font-family: monospace;"></span>). Then each particle is a representative for a certain number of droplets. The droplet 3025 features (number of droplets, initial radius, etc.) can be steered with 3026 the respective particle parameters (see e.g. <a href="#chapter_4.2.html#radius">radius</a>). 3027 The real number of initial droplets in a grid cell is equal to the 3028 initial number of droplets (defined by the particle source parameters <span lang="en-GB"><font face="Thorndale, serif"> </font></span><a href="chapter_4.2.html#pst"><span lang="en-GB"><font face="Thorndale, serif">pst</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psl"><span lang="en-GB"><font face="Thorndale, serif">psl</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psr"><span lang="en-GB"><font face="Thorndale, serif">psr</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pss"><span lang="en-GB"><font face="Thorndale, serif">pss</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psn"><span lang="en-GB"><font face="Thorndale, serif">psn</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psb"><span lang="en-GB"><font face="Thorndale, serif">psb</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdx"><span lang="en-GB"><font face="Thorndale, serif">pdx</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdy"><span lang="en-GB"><font face="Thorndale, serif">pdy</font></span></a> 3029 <span lang="en-GB"><font face="Thorndale, serif">and 3030 </font></span><a href="chapter_4.2.html#pdz"><span lang="en-GB"><font face="Thorndale, serif">pdz</font></span></a><span lang="en-GB"></span><span lang="en-GB"></span>) 3031 times the <a href="#initial_weighting_factor">initial_weighting_factor</a>.<br> 3032 3033 3034 3035 3036 3037 3038 3039 <br> 3040 3041 3042 3043 3044 3045 3046 3047 In case of using cloud droplets, the default condensation scheme in 3048 PALM cannot be used, i.e. <a href="#cloud_physics">cloud_physics</a> 3049 must be set <span style="font-style: italic;">.F.</span>.<br> 3050 3051 3052 3053 3054 3055 3056 3057 </td> 3058 3059 3060 3061 3062 3063 3064 </tr> 3065 3066 3067 3068 3069 3070 3071 <tr> 3072 3073 3074 3075 3076 3077 3078 <td style="vertical-align: top;"> 3079 3080 3081 3082 3083 3084 3085 <p><a name="cloud_physics"></a><b>cloud_physics</b></p> 3086 3087 3088 3089 3090 3091 3092 3093 </td> 3094 3095 3096 3097 3098 3099 3100 <td style="vertical-align: top;">L<br> 3101 3102 3103 3104 3105 3106 3107 </td> 3108 3109 3110 3111 3112 3113 3114 3115 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 3116 3117 3118 3119 3120 3121 3122 <td style="vertical-align: top;"> 3123 3124 3125 3126 3127 3128 3129 <p>Parameter to switch 3130 on the condensation scheme. </p> 3131 3132 3133 3134 3135 3136 3137 3138 For <b>cloud_physics =</b> <span style="font-style: italic;">.TRUE.</span>, equations 3139 for the 3140 liquid water 3141 content and the liquid water potential temperature are solved instead 3142 of those for specific humidity and potential temperature. Note 3143 that a grid volume is assumed to be either completely saturated or 3144 completely 3145 unsaturated (0%-or-100%-scheme). A simple precipitation scheme can 3146 additionally be switched on with parameter <a href="#precipitation">precipitation</a>. 3147 Also cloud-top cooling by longwave radiation can be utilized (see <a href="#radiation">radiation</a>)<br> 3148 3149 3150 3151 3152 3153 3154 <b><br> 3155 3156 3157 3158 3159 3160 3161 3162 cloud_physics =</b> <span style="font-style: italic;">.TRUE. 3163 </span>requires <a href="#humidity">humidity</a> 3164 =<span style="font-style: italic;"> .TRUE.</span> .<br> 3165 3166 3167 3168 3169 3170 3171 3172 Detailed information about the condensation scheme is given in the 3173 description of the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM-1/Dokumentationen/Cloud_physics/wolken.pdf">cloud 3174 physics module</a> (pdf-file, only in German).<br> 3175 3176 3177 3178 3179 3180 3181 <br> 3182 3183 3184 3185 3186 3187 3188 3189 This condensation scheme is not allowed if cloud droplets are simulated 3190 explicitly (see <a href="#cloud_droplets">cloud_droplets</a>).<br> 3191 3192 3193 3194 3195 3196 3197 3198 </td> 3199 3200 3201 3202 3203 3204 3205 </tr> 3206 3207 3208 3209 3210 3211 3212 <tr> 3213 3214 3215 3216 3217 3218 3219 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow"></a>conserve_volume_flow</span></td> 3220 3221 3222 3223 3224 3225 3226 3227 <td style="vertical-align: top;">L</td> 3228 3229 3230 3231 3232 3233 3234 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 3235 3236 3237 3238 3239 3240 3241 <td>Conservation 3242 of volume flow in x- and y-direction.<br> 3243 3244 3245 3246 3247 3248 3249 <br> 3250 3251 3252 3253 3254 3255 3256 <span style="font-weight: bold;">conserve_volume_flow</span> 3257 = <span style="font-style: italic;">.T.</span> 3258 guarantees that the volume flow through the xz- and yz-cross-sections of 3259 the total model domain remains constant throughout the run depending on the chosen <a href="#conserve_volume_flow_mode">conserve_volume_flow_mode</a>.<br><br>Note that <span style="font-weight: bold;">conserve_volume_flow</span> 3260 = <span style="font-style: italic;">.T.</span> requires <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.F.</span> .<br> 3261 3262 3263 3264 3265 3266 3267 3268 </td> 3269 3270 3271 3272 3273 3274 3275 </tr> 3276 3277 3278 3279 3280 3281 3282 <tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow_mode"></a>conserve_volume_flow_mode</span></td><td style="vertical-align: top;">C * 16</td><td style="vertical-align: top;"><span style="font-style: italic;">'default'</span></td><td>Modus of volume flow conservation.<br><br>The following values are allowed:<br><p style="font-style: normal;"><span style="font-style: italic;">'default'</span> 3283 </p> 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 <ul><p>Per default, PALM uses <span style="font-style: italic;">'initial_profiles'</span> for cyclic lateral boundary conditions (<a href="#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>) and <span style="font-style: italic;">'inflow_profile'</span> for non-cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> /= <span style="font-style: italic;">'cyclic'</span> or <a href="chapter_4.1.html#bc_ns">bc_ns</a> /= <span style="font-style: italic;">'cyclic'</span>).</p></ul> 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 <p style="font-style: italic;">'initial_profiles' </p> 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 <ul><p>The 3326 target volume flow is calculated at t=0 from the initial profiles 3327 of u and v. This setting is only allowed for cyclic lateral 3328 boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="chapter_4.1.html#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>).</p></ul> 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 <p style="font-style: normal;"><span style="font-style: italic;">'inflow_profile'</span> 3343 </p> 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 <ul><p>The 3358 target volume flow is calculated at every timestep from the 3359 inflow profile of u or v, respectively. This setting is only 3360 allowed for non-cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> /= <span style="font-style: italic;">'cyclic'</span> or <a href="chapter_4.1.html#bc_ns">bc_ns</a> /= <span style="font-style: italic;">'cyclic'</span>).</p></ul> 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 <p style="font-style: italic;">'bulk_velocity' </p> 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 <ul><p>The target volume flow is calculated from a predefined bulk velocity (see <a href="#u_bulk">u_bulk</a> and <a href="#v_bulk">v_bulk</a>). This setting is only allowed for cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="chapter_4.1.html#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>).</p></ul> 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 <span style="font-style: italic;"></span>Note that <span style="font-weight: bold;">conserve_volume_flow_mode</span> 3403 only comes into effect if <a href="#conserve_volume_flow">conserve_volume_flow</a> = <span style="font-style: italic;">.T. .</span> </td></tr><tr> 3404 3405 3406 3407 <td style="vertical-align: top;"><a name="cthf"></a><span style="font-weight: bold;">cthf</span></td> 3408 3409 <td style="vertical-align: top;">R</td> 3410 3411 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 3412 3413 <td style="vertical-align: top;">Average heat flux that is prescribed at the top of the plant canopy.<br> 3414 3415 3416 <br> 3417 3418 3419 If <a href="#plant_canopy">plant_canopy</a> is set <span style="font-style: italic;">.T.</span>, the user can prescribe a heat flux at the top of the plant canopy.<br> 3420 3421 3422 It is assumed that solar radiation penetrates the canopy and warms the 3423 foliage which, in turn, warms the air in contact with it. <br> 3424 3425 3426 Note: Instead of using the value prescribed by <a href="#surface_heatflux">surface_heatflux</a>, 3427 the near surface heat flux is determined from an exponential function 3428 that is dependent on the cumulative leaf_area_index (Shaw and Schumann 3429 (1992, Boundary Layer Meteorol., 61, 47-64)).</td> 3430 3431 </tr> 3432 <td style="vertical-align: top;"><a name="coupling_start_time"></a><span style="font-weight: bold;">coupling_start_time</span></td> 3433 3434 <td style="vertical-align: top;">R</td> 3435 3436 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 3437 3438 <td style="vertical-align: top;">Simulation time of precursor run. 3439 <br> 3440 <br> 3441 Sets the time period a precursor run shall run uncoupled. This parameter is used to set up the precursor run control for atmosphere-ocean-coupled runs. It has to be set individually to the atmospheric / oceanic precursor run. The time in the data output will show negative values during the precursor run. See documentation for further information. 3442 3443 </td> 3444 3445 </tr> 3446 <tr> 3447 3448 3449 3450 3451 3452 3453 <td style="vertical-align: top;"> 3454 3455 3456 3457 3458 3459 3460 <p><a name="cut_spline_overshoot"></a><b>cut_spline_overshoot</b></p> 3461 3462 3463 3464 3465 3466 3467 3468 </td> 3469 3470 3471 3472 3473 3474 3475 <td style="vertical-align: top;">L</td> 3476 3477 3478 3479 3480 3481 3482 3483 <td style="vertical-align: top;"><span style="font-style: italic;">.T.</span></td> 3484 3485 3486 3487 3488 3489 3490 <td style="vertical-align: top;"> 3491 3492 3493 3494 3495 3496 3497 <p>Cuts off of 3498 so-called overshoots, which can occur with the 3499 upstream-spline scheme. </p> 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 <p><font color="#000000">The cubic splines tend to overshoot in 3514 case of discontinuous changes of variables between neighbouring grid 3515 points.</font><font color="#ff0000"> </font><font color="#000000">This 3516 may lead to errors in calculating the advection tendency.</font> 3517 Choice 3518 of <b>cut_spline_overshoot</b> = <i>.TRUE.</i> 3519 (switched on by 3520 default) 3521 allows variable values not to exceed an interval defined by the 3522 respective adjacent grid points. This interval can be adjusted 3523 seperately for every prognostic variable (see initialization parameters 3524 <a href="#overshoot_limit_e">overshoot_limit_e</a>, <a href="#overshoot_limit_pt">overshoot_limit_pt</a>, <a href="#overshoot_limit_u">overshoot_limit_u</a>, 3525 etc.). This might be necessary in case that the 3526 default interval has a non-tolerable effect on the model 3527 results. </p> 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 <p>Overshoots may also be removed 3542 using the parameters <a href="#ups_limit_e">ups_limit_e</a>, 3543 <a href="#ups_limit_pt">ups_limit_pt</a>, 3544 etc. as well as by applying a long-filter (see <a href="#long_filter_factor">long_filter_factor</a>).</p> 3545 3546 3547 3548 3549 3550 3551 3552 </td> 3553 3554 3555 3556 3557 3558 3559 </tr> 3560 3561 3562 3563 3564 3565 3566 <tr> 3567 3568 3569 3570 3571 3572 3573 <td style="vertical-align: top;"> 3574 3575 3576 3577 3578 3579 3580 <p><a name="damp_level_1d"></a><b>damp_level_1d</b></p> 3581 3582 3583 3584 3585 3586 3587 3588 </td> 3589 3590 3591 3592 3593 3594 3595 <td style="vertical-align: top;">R</td> 3596 3597 3598 3599 3600 3601 3602 3603 <td style="vertical-align: top;"><span style="font-style: italic;">zu(nz+1)</span></td> 3604 3605 3606 3607 3608 3609 3610 3611 <td style="vertical-align: top;"> 3612 3613 3614 3615 3616 3617 3618 <p>Height where 3619 the damping layer begins in the 1d-model 3620 (in m). </p> 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 <p>This parameter is used to 3635 switch on a damping layer for the 3636 1d-model, which is generally needed for the damping of inertia 3637 oscillations. Damping is done by gradually increasing the value 3638 of the eddy diffusivities about 10% per vertical grid level 3639 (starting with the value at the height given by <b>damp_level_1d</b>, 3640 or possibly from the next grid pint above), i.e. K<sub>m</sub>(k+1) 3641 = 3642 1.1 * K<sub>m</sub>(k). 3643 The values of K<sub>m</sub> are limited to 10 m**2/s at 3644 maximum. <br> 3645 3646 3647 3648 3649 3650 3651 3652 This parameter only comes into effect if the 1d-model is switched on 3653 for 3654 the initialization of the 3d-model using <a href="#initializing_actions">initializing_actions</a> 3655 = <span style="font-style: italic;">'set_1d-model_profiles'</span>. 3656 <br> 3657 3658 3659 3660 3661 3662 3663 </p> 3664 3665 3666 3667 3668 3669 3670 </td> 3671 3672 3673 3674 3675 3676 3677 </tr> 3678 3679 3680 3681 3682 3683 3684 <tr> 3685 3686 3687 3688 3689 3690 3691 <td style="vertical-align: top;"><a name="dissipation_1d"></a><span style="font-weight: bold;">dissipation_1d</span><br> 3692 3693 3694 3695 3696 3697 3698 3699 </td> 3700 3701 3702 3703 3704 3705 3706 <td style="vertical-align: top;">C*20<br> 3707 3708 3709 3710 3711 3712 3713 3714 </td> 3715 3716 3717 3718 3719 3720 3721 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;"> 3722 3723 3724 3725 3726 3727 3728 <span style="font-style: italic;">model'</span><br> 3729 3730 3731 3732 3733 3734 3735 </td> 3736 3737 3738 3739 3740 3741 3742 3743 <td style="vertical-align: top;">Calculation method for 3744 the energy dissipation term in the TKE equation of the 1d-model.<br> 3745 3746 3747 3748 3749 3750 3751 3752 <br> 3753 3754 3755 3756 3757 3758 3759 3760 By default the dissipation is calculated as in the 3d-model using diss 3761 = (0.19 + 0.74 * l / l_grid) * e**1.5 / l.<br> 3762 3763 3764 3765 3766 3767 3768 <br> 3769 3770 3771 3772 3773 3774 3775 3776 Setting <span style="font-weight: bold;">dissipation_1d</span> 3777 = <span style="font-style: italic;">'detering'</span> 3778 forces the dissipation to be calculated as diss = 0.064 * e**1.5 / l.<br> 3779 3780 3781 3782 3783 3784 3785 3786 </td> 3787 3788 3789 3790 3791 3792 3793 </tr> 3794 <tr><td style="vertical-align: top;"><p><a name="dp_external"></a><b>dp_external</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top; font-style: italic;">.F.</td><td>External pressure gradient switch.<br><br>This 3795 parameter is used to switch on/off an external pressure gradient as 3796 driving force. The external pressure gradient is controlled by the 3797 parameters <a href="#dp_smooth">dp_smooth</a>, <a href="#dp_level_b">dp_level_b</a> and <a href="#dpdxy">dpdxy</a>.<br><br>Note that <span style="font-weight: bold;">dp_external</span> = <span style="font-style: italic;">.T.</span> requires <a href="#conserve_volume_flow">conserve_volume_flow</a> =<span style="font-style: italic;"> .F. </span>It is normally recommended to disable the Coriolis force by setting <a href="l#omega">omega</a> = 0.0.</td></tr><tr><td style="vertical-align: top;"><p><a name="dp_smooth"></a><b>dp_smooth</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top; font-style: italic;">.F.</td><td>Vertically smooth the external pressure gradient using a sinusoidal smoothing function.<br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span>. It is useful in combination with <a href="#dp_level_b">dp_level_b</a> >> 0 to generate a non-accelerated boundary layer well below <a href="#dp_level_b">dp_level_b</a>.</td></tr><tr><td style="vertical-align: top;"><p><a name="dp_level_b"></a><b>dp_level_b</b></p></td><td style="vertical-align: top;">R</td><td style="vertical-align: top; font-style: italic;">0.0</td><td><font size="3">Lower 3798 limit of the vertical range for which the external pressure gradient is applied (</font>in <font size="3">m).</font><br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span><span lang="en-GB">It 3799 must hold the condition zu(0) <= <b>dp_level_b</b> 3800 <= zu(</span><a href="#nz"><span lang="en-GB">nz</span></a><span lang="en-GB">)</span><span lang="en-GB">. </span>It can be used in combination with <a href="#dp_smooth">dp_smooth</a> = <span style="font-style: italic;">.T.</span> to generate a non-accelerated boundary layer well below <span style="font-weight: bold;">dp_level_b</span> if <span style="font-weight: bold;">dp_level_b</span> >> 0.<br><br>Note 3801 that there is no upper limit of the vertical range because the external 3802 pressure gradient is always applied up to the top of the model domain.</td></tr><tr><td style="vertical-align: top;"><p><a name="dpdxy"></a><b>dpdxy</b></p></td><td style="vertical-align: top;">R(2)</td><td style="font-style: italic; vertical-align: top;">2 * 0.0</td><td>Values of the external pressure gradient applied in x- and y-direction, respectively (in Pa/m).<br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span>It sets the pressure gradient values. Negative values mean an acceleration, positive values mean deceleration. For example, <span style="font-weight: bold;">dpdxy</span> = -0.0002, 0.0, drives the flow in positive x-direction, <span lang="en-GB"></span></td></tr> 3803 3804 3805 3806 3807 3808 3809 <tr> 3810 3811 <td style="vertical-align: top;"><a name="drag_coefficient"></a><span style="font-weight: bold;">drag_coefficient</span></td> 3812 3813 <td style="vertical-align: top;">R</td> 3814 3815 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 3816 3817 <td style="vertical-align: top;">Drag coefficient used in the plant canopy model.<br> 3818 3819 <br> 3820 3821 This parameter has to be non-zero, if the parameter <a href="#plant_canopy">plant_canopy</a> is set <span style="font-style: italic;">.T.</span>.</td> 3822 3823 </tr> 3824 3825 <tr> 3826 3827 3828 3829 3830 3831 3832 <td style="vertical-align: top;"> 3833 3834 3835 3836 3837 3838 3839 <p><a name="dt"></a><b>dt</b></p> 3840 3841 3842 3843 3844 3845 3846 </td> 3847 3848 3849 3850 3851 3852 3853 3854 <td style="vertical-align: top;">R</td> 3855 3856 3857 3858 3859 3860 3861 <td style="vertical-align: top;"><span style="font-style: italic;">variable</span></td> 3862 3863 3864 3865 3866 3867 3868 3869 <td style="vertical-align: top;"> 3870 3871 3872 3873 3874 3875 3876 <p>Time step for 3877 the 3d-model (in s). </p> 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 <p>By default, (i.e. 3892 if a Runge-Kutta scheme is used, see <a href="#timestep_scheme">timestep_scheme</a>) 3893 the value of the time step is calculating after each time step 3894 (following the time step criteria) and 3895 used for the next step.</p> 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 <p>If the user assigns <b>dt</b> 3910 a value, then the time step is 3911 fixed to this value throughout the whole run (whether it fulfills the 3912 time step 3913 criteria or not). However, changes are allowed for restart runs, 3914 because <b>dt</b> can also be used as a <a href="chapter_4.2.html#dt_laufparameter">run 3915 parameter</a>. </p> 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 <p>In case that the 3930 calculated time step meets the condition<br> 3931 3932 3933 3934 3935 3936 3937 </p> 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 <ul> 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 <p><b>dt</b> < 0.00001 * <a href="chapter_4.2.html#dt_max">dt_max</a> (with dt_max 3966 = 20.0)</p> 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 </ul> 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 <p>the simulation will be 3995 aborted. Such situations usually arise 3996 in case of any numerical problem / instability which causes a 3997 non-realistic increase of the wind speed. </p> 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 <p>A 4012 small time step due to a large mean horizontal windspeed 4013 speed may be enlarged by using a coordinate transformation (see <a href="#galilei_transformation">galilei_transformation</a>), 4014 in order to spare CPU time.<br> 4015 4016 4017 4018 4019 4020 4021 </p> 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 <p>If the 4036 leapfrog timestep scheme is used (see <a href="#timestep_scheme">timestep_scheme</a>) 4037 a temporary time step value dt_new is calculated first, with dt_new = <a href="chapter_4.2.html#fcl_factor">cfl_factor</a> 4038 * dt_crit where dt_crit is the maximum timestep allowed by the CFL and 4039 diffusion condition. Next it is examined whether dt_new exceeds or 4040 falls below the 4041 value of the previous timestep by at 4042 least +5 % / -2%. If it is smaller, <span style="font-weight: bold;">dt</span> 4043 = dt_new is immediately used for the next timestep. If it is larger, 4044 then <span style="font-weight: bold;">dt </span>= 4045 1.02 * dt_prev 4046 (previous timestep) is used as the new timestep, however the time 4047 step is only increased if the last change of the time step is dated 4048 back at 4049 least 30 iterations. If dt_new is located in the interval mentioned 4050 above, then dt 4051 does not change at all. By doing so, permanent time step changes as 4052 well as large 4053 sudden changes (increases) in the time step are avoided.</p> 4054 4055 4056 4057 4058 4059 4060 </td> 4061 4062 4063 4064 4065 4066 4067 4068 </tr> 4069 4070 4071 4072 4073 4074 4075 <tr> 4076 4077 4078 4079 4080 4081 4082 <td style="vertical-align: top;"> 4083 4084 4085 4086 4087 4088 4089 <p><a name="dt_pr_1d"></a><b>dt_pr_1d</b></p> 4090 4091 4092 4093 4094 4095 4096 4097 </td> 4098 4099 4100 4101 4102 4103 4104 <td style="vertical-align: top;">R</td> 4105 4106 4107 4108 4109 4110 4111 4112 <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td> 4113 4114 4115 4116 4117 4118 4119 4120 <td style="vertical-align: top;"> 4121 4122 4123 4124 4125 4126 4127 <p>Temporal 4128 interval of vertical profile output of the 1D-model 4129 (in s). </p> 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 <p>Data are written in ASCII 4144 format to file <a href="chapter_3.4.html#LIST_PROFIL_1D">LIST_PROFIL_1D</a>. 4145 This parameter is only in effect if the 1d-model has been switched on 4146 for the 4147 initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a> 4148 = <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p> 4149 4150 4151 4152 4153 4154 4155 4156 </td> 4157 4158 4159 4160 4161 4162 4163 </tr> 4164 4165 4166 4167 4168 4169 4170 <tr> 4171 4172 4173 4174 4175 4176 4177 <td style="vertical-align: top;"> 4178 4179 4180 4181 4182 4183 4184 <p><a name="dt_run_control_1d"></a><b>dt_run_control_1d</b></p> 4185 4186 4187 4188 4189 4190 4191 4192 </td> 4193 4194 4195 4196 4197 4198 4199 <td style="vertical-align: top;">R</td> 4200 4201 4202 4203 4204 4205 4206 4207 <td style="vertical-align: top;"><span style="font-style: italic;">60.0</span></td> 4208 4209 4210 4211 4212 4213 4214 <td style="vertical-align: top;"> 4215 4216 4217 4218 4219 4220 4221 <p>Temporal interval of 4222 runtime control output of the 1d-model 4223 (in s). </p> 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 <p>Data are written in ASCII 4238 format to file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>. 4239 This parameter is only in effect if the 1d-model is switched on for the 4240 initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a> 4241 = <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p> 4242 4243 4244 4245 4246 4247 4248 4249 </td> 4250 4251 4252 4253 4254 4255 4256 </tr> 4257 4258 4259 4260 4261 4262 4263 <tr> 4264 4265 4266 4267 4268 4269 4270 <td style="vertical-align: top;"> 4271 4272 4273 4274 4275 4276 4277 <p><a name="dx"></a><b>dx</b></p> 4278 4279 4280 4281 4282 4283 4284 4285 </td> 4286 4287 4288 4289 4290 4291 4292 <td style="vertical-align: top;">R</td> 4293 4294 4295 4296 4297 4298 4299 4300 <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td> 4301 4302 4303 4304 4305 4306 4307 <td style="vertical-align: top;"> 4308 4309 4310 4311 4312 4313 4314 <p>Horizontal grid 4315 spacing along the x-direction (in m). </p> 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 <p>Along 4330 x-direction only a constant grid spacing is allowed.</p> 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a> 4344 and <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p> 4345 4346 4347 4348 4349 4350 4351 </td> 4352 4353 4354 4355 4356 4357 4358 4359 </tr> 4360 4361 4362 4363 4364 4365 4366 <tr> 4367 4368 4369 4370 4371 4372 4373 <td style="vertical-align: top;"> 4374 4375 4376 4377 4378 4379 4380 <p><a name="dy"></a><b>dy</b></p> 4381 4382 4383 4384 4385 4386 4387 4388 </td> 4389 4390 4391 4392 4393 4394 4395 <td style="vertical-align: top;">R</td> 4396 4397 4398 4399 4400 4401 4402 4403 <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td> 4404 4405 4406 4407 4408 4409 4410 <td style="vertical-align: top;"> 4411 4412 4413 4414 4415 4416 4417 <p>Horizontal grid 4418 spacing along the y-direction (in m). </p> 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 <p>Along y-direction only a constant grid spacing is allowed.</p> 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a> 4446 and <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p> 4447 4448 4449 4450 4451 4452 4453 </td> 4454 4455 4456 4457 4458 4459 4460 4461 </tr> 4462 4463 4464 4465 4466 4467 4468 <tr> 4469 4470 4471 4472 4473 4474 4475 <td style="vertical-align: top;"> 4476 4477 4478 4479 4480 4481 4482 <p><a name="dz"></a><b>dz</b></p> 4483 4484 4485 4486 4487 4488 4489 4490 </td> 4491 4492 4493 4494 4495 4496 4497 <td style="vertical-align: top;">R</td> 4498 4499 4500 4501 4502 4503 4504 4505 <td style="vertical-align: top;"><br> 4506 4507 4508 4509 4510 4511 4512 </td> 4513 4514 4515 4516 4517 4518 4519 <td style="vertical-align: top;"> 4520 4521 4522 4523 4524 4525 4526 <p>Vertical grid 4527 spacing (in m). </p> 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 <p>This parameter must be 4542 assigned by the user, because no 4543 default value is given.<br> 4544 4545 4546 4547 4548 4549 4550 </p> 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 <p>By default, the 4565 model uses constant grid spacing along z-direction, but it can be 4566 stretched using the parameters <a href="#dz_stretch_level">dz_stretch_level</a> 4567 and <a href="#dz_stretch_factor">dz_stretch_factor</a>. 4568 In case of stretching, a maximum allowed grid spacing can be given by <a href="#dz_max">dz_max</a>.<br> 4569 4570 4571 4572 4573 4574 4575 </p> 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 <p>Assuming 4590 a constant <span style="font-weight: bold;">dz</span>, 4591 the scalar levels (zu) are calculated directly by: </p> 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 <ul> 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 <p>zu(0) = - dz * 0.5 <br> 4620 4621 4622 4623 4624 4625 4626 4627 zu(1) = dz * 0.5</p> 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 </ul> 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 <p>The w-levels lie 4656 half between them: </p> 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 <ul> 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 <p>zw(k) = 4685 ( zu(k) + zu(k+1) ) * 0.5</p> 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 </ul> 4700 4701 4702 4703 4704 4705 4706 </td> 4707 4708 4709 4710 4711 4712 4713 </tr> 4714 4715 4716 4717 4718 4719 4720 4721 <tr> 4722 4723 4724 4725 4726 4727 4728 <td style="vertical-align: top;"><a name="dz_max"></a><span style="font-weight: bold;">dz_max</span></td> 4729 4730 4731 4732 4733 4734 4735 <td style="vertical-align: top;">R</td> 4736 4737 4738 4739 4740 4741 4742 <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td> 4743 4744 4745 4746 4747 4748 4749 <td style="vertical-align: top;">Allowed maximum vertical grid 4750 spacing (in m).<br> 4751 4752 4753 4754 4755 4756 4757 <br> 4758 4759 4760 4761 4762 4763 4764 If the vertical grid is stretched 4765 (see <a href="#dz_stretch_factor">dz_stretch_factor</a> 4766 and <a href="#dz_stretch_level">dz_stretch_level</a>), 4767 <span style="font-weight: bold;">dz_max</span> can 4768 be used to limit the vertical grid spacing.</td> 4769 4770 4771 4772 4773 4774 4775 </tr> 4776 4777 4778 4779 4780 4781 4782 <tr> 4783 4784 4785 4786 4787 4788 4789 4790 <td style="vertical-align: top;"> 4791 4792 4793 4794 4795 4796 4797 <p><a name="dz_stretch_factor"></a><b>dz_stretch_factor</b></p> 4798 4799 4800 4801 4802 4803 4804 4805 </td> 4806 4807 4808 4809 4810 4811 4812 <td style="vertical-align: top;">R</td> 4813 4814 4815 4816 4817 4818 4819 4820 <td style="vertical-align: top;"><span style="font-style: italic;">1.08</span></td> 4821 4822 4823 4824 4825 4826 4827 <td style="vertical-align: top;"> 4828 4829 4830 4831 4832 4833 4834 <p>Stretch factor for a 4835 vertically stretched grid (see <a href="#dz_stretch_level">dz_stretch_level</a>). 4836 </p> 4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 <p>The stretch factor should not exceed a value of 4851 approx. 1.10 - 4852 1.12, otherwise the discretization errors due to the stretched grid not 4853 negligible any more. (refer Kalnay de Rivas)</p> 4854 4855 4856 4857 4858 4859 4860 </td> 4861 4862 4863 4864 4865 4866 4867 </tr> 4868 4869 4870 4871 4872 4873 4874 4875 <tr> 4876 4877 4878 4879 4880 4881 4882 <td style="vertical-align: top;"> 4883 4884 4885 4886 4887 4888 4889 <p><a name="dz_stretch_level"></a><b>dz_stretch_level</b></p> 4890 4891 4892 4893 4894 4895 4896 4897 </td> 4898 4899 4900 4901 4902 4903 4904 <td style="vertical-align: top;">R</td> 4905 4906 4907 4908 4909 4910 4911 4912 <td style="vertical-align: top;"><span style="font-style: italic;">100000.0</span><br> 4913 4914 4915 4916 4917 4918 4919 </td> 4920 4921 4922 4923 4924 4925 4926 4927 <td style="vertical-align: top;"> 4928 4929 4930 4931 4932 4933 4934 <p>Height level 4935 above/below which the grid is to be stretched 4936 vertically (in m). </p> 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 <p>For <a href="chapter_4.1.html#ocean">ocean</a> = .F., <b>dz_stretch_level </b>is the height level (in m) <span style="font-weight: bold;">above </span>which the grid is to be stretched 4951 vertically. The vertical grid 4952 spacings <a href="#dz">dz</a> 4953 above this level are calculated as </p> 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 <ul> 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 <p><b>dz</b>(k+1) 4982 = <b>dz</b>(k) * <a href="#dz_stretch_factor">dz_stretch_factor</a></p> 4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 </ul> 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010 <p>and used as spacings for the scalar levels (zu). 5011 The 5012 w-levels are then defined as: </p> 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 <ul> 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 <p>zw(k) 5041 = ( zu(k) + zu(k+1) ) * 0.5. 5042 5043 5044 5045 </p> 5046 5047 5048 5049 5050 5051 5052 5053 5054 </ul> 5055 5056 5057 5058 5059 5060 5061 5062 5063 <p>For <a href="#ocean">ocean</a> = .T., <b>dz_stretch_level </b>is the height level (in m, negative) <span style="font-weight: bold;">below</span> which the grid is to be stretched 5064 vertically. The vertical grid 5065 spacings <a href="chapter_4.1.html#dz">dz</a> below this level are calculated correspondingly as 5066 5067 5068 5069 </p> 5070 5071 5072 5073 5074 5075 5076 5077 5078 <ul> 5079 5080 5081 5082 5083 5084 5085 5086 5087 <p><b>dz</b>(k-1) 5088 = <b>dz</b>(k) * <a href="chapter_4.1.html#dz_stretch_factor">dz_stretch_factor</a>.</p> 5089 5090 5091 5092 5093 5094 5095 5096 5097 </ul> 5098 5099 5100 5101 5102 5103 5104 </td> 5105 5106 5107 5108 5109 5110 5111 </tr> 5112 5113 5114 5115 5116 5117 5118 5119 <tr> 5120 5121 5122 5123 5124 5125 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_init"></a>e_init</span></td> 5126 5127 5128 5129 5130 5131 <td style="vertical-align: top;">R</td> 5132 5133 5134 5135 5136 5137 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 5138 5139 5140 5141 5142 5143 <td>Initial subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br> 5144 5145 5146 5147 5148 5149 5150 5151 <br> 5152 5153 5154 5155 5156 5157 5158 This 5159 option prescribes an initial subgrid-scale TKE from which the initial diffusion coefficients K<sub>m</sub> and K<sub>h</sub> will be calculated if <span style="font-weight: bold;">e_init</span> is positive. This option only has an effect if <a href="#km_constant">km_constant</a> is not set.</td> 5160 5161 5162 5163 5164 5165 </tr> 5166 5167 5168 5169 5170 5171 <tr> 5172 5173 5174 5175 5176 5177 5178 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_min"></a>e_min</span></td> 5179 5180 5181 5182 5183 5184 5185 5186 <td style="vertical-align: top;">R</td> 5187 5188 5189 5190 5191 5192 5193 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 5194 5195 5196 5197 5198 5199 5200 <td>Minimum 5201 subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br> 5202 5203 5204 5205 5206 5207 5208 5209 <br> 5210 5211 5212 5213 5214 5215 5216 This 5217 option adds artificial viscosity to the flow by ensuring that 5218 the 5219 subgrid-scale TKE does not fall below the minimum threshold <span style="font-weight: bold;">e_min</span>.</td> 5220 5221 5222 5223 5224 5225 5226 </tr> 5227 5228 5229 5230 5231 5232 5233 5234 <tr> 5235 5236 5237 5238 5239 5240 5241 <td style="vertical-align: top;"> 5242 5243 5244 5245 5246 5247 5248 <p><a name="end_time_1d"></a><b>end_time_1d</b></p> 5249 5250 5251 5252 5253 5254 5255 5256 </td> 5257 5258 5259 5260 5261 5262 5263 <td style="vertical-align: top;">R</td> 5264 5265 5266 5267 5268 5269 5270 5271 <td style="vertical-align: top;"><span style="font-style: italic;">864000.0</span><br> 5272 5273 5274 5275 5276 5277 5278 </td> 5279 5280 5281 5282 5283 5284 5285 5286 <td style="vertical-align: top;"> 5287 5288 5289 5290 5291 5292 5293 <p>Time to be 5294 simulated for the 1d-model (in s). </p> 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 <p>The 5309 default value corresponds to a simulated time of 10 days. 5310 Usually, after such a period the inertia oscillations have completely 5311 decayed and the solution of the 1d-model can be regarded as stationary 5312 (see <a href="#damp_level_1d">damp_level_1d</a>). 5313 This parameter is only in effect if the 1d-model is switched on for the 5314 initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a> 5315 = <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p> 5316 5317 5318 5319 5320 5321 5322 5323 </td> 5324 5325 5326 5327 5328 5329 5330 </tr> 5331 5332 5333 5334 5335 5336 5337 <tr> 5338 5339 5340 5341 5342 5343 5344 <td style="vertical-align: top;"> 5345 5346 5347 5348 5349 5350 5351 <p><a name="fft_method"></a><b>fft_method</b></p> 5352 5353 5354 5355 5356 5357 5358 5359 </td> 5360 5361 5362 5363 5364 5365 5366 <td style="vertical-align: top;">C * 20</td> 5367 5368 5369 5370 5371 5372 5373 5374 <td style="vertical-align: top;"><span style="font-style: italic;">'system-</span><br style="font-style: italic;"> 5375 5376 5377 5378 5379 5380 5381 <span style="font-style: italic;">specific'</span></td> 5382 5383 5384 5385 5386 5387 5388 5389 <td style="vertical-align: top;"> 5390 5391 5392 5393 5394 5395 5396 <p>FFT-method to 5397 be used.<br> 5398 5399 5400 5401 5402 5403 5404 </p> 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 <p><br> 5419 5420 5421 5422 5423 5424 5425 5426 The fast fourier transformation (FFT) is used for solving the 5427 perturbation pressure equation with a direct method (see <a href="chapter_4.2.html#psolver">psolver</a>) 5428 and for calculating power spectra (see optional software packages, 5429 section <a href="chapter_4.2.html#spectra_package">4.2</a>).</p> 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 <p><br> 5444 5445 5446 5447 5448 5449 5450 5451 By default, system-specific, optimized routines from external 5452 vendor libraries are used. However, these are available only on certain 5453 computers and there are more or less severe restrictions concerning the 5454 number of gridpoints to be used with them.<br> 5455 5456 5457 5458 5459 5460 5461 </p> 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 <p>There 5476 are two other PALM internal methods available on every 5477 machine (their respective source code is part of the PALM source code):</p> 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 <p>1.: The <span style="font-weight: bold;">Temperton</span>-method 5492 from Clive Temperton (ECWMF) which is computationally very fast and 5493 switched on with <b>fft_method</b> = <span style="font-style: italic;">'temperton-algorithm'</span>. 5494 The number of horizontal gridpoints (nx+1, ny+1) to be used with this 5495 method must be composed of prime factors 2, 3 and 5.<br> 5496 5497 5498 5499 5500 5501 5502 </p> 5503 5504 5505 5506 5507 5508 5509 5510 2.: The <span style="font-weight: bold;">Singleton</span>-method 5511 which is very slow but has no restrictions concerning the number of 5512 gridpoints to be used with, switched on with <b>fft_method</b> 5513 = <span style="font-style: italic;">'singleton-algorithm'</span>. 5514 </td> 5515 5516 5517 5518 5519 5520 5521 </tr> 5522 5523 5524 5525 5526 5527 5528 <tr> 5529 5530 5531 5532 5533 5534 5535 <td style="vertical-align: top;"> 5536 5537 5538 5539 5540 5541 5542 <p><a name="galilei_transformation"></a><b>galilei_transformation</b></p> 5543 5544 5545 5546 5547 5548 5549 5550 </td> 5551 5552 5553 5554 5555 5556 5557 <td style="vertical-align: top;">L</td> 5558 5559 5560 5561 5562 5563 5564 5565 <td style="vertical-align: top;"><i>.F.</i></td> 5566 5567 5568 5569 5570 5571 5572 5573 <td style="vertical-align: top;">Application of a 5574 Galilei-transformation to the 5575 coordinate 5576 system of the model.<br> 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 <p>With <b>galilei_transformation</b> 5590 = <i>.T.,</i> a so-called 5591 Galilei-transformation is switched on which ensures that the coordinate 5592 system of the model is moved along with the geostrophical wind. 5593 Alternatively, the model domain can be moved along with the averaged 5594 horizontal wind (see <a href="#use_ug_for_galilei_tr">use_ug_for_galilei_tr</a>, 5595 this can and will naturally change in time). With this method, 5596 numerical inaccuracies of the Piascek - Williams - scheme (concerns in 5597 particular the momentum advection) are minimized. Beyond that, in the 5598 majority of cases the lower relative velocities in the moved system 5599 permit a larger time step (<a href="#dt">dt</a>). 5600 Switching the transformation on is only worthwhile if the geostrophical 5601 wind (ug, vg) 5602 and the averaged horizontal wind clearly deviate from the value 0. In 5603 each case, the distance the coordinate system has been moved is written 5604 to the file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>. 5605 </p> 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 <p>Non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a> 5620 and <a href="#bc_ns">bc_ns</a>), the specification 5621 of a gestrophic 5622 wind that is not constant with height 5623 as well as e.g. stationary inhomogeneities at the bottom boundary do 5624 not allow the use of this transformation.</p> 5625 5626 5627 5628 5629 5630 5631 </td> 5632 5633 5634 5635 5636 5637 5638 </tr> 5639 5640 5641 5642 5643 5644 5645 5646 <tr> 5647 5648 5649 5650 5651 5652 5653 <td style="vertical-align: top;"> 5654 5655 5656 5657 5658 5659 5660 <p><a name="grid_matching"></a><b>grid_matching</b></p> 5661 5662 5663 5664 5665 5666 5667 5668 </td> 5669 5670 5671 5672 5673 5674 5675 <td style="vertical-align: top;">C * 6</td> 5676 5677 5678 5679 5680 5681 5682 5683 <td style="vertical-align: top;"><span style="font-style: italic;">'strict'</span></td> 5684 5685 5686 5687 5688 5689 5690 <td style="vertical-align: top;">Variable to adjust the 5691 subdomain 5692 sizes in parallel runs.<br> 5693 5694 5695 5696 5697 5698 5699 <br> 5700 5701 5702 5703 5704 5705 5706 5707 For <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>, 5708 the subdomains are forced to have an identical 5709 size on all processors. In this case the processor numbers in the 5710 respective directions of the virtual processor net must fulfill certain 5711 divisor conditions concerning the grid point numbers in the three 5712 directions (see <a href="#nx">nx</a>, <a href="#ny">ny</a> 5713 and <a href="#nz">nz</a>). 5714 Advantage of this method is that all PEs bear the same computational 5715 load.<br> 5716 5717 5718 5719 5720 5721 5722 <br> 5723 5724 5725 5726 5727 5728 5729 5730 There is no such restriction by default, because then smaller 5731 subdomains are allowed on those processors which 5732 form the right and/or north boundary of the virtual processor grid. On 5733 all other processors the subdomains are of same size. Whether smaller 5734 subdomains are actually used, depends on the number of processors and 5735 the grid point numbers used. Information about the respective settings 5736 are given in file <a href="file:///home/raasch/public_html/PALM_group/home/raasch/public_html/PALM_group/doc/app/chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.<br> 5737 5738 5739 5740 5741 5742 5743 5744 <br> 5745 5746 5747 5748 5749 5750 5751 5752 When using a multi-grid method for solving the Poisson equation (see <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</a>) 5753 only <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span> 5754 is allowed.<br> 5755 5756 5757 5758 5759 5760 5761 <br> 5762 5763 5764 5765 5766 5767 5768 <b>Note:</b><br> 5769 5770 5771 5772 5773 5774 5775 5776 In some cases for small processor numbers there may be a very bad load 5777 balancing among the 5778 processors which may reduce the performance of the code.</td> 5779 5780 5781 5782 5783 5784 5785 </tr> 5786 5787 5788 5789 5790 5791 5792 5793 <tr><td style="vertical-align: top;"><p><a name="humidity"></a><b>humidity</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top;"><i>.F.</i></td><td style="vertical-align: top;"><p>Parameter to 5794 switch on the prognostic equation for specific 5795 humidity q.<br> 5796 5797 5798 5799 5800 5801 5802 </p> 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 <p>The initial vertical 5817 profile of q can be set via parameters <a href="chapter_4.1.html#q_surface">q_surface</a>, <a href="chapter_4.1.html#q_vertical_gradient">q_vertical_gradient</a> 5818 and <a href="chapter_4.1.html#q_vertical_gradient_level">q_vertical_gradient_level</a>. 5819 Boundary conditions can be set via <a href="chapter_4.1.html#q_surface_initial_change">q_surface_initial_change</a> 5820 and <a href="chapter_4.1.html#surface_waterflux">surface_waterflux</a>.<br> 5821 5822 5823 5824 5825 5826 5827 5828 </p> 5829 5830 5831 5832 5833 5834 5835 5836 If the condensation scheme is switched on (<a href="chapter_4.1.html#cloud_physics">cloud_physics</a> 5837 = .TRUE.), q becomes the total liquid water content (sum of specific 5838 humidity and liquid water content).</td></tr><tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="inflow_damping_height"></a>inflow_damping_height</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">from precursor run</span></td><td style="vertical-align: top;">Height below which the turbulence signal is used for turbulence recycling (in m).<br><br>In case of a turbulent inflow (see <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a>), 5839 this parameter defines the vertical thickness of the turbulent layer up 5840 to which the turbulence extracted at the recycling plane (see <a href="chapter_4.1.html#recycling_width">recycling_width</a>) 5841 shall be imposed to the inflow. Above this level the turbulence signal 5842 is linearly damped to zero. The transition range within which the 5843 signal falls to zero is given by the parameter <a href="chapter_4.1.html#inflow_damping_width">inflow_damping_width</a>.<br><br>By default, this height is set as the height of the convective boundary layer as calculated from a precursor run. See <a href="chapter_3.9.html">chapter 3.9</a> about proper settings for getting this CBL height from a precursor run. </td></tr><tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="inflow_damping_width"></a>inflow_damping_width</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">0.1 * <a href="chapter_4.1.html#inflow_damping_height">inflow_damping</a></span><a href="chapter_4.1.html#inflow_damping_height"><br style="font-style: italic;"><span style="font-style: italic;">_height</span></a></td><td style="vertical-align: top;">Transition range within which the turbulance signal is damped to zero (in m).<br><br>See <a href="chapter_4.1.html#inflow_damping_height">inflow_damping_height</a> for explanation.</td></tr><tr> 5844 5845 5846 5847 5848 5849 5850 <td style="vertical-align: top;"><a name="inflow_disturbance_begin"></a><b>inflow_disturbance_<br> 5851 5852 5853 5854 5855 5856 5857 5858 begin</b></td> 5859 5860 5861 5862 5863 5864 5865 <td style="vertical-align: top;">I</td> 5866 5867 5868 5869 5870 5871 5872 5873 <td style="vertical-align: top;"><span style="font-style: italic;">MIN(10,</span><br style="font-style: italic;"> 5874 5875 5876 5877 5878 5879 5880 <span style="font-style: italic;">nx/2 or ny/2)</span></td> 5881 5882 5883 5884 5885 5886 5887 5888 <td style="vertical-align: top;">Lower 5889 limit of the horizontal range for which random perturbations are to be 5890 imposed on the horizontal velocity field (gridpoints).<br> 5891 5892 5893 5894 5895 5896 5897 <br> 5898 5899 5900 5901 5902 5903 5904 5905 If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a> 5906 or <a href="#bc_ns">bc_ns</a>), 5907 this parameter gives the gridpoint number (counted horizontally from 5908 the inflow) from which on perturbations are imposed on the 5909 horizontal velocity field. Perturbations must be switched on with 5910 parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td> 5911 5912 5913 5914 5915 5916 5917 5918 </tr> 5919 5920 5921 5922 5923 5924 5925 <tr> 5926 5927 5928 5929 5930 5931 5932 <td style="vertical-align: top;"><a name="inflow_disturbance_end"></a><b>inflow_disturbance_<br> 5933 5934 5935 5936 5937 5938 5939 5940 end</b></td> 5941 5942 5943 5944 5945 5946 5947 <td style="vertical-align: top;">I</td> 5948 5949 5950 5951 5952 5953 5954 5955 <td style="vertical-align: top;"><span style="font-style: italic;">MIN(100,</span><br style="font-style: italic;"> 5956 5957 5958 5959 5960 5961 5962 <span style="font-style: italic;">3/4*nx or</span><br style="font-style: italic;"> 5963 5964 5965 5966 5967 5968 5969 <span style="font-style: italic;">3/4*ny)</span></td> 5970 5971 5972 5973 5974 5975 5976 <td style="vertical-align: top;">Upper 5977 limit of the horizontal range for which random perturbations are 5978 to be imposed on the horizontal velocity field (gridpoints).<br> 5979 5980 5981 5982 5983 5984 5985 <br> 5986 5987 5988 5989 5990 5991 5992 5993 If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a> 5994 or <a href="#bc_ns">bc_ns</a>), 5995 this parameter gives the gridpoint number (counted horizontally from 5996 the inflow) unto which perturbations are imposed on the 5997 horizontal 5998 velocity field. Perturbations must be switched on with parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td> 5999 6000 6001 6002 6003 6004 6005 6006 </tr> 6007 6008 6009 6010 6011 6012 6013 <tr> 6014 6015 6016 6017 6018 6019 6020 <td style="vertical-align: top;"> 6021 6022 6023 6024 6025 6026 6027 <p><a name="initializing_actions"></a><b>initializing_actions</b></p> 6028 6029 6030 6031 6032 6033 6034 6035 </td> 6036 6037 6038 6039 6040 6041 6042 <td style="vertical-align: top;">C * 100</td> 6043 6044 6045 6046 6047 6048 6049 6050 <td style="vertical-align: top;"><br> 6051 6052 6053 6054 6055 6056 6057 </td> 6058 6059 6060 6061 6062 6063 6064 <td style="vertical-align: top;"> 6065 6066 6067 6068 6069 6070 6071 <p style="font-style: normal;">Initialization actions 6072 to be carried out. </p> 6073 6074 6075 6076 6077 6078 6079 6080 6081 6082 6083 6084 6085 6086 <p style="font-style: normal;">This parameter does not have a 6087 default value and therefore must be assigned with each model run. For 6088 restart runs <b>initializing_actions</b> = <span style="font-style: italic;">'read_restart_data'</span> 6089 must be set. For the initial run of a job chain the following values 6090 are allowed: </p> 6091 6092 6093 6094 6095 6096 6097 6098 6099 6100 6101 6102 6103 6104 <p style="font-style: normal;"><span style="font-style: italic;">'set_constant_profiles'</span> 6105 </p> 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116 6117 6118 6119 <ul> 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 <p>A horizontal wind profile consisting 6134 of linear sections (see <a href="#ug_surface">ug_surface</a>, 6135 <a href="#ug_vertical_gradient">ug_vertical_gradient</a>, 6136 <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a> 6137 and <a href="#vg_surface">vg_surface</a>, <a href="#vg_vertical_gradient">vg_vertical_gradient</a>, 6138 <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>, 6139 respectively) as well as a vertical temperature (humidity) profile 6140 consisting of 6141 linear sections (see <a href="#pt_surface">pt_surface</a>, 6142 <a href="#pt_vertical_gradient">pt_vertical_gradient</a>, 6143 <a href="#q_surface">q_surface</a> 6144 and <a href="#q_vertical_gradient">q_vertical_gradient</a>) 6145 are assumed as initial profiles. The subgrid-scale TKE is set to 0 but K<sub>m</sub> 6146 and K<sub>h</sub> are set to very small values because 6147 otherwise no TKE 6148 would be generated.</p> 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162 </ul> 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172 6173 6174 6175 6176 <p style="font-style: italic;">'set_1d-model_profiles' </p> 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 <ul> 6191 6192 6193 6194 6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 <p>The arrays of the 3d-model are initialized with 6205 the 6206 (stationary) solution of the 1d-model. These are the variables e, kh, 6207 km, u, v and with Prandtl layer switched on rif, us, usws, vsws. The 6208 temperature (humidity) profile consisting of linear sections is set as 6209 for 'set_constant_profiles' and assumed as constant in time within the 6210 1d-model. For steering of the 1d-model a set of parameters with suffix 6211 "_1d" (e.g. <a href="#end_time_1d">end_time_1d</a>, 6212 <a href="#damp_level_1d">damp_level_1d</a>) 6213 is available.</p> 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 </ul> 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 <p><span style="font-style: italic;">'by_user'</span></p> 6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 <p style="margin-left: 40px;">The initialization of the arrays 6255 of the 3d-model is under complete control of the user and has to be 6256 done in routine <a href="chapter_3.5.1.html#user_init_3d_model">user_init_3d_model</a> 6257 of the user-interface.<span style="font-style: italic;"></span></p> 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 <p><span style="font-style: italic;">'initialize_vortex'</span> 6271 </p> 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 <div style="margin-left: 40px;">The initial 6286 velocity field of the 6287 3d-model corresponds to a 6288 Rankine-vortex with vertical axis. This setting may be used to test 6289 advection schemes. Free-slip boundary conditions for u and v (see <a href="#bc_uv_b">bc_uv_b</a>, <a href="#bc_uv_t">bc_uv_t</a>) 6290 are necessary. In order not to distort the vortex, an initial 6291 horizontal wind profile constant 6292 with height is necessary (to be set by <b>initializing_actions</b> 6293 = <span style="font-style: italic;">'set_constant_profiles'</span>) 6294 and some other conditions have to be met (neutral stratification, 6295 diffusion must be 6296 switched off, see <a href="#km_constant">km_constant</a>). 6297 The center of the vortex is located at jc = (nx+1)/2. It 6298 extends from k = 0 to k = nz+1. Its radius is 8 * <a href="#dx">dx</a> 6299 and the exponentially decaying part ranges to 32 * <a href="#dx">dx</a> 6300 (see init_rankine.f90). </div> 6301 6302 6303 6304 6305 6306 6307 6308 6309 6310 6311 6312 6313 6314 <p><span style="font-style: italic;">'initialize_ptanom'</span> 6315 </p> 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 <ul> 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343 <p>A 2d-Gauss-like shape disturbance 6344 (x,y) is added to the 6345 initial temperature field with radius 10.0 * <a href="#dx">dx</a> 6346 and center at jc = (nx+1)/2. This may be used for tests of scalar 6347 advection schemes 6348 (see <a href="#scalar_advec">scalar_advec</a>). 6349 Such tests require a horizontal wind profile constant with hight and 6350 diffusion 6351 switched off (see <span style="font-style: italic;">'initialize_vortex'</span>). 6352 Additionally, the buoyancy term 6353 must be switched of in the equation of motion for w (this 6354 requires the user to comment out the call of <span style="font-family: monospace;">buoyancy</span> in the 6355 source code of <span style="font-family: monospace;">prognostic_equations.f90</span>).</p></ul> 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 <p style="font-style: italic;">'cyclic_fill'</p><p style="font-style: normal; margin-left: 40px;">Here, 6370 3d-data from a precursor run are read by the initial (main) run. The 6371 precursor run is allowed to have a smaller domain along x and y 6372 compared with the main run. Also, different numbers of processors can 6373 be used for these two runs. Limitations are that the precursor run must 6374 use cyclic horizontal boundary conditions and that the number of vertical grid points, <a href="#nz">nz</a>, must be same for the precursor run and the main run. If the total domain of the main run is larger than that of the precursor 6375 run, the domain is filled by cyclic repetition of the (cyclic) 6376 precursor data. This initialization method is recommended if a 6377 turbulent inflow is used (see <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a>). 3d-data must be made available to the run by activating an appropriate file connection statement for local file BININ. See <a href="chapter_3.9.html">chapter 3.9</a> for more details, where usage of a turbulent inflow is explained. </p><p style="font-style: normal;">Values may be 6378 combined, e.g. <b>initializing_actions</b> = <span style="font-style: italic;">'set_constant_profiles 6379 initialize_vortex'</span>, but the values of <span style="font-style: italic;">'set_constant_profiles'</span>, 6380 <span style="font-style: italic;">'set_1d-model_profiles'</span> 6381 , and <span style="font-style: italic;">'by_user'</span> 6382 must not be given at the same time.</p> 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 </td> 6404 6405 6406 6407 6408 6409 6410 </tr> 6411 6412 6413 6414 6415 6416 6417 6418 <tr> 6419 6420 6421 6422 6423 6424 6425 <td style="vertical-align: top;"> 6426 6427 6428 6429 6430 6431 6432 <p><a name="km_constant"></a><b>km_constant</b></p> 6433 6434 6435 6436 6437 6438 6439 6440 </td> 6441 6442 6443 6444 6445 6446 6447 <td style="vertical-align: top;">R</td> 6448 6449 6450 6451 6452 6453 6454 6455 <td style="vertical-align: top;"><i>variable<br> 6456 6457 6458 6459 6460 6461 6462 6463 (computed from TKE)</i></td> 6464 6465 6466 6467 6468 6469 6470 <td style="vertical-align: top;"> 6471 6472 6473 6474 6475 6476 6477 <p>Constant eddy 6478 diffusivities are used (laminar 6479 simulations). </p> 6480 6481 6482 6483 6484 6485 6486 6487 6488 6489 6490 6491 6492 6493 <p>If this parameter is 6494 specified, both in the 1d and in the 6495 3d-model constant values for the eddy diffusivities are used in 6496 space and time with K<sub>m</sub> = <b>km_constant</b> 6497 and K<sub>h</sub> = K<sub>m</sub> / <a href="chapter_4.2.html#prandtl_number">prandtl_number</a>. 6498 The prognostic equation for the subgrid-scale TKE is switched off. 6499 Constant eddy diffusivities are only allowed with the Prandtl layer (<a href="#prandtl_layer">prandtl_layer</a>) 6500 switched off.</p> 6501 6502 6503 6504 6505 6506 6507 </td> 6508 6509 6510 6511 6512 6513 6514 </tr> 6515 6516 6517 6518 6519 6520 6521 <tr> 6522 6523 6524 6525 6526 6527 6528 <td style="vertical-align: top;"> 6529 6530 6531 6532 6533 6534 6535 <p><a name="km_damp_max"></a><b>km_damp_max</b></p> 6536 6537 6538 6539 6540 6541 6542 6543 </td> 6544 6545 6546 6547 6548 6549 6550 <td style="vertical-align: top;">R</td> 6551 6552 6553 6554 6555 6556 6557 6558 <td style="vertical-align: top;"><span style="font-style: italic;">0.5*(dx 6559 or dy)</span></td> 6560 6561 6562 6563 6564 6565 6566 <td style="vertical-align: top;">Maximum 6567 diffusivity used for filtering the velocity field in the vicinity of 6568 the outflow (in m<sup>2</sup>/s).<br> 6569 6570 6571 6572 6573 6574 6575 <br> 6576 6577 6578 6579 6580 6581 6582 6583 When using non-cyclic lateral boundaries (see <a href="#bc_lr">bc_lr</a> 6584 or <a href="#bc_ns">bc_ns</a>), 6585 a smoothing has to be applied to the 6586 velocity field in the vicinity of the outflow in order to suppress any 6587 reflections of outgoing disturbances. Smoothing is done by increasing 6588 the eddy diffusivity along the horizontal direction which is 6589 perpendicular to the outflow boundary. Only velocity components 6590 parallel to the outflow boundary are filtered (e.g. v and w, if the 6591 outflow is along x). Damping is applied from the bottom to the top of 6592 the domain.<br> 6593 6594 6595 6596 6597 6598 6599 <br> 6600 6601 6602 6603 6604 6605 6606 6607 The horizontal range of the smoothing is controlled by <a href="#outflow_damping_width">outflow_damping_width</a> 6608 which defines the number of gridpoints (counted from the outflow 6609 boundary) from where on the smoothing is applied. Starting from that 6610 point, the eddy diffusivity is linearly increased (from zero to its 6611 maximum value given by <span style="font-weight: bold;">km_damp_max</span>) 6612 until half of the damping range width, from where it remains constant 6613 up to the outflow boundary. If at a certain grid point the eddy 6614 diffusivity calculated from the flow field is larger than as described 6615 above, it is used instead.<br> 6616 6617 6618 6619 6620 6621 6622 <br> 6623 6624 6625 6626 6627 6628 6629 6630 The default value of <span style="font-weight: bold;">km_damp_max</span> 6631 has been empirically proven to be sufficient.</td> 6632 6633 6634 6635 6636 6637 6638 </tr> 6639 6640 6641 6642 6643 6644 6645 <tr> 6646 6647 <td style="vertical-align: top;"><a name="lad_surface"></a><span style="font-weight: bold;">lad_surface</span></td> 6648 6649 <td style="vertical-align: top;">R</td> 6650 6651 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 6652 6653 <td style="vertical-align: top;">Surface value of the leaf area density (in m<sup>2</sup>/m<sup>3</sup>).<br> 6654 6655 <br> 6656 6657 This 6658 parameter assigns the value of the leaf area density <span style="font-weight: bold;">lad</span> at the surface (k=0)<b>.</b> Starting from this value, 6659 the leaf area density profile is constructed with <a href="#lad_vertical_gradient">lad_vertical_gradient</a> 6660 and <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level 6661 </a>.</td> 6662 6663 </tr> 6664 6665 <tr> 6666 6667 <td style="vertical-align: top;"><a name="lad_vertical_gradient"></a><span style="font-weight: bold;">lad_vertical_gradient</span></td> 6668 6669 <td style="vertical-align: top;">R (10)</td> 6670 6671 <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td> 6672 6673 <td style="vertical-align: top;">Gradient(s) of the leaf area density (in m<sup>2</sup>/m<sup>4</sup>).<br> 6674 6675 <br> 6676 6677 6678 <p>This leaf area density gradient 6679 holds starting from the height 6680 level defined by <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a> 6681 (precisely: for all uv levels k where zu(k) > lad_vertical_gradient_level, lad(k) is set: lad(k) = lad(k-1) + dzu(k) * <b>lad_vertical_gradient</b>) 6682 up to the level defined by <a href="#pch_index">pch_index</a>. Above that level lad(k) will automatically set to 0.0. A total of 10 different gradients for 11 height intervals (10 intervals 6683 if <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>(1) 6684 = <i>0.0</i>) can be assigned. The leaf area density at the surface is 6685 assigned via <a href="#lad_surface">lad_surface</a>. 6686 </p> 6687 6688 </td> 6689 6690 </tr> 6691 6692 <tr> 6693 6694 <td style="vertical-align: top;"><a name="lad_vertical_gradient_level"></a><span style="font-weight: bold;">lad_vertical_gradient_level</span></td> 6695 6696 <td style="vertical-align: top;">R (10)</td> 6697 6698 <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td> 6699 6700 <td style="vertical-align: top;">Height level from which on the gradient 6701 of the leaf area density defined by <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a> 6702 is effective (in m).<br> 6703 6704 <br> 6705 6706 The height levels have to be assigned in ascending order. The 6707 default values result in a leaf area density that is constant with height uup to the top of the plant canopy layer defined by <a href="#pch_index">pch_index</a>. For the piecewise construction of temperature profiles see <a href="#lad_vertical_gradient">lad_vertical_gradient</a>.</td> 6708 6709 </tr> 6710 6711 <tr> 6712 6713 <td style="vertical-align: top;"><a name="leaf_surface_concentration"></a><b>leaf_surface_concentration</b></td> 6714 6715 <td style="vertical-align: top;">R</td> 6716 6717 <td style="vertical-align: top;"><i>0.0</i></td> 6718 6719 <td style="vertical-align: top;">Concentration of a passive scalar at the surface of a leaf (in K m/s).<br> 6720 6721 6722 <br> 6723 6724 6725 This parameter is only of importance in cases in that both, <a href="#plant_canopy">plant_canopy</a> and <a href="#passive_scalar">passive_scalar</a>, are set <span style="font-style: italic;">.T.</span>. 6726 The value of the concentration of a passive scalar at the surface of a 6727 leaf is required for the parametrisation of the sources and sinks of 6728 scalar concentration due to the canopy.</td> 6729 6730 </tr> 6731 6732 <tr> 6733 6734 6735 6736 6737 6738 6739 6740 <td style="vertical-align: top;"> 6741 6742 6743 6744 6745 6746 6747 <p><a name="long_filter_factor"></a><b>long_filter_factor</b></p> 6748 6749 6750 6751 6752 6753 6754 6755 </td> 6756 6757 6758 6759 6760 6761 6762 <td style="vertical-align: top;">R</td> 6763 6764 6765 6766 6767 6768 6769 6770 <td style="vertical-align: top;"><i>0.0</i></td> 6771 6772 6773 6774 6775 6776 6777 6778 <td style="vertical-align: top;"> 6779 6780 6781 6782 6783 6784 6785 <p>Filter factor 6786 for the so-called Long-filter.<br> 6787 6788 6789 6790 6791 6792 6793 </p> 6794 6795 6796 6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 <p><br> 6808 6809 6810 6811 6812 6813 6814 6815 This filter very efficiently 6816 eliminates 2-delta-waves sometimes cauesed by the upstream-spline 6817 scheme (see Mahrer and 6818 Pielke, 1978: Mon. Wea. Rev., 106, 818-830). It works in all three 6819 directions in space. A value of <b>long_filter_factor</b> 6820 = <i>0.01</i> 6821 sufficiently removes the small-scale waves without affecting the 6822 longer waves.<br> 6823 6824 6825 6826 6827 6828 6829 </p> 6830 6831 6832 6833 6834 6835 6836 6837 6838 6839 6840 6841 6842 6843 <p>By default, the filter is 6844 switched off (= <i>0.0</i>). 6845 It is exclusively applied to the tendencies calculated by the 6846 upstream-spline scheme (see <a href="#momentum_advec">momentum_advec</a> 6847 and <a href="#scalar_advec">scalar_advec</a>), 6848 not to the prognostic variables themselves. At the bottom and top 6849 boundary of the model domain the filter effect for vertical 6850 2-delta-waves is reduced. There, the amplitude of these waves is only 6851 reduced by approx. 50%, otherwise by nearly 100%. <br> 6852 6853 6854 6855 6856 6857 6858 6859 Filter factors with values > <i>0.01</i> also 6860 reduce the amplitudes 6861 of waves with wavelengths longer than 2-delta (see the paper by Mahrer 6862 and 6863 Pielke, quoted above). </p> 6864 6865 6866 6867 6868 6869 6870 </td> 6871 6872 6873 6874 6875 6876 6877 </tr> 6878 6879 6880 6881 6882 6883 6884 <tr> 6885 6886 6887 6888 6889 6890 6891 <td style="vertical-align: top;"><a name="loop_optimization"></a><span style="font-weight: bold;">loop_optimization</span></td> 6892 6893 6894 6895 6896 6897 6898 <td style="vertical-align: top;">C*16</td> 6899 6900 6901 6902 6903 6904 6905 <td style="vertical-align: top;"><span style="font-style: italic;">see right</span></td> 6906 6907 6908 6909 6910 6911 6912 <td>Method used to optimize loops for solving the prognostic equations .<br> 6913 6914 6915 6916 6917 6918 6919 <br> 6920 6921 6922 6923 6924 6925 6926 By 6927 default, the optimization method depends on the host on which PALM is 6928 running. On machines with vector-type CPUs, single 3d-loops are used to 6929 calculate each tendency term of each prognostic equation, while on all 6930 other machines, all prognostic equations are solved within one big loop 6931 over the two horizontal indices<span style="font-family: Courier New,Courier,monospace;"> i </span>and<span style="font-family: Courier New,Courier,monospace;"> j </span>(giving a good cache uitilization).<br> 6932 6933 6934 6935 6936 6937 6938 <br> 6939 6940 6941 6942 6943 6944 6945 The default behaviour can be changed by setting either <span style="font-weight: bold;">loop_optimization</span> = <span style="font-style: italic;">'vector'</span> or <span style="font-weight: bold;">loop_optimization</span> = <span style="font-style: italic;">'cache'</span>.</td> 6946 6947 6948 6949 6950 6951 6952 </tr> 6953 6954 6955 6956 6957 6958 6959 <tr> 6960 6961 6962 6963 6964 6965 6966 6967 <td style="vertical-align: top;"><a name="mixing_length_1d"></a><span style="font-weight: bold;">mixing_length_1d</span><br> 6968 6969 6970 6971 6972 6973 6974 6975 </td> 6976 6977 6978 6979 6980 6981 6982 <td style="vertical-align: top;">C*20<br> 6983 6984 6985 6986 6987 6988 6989 6990 </td> 6991 6992 6993 6994 6995 6996 6997 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;"> 6998 6999 7000 7001 7002 7003 7004 <span style="font-style: italic;">model'</span><br> 7005 7006 7007 7008 7009 7010 7011 </td> 7012 7013 7014 7015 7016 7017 7018 7019 <td style="vertical-align: top;">Mixing length used in the 7020 1d-model.<br> 7021 7022 7023 7024 7025 7026 7027 <br> 7028 7029 7030 7031 7032 7033 7034 7035 By default the mixing length is calculated as in the 3d-model (i.e. it 7036 depends on the grid spacing).<br> 7037 7038 7039 7040 7041 7042 7043 <br> 7044 7045 7046 7047 7048 7049 7050 7051 By setting <span style="font-weight: bold;">mixing_length_1d</span> 7052 = <span style="font-style: italic;">'blackadar'</span>, 7053 the so-called Blackadar mixing length is used (l = kappa * z / ( 1 + 7054 kappa * z / lambda ) with the limiting value lambda = 2.7E-4 * u_g / f).<br> 7055 7056 7057 7058 7059 7060 7061 7062 </td> 7063 7064 7065 7066 7067 7068 7069 </tr> 7070 7071 7072 7073 7074 7075 7076 7077 7078 7079 7080 7081 7082 7083 7084 <tr> 7085 7086 7087 7088 7089 7090 7091 <td style="vertical-align: top;"> 7092 7093 7094 7095 7096 7097 7098 <p><a name="momentum_advec"></a><b>momentum_advec</b></p> 7099 7100 7101 7102 7103 7104 7105 7106 </td> 7107 7108 7109 7110 7111 7112 7113 <td style="vertical-align: top;">C * 10</td> 7114 7115 7116 7117 7118 7119 7120 7121 <td style="vertical-align: top;"><i>'pw-scheme'</i></td> 7122 7123 7124 7125 7126 7127 7128 7129 <td style="vertical-align: top;"> 7130 7131 7132 7133 7134 7135 7136 <p>Advection 7137 scheme to be used for the momentum equations.<br> 7138 7139 7140 7141 7142 7143 7144 <br> 7145 7146 7147 7148 7149 7150 7151 7152 The user can choose between the following schemes:<br> 7153 7154 7155 7156 7157 7158 7159 7160 <br> 7161 7162 7163 7164 7165 7166 7167 <br> 7168 7169 7170 7171 7172 7173 7174 <span style="font-style: italic;">'pw-scheme'</span><br> 7175 7176 7177 7178 7179 7180 7181 7182 </p> 7183 7184 7185 7186 7187 7188 7189 7190 7191 7192 7193 7194 7195 7196 <div style="margin-left: 40px;">The scheme of 7197 Piascek and 7198 Williams (1970, J. Comp. Phys., 6, 7199 392-405) with central differences in the form C3 is used.<br> 7200 7201 7202 7203 7204 7205 7206 7207 If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a> 7208 = <span style="font-style: italic;">'leapfrog+euler'</span> 7209 the 7210 advection scheme is - for the Euler-timestep - automatically switched 7211 to an upstream-scheme.<br> 7212 7213 7214 7215 7216 7217 7218 </div> 7219 7220 7221 7222 7223 7224 7225 7226 7227 7228 7229 7230 7231 7232 <p> </p> 7233 7234 7235 7236 7237 7238 7239 7240 7241 7242 7243 7244 7245 7246 <p><span style="font-style: italic;">'ups-scheme'</span><br> 7247 7248 7249 7250 7251 7252 7253 7254 </p> 7255 7256 7257 7258 7259 7260 7261 7262 7263 7264 7265 7266 7267 7268 <div style="margin-left: 40px;">The 7269 upstream-spline scheme is 7270 used 7271 (see Mahrer and Pielke, 7272 1978: Mon. Wea. Rev., 106, 818-830). In opposite to the 7273 Piascek-Williams scheme, this is characterized by much better numerical 7274 features (less numerical diffusion, better preservation of flow 7275 structures, e.g. vortices), but computationally it is much more 7276 expensive. In 7277 addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a> 7278 = <span style="font-style: italic;">'</span><i>euler'</i>), 7279 i.e. the 7280 timestep accuracy is only of first order. 7281 For this reason the advection of scalar variables (see <a href="#scalar_advec">scalar_advec</a>) 7282 should then also be carried out with the upstream-spline scheme, 7283 because otherwise the scalar variables would 7284 be subject to large numerical diffusion due to the upstream 7285 scheme. </div> 7286 7287 7288 7289 7290 7291 7292 7293 7294 7295 7296 7297 7298 7299 <p style="margin-left: 40px;">Since 7300 the cubic splines used tend 7301 to overshoot under 7302 certain circumstances, this effect must be adjusted by suitable 7303 filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>, 7304 <a href="#long_filter_factor">long_filter_factor</a>, 7305 <a href="#ups_limit_pt">ups_limit_pt</a>, <a href="#ups_limit_u">ups_limit_u</a>, <a href="#ups_limit_v">ups_limit_v</a>, <a href="#ups_limit_w">ups_limit_w</a>). 7306 This is always neccessary for runs with stable stratification, 7307 even if this stratification appears only in parts of the model domain.<br> 7308 7309 7310 7311 7312 7313 7314 7315 </p> 7316 7317 7318 7319 7320 7321 7322 7323 7324 7325 7326 7327 7328 7329 <div style="margin-left: 40px;">With stable 7330 stratification the 7331 upstream-spline scheme also 7332 produces gravity waves with large amplitude, which must be 7333 suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br> 7334 7335 7336 7337 7338 7339 7340 7341 <br> 7342 7343 7344 7345 7346 7347 7348 <span style="font-weight: bold;">Important: </span>The 7349 upstream-spline scheme is not implemented for humidity and passive 7350 scalars (see <a href="#humidity">humidity</a> 7351 and <a href="#passive_scalar">passive_scalar</a>) 7352 and requires the use of a 2d-domain-decomposition. The last conditions 7353 severely restricts code optimization on several machines leading to 7354 very long execution times! The scheme is also not allowed for 7355 non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a> 7356 and <a href="#bc_ns">bc_ns</a>).</div> 7357 7358 7359 7360 7361 7362 7363 </td> 7364 7365 7366 7367 7368 7369 7370 7371 </tr> 7372 7373 7374 7375 7376 7377 7378 <tr> 7379 7380 7381 7382 7383 7384 7385 <td style="vertical-align: top;"><a name="netcdf_precision"></a><span style="font-weight: bold;">netcdf_precision</span><br> 7386 7387 7388 7389 7390 7391 7392 7393 </td> 7394 7395 7396 7397 7398 7399 7400 <td style="vertical-align: top;">C*20<br> 7401 7402 7403 7404 7405 7406 7407 7408 (10)<br> 7409 7410 7411 7412 7413 7414 7415 </td> 7416 7417 7418 7419 7420 7421 7422 <td style="vertical-align: top;"><span style="font-style: italic;">single preci-</span><br style="font-style: italic;"> 7423 7424 7425 7426 7427 7428 7429 <span style="font-style: italic;">sion for all</span><br style="font-style: italic;"> 7430 7431 7432 7433 7434 7435 7436 <span style="font-style: italic;">output quan-</span><br style="font-style: italic;"> 7437 7438 7439 7440 7441 7442 7443 <span style="font-style: italic;">tities</span><br> 7444 7445 7446 7447 7448 7449 7450 </td> 7451 7452 7453 7454 7455 7456 7457 7458 <td style="vertical-align: top;">Defines the accuracy of 7459 the NetCDF output.<br> 7460 7461 7462 7463 7464 7465 7466 <br> 7467 7468 7469 7470 7471 7472 7473 7474 By default, all NetCDF output data (see <a href="chapter_4.2.html#data_output_format">data_output_format</a>) 7475 have single precision (4 byte) accuracy. Double precision (8 7476 byte) can be choosen alternatively.<br> 7477 7478 7479 7480 7481 7482 7483 7484 Accuracy for the different output data (cross sections, 3d-volume data, 7485 spectra, etc.) can be set independently.<br> 7486 7487 7488 7489 7490 7491 7492 <span style="font-style: italic;">'<out>_NF90_REAL4'</span> 7493 (single precision) or <span style="font-style: italic;">'<out>_NF90_REAL8'</span> 7494 (double precision) are the two principally allowed values for <span style="font-weight: bold;">netcdf_precision</span>, 7495 where the string <span style="font-style: italic;">'<out>' 7496 </span>can be chosen out of the following list:<br> 7497 7498 7499 7500 7501 7502 7503 <br> 7504 7505 7506 7507 7508 7509 7510 7511 7512 7513 7514 7515 7516 7517 <table style="text-align: left; width: 284px; height: 234px;" border="1" cellpadding="2" cellspacing="2"> 7518 7519 7520 7521 7522 7523 7524 <tbody> 7525 7526 7527 7528 7529 7530 7531 7532 <tr> 7533 7534 7535 7536 7537 7538 7539 <td style="vertical-align: top;"><span style="font-style: italic;">'xy'</span><br> 7540 7541 7542 7543 7544 7545 7546 </td> 7547 7548 7549 7550 7551 7552 7553 7554 <td style="vertical-align: top;">horizontal cross section<br> 7555 7556 7557 7558 7559 7560 7561 7562 </td> 7563 7564 7565 7566 7567 7568 7569 </tr> 7570 7571 7572 7573 7574 7575 7576 <tr> 7577 7578 7579 7580 7581 7582 7583 <td style="vertical-align: top;"><span style="font-style: italic;">'xz'</span><br> 7584 7585 7586 7587 7588 7589 7590 </td> 7591 7592 7593 7594 7595 7596 7597 7598 <td style="vertical-align: top;">vertical (xz) cross 7599 section<br> 7600 7601 7602 7603 7604 7605 7606 </td> 7607 7608 7609 7610 7611 7612 7613 </tr> 7614 7615 7616 7617 7618 7619 7620 <tr> 7621 7622 7623 7624 7625 7626 7627 <td style="vertical-align: top;"><span style="font-style: italic;">'yz'</span><br> 7628 7629 7630 7631 7632 7633 7634 </td> 7635 7636 7637 7638 7639 7640 7641 7642 <td style="vertical-align: top;">vertical (yz) cross 7643 section<br> 7644 7645 7646 7647 7648 7649 7650 </td> 7651 7652 7653 7654 7655 7656 7657 </tr> 7658 7659 7660 7661 7662 7663 7664 <tr> 7665 7666 7667 7668 7669 7670 7671 <td style="vertical-align: top;"><span style="font-style: italic;">'2d'</span><br> 7672 7673 7674 7675 7676 7677 7678 </td> 7679 7680 7681 7682 7683 7684 7685 7686 <td style="vertical-align: top;">all cross sections<br> 7687 7688 7689 7690 7691 7692 7693 7694 </td> 7695 7696 7697 7698 7699 7700 7701 </tr> 7702 7703 7704 7705 7706 7707 7708 <tr> 7709 7710 7711 7712 7713 7714 7715 <td style="vertical-align: top;"><span style="font-style: italic;">'3d'</span><br> 7716 7717 7718 7719 7720 7721 7722 </td> 7723 7724 7725 7726 7727 7728 7729 7730 <td style="vertical-align: top;">volume data<br> 7731 7732 7733 7734 7735 7736 7737 </td> 7738 7739 7740 7741 7742 7743 7744 7745 </tr> 7746 7747 7748 7749 7750 7751 7752 <tr> 7753 7754 7755 7756 7757 7758 7759 <td style="vertical-align: top;"><span style="font-style: italic;">'pr'</span><br> 7760 7761 7762 7763 7764 7765 7766 </td> 7767 7768 7769 7770 7771 7772 7773 7774 <td style="vertical-align: top;">vertical profiles<br> 7775 7776 7777 7778 7779 7780 7781 7782 </td> 7783 7784 7785 7786 7787 7788 7789 </tr> 7790 7791 7792 7793 7794 7795 7796 <tr> 7797 7798 7799 7800 7801 7802 7803 <td style="vertical-align: top;"><span style="font-style: italic;">'ts'</span><br> 7804 7805 7806 7807 7808 7809 7810 </td> 7811 7812 7813 7814 7815 7816 7817 7818 <td style="vertical-align: top;">time series, particle 7819 time series<br> 7820 7821 7822 7823 7824 7825 7826 </td> 7827 7828 7829 7830 7831 7832 7833 </tr> 7834 7835 7836 7837 7838 7839 7840 <tr> 7841 7842 7843 7844 7845 7846 7847 <td style="vertical-align: top;"><span style="font-style: italic;">'sp'</span><br> 7848 7849 7850 7851 7852 7853 7854 </td> 7855 7856 7857 7858 7859 7860 7861 7862 <td style="vertical-align: top;">spectra<br> 7863 7864 7865 7866 7867 7868 7869 </td> 7870 7871 7872 7873 7874 7875 7876 7877 </tr> 7878 7879 7880 7881 7882 7883 7884 <tr> 7885 7886 7887 7888 7889 7890 7891 <td style="vertical-align: top;"><span style="font-style: italic;">'prt'</span><br> 7892 7893 7894 7895 7896 7897 7898 </td> 7899 7900 7901 7902 7903 7904 7905 7906 <td style="vertical-align: top;">particles<br> 7907 7908 7909 7910 7911 7912 7913 </td> 7914 7915 7916 7917 7918 7919 7920 7921 </tr> 7922 7923 7924 7925 7926 7927 7928 <tr> 7929 7930 7931 7932 7933 7934 7935 <td style="vertical-align: top;"><span style="font-style: italic;">'all'</span><br> 7936 7937 7938 7939 7940 7941 7942 </td> 7943 7944 7945 7946 7947 7948 7949 7950 <td style="vertical-align: top;">all output quantities<br> 7951 7952 7953 7954 7955 7956 7957 7958 </td> 7959 7960 7961 7962 7963 7964 7965 </tr> 7966 7967 7968 7969 7970 7971 7972 7973 7974 7975 7976 7977 7978 7979 </tbody> 7980 7981 7982 7983 7984 7985 7986 </table> 7987 7988 7989 7990 7991 7992 7993 <br> 7994 7995 7996 7997 7998 7999 8000 <span style="font-weight: bold;">Example:</span><br> 8001 8002 8003 8004 8005 8006 8007 8008 If all cross section data and the particle data shall be output in 8009 double precision and all other quantities in single precision, then <span style="font-weight: bold;">netcdf_precision</span> = <span style="font-style: italic;">'2d_NF90_REAL8'</span>, <span style="font-style: italic;">'prt_NF90_REAL8'</span> 8010 has to be assigned.<br> 8011 8012 8013 8014 8015 8016 8017 </td> 8018 8019 8020 8021 8022 8023 8024 </tr> 8025 8026 8027 8028 8029 8030 8031 8032 8033 8034 8035 8036 8037 8038 8039 8040 8041 8042 8043 8044 8045 8046 8047 <tr> 8048 8049 8050 8051 8052 8053 8054 <td style="vertical-align: top;"> 8055 8056 8057 8058 8059 8060 8061 <p><a name="nsor_ini"></a><b>nsor_ini</b></p> 8062 8063 8064 8065 8066 8067 8068 8069 </td> 8070 8071 8072 8073 8074 8075 8076 <td style="vertical-align: top;">I</td> 8077 8078 8079 8080 8081 8082 8083 8084 <td style="vertical-align: top;"><i>100</i></td> 8085 8086 8087 8088 8089 8090 8091 8092 <td style="vertical-align: top;"> 8093 8094 8095 8096 8097 8098 8099 <p>Initial number 8100 of iterations with the SOR algorithm. </p> 8101 8102 8103 8104 8105 8106 8107 8108 8109 8110 8111 8112 8113 8114 <p>This 8115 parameter is only effective if the SOR algorithm was 8116 selected as the pressure solver scheme (<a href="chapter_4.2.html#psolver">psolver</a> 8117 = <span style="font-style: italic;">'sor'</span>) 8118 and specifies the 8119 number of initial iterations of the SOR 8120 scheme (at t = 0). The number of subsequent iterations at the following 8121 timesteps is determined 8122 with the parameter <a href="#nsor">nsor</a>. 8123 Usually <b>nsor</b> < <b>nsor_ini</b>, 8124 since in each case 8125 subsequent calls to <a href="chapter_4.2.html#psolver">psolver</a> 8126 use the solution of the previous call as initial value. Suitable 8127 test runs should determine whether sufficient convergence of the 8128 solution is obtained with the default value and if necessary the value 8129 of <b>nsor_ini</b> should be changed.</p> 8130 8131 8132 8133 8134 8135 8136 </td> 8137 8138 8139 8140 8141 8142 8143 8144 </tr> 8145 8146 8147 8148 8149 8150 8151 <tr> 8152 8153 8154 8155 8156 8157 8158 <td style="vertical-align: top;"> 8159 8160 8161 8162 8163 8164 8165 <p><a name="nx"></a><b>nx</b></p> 8166 8167 8168 8169 8170 8171 8172 8173 </td> 8174 8175 8176 8177 8178 8179 8180 <td style="vertical-align: top;">I</td> 8181 8182 8183 8184 8185 8186 8187 8188 <td style="vertical-align: top;"><br> 8189 8190 8191 8192 8193 8194 8195 </td> 8196 8197 8198 8199 8200 8201 8202 <td style="vertical-align: top;"> 8203 8204 8205 8206 8207 8208 8209 <p>Number of grid 8210 points in x-direction. </p> 8211 8212 8213 8214 8215 8216 8217 8218 8219 8220 8221 8222 8223 8224 <p>A value for this 8225 parameter must be assigned. Since the lower 8226 array bound in PALM 8227 starts with i = 0, the actual number of grid points is equal to <b>nx+1</b>. 8228 In case of cyclic boundary conditions along x, the domain size is (<b>nx+1</b>)* 8229 <a href="#dx">dx</a>.</p> 8230 8231 8232 8233 8234 8235 8236 8237 8238 8239 8240 8241 8242 8243 <p>For 8244 parallel runs, in case of <a href="#grid_matching">grid_matching</a> 8245 = <span style="font-style: italic;">'strict'</span>, 8246 <b>nx+1</b> must 8247 be an integral multiple 8248 of the processor numbers (see <a href="#npex">npex</a> 8249 and <a href="#npey">npey</a>) 8250 along x- as well as along y-direction (due to data 8251 transposition restrictions).</p> 8252 8253 8254 8255 8256 8257 8258 8259 8260 8261 8262 8263 8264 <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a> 8265 and <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p> 8266 8267 8268 8269 8270 8271 8272 </td> 8273 8274 8275 8276 8277 8278 8279 </tr> 8280 8281 8282 8283 8284 8285 8286 <tr> 8287 8288 8289 8290 8291 8292 8293 8294 <td style="vertical-align: top;"> 8295 8296 8297 8298 8299 8300 8301 <p><a name="ny"></a><b>ny</b></p> 8302 8303 8304 8305 8306 8307 8308 8309 </td> 8310 8311 8312 8313 8314 8315 8316 <td style="vertical-align: top;">I</td> 8317 8318 8319 8320 8321 8322 8323 8324 <td style="vertical-align: top;"><br> 8325 8326 8327 8328 8329 8330 8331 </td> 8332 8333 8334 8335 8336 8337 8338 <td style="vertical-align: top;"> 8339 8340 8341 8342 8343 8344 8345 <p>Number of grid 8346 points in y-direction. </p> 8347 8348 8349 8350 8351 8352 8353 8354 8355 8356 8357 8358 8359 8360 <p>A value for this 8361 parameter must be assigned. Since the lower 8362 array bound in PALM starts with j = 0, the actual number of grid points 8363 is equal to <b>ny+1</b>. In case of cyclic boundary 8364 conditions along 8365 y, the domain size is (<b>ny+1</b>) * <a href="#dy">dy</a>.</p> 8366 8367 8368 8369 8370 8371 8372 8373 8374 8375 8376 8377 8378 8379 <p>For parallel runs, in case of <a href="#grid_matching">grid_matching</a> 8380 = <span style="font-style: italic;">'strict'</span>, 8381 <b>ny+1</b> must 8382 be an integral multiple 8383 of the processor numbers (see <a href="#npex">npex</a> 8384 and <a href="#npey">npey</a>) 8385 along y- as well as along x-direction (due to data 8386 transposition restrictions).</p> 8387 8388 8389 8390 8391 8392 8393 8394 8395 8396 8397 8398 8399 <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a> 8400 and <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p> 8401 8402 8403 8404 8405 8406 8407 </td> 8408 8409 8410 8411 8412 8413 8414 </tr> 8415 8416 8417 8418 8419 8420 8421 <tr> 8422 8423 8424 8425 8426 8427 8428 8429 <td style="vertical-align: top;"> 8430 8431 8432 8433 8434 8435 8436 <p><a name="nz"></a><b>nz</b></p> 8437 8438 8439 8440 8441 8442 8443 8444 </td> 8445 8446 8447 8448 8449 8450 8451 <td style="vertical-align: top;">I</td> 8452 8453 8454 8455 8456 8457 8458 8459 <td style="vertical-align: top;"><br> 8460 8461 8462 8463 8464 8465 8466 </td> 8467 8468 8469 8470 8471 8472 8473 <td style="vertical-align: top;"> 8474 8475 8476 8477 8478 8479 8480 <p>Number of grid 8481 points in z-direction. </p> 8482 8483 8484 8485 8486 8487 8488 8489 8490 8491 8492 8493 8494 8495 <p>A value for this 8496 parameter must be assigned. Since the lower 8497 array bound in PALM 8498 starts with k = 0 and since one additional grid point is added at the 8499 top boundary (k = <b>nz+1</b>), the actual number of grid 8500 points is <b>nz+2</b>. 8501 However, the prognostic equations are only solved up to <b>nz</b> 8502 (u, 8503 v) 8504 or up to <b>nz-1</b> (w, scalar quantities). The top 8505 boundary for u 8506 and v is at k = <b>nz+1</b> (u, v) while at k = <b>nz</b> 8507 for all 8508 other quantities. </p> 8509 8510 8511 8512 8513 8514 8515 8516 8517 8518 8519 8520 8521 8522 <p>For parallel 8523 runs, in case of <a href="#grid_matching">grid_matching</a> 8524 = <span style="font-style: italic;">'strict'</span>, 8525 <b>nz</b> must 8526 be an integral multiple of 8527 the number of processors in x-direction (due to data transposition 8528 restrictions).</p> 8529 8530 8531 8532 8533 8534 8535 </td> 8536 8537 8538 8539 8540 8541 8542 </tr> 8543 8544 8545 8546 8547 8548 8549 <tr> 8550 8551 8552 8553 8554 8555 8556 <td style="vertical-align: top;"><a name="ocean"></a><span style="font-weight: bold;">ocean</span></td> 8557 8558 8559 8560 8561 8562 8563 <td style="vertical-align: top;">L</td> 8564 8565 8566 8567 8568 8569 8570 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 8571 8572 8573 8574 8575 8576 8577 <td style="vertical-align: top;">Parameter to switch on ocean runs.<br> 8578 8579 8580 8581 8582 8583 8584 <br> 8585 8586 8587 8588 8589 8590 8591 By default PALM is configured to simulate atmospheric flows. However, starting from version 3.3, <span style="font-weight: bold;">ocean</span> = <span style="font-style: italic;">.T.</span> allows simulation of ocean turbulent flows. Setting this switch has several effects:<br> 8592 8593 8594 8595 8596 8597 8598 <br> 8599 8600 8601 8602 8603 8604 8605 8606 8607 8608 8609 8610 8611 <ul> 8612 8613 8614 8615 8616 8617 8618 <li>An additional prognostic equation for salinity is solved.</li> 8619 8620 8621 8622 8623 8624 8625 <li>Potential temperature in buoyancy and stability-related terms is replaced by potential density.</li> 8626 8627 8628 8629 8630 8631 8632 <li>Potential 8633 density is calculated from the equation of state for seawater after 8634 each timestep, using the algorithm proposed by Jackett et al. (2006, J. 8635 Atmos. Oceanic Technol., <span style="font-weight: bold;">23</span>, 1709-1728).<br> 8636 8637 8638 8639 8640 8641 8642 So far, only the initial hydrostatic pressure is entered into this equation.</li> 8643 8644 8645 8646 8647 8648 8649 <li>z=0 (sea surface) is assumed at the model top (vertical grid index <span style="font-family: Courier New,Courier,monospace;">k=nzt</span> on the w-grid), with negative values of z indicating the depth.</li> 8650 8651 8652 8653 8654 8655 8656 <li>Initial profiles are constructed (e.g. from <a href="#pt_vertical_gradient">pt_vertical_gradient</a> / <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>) starting from the sea surface, using surface values given by <a href="#pt_surface">pt_surface</a>, <a href="#sa_surface">sa_surface</a>, <a href="#ug_surface">ug_surface</a>, and <a href="#vg_surface">vg_surface</a>.</li> 8657 8658 8659 8660 8661 8662 8663 <li>Zero salinity flux is used as default boundary condition at the bottom of the sea.</li> 8664 8665 8666 8667 8668 8669 8670 <li>If switched on, random perturbations are by default imposed to the upper model domain from zu(nzt*2/3) to zu(nzt-3).</li> 8671 8672 8673 8674 8675 8676 8677 8678 8679 8680 8681 8682 8683 </ul> 8684 8685 8686 8687 8688 8689 8690 <br> 8691 8692 8693 8694 8695 8696 8697 Relevant parameters to be exclusively used for steering ocean runs are <a href="#bc_sa_t">bc_sa_t</a>, <a href="#bottom_salinityflux">bottom_salinityflux</a>, <a href="#sa_surface">sa_surface</a>, <a href="#sa_vertical_gradient">sa_vertical_gradient</a>, <a href="#sa_vertical_gradient_level">sa_vertical_gradient_level</a>, and <a href="#top_salinityflux">top_salinityflux</a>.<br> 8698 8699 8700 8701 8702 8703 8704 <br> 8705 8706 8707 8708 8709 8710 8711 Section <a href="chapter_4.2.2.html">4.4.2</a> gives an example for appropriate settings of these and other parameters neccessary for ocean runs.<br> 8712 8713 8714 8715 8716 8717 8718 <br> 8719 8720 8721 8722 8723 8724 8725 <span style="font-weight: bold;">ocean</span> = <span style="font-style: italic;">.T.</span> does not allow settings of <a href="#timestep_scheme">timestep_scheme</a> = <span style="font-style: italic;">'leapfrog'</span> or <span style="font-style: italic;">'leapfrog+euler'</span> as well as <a href="#scalar_advec">scalar_advec</a> = <span style="font-style: italic;">'ups-scheme'</span>.<span style="font-weight: bold;"></span><br> 8726 8727 8728 8729 </td> 8730 8731 8732 8733 8734 8735 8736 </tr> 8737 8738 8739 8740 8741 8742 8743 <tr> 8744 8745 8746 8747 8748 8749 8750 <td style="vertical-align: top;"> 8751 8752 8753 8754 8755 8756 8757 <p><a name="omega"></a><b>omega</b></p> 8758 8759 8760 8761 8762 8763 8764 8765 </td> 8766 8767 8768 8769 8770 8771 8772 <td style="vertical-align: top;">R</td> 8773 8774 8775 8776 8777 8778 8779 8780 <td style="vertical-align: top;"><i>7.29212E-5</i></td> 8781 8782 8783 8784 8785 8786 8787 8788 <td style="vertical-align: top;"> 8789 8790 8791 8792 8793 8794 8795 <p>Angular 8796 velocity of the rotating system (in rad s<sup>-1</sup>). 8797 </p> 8798 8799 8800 8801 8802 8803 8804 8805 8806 8807 8808 8809 8810 8811 <p>The angular velocity of the earth is set by 8812 default. The 8813 values 8814 of the Coriolis parameters are calculated as: </p> 8815 8816 8817 8818 8819 8820 8821 8822 8823 8824 8825 8826 8827 8828 <ul> 8829 8830 8831 8832 8833 8834 8835 8836 8837 8838 8839 8840 8841 8842 <p>f = 2.0 * <b>omega</b> * sin(<a href="#phi">phi</a>) 8843 <br> 8844 8845 8846 8847 8848 8849 8850 f* = 2.0 * <b>omega</b> * cos(<a href="#phi">phi</a>)</p> 8851 8852 8853 8854 8855 8856 8857 8858 8859 8860 8861 8862 8863 8864 </ul> 8865 8866 8867 8868 8869 8870 8871 </td> 8872 8873 8874 8875 8876 8877 8878 </tr> 8879 8880 8881 8882 8883 8884 8885 <tr> 8886 8887 8888 8889 8890 8891 8892 <td style="vertical-align: top;"> 8893 8894 8895 8896 8897 8898 8899 <p><a name="outflow_damping_width"></a><b>outflow_damping_width</b></p> 8900 8901 8902 8903 8904 8905 8906 8907 </td> 8908 8909 8910 8911 8912 8913 8914 <td style="vertical-align: top;">I</td> 8915 8916 8917 8918 8919 8920 8921 8922 <td style="vertical-align: top;"><span style="font-style: italic;">MIN(20, 8923 nx/2</span> or <span style="font-style: italic;">ny/2)</span></td> 8924 8925 8926 8927 8928 8929 8930 8931 <td style="vertical-align: top;">Width of 8932 the damping range in the vicinity of the outflow (gridpoints).<br> 8933 8934 8935 8936 8937 8938 8939 8940 <br> 8941 8942 8943 8944 8945 8946 8947 8948 When using non-cyclic lateral boundaries (see <a href="chapter_4.1.html#bc_lr">bc_lr</a> 8949 or <a href="chapter_4.1.html#bc_ns">bc_ns</a>), 8950 a smoothing has to be applied to the 8951 velocity field in the vicinity of the outflow in order to suppress any 8952 reflections of outgoing disturbances. This parameter controlls the 8953 horizontal range to which the smoothing is applied. The range is given 8954 in gridpoints counted from the respective outflow boundary. For further 8955 details about the smoothing see parameter <a href="chapter_4.1.html#km_damp_max">km_damp_max</a>, 8956 which defines the magnitude of the damping.</td> 8957 8958 8959 8960 8961 8962 8963 </tr> 8964 8965 8966 8967 8968 8969 8970 8971 <tr> 8972 8973 8974 8975 8976 8977 8978 <td style="vertical-align: top;"> 8979 8980 8981 8982 8983 8984 8985 <p><a name="overshoot_limit_e"></a><b>overshoot_limit_e</b></p> 8986 8987 8988 8989 8990 8991 8992 8993 </td> 8994 8995 8996 8997 8998 8999 9000 <td style="vertical-align: top;">R</td> 9001 9002 9003 9004 9005 9006 9007 9008 <td style="vertical-align: top;"><i>0.0</i></td> 9009 9010 9011 9012 9013 9014 9015 9016 <td style="vertical-align: top;"> 9017 9018 9019 9020 9021 9022 9023 <p>Allowed limit 9024 for the overshooting of subgrid-scale TKE in 9025 case that the upstream-spline scheme is switched on (in m<sup>2</sup>/s<sup>2</sup>). 9026 </p> 9027 9028 9029 9030 9031 9032 9033 9034 9035 9036 9037 9038 9039 9040 <p>By deafult, if cut-off of overshoots is switched 9041 on for the 9042 upstream-spline scheme (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>), 9043 no overshoots are permitted at all. If <b>overshoot_limit_e</b> 9044 is given a non-zero value, overshoots with the respective 9045 amplitude (both upward and downward) are allowed. </p> 9046 9047 9048 9049 9050 9051 9052 9053 9054 9055 9056 9057 9058 9059 <p>Only positive values are allowed for <b>overshoot_limit_e</b>.</p> 9060 9061 9062 9063 9064 9065 9066 9067 </td> 9068 9069 9070 9071 9072 9073 9074 </tr> 9075 9076 9077 9078 9079 9080 9081 <tr> 9082 9083 9084 9085 9086 9087 9088 <td style="vertical-align: top;"> 9089 9090 9091 9092 9093 9094 9095 <p><a name="overshoot_limit_pt"></a><b>overshoot_limit_pt</b></p> 9096 9097 9098 9099 9100 9101 9102 9103 </td> 9104 9105 9106 9107 9108 9109 9110 <td style="vertical-align: top;">R</td> 9111 9112 9113 9114 9115 9116 9117 9118 <td style="vertical-align: top;"><i>0.0</i></td> 9119 9120 9121 9122 9123 9124 9125 9126 <td style="vertical-align: top;"> 9127 9128 9129 9130 9131 9132 9133 <p>Allowed limit 9134 for the overshooting of potential temperature in 9135 case that the upstream-spline scheme is switched on (in K). </p> 9136 9137 9138 9139 9140 9141 9142 9143 9144 9145 9146 9147 9148 9149 <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>. 9150 </p> 9151 9152 9153 9154 9155 9156 9157 9158 9159 9160 9161 9162 9163 9164 <p>Only positive values are allowed for <b>overshoot_limit_pt</b>.</p> 9165 9166 9167 9168 9169 9170 9171 9172 </td> 9173 9174 9175 9176 9177 9178 9179 </tr> 9180 9181 9182 9183 9184 9185 9186 <tr> 9187 9188 9189 9190 9191 9192 9193 <td style="vertical-align: top;"> 9194 9195 9196 9197 9198 9199 9200 <p><a name="overshoot_limit_u"></a><b>overshoot_limit_u</b></p> 9201 9202 9203 9204 9205 9206 9207 9208 </td> 9209 9210 9211 9212 9213 9214 9215 <td style="vertical-align: top;">R</td> 9216 9217 9218 9219 9220 9221 9222 9223 <td style="vertical-align: top;"><i>0.0</i></td> 9224 9225 9226 9227 9228 9229 9230 9231 <td style="vertical-align: top;">Allowed limit for the 9232 overshooting of 9233 the u-component of velocity in case that the upstream-spline scheme is 9234 switched on (in m/s). 9235 9236 9237 9238 9239 9240 9241 <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>. 9242 </p> 9243 9244 9245 9246 9247 9248 9249 9250 9251 9252 9253 9254 9255 9256 <p>Only positive values are allowed for <b>overshoot_limit_u</b>.</p> 9257 9258 9259 9260 9261 9262 9263 9264 </td> 9265 9266 9267 9268 9269 9270 9271 </tr> 9272 9273 9274 9275 9276 9277 9278 <tr> 9279 9280 9281 9282 9283 9284 9285 <td style="vertical-align: top;"> 9286 9287 9288 9289 9290 9291 9292 <p><a name="overshoot_limit_v"></a><b>overshoot_limit_v</b></p> 9293 9294 9295 9296 9297 9298 9299 9300 </td> 9301 9302 9303 9304 9305 9306 9307 <td style="vertical-align: top;">R</td> 9308 9309 9310 9311 9312 9313 9314 9315 <td style="vertical-align: top;"><i>0.0</i></td> 9316 9317 9318 9319 9320 9321 9322 9323 <td style="vertical-align: top;"> 9324 9325 9326 9327 9328 9329 9330 <p>Allowed limit 9331 for the overshooting of the v-component of 9332 velocity in case that the upstream-spline scheme is switched on 9333 (in m/s). </p> 9334 9335 9336 9337 9338 9339 9340 9341 9342 9343 9344 9345 9346 9347 <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>. 9348 </p> 9349 9350 9351 9352 9353 9354 9355 9356 9357 9358 9359 9360 9361 9362 <p>Only positive values are allowed for <b>overshoot_limit_v</b>.</p> 9363 9364 9365 9366 9367 9368 9369 9370 </td> 9371 9372 9373 9374 9375 9376 9377 </tr> 9378 9379 9380 9381 9382 9383 9384 <tr> 9385 9386 9387 9388 9389 9390 9391 <td style="vertical-align: top;"> 9392 9393 9394 9395 9396 9397 9398 <p><a name="overshoot_limit_w"></a><b>overshoot_limit_w</b></p> 9399 9400 9401 9402 9403 9404 9405 9406 </td> 9407 9408 9409 9410 9411 9412 9413 <td style="vertical-align: top;">R</td> 9414 9415 9416 9417 9418 9419 9420 9421 <td style="vertical-align: top;"><i>0.0</i></td> 9422 9423 9424 9425 9426 9427 9428 9429 <td style="vertical-align: top;"> 9430 9431 9432 9433 9434 9435 9436 <p>Allowed limit 9437 for the overshooting of the w-component of 9438 velocity in case that the upstream-spline scheme is switched on 9439 (in m/s). </p> 9440 9441 9442 9443 9444 9445 9446 9447 9448 9449 9450 9451 9452 9453 <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>. 9454 </p> 9455 9456 9457 9458 9459 9460 9461 9462 9463 9464 9465 9466 9467 9468 <p>Only positive values are permitted for <b>overshoot_limit_w</b>.</p> 9469 9470 9471 9472 9473 9474 9475 9476 </td> 9477 9478 9479 9480 9481 9482 9483 </tr> 9484 9485 9486 9487 9488 9489 9490 <tr> 9491 9492 9493 9494 9495 9496 9497 <td style="vertical-align: top;"> 9498 9499 9500 9501 9502 9503 9504 <p><a name="passive_scalar"></a><b>passive_scalar</b></p> 9505 9506 9507 9508 9509 9510 9511 9512 </td> 9513 9514 9515 9516 9517 9518 9519 <td style="vertical-align: top;">L</td> 9520 9521 9522 9523 9524 9525 9526 9527 <td style="vertical-align: top;"><i>.F.</i></td> 9528 9529 9530 9531 9532 9533 9534 9535 <td style="vertical-align: top;"> 9536 9537 9538 9539 9540 9541 9542 <p>Parameter to 9543 switch on the prognostic equation for a passive 9544 scalar. <br> 9545 9546 9547 9548 9549 9550 9551 </p> 9552 9553 9554 9555 9556 9557 9558 9559 9560 9561 9562 9563 9564 9565 <p>The initial vertical profile 9566 of s can be set via parameters <a href="#s_surface">s_surface</a>, 9567 <a href="#s_vertical_gradient">s_vertical_gradient</a> 9568 and <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>. 9569 Boundary conditions can be set via <a href="#s_surface_initial_change">s_surface_initial_change</a> 9570 and <a href="#surface_scalarflux">surface_scalarflux</a>. 9571 </p> 9572 9573 9574 9575 9576 9577 9578 9579 9580 9581 9582 9583 9584 9585 <p><b>Note:</b> <br> 9586 9587 9588 9589 9590 9591 9592 9593 With <span style="font-weight: bold;">passive_scalar</span> 9594 switched 9595 on, the simultaneous use of humidity (see <a href="#humidity">humidity</a>) 9596 is impossible.</p> 9597 9598 9599 9600 9601 9602 9603 </td> 9604 9605 9606 9607 9608 9609 9610 </tr> 9611 9612 9613 9614 9615 9616 9617 <tr> 9618 9619 <td style="vertical-align: top;"><a name="pch_index"></a><span style="font-weight: bold;">pch_index</span></td> 9620 9621 <td style="vertical-align: top;">I</td> 9622 9623 <td style="vertical-align: top;"><span style="font-style: italic;">0</span></td> 9624 9625 <td style="vertical-align: top;">Grid point index (scalar) of the upper boundary of the plant canopy layer.<br> 9626 9627 <br> 9628 9629 Above <span style="font-weight: bold;">pch_index</span> the arrays of leaf area density and drag_coeffient are automatically set to zero in case of <a href="#plant_canopy">plant_canopy</a> = .T.. Up to <span style="font-weight: bold;">pch_index</span> a leaf area density profile can be prescribed by using the parameters <a href="#lad_surface">lad_surface</a>, <a href="#lad_vertical_gradient">lad_vertical_gradient</a> and <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>.</td> 9630 9631 </tr> 9632 9633 <tr> 9634 9635 9636 9637 9638 9639 9640 <td style="vertical-align: top;"> 9641 9642 9643 9644 9645 9646 9647 <p><a name="phi"></a><b>phi</b></p> 9648 9649 9650 9651 9652 9653 9654 9655 </td> 9656 9657 9658 9659 9660 9661 9662 <td style="vertical-align: top;">R</td> 9663 9664 9665 9666 9667 9668 9669 9670 <td style="vertical-align: top;"><i>55.0</i></td> 9671 9672 9673 9674 9675 9676 9677 9678 <td style="vertical-align: top;"> 9679 9680 9681 9682 9683 9684 9685 <p>Geographical 9686 latitude (in degrees). </p> 9687 9688 9689 9690 9691 9692 9693 9694 9695 9696 9697 9698 9699 9700 <p>The value of 9701 this parameter determines the value of the 9702 Coriolis parameters f and f*, provided that the angular velocity (see <a href="#omega">omega</a>) 9703 is non-zero.</p> 9704 9705 9706 9707 9708 9709 9710 </td> 9711 9712 9713 9714 9715 9716 9717 </tr> 9718 9719 9720 9721 9722 9723 9724 <tr> 9725 9726 <td style="vertical-align: top;"><a name="plant_canopy"></a><span style="font-weight: bold;">plant_canopy</span></td> 9727 9728 <td style="vertical-align: top;">L</td> 9729 9730 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 9731 9732 <td style="vertical-align: top;">Switch for the plant_canopy_model.<br> 9733 9734 <br> 9735 9736 If <span style="font-weight: bold;">plant_canopy</span> is set <span style="font-style: italic;">.T.</span>, the plant canopy model of Watanabe (2004, BLM 112, 307-341) is used. <br> 9737 9738 The 9739 impact of a plant canopy on a turbulent flow is considered by an 9740 additional drag term in the momentum equations and an additional sink 9741 term in the prognostic equation for the subgrid-scale TKE. These 9742 additional terms are dependent on the leaf drag coefficient (see <a href="#drag_coefficient">drag_coefficient</a>) and the leaf area density (see <a href="#lad_surface">lad_surface</a>, <a href="#lad_vertical_gradient">lad_vertical_gradient</a>, <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>). The top boundary of the plant canopy is determined by the parameter <a href="#pch_index">pch_index</a>. For all heights equal to or larger than zw(k=<span style="font-weight: bold;">pch_index</span>) the leaf area density is 0 (i.e. there is no canopy at these heights!). <br> 9743 9744 By default, a horizontally homogeneous plant canopy is prescribed, if <span style="font-weight: bold;">plant_canopy</span> is set <span style="font-style: italic;">.T.</span>. However, the user can define other types of plant canopies (see <a href="#canopy_mode">canopy_mode</a>).<br><br>If <span style="font-weight: bold;">plant_canopy</span> and <span style="font-weight: bold;">passive_scalar</span><span style="font-style: italic;"> </span>are set <span style="font-style: italic;">.T.</span>, 9745 the canopy acts as an additional source or sink, respectively, of 9746 scalar concentration. The source/sink strength is dependent on the 9747 scalar concentration at the leaf surface, which is generally constant 9748 with time in PALM and which can be specified by specifying the 9749 parameter <a href="#leaf_surface_concentration">leaf_surface_concentration</a>. <br><br>Additional heating of the air by the plant canopy is taken into account, when the default value of the parameter <a href="#cthf">cthf</a> is altered in the parameter file. In that case the value of <a href="#surface_heatflux">surface_heatflux</a> 9750 specified in the parameter file is not used in the model. Instead the 9751 near-surface heat flux is derived from an expontial function that is 9752 dependent on the cumulative leaf area index. <br> 9753 9754 <br> 9755 9756 <span style="font-weight: bold;">plant_canopy</span> = <span style="font-style: italic;">.T. </span>is only allowed together with a non-zero <a href="#drag_coefficient">drag_coefficient</a>.</td> 9757 9758 </tr> 9759 9760 <tr> 9761 9762 9763 9764 9765 9766 9767 <td style="vertical-align: top;"> 9768 9769 9770 9771 9772 9773 9774 <p><a name="prandtl_layer"></a><b>prandtl_layer</b></p> 9775 9776 9777 9778 9779 9780 9781 9782 </td> 9783 9784 9785 9786 9787 9788 9789 <td style="vertical-align: top;">L</td> 9790 9791 9792 9793 9794 9795 9796 9797 <td style="vertical-align: top;"><i>.T.</i></td> 9798 9799 9800 9801 9802 9803 9804 9805 <td style="vertical-align: top;"> 9806 9807 9808 9809 9810 9811 9812 <p>Parameter to 9813 switch on a Prandtl layer. </p> 9814 9815 9816 9817 9818 9819 9820 9821 9822 9823 9824 9825 9826 9827 <p>By default, 9828 a Prandtl layer is switched on at the bottom 9829 boundary between z = 0 and z = 0.5 * <a href="#dz">dz</a> 9830 (the first computational grid point above ground for u, v and the 9831 scalar quantities). 9832 In this case, at the bottom boundary, free-slip conditions for u and v 9833 (see <a href="#bc_uv_b">bc_uv_b</a>) 9834 are not allowed. Likewise, laminar 9835 simulations with constant eddy diffusivities (<a href="#km_constant">km_constant</a>) 9836 are forbidden. </p> 9837 9838 9839 9840 9841 9842 9843 9844 9845 9846 9847 9848 9849 9850 <p>With Prandtl-layer 9851 switched off, the TKE boundary condition <a href="#bc_e_b">bc_e_b</a> 9852 = '<i>(u*)**2+neumann'</i> must not be used and is 9853 automatically 9854 changed to <i>'neumann'</i> if necessary. Also, 9855 the pressure 9856 boundary condition <a href="#bc_p_b">bc_p_b</a> 9857 = <i>'neumann+inhomo'</i> is not allowed. </p> 9858 9859 9860 9861 9862 9863 9864 9865 9866 9867 9868 9869 9870 9871 <p>The roughness length is declared via the parameter <a href="#roughness_length">roughness_length</a>.</p> 9872 9873 9874 9875 9876 9877 9878 9879 </td> 9880 9881 9882 9883 9884 9885 9886 </tr> 9887 9888 9889 9890 9891 9892 9893 <tr> 9894 9895 9896 9897 9898 9899 9900 <td style="vertical-align: top;"> 9901 9902 9903 9904 9905 9906 9907 <p><a name="precipitation"></a><b>precipitation</b></p> 9908 9909 9910 9911 9912 9913 9914 9915 </td> 9916 9917 9918 9919 9920 9921 9922 <td style="vertical-align: top;">L</td> 9923 9924 9925 9926 9927 9928 9929 9930 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 9931 9932 9933 9934 9935 9936 9937 <td style="vertical-align: top;"> 9938 9939 9940 9941 9942 9943 9944 <p>Parameter to switch 9945 on the precipitation scheme.<br> 9946 9947 9948 9949 9950 9951 9952 </p> 9953 9954 9955 9956 9957 9958 9959 9960 9961 9962 9963 9964 9965 9966 <p>For 9967 precipitation processes PALM uses a simplified Kessler 9968 scheme. This scheme only considers the 9969 so-called autoconversion, that means the generation of rain water by 9970 coagulation of cloud drops among themselves. Precipitation begins and 9971 is immediately removed from the flow as soon as the liquid water 9972 content exceeds the critical value of 0.5 g/kg.</p> 9973 9974 9975 9976 9977 9978 9979 9980 9981 9982 9983 9984 9985 <p>The precipitation rate and amount can be output by assigning the runtime parameter <a href="chapter_4.2.html#data_output">data_output</a> = <span style="font-style: italic;">'prr*'</span> or <span style="font-style: italic;">'pra*'</span>, respectively. The time interval on which the precipitation amount is defined can be controlled via runtime parameter <a href="chapter_4.2.html#precipitation_amount_interval">precipitation_amount_interval</a>.</p> 9986 9987 9988 9989 9990 9991 9992 </td> 9993 9994 9995 9996 9997 9998 9999 </tr> 10000 10001 10002 10003 10004 10005 10006 10007 <tr> 10008 10009 10010 10011 10012 10013 10014 <td style="vertical-align: top;"><a name="pt_reference"></a><span style="font-weight: bold;">pt_reference</span></td> 10015 10016 10017 10018 10019 10020 10021 <td style="vertical-align: top;">R</td> 10022 10023 10024 10025 10026 10027 10028 <td style="vertical-align: top;"><span style="font-style: italic;">use horizontal average as 10029 refrence</span></td> 10030 10031 10032 10033 10034 10035 10036 <td style="vertical-align: top;">Reference 10037 temperature to be used in all buoyancy terms (in K).<br> 10038 10039 10040 10041 10042 10043 10044 <br> 10045 10046 10047 10048 10049 10050 10051 By 10052 default, the instantaneous horizontal average over the total model 10053 domain is used.<br> 10054 10055 10056 10057 10058 10059 10060 <br> 10061 10062 10063 10064 10065 10066 10067 <span style="font-weight: bold;">Attention:</span><br> 10068 10069 10070 10071 10072 10073 10074 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), always a reference temperature is used in the buoyancy terms with a default value of <span style="font-weight: bold;">pt_reference</span> = <a href="#pt_surface">pt_surface</a>.</td> 10075 10076 10077 10078 10079 10080 10081 </tr> 10082 10083 10084 10085 10086 10087 10088 <tr> 10089 10090 10091 10092 10093 10094 10095 <td style="vertical-align: top;"> 10096 10097 10098 10099 10100 10101 10102 <p><a name="pt_surface"></a><b>pt_surface</b></p> 10103 10104 10105 10106 10107 10108 10109 10110 </td> 10111 10112 10113 10114 10115 10116 10117 <td style="vertical-align: top;">R</td> 10118 10119 10120 10121 10122 10123 10124 10125 <td style="vertical-align: top;"><i>300.0</i></td> 10126 10127 10128 10129 10130 10131 10132 10133 <td style="vertical-align: top;"> 10134 10135 10136 10137 10138 10139 10140 <p>Surface 10141 potential temperature (in K). </p> 10142 10143 10144 10145 10146 10147 10148 10149 10150 10151 10152 10153 10154 10155 <p>This 10156 parameter assigns the value of the potential temperature 10157 <span style="font-weight: bold;">pt</span> at the surface (k=0)<b>.</b> Starting from this value, 10158 the 10159 initial vertical temperature profile is constructed with <a href="#pt_vertical_gradient">pt_vertical_gradient</a> 10160 and <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level 10161 </a>. 10162 This profile is also used for the 1d-model as a stationary profile.</p> 10163 10164 10165 10166 10167 10168 10169 10170 10171 10172 10173 10174 10175 <p><span style="font-weight: bold;">Attention:</span><br> 10176 10177 10178 10179 10180 10181 10182 In case of ocean runs (see <a href="#ocean">ocean</a>), 10183 this parameter gives the temperature value at the sea surface, which is 10184 at k=nzt. The profile is then constructed from the surface down to the 10185 bottom of the model.</p> 10186 10187 10188 10189 10190 10191 10192 10193 </td> 10194 10195 10196 10197 10198 10199 10200 </tr> 10201 10202 10203 10204 10205 10206 10207 <tr> 10208 10209 10210 10211 10212 10213 10214 <td style="vertical-align: top;"> 10215 10216 10217 10218 10219 10220 10221 <p><a name="pt_surface_initial_change"></a><b>pt_surface_initial</b> 10222 <br> 10223 10224 10225 10226 10227 10228 10229 <b>_change</b></p> 10230 10231 10232 10233 10234 10235 10236 </td> 10237 10238 10239 10240 10241 10242 10243 <td style="vertical-align: top;">R</td> 10244 10245 10246 10247 10248 10249 10250 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br> 10251 10252 10253 10254 10255 10256 10257 </td> 10258 10259 10260 10261 10262 10263 10264 10265 <td style="vertical-align: top;"> 10266 10267 10268 10269 10270 10271 10272 <p>Change in 10273 surface temperature to be made at the beginning of 10274 the 3d run 10275 (in K). </p> 10276 10277 10278 10279 10280 10281 10282 10283 10284 10285 10286 10287 10288 10289 <p>If <b>pt_surface_initial_change</b> 10290 is set to a non-zero 10291 value, the near surface sensible heat flux is not allowed to be given 10292 simultaneously (see <a href="#surface_heatflux">surface_heatflux</a>).</p> 10293 10294 10295 10296 10297 10298 10299 10300 </td> 10301 10302 10303 10304 10305 10306 10307 </tr> 10308 10309 10310 10311 10312 10313 10314 <tr> 10315 10316 10317 10318 10319 10320 10321 <td style="vertical-align: top;"> 10322 10323 10324 10325 10326 10327 10328 <p><a name="pt_vertical_gradient"></a><b>pt_vertical_gradient</b></p> 10329 10330 10331 10332 10333 10334 10335 10336 </td> 10337 10338 10339 10340 10341 10342 10343 <td style="vertical-align: top;">R (10)</td> 10344 10345 10346 10347 10348 10349 10350 10351 <td style="vertical-align: top;"><i>10 * 0.0</i></td> 10352 10353 10354 10355 10356 10357 10358 10359 <td style="vertical-align: top;"> 10360 10361 10362 10363 10364 10365 10366 <p>Temperature 10367 gradient(s) of the initial temperature profile (in 10368 K 10369 / 100 m). </p> 10370 10371 10372 10373 10374 10375 10376 10377 10378 10379 10380 10381 10382 10383 <p>This temperature gradient 10384 holds starting from the height 10385 level defined by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a> 10386 (precisely: for all uv levels k where zu(k) > 10387 pt_vertical_gradient_level, 10388 pt_init(k) is set: pt_init(k) = pt_init(k-1) + dzu(k) * <b>pt_vertical_gradient</b>) 10389 up to the top boundary or up to the next height level defined 10390 by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>. 10391 A total of 10 different gradients for 11 height intervals (10 intervals 10392 if <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>(1) 10393 = <i>0.0</i>) can be assigned. The surface temperature is 10394 assigned via <a href="#pt_surface">pt_surface</a>. 10395 </p> 10396 10397 10398 10399 10400 10401 10402 10403 10404 10405 10406 10407 10408 10409 <p>Example: </p> 10410 10411 10412 10413 10414 10415 10416 10417 10418 10419 10420 10421 10422 10423 <ul> 10424 10425 10426 10427 10428 10429 10430 10431 10432 10433 10434 10435 10436 10437 <p><b>pt_vertical_gradient</b> 10438 = <i>1.0</i>, <i>0.5</i>, <br> 10439 10440 10441 10442 10443 10444 10445 10446 <b>pt_vertical_gradient_level</b> = <i>500.0</i>, 10447 <i>1000.0</i>,</p> 10448 10449 10450 10451 10452 10453 10454 10455 10456 10457 10458 10459 10460 10461 </ul> 10462 10463 10464 10465 10466 10467 10468 10469 10470 10471 10472 10473 10474 10475 <p>That 10476 defines the temperature profile to be neutrally 10477 stratified 10478 up to z = 500.0 m with a temperature given by <a href="#pt_surface">pt_surface</a>. 10479 For 500.0 m < z <= 1000.0 m the temperature gradient is 10480 1.0 K / 10481 100 m and for z > 1000.0 m up to the top boundary it is 10482 0.5 K / 100 m (it is assumed that the assigned height levels correspond 10483 with uv levels).</p> 10484 10485 10486 10487 10488 10489 10490 10491 10492 10493 10494 10495 10496 <p><span style="font-weight: bold;">Attention:</span><br> 10497 10498 10499 10500 10501 10502 10503 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), 10504 the profile is constructed like described above, but starting from the 10505 sea surface (k=nzt) down to the bottom boundary of the model. Height 10506 levels have then to be given as negative values, e.g. <span style="font-weight: bold;">pt_vertical_gradient_level</span> = <span style="font-style: italic;">-500.0</span>, <span style="font-style: italic;">-1000.0</span>.</p> 10507 10508 10509 10510 10511 10512 10513 </td> 10514 10515 10516 10517 10518 10519 10520 </tr> 10521 10522 10523 10524 10525 10526 10527 <tr> 10528 10529 10530 10531 10532 10533 10534 <td style="vertical-align: top;"> 10535 10536 10537 10538 10539 10540 10541 <p><a name="pt_vertical_gradient_level"></a><b>pt_vertical_gradient</b> 10542 <br> 10543 10544 10545 10546 10547 10548 10549 <b>_level</b></p> 10550 10551 10552 10553 10554 10555 10556 </td> 10557 10558 10559 10560 10561 10562 10563 <td style="vertical-align: top;">R (10)</td> 10564 10565 10566 10567 10568 10569 10570 <td style="vertical-align: top;"> 10571 10572 10573 10574 10575 10576 10577 <p><i>10 *</i> 10578 <span style="font-style: italic;">0.0</span><br> 10579 10580 10581 10582 10583 10584 10585 10586 </p> 10587 10588 10589 10590 10591 10592 10593 </td> 10594 10595 10596 10597 10598 10599 10600 <td style="vertical-align: top;"> 10601 10602 10603 10604 10605 10606 10607 <p>Height level from which on the temperature gradient defined by 10608 <a href="#pt_vertical_gradient">pt_vertical_gradient</a> 10609 is effective (in m). </p> 10610 10611 10612 10613 10614 10615 10616 10617 10618 10619 10620 10621 10622 10623 <p>The height levels have to be assigned in ascending order. The 10624 default values result in a neutral stratification regardless of the 10625 values of <a href="#pt_vertical_gradient">pt_vertical_gradient</a> 10626 (unless the top boundary of the model is higher than 100000.0 m). 10627 For the piecewise construction of temperature profiles see <a href="#pt_vertical_gradient">pt_vertical_gradient</a>.</p> 10628 10629 10630 10631 10632 10633 10634 <span style="font-weight: bold;">Attention:</span><br> 10635 10636 10637 10638 10639 10640 10641 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), the (negative) height levels have to be assigned in descending order. 10642 </td> 10643 10644 10645 10646 10647 10648 10649 </tr> 10650 10651 10652 10653 10654 10655 10656 <tr> 10657 10658 10659 10660 10661 10662 10663 <td style="vertical-align: top;"> 10664 10665 10666 10667 10668 10669 10670 <p><a name="q_surface"></a><b>q_surface</b></p> 10671 10672 10673 10674 10675 10676 10677 10678 </td> 10679 10680 10681 10682 10683 10684 10685 <td style="vertical-align: top;">R</td> 10686 10687 10688 10689 10690 10691 10692 10693 <td style="vertical-align: top;"><i>0.0</i></td> 10694 10695 10696 10697 10698 10699 10700 10701 <td style="vertical-align: top;"> 10702 10703 10704 10705 10706 10707 10708 <p>Surface 10709 specific humidity / total water content (kg/kg). </p> 10710 10711 10712 10713 10714 10715 10716 10717 10718 10719 10720 10721 10722 10723 <p>This 10724 parameter assigns the value of the specific humidity q at 10725 the surface (k=0). Starting from this value, the initial 10726 humidity 10727 profile is constructed with <a href="#q_vertical_gradient">q_vertical_gradient</a> 10728 and <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>. 10729 This profile is also used for the 1d-model as a stationary profile.</p> 10730 10731 10732 10733 10734 10735 10736 10737 </td> 10738 10739 10740 10741 10742 10743 10744 </tr> 10745 10746 10747 10748 10749 10750 10751 <tr> 10752 10753 10754 10755 10756 10757 10758 <td style="vertical-align: top;"> 10759 10760 10761 10762 10763 10764 10765 <p><a name="q_surface_initial_change"></a><b>q_surface_initial</b> 10766 <br> 10767 10768 10769 10770 10771 10772 10773 <b>_change</b></p> 10774 10775 10776 10777 10778 10779 10780 </td> 10781 10782 10783 10784 10785 10786 10787 <td style="vertical-align: top;">R<br> 10788 10789 10790 10791 10792 10793 10794 </td> 10795 10796 10797 10798 10799 10800 10801 <td style="vertical-align: top;"><i>0.0</i></td> 10802 10803 10804 10805 10806 10807 10808 10809 <td style="vertical-align: top;"> 10810 10811 10812 10813 10814 10815 10816 <p>Change in 10817 surface specific humidity / total water content to 10818 be made at the beginning 10819 of the 3d run (kg/kg). </p> 10820 10821 10822 10823 10824 10825 10826 10827 10828 10829 10830 10831 10832 10833 <p>If <b>q_surface_initial_change</b><i> 10834 </i>is set to a 10835 non-zero value the 10836 near surface latent heat flux (water flux) is not allowed to be given 10837 simultaneously (see <a href="#surface_waterflux">surface_waterflux</a>).</p> 10838 10839 10840 10841 10842 10843 10844 10845 </td> 10846 10847 10848 10849 10850 10851 10852 </tr> 10853 10854 10855 10856 10857 10858 10859 <tr> 10860 10861 10862 10863 10864 10865 10866 <td style="vertical-align: top;"> 10867 10868 10869 10870 10871 10872 10873 <p><a name="q_vertical_gradient"></a><b>q_vertical_gradient</b></p> 10874 10875 10876 10877 10878 10879 10880 10881 </td> 10882 10883 10884 10885 10886 10887 10888 <td style="vertical-align: top;">R (10)</td> 10889 10890 10891 10892 10893 10894 10895 10896 <td style="vertical-align: top;"><i>10 * 0.0</i></td> 10897 10898 10899 10900 10901 10902 10903 10904 <td style="vertical-align: top;"> 10905 10906 10907 10908 10909 10910 10911 <p>Humidity 10912 gradient(s) of the initial humidity profile 10913 (in 1/100 m). </p> 10914 10915 10916 10917 10918 10919 10920 10921 10922 10923 10924 10925 10926 10927 <p>This humidity gradient 10928 holds starting from the height 10929 level defined by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a> 10930 (precisely: for all uv levels k, where zu(k) > 10931 q_vertical_gradient_level, 10932 q_init(k) is set: q_init(k) = q_init(k-1) + dzu(k) * <b>q_vertical_gradient</b>) 10933 up to the top boundary or up to the next height level defined 10934 by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>. 10935 A total of 10 different gradients for 11 height intervals (10 intervals 10936 if <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>(1) 10937 = <i>0.0</i>) can be asigned. The surface humidity is 10938 assigned 10939 via <a href="#q_surface">q_surface</a>. </p> 10940 10941 10942 10943 10944 10945 10946 10947 10948 10949 10950 10951 10952 10953 <p>Example: </p> 10954 10955 10956 10957 10958 10959 10960 10961 10962 10963 10964 10965 10966 10967 <ul> 10968 10969 10970 10971 10972 10973 10974 10975 10976 10977 10978 10979 10980 10981 <p><b>q_vertical_gradient</b> 10982 = <i>0.001</i>, <i>0.0005</i>, <br> 10983 10984 10985 10986 10987 10988 10989 10990 <b>q_vertical_gradient_level</b> = <i>500.0</i>, 10991 <i>1000.0</i>,</p> 10992 10993 10994 10995 10996 10997 10998 10999 11000 11001 11002 11003 11004 11005 </ul> 11006 11007 11008 11009 11010 11011 11012 11013 That defines the humidity to be constant with height up to z = 11014 500.0 11015 m with a 11016 value given by <a href="#q_surface">q_surface</a>. 11017 For 500.0 m < z <= 1000.0 m the humidity gradient is 11018 0.001 / 100 11019 m and for z > 1000.0 m up to the top boundary it is 11020 0.0005 / 100 m (it is assumed that the assigned height levels 11021 correspond with uv 11022 levels). </td> 11023 11024 11025 11026 11027 11028 11029 </tr> 11030 11031 11032 11033 11034 11035 11036 <tr> 11037 11038 11039 11040 11041 11042 11043 <td style="vertical-align: top;"> 11044 11045 11046 11047 11048 11049 11050 <p><a name="q_vertical_gradient_level"></a><b>q_vertical_gradient</b> 11051 <br> 11052 11053 11054 11055 11056 11057 11058 <b>_level</b></p> 11059 11060 11061 11062 11063 11064 11065 </td> 11066 11067 11068 11069 11070 11071 11072 <td style="vertical-align: top;">R (10)</td> 11073 11074 11075 11076 11077 11078 11079 <td style="vertical-align: top;"> 11080 11081 11082 11083 11084 11085 11086 <p><i>10 *</i> 11087 <i>0.0</i></p> 11088 11089 11090 11091 11092 11093 11094 </td> 11095 11096 11097 11098 11099 11100 11101 <td style="vertical-align: top;"> 11102 11103 11104 11105 11106 11107 11108 <p>Height level from 11109 which on the humidity gradient defined by <a href="#q_vertical_gradient">q_vertical_gradient</a> 11110 is effective (in m). </p> 11111 11112 11113 11114 11115 11116 11117 11118 11119 11120 11121 11122 11123 11124 <p>The height levels 11125 are to be assigned in ascending order. The 11126 default values result in a humidity constant with height regardless of 11127 the values of <a href="#q_vertical_gradient">q_vertical_gradient</a> 11128 (unless the top boundary of the model is higher than 100000.0 m). For 11129 the piecewise construction of humidity profiles see <a href="#q_vertical_gradient">q_vertical_gradient</a>.</p> 11130 11131 11132 11133 11134 11135 11136 11137 </td> 11138 11139 11140 11141 11142 11143 11144 </tr> 11145 11146 11147 11148 11149 11150 11151 <tr> 11152 11153 11154 11155 11156 11157 11158 <td style="vertical-align: top;"> 11159 11160 11161 11162 11163 11164 11165 <p><a name="radiation"></a><b>radiation</b></p> 11166 11167 11168 11169 11170 11171 11172 11173 </td> 11174 11175 11176 11177 11178 11179 11180 <td style="vertical-align: top;">L</td> 11181 11182 11183 11184 11185 11186 11187 11188 <td style="vertical-align: top;"><i>.F.</i></td> 11189 11190 11191 11192 11193 11194 11195 11196 <td style="vertical-align: top;"> 11197 11198 11199 11200 11201 11202 11203 <p>Parameter to 11204 switch on longwave radiation cooling at 11205 cloud-tops. </p> 11206 11207 11208 11209 11210 11211 11212 11213 11214 11215 11216 11217 11218 11219 <p>Long-wave radiation 11220 processes are parameterized by the 11221 effective emissivity, which considers only the absorption and emission 11222 of long-wave radiation at cloud droplets. The radiation scheme can be 11223 used only with <a href="#cloud_physics">cloud_physics</a> 11224 = .TRUE. .</p> 11225 11226 11227 11228 11229 11230 11231 </td> 11232 11233 11234 11235 11236 11237 11238 </tr> 11239 11240 11241 11242 11243 11244 11245 <tr> 11246 11247 11248 11249 11250 11251 11252 <td style="vertical-align: top;"> 11253 11254 11255 11256 11257 11258 11259 <p><a name="random_generator"></a><b>random_generator</b></p> 11260 11261 11262 11263 11264 11265 11266 11267 </td> 11268 11269 11270 11271 11272 11273 11274 <td style="vertical-align: top;">C * 20</td> 11275 11276 11277 11278 11279 11280 11281 11282 <td style="vertical-align: top;"> 11283 11284 11285 11286 11287 11288 11289 <p><i>'numerical</i><br> 11290 11291 11292 11293 11294 11295 11296 11297 <i>recipes'</i></p> 11298 11299 11300 11301 11302 11303 11304 </td> 11305 11306 11307 11308 11309 11310 11311 <td style="vertical-align: top;"> 11312 11313 11314 11315 11316 11317 11318 <p>Random number 11319 generator to be used for creating uniformly 11320 distributed random numbers. <br> 11321 11322 11323 11324 11325 11326 11327 </p> 11328 11329 11330 11331 11332 11333 11334 11335 11336 11337 11338 11339 11340 11341 <p>It is 11342 used if random perturbations are to be imposed on the 11343 velocity field or on the surface heat flux field (see <a href="chapter_4.2.html#create_disturbances">create_disturbances</a> 11344 and <a href="chapter_4.2.html#random_heatflux">random_heatflux</a>). 11345 By default, the "Numerical Recipes" random number generator is used. 11346 This one provides exactly the same order of random numbers on all 11347 different machines and should be used in particular for comparison runs.<br> 11348 11349 11350 11351 11352 11353 11354 11355 <br> 11356 11357 11358 11359 11360 11361 11362 11363 Besides, a system-specific generator is available ( <b>random_generator</b> 11364 = <i>'system-specific')</i> which should particularly be 11365 used for runs 11366 on vector parallel computers (NEC), because the default generator 11367 cannot be vectorized and therefore significantly drops down the code 11368 performance on these machines.<br> 11369 11370 11371 11372 11373 11374 11375 </p> 11376 11377 11378 11379 11380 11381 11382 <span style="font-weight: bold;">Note:</span><br> 11383 11384 11385 11386 11387 11388 11389 11390 Results from two otherwise identical model runs will not be comparable 11391 one-to-one if they used different random number generators.</td> 11392 11393 11394 11395 11396 11397 11398 </tr> 11399 11400 11401 11402 11403 11404 11405 11406 <tr> 11407 11408 11409 11410 11411 11412 11413 <td style="vertical-align: top;"> 11414 11415 11416 11417 11418 11419 11420 <p><a name="random_heatflux"></a><b>random_heatflux</b></p> 11421 11422 11423 11424 11425 11426 11427 11428 </td> 11429 11430 11431 11432 11433 11434 11435 <td style="vertical-align: top;">L</td> 11436 11437 11438 11439 11440 11441 11442 11443 <td style="vertical-align: top;"><i>.F.</i></td> 11444 11445 11446 11447 11448 11449 11450 11451 <td style="vertical-align: top;"> 11452 11453 11454 11455 11456 11457 11458 <p>Parameter to 11459 impose random perturbations on the internal two-dimensional near 11460 surface heat flux field <span style="font-style: italic;">shf</span>. 11461 <br> 11462 11463 11464 11465 11466 11467 11468 </p> 11469 11470 11471 11472 11473 11474 11475 If a near surface heat flux is used as bottom 11476 boundary 11477 condition (see <a href="#surface_heatflux">surface_heatflux</a>), 11478 it is by default assumed to be horizontally homogeneous. Random 11479 perturbations can be imposed on the internal 11480 two-dimensional heat flux field <span style="font-style: italic;">shf</span> by assigning <b>random_heatflux</b> 11481 = <i>.T.</i>. The disturbed heat flux field is calculated 11482 by 11483 multiplying the 11484 values at each mesh point with a normally distributed random number 11485 with a mean value and standard deviation of 1. This is repeated after 11486 every timestep.<br> 11487 11488 11489 11490 11491 11492 11493 <br> 11494 11495 11496 11497 11498 11499 11500 11501 In case of a non-flat <a href="#topography">topography</a>, assigning 11502 <b>random_heatflux</b> 11503 = <i>.T.</i> imposes random perturbations on the 11504 combined heat 11505 flux field <span style="font-style: italic;">shf</span> 11506 composed of <a href="#surface_heatflux">surface_heatflux</a> 11507 at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a> 11508 at the topography top face.</td> 11509 11510 11511 11512 11513 11514 11515 </tr> 11516 11517 11518 11519 11520 11521 11522 <tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="recycling_width"></a>recycling_width</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">0.1 * <a href="chapter_4.1.html#nx">nx</a> * <a href="chapter_4.1.html#dx">dx</a></span></td><td style="vertical-align: top;">Distance of the recycling plane from the inflow boundary (in m).<br><br>This 11523 parameter sets the horizontal extension (along the direction of the 11524 main flow) of the so-called recycling domain which is used to generate 11525 a turbulent inflow (see <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a>). <span style="font-weight: bold;">recycling_width</span> must be larger than the grid spacing (dx) and smaller than the length of the total domain (nx * dx).</td></tr><tr> 11526 11527 11528 11529 11530 11531 11532 <td style="vertical-align: top;"> 11533 11534 11535 11536 11537 11538 11539 <p><a name="rif_max"></a><b>rif_max</b></p> 11540 11541 11542 11543 11544 11545 11546 11547 </td> 11548 11549 11550 11551 11552 11553 11554 <td style="vertical-align: top;">R</td> 11555 11556 11557 11558 11559 11560 11561 11562 <td style="vertical-align: top;"><i>1.0</i></td> 11563 11564 11565 11566 11567 11568 11569 11570 <td style="vertical-align: top;"> 11571 11572 11573 11574 11575 11576 11577 <p>Upper limit of 11578 the flux-Richardson number. </p> 11579 11580 11581 11582 11583 11584 11585 11586 11587 11588 11589 11590 11591 11592 <p>With the 11593 Prandtl layer switched on (see <a href="#prandtl_layer">prandtl_layer</a>), 11594 flux-Richardson numbers (rif) are calculated for z=z<sub>p</sub> 11595 (k=1) 11596 in the 3d-model (in the 1d model for all heights). Their values in 11597 particular determine the 11598 values of the friction velocity (1d- and 3d-model) and the values of 11599 the eddy diffusivity (1d-model). With small wind velocities at the 11600 Prandtl layer top or small vertical wind shears in the 1d-model, rif 11601 can take up unrealistic large values. They are limited by an upper (<span style="font-weight: bold;">rif_max</span>) and lower 11602 limit (see <a href="#rif_min">rif_min</a>) 11603 for the flux-Richardson number. The condition <b>rif_max</b> 11604 > <b>rif_min</b> 11605 must be met.</p> 11606 11607 11608 11609 11610 11611 11612 </td> 11613 11614 11615 11616 11617 11618 11619 </tr> 11620 11621 11622 11623 11624 11625 11626 <tr> 11627 11628 11629 11630 11631 11632 11633 <td style="vertical-align: top;"> 11634 11635 11636 11637 11638 11639 11640 <p><a name="rif_min"></a><b>rif_min</b></p> 11641 11642 11643 11644 11645 11646 11647 11648 </td> 11649 11650 11651 11652 11653 11654 11655 <td style="vertical-align: top;">R</td> 11656 11657 11658 11659 11660 11661 11662 11663 <td style="vertical-align: top;"><i>- 5.0</i></td> 11664 11665 11666 11667 11668 11669 11670 11671 <td style="vertical-align: top;"> 11672 11673 11674 11675 11676 11677 11678 <p>Lower limit of 11679 the flux-Richardson number. </p> 11680 11681 11682 11683 11684 11685 11686 11687 11688 11689 11690 11691 11692 11693 <p>For further 11694 explanations see <a href="#rif_max">rif_max</a>. 11695 The condition <b>rif_max</b> > <b>rif_min </b>must 11696 be met.</p> 11697 11698 11699 11700 11701 11702 11703 </td> 11704 11705 11706 11707 11708 11709 11710 </tr> 11711 11712 11713 11714 11715 11716 11717 <tr> 11718 11719 11720 11721 11722 11723 11724 <td style="vertical-align: top;"> 11725 11726 11727 11728 11729 11730 11731 <p><a name="roughness_length"></a><b>roughness_length</b></p> 11732 11733 11734 11735 11736 11737 11738 11739 </td> 11740 11741 11742 11743 11744 11745 11746 <td style="vertical-align: top;">R</td> 11747 11748 11749 11750 11751 11752 11753 11754 <td style="vertical-align: top;"><i>0.1</i></td> 11755 11756 11757 11758 11759 11760 11761 11762 <td style="vertical-align: top;"> 11763 11764 11765 11766 11767 11768 11769 <p>Roughness 11770 length (in m). </p> 11771 11772 11773 11774 11775 11776 11777 11778 11779 11780 11781 11782 11783 11784 <p>This parameter is 11785 effective only in case that a Prandtl layer 11786 is switched 11787 on (see <a href="#prandtl_layer">prandtl_layer</a>).</p> 11788 11789 11790 11791 11792 11793 11794 11795 </td> 11796 11797 11798 11799 11800 11801 11802 </tr> 11803 11804 11805 11806 11807 11808 11809 <tr> 11810 11811 11812 11813 11814 11815 11816 <td style="vertical-align: top;"><a name="sa_surface"></a><span style="font-weight: bold;">sa_surface</span></td> 11817 11818 11819 11820 11821 11822 11823 <td style="vertical-align: top;">R</td> 11824 11825 11826 11827 11828 11829 11830 <td style="vertical-align: top;"><span style="font-style: italic;">35.0</span></td> 11831 11832 11833 11834 11835 11836 11837 <td style="vertical-align: top;"> 11838 11839 11840 11841 11842 11843 11844 <p>Surface salinity (in psu). </p> 11845 11846 11847 11848 11849 11850 11851 This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>). 11852 11853 11854 11855 11856 11857 11858 <p>This 11859 parameter assigns the value of the salinity <span style="font-weight: bold;">sa</span> at the sea surface (k=nzt)<b>.</b> Starting from this value, 11860 the 11861 initial vertical salinity profile is constructed from the surface down to the bottom of the model (k=0) by using <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a> 11862 and <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level 11863 </a>.</p> 11864 11865 11866 11867 11868 11869 11870 </td> 11871 11872 11873 11874 11875 11876 11877 </tr> 11878 11879 11880 11881 11882 11883 11884 <tr> 11885 11886 11887 11888 11889 11890 11891 <td style="vertical-align: top;"><a name="sa_vertical_gradient"></a><span style="font-weight: bold;">sa_vertical_gradient</span></td> 11892 11893 11894 11895 11896 11897 11898 <td style="vertical-align: top;">R(10)</td> 11899 11900 11901 11902 11903 11904 11905 <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td> 11906 11907 11908 11909 11910 11911 11912 <td style="vertical-align: top;"> 11913 11914 11915 11916 11917 11918 11919 <p>Salinity gradient(s) of the initial salinity profile (in psu 11920 / 100 m). </p> 11921 11922 11923 11924 11925 11926 11927 11928 11929 11930 11931 11932 11933 11934 <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p> 11935 11936 11937 11938 11939 11940 11941 11942 11943 11944 11945 11946 11947 <p>This salinity gradient 11948 holds starting from the height 11949 level defined by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a> 11950 (precisely: for all uv levels k where zu(k) < 11951 sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) = 11952 sa_init(k+1) - dzu(k+1) * <b>sa_vertical_gradient</b>) down to the bottom boundary or down to the next height level defined 11953 by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>. 11954 A total of 10 different gradients for 11 height intervals (10 intervals 11955 if <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>(1) 11956 = <i>0.0</i>) can be assigned. The surface salinity at k=nzt is 11957 assigned via <a href="chapter_4.1.html#sa_surface">sa_surface</a>. 11958 </p> 11959 11960 11961 11962 11963 11964 11965 11966 11967 11968 11969 11970 11971 11972 <p>Example: </p> 11973 11974 11975 11976 11977 11978 11979 11980 11981 11982 11983 11984 11985 11986 <ul> 11987 11988 11989 11990 11991 11992 11993 11994 11995 11996 11997 11998 11999 <p><b>sa_vertical_gradient</b> 12000 = <i>1.0</i>, <i>0.5</i>, <br> 12001 12002 12003 12004 12005 12006 12007 12008 <b>sa_vertical_gradient_level</b> = <i>-500.0</i>, 12009 -<i>1000.0</i>,</p> 12010 12011 12012 12013 12014 12015 12016 12017 12018 12019 12020 12021 12022 </ul> 12023 12024 12025 12026 12027 12028 12029 12030 12031 12032 12033 12034 12035 12036 <p>That 12037 defines the salinity to be constant down to z = -500.0 m with a salinity given by <a href="chapter_4.1.html#sa_surface">sa_surface</a>. 12038 For -500.0 m < z <= -1000.0 m the salinity gradient is 12039 1.0 psu / 12040 100 m and for z < -1000.0 m down to the bottom boundary it is 12041 0.5 psu / 100 m (it is assumed that the assigned height levels correspond 12042 with uv levels).</p> 12043 12044 12045 12046 12047 12048 12049 </td> 12050 12051 12052 12053 12054 12055 12056 </tr> 12057 12058 12059 12060 12061 12062 12063 <tr> 12064 12065 12066 12067 12068 12069 12070 <td style="vertical-align: top;"><a name="sa_vertical_gradient_level"></a><span style="font-weight: bold;">sa_vertical_gradient_level</span></td> 12071 12072 12073 12074 12075 12076 12077 <td style="vertical-align: top;">R(10)</td> 12078 12079 12080 12081 12082 12083 12084 <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td> 12085 12086 12087 12088 12089 12090 12091 <td style="vertical-align: top;"> 12092 12093 12094 12095 12096 12097 12098 <p>Height level from which on the salinity gradient defined by <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a> 12099 is effective (in m). </p> 12100 12101 12102 12103 12104 12105 12106 12107 12108 12109 12110 12111 12112 12113 <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p> 12114 12115 12116 12117 12118 12119 12120 12121 12122 12123 12124 12125 12126 <p>The height levels have to be assigned in descending order. The 12127 default values result in a constant salinity profile regardless of the 12128 values of <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a> 12129 (unless the bottom boundary of the model is lower than -100000.0 m). 12130 For the piecewise construction of salinity profiles see <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>.</p> 12131 12132 12133 12134 12135 12136 12137 </td> 12138 12139 12140 12141 12142 12143 12144 </tr> 12145 12146 12147 12148 12149 12150 12151 <tr> 12152 12153 12154 12155 12156 12157 12158 <td style="vertical-align: top;"> 12159 12160 12161 12162 12163 12164 12165 <p><a name="scalar_advec"></a><b>scalar_advec</b></p> 12166 12167 12168 12169 12170 12171 12172 12173 </td> 12174 12175 12176 12177 12178 12179 12180 <td style="vertical-align: top;">C * 10</td> 12181 12182 12183 12184 12185 12186 12187 12188 <td style="vertical-align: top;"><i>'pw-scheme'</i></td> 12189 12190 12191 12192 12193 12194 12195 12196 <td style="vertical-align: top;"> 12197 12198 12199 12200 12201 12202 12203 <p>Advection 12204 scheme to be used for the scalar quantities. </p> 12205 12206 12207 12208 12209 12210 12211 12212 12213 12214 12215 12216 12217 12218 <p>The 12219 user can choose between the following schemes:<br> 12220 12221 12222 12223 12224 12225 12226 </p> 12227 12228 12229 12230 12231 12232 12233 12234 12235 12236 12237 12238 12239 12240 <p><span style="font-style: italic;">'pw-scheme'</span><br> 12241 12242 12243 12244 12245 12246 12247 12248 </p> 12249 12250 12251 12252 12253 12254 12255 12256 12257 12258 12259 12260 12261 12262 <div style="margin-left: 40px;">The scheme of 12263 Piascek and 12264 Williams (1970, J. Comp. Phys., 6, 12265 392-405) with central differences in the form C3 is used.<br> 12266 12267 12268 12269 12270 12271 12272 12273 If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a> 12274 = <span style="font-style: italic;">'leapfrog+euler'</span> 12275 the 12276 advection scheme is - for the Euler-timestep - automatically switched 12277 to an upstream-scheme. <br> 12278 12279 12280 12281 12282 12283 12284 </div> 12285 12286 12287 12288 12289 12290 12291 <br> 12292 12293 12294 12295 12296 12297 12298 12299 12300 12301 12302 12303 12304 12305 <p><span style="font-style: italic;">'bc-scheme'</span><br> 12306 12307 12308 12309 12310 12311 12312 12313 </p> 12314 12315 12316 12317 12318 12319 12320 12321 12322 12323 12324 12325 12326 12327 <div style="margin-left: 40px;">The Bott 12328 scheme modified by 12329 Chlond (1994, Mon. 12330 Wea. Rev., 122, 111-125). This is a conservative monotonous scheme with 12331 very small numerical diffusion and therefore very good conservation of 12332 scalar flow features. The scheme however, is computationally very 12333 expensive both because it is expensive itself and because it does (so 12334 far) not allow specific code optimizations (e.g. cache optimization). 12335 Choice of this 12336 scheme forces the Euler timestep scheme to be used for the scalar 12337 quantities. For output of horizontally averaged 12338 profiles of the resolved / total heat flux, <a href="chapter_4.2.html#data_output_pr">data_output_pr</a> 12339 = <i>'w*pt*BC'</i> / <i>'wptBC' </i>should 12340 be used, instead of the 12341 standard profiles (<span style="font-style: italic;">'w*pt*'</span> 12342 and <span style="font-style: italic;">'wpt'</span>) 12343 because these are 12344 too inaccurate with this scheme. However, for subdomain analysis (see <a href="#statistic_regions">statistic_regions</a>) 12345 exactly the reverse holds: here <i>'w*pt*BC'</i> and <i>'wptBC'</i> 12346 show very large errors and should not be used.<br> 12347 12348 12349 12350 12351 12352 12353 <br> 12354 12355 12356 12357 12358 12359 12360 12361 This scheme is not allowed for non-cyclic lateral boundary conditions 12362 (see <a href="#bc_lr">bc_lr</a> 12363 and <a href="#bc_ns">bc_ns</a>).<br> 12364 12365 12366 12367 12368 12369 12370 <br> 12371 12372 12373 12374 12375 12376 12377 12378 </div> 12379 12380 12381 12382 12383 12384 12385 <span style="font-style: italic;">'ups-scheme'</span><br> 12386 12387 12388 12389 12390 12391 12392 12393 12394 12395 12396 12397 12398 12399 <p style="margin-left: 40px;">The upstream-spline-scheme 12400 is used 12401 (see Mahrer and Pielke, 12402 1978: Mon. Wea. Rev., 106, 818-830). In opposite to the Piascek 12403 Williams scheme, this is characterized by much better numerical 12404 features (less numerical diffusion, better preservation of flux 12405 structures, e.g. vortices), but computationally it is much more 12406 expensive. In 12407 addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a> 12408 = <span style="font-style: italic;">'</span><i>euler'</i>), 12409 i.e. the 12410 timestep accuracy is only first order. For this reason the advection of 12411 momentum (see <a href="#momentum_advec">momentum_advec</a>) 12412 should then also be carried out with the upstream-spline scheme, 12413 because otherwise the momentum would 12414 be subject to large numerical diffusion due to the upstream 12415 scheme. </p> 12416 12417 12418 12419 12420 12421 12422 12423 12424 12425 12426 12427 12428 12429 <p style="margin-left: 40px;">Since 12430 the cubic splines used tend 12431 to overshoot under 12432 certain circumstances, this effect must be adjusted by suitable 12433 filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>, 12434 <a href="#long_filter_factor">long_filter_factor</a>, 12435 <a href="#ups_limit_pt">ups_limit_pt</a>, <a href="#ups_limit_u">ups_limit_u</a>, <a href="#ups_limit_v">ups_limit_v</a>, <a href="#ups_limit_w">ups_limit_w</a>). 12436 This is always neccesssary for runs with stable stratification, 12437 even if this stratification appears only in parts of the model 12438 domain. </p> 12439 12440 12441 12442 12443 12444 12445 12446 12447 12448 12449 12450 12451 12452 <p style="margin-left: 40px;">With 12453 stable stratification the 12454 upstream-upline scheme also produces gravity waves with large 12455 amplitude, which must be 12456 suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br> 12457 12458 12459 12460 12461 12462 12463 12464 </p> 12465 12466 12467 12468 12469 12470 12471 12472 12473 12474 12475 12476 12477 12478 <p style="margin-left: 40px;"><span style="font-weight: bold;">Important: </span>The 12479 upstream-spline scheme is not implemented for humidity and passive 12480 scalars (see <a href="#humidity">humidity</a> 12481 and <a href="#passive_scalar">passive_scalar</a>) 12482 and requires the use of a 2d-domain-decomposition. The last conditions 12483 severely restricts code optimization on several machines leading to 12484 very long execution times! This scheme is also not allowed for 12485 non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a> 12486 and <a href="#bc_ns">bc_ns</a>).</p> 12487 12488 12489 12490 12491 12492 12493 <br> 12494 12495 12496 12497 12498 12499 12500 A 12501 differing advection scheme can be choosed for the subgrid-scale TKE 12502 using parameter <a href="chapter_4.1.html#use_upstream_for_tke">use_upstream_for_tke</a>.</td> 12503 12504 12505 12506 12507 12508 12509 12510 </tr> 12511 12512 12513 12514 12515 12516 12517 <tr> 12518 12519 <td style="vertical-align: top;"><a name="scalar_exchange_coefficient"></a><b>scalar_exchange_coefficient</b></td> 12520 12521 <td style="vertical-align: top;">R</td> 12522 12523 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td> 12524 12525 <td style="vertical-align: top;">Scalar exchange coefficient for a leaf (dimensionless).<br> 12526 12527 12528 <br> 12529 12530 12531 This parameter is only of importance in cases in that both, <a href="../../../../../DEVELOPER_VERSION/chapter_4.1_adjusted.html#plant_canopy">plant_canopy</a> and <a href="../../../../../DEVELOPER_VERSION/chapter_4.1_adjusted.html#passive_scalar">passive_scalar</a>, are set <span style="font-style: italic;">.T.</span>. 12532 The value of the scalar exchange coefficient is required for the parametrisation of the sources and sinks of 12533 scalar concentration due to the canopy.</td> 12534 12535 </tr> 12536 12537 <tr> 12538 12539 12540 12541 12542 12543 12544 <td style="vertical-align: top;"> 12545 12546 12547 12548 12549 12550 12551 <p><a name="statistic_regions"></a><b>statistic_regions</b></p> 12552 12553 12554 12555 12556 12557 12558 12559 </td> 12560 12561 12562 12563 12564 12565 12566 <td style="vertical-align: top;">I</td> 12567 12568 12569 12570 12571 12572 12573 12574 <td style="vertical-align: top;"><i>0</i></td> 12575 12576 12577 12578 12579 12580 12581 12582 <td style="vertical-align: top;"> 12583 12584 12585 12586 12587 12588 12589 <p>Number of 12590 additional user-defined subdomains for which 12591 statistical analysis 12592 and corresponding output (profiles, time series) shall be 12593 made. </p> 12594 12595 12596 12597 12598 12599 12600 12601 12602 12603 12604 12605 12606 12607 <p>By default, vertical profiles and 12608 other statistical quantities 12609 are calculated as horizontal and/or volume average of the total model 12610 domain. Beyond that, these calculations can also be carried out for 12611 subdomains which can be defined using the field <a href="chapter_3.5.3.html">rmask </a>within the 12612 user-defined software 12613 (see <a href="chapter_3.5.3.html">chapter 12614 3.5.3</a>). The number of these subdomains is determined with the 12615 parameter <b>statistic_regions</b>. Maximum 9 additional 12616 subdomains 12617 are allowed. The parameter <a href="chapter_4.3.html#region">region</a> 12618 can be used to assigned names (identifier) to these subdomains which 12619 are then used in the headers 12620 of the output files and plots.</p> 12621 12622 12623 12624 12625 12626 12627 12628 12629 12630 12631 12632 12633 <p>If the default NetCDF 12634 output format is selected (see parameter <a href="chapter_4.2.html#data_output_format">data_output_format</a>), 12635 data for the total domain and all defined subdomains are output to the 12636 same file(s) (<a href="chapter_3.4.html#DATA_1D_PR_NETCDF">DATA_1D_PR_NETCDF</a>, 12637 <a href="chapter_3.4.html#DATA_1D_TS_NETCDF">DATA_1D_TS_NETCDF</a>). 12638 In case of <span style="font-weight: bold;">statistic_regions</span> 12639 > <span style="font-style: italic;">0</span>, 12640 data on the file for the different domains can be distinguished by a 12641 suffix which is appended to the quantity names. Suffix 0 means data for 12642 the total domain, suffix 1 means data for subdomain 1, etc.</p> 12643 12644 12645 12646 12647 12648 12649 12650 12651 12652 12653 12654 12655 <p>In 12656 case of <span style="font-weight: bold;">data_output_format</span> 12657 = <span style="font-style: italic;">'profil'</span>, 12658 individual local files for profiles (<a href="chapter_3.4.html#PLOT1D_DATA">PLOT1D_DATA</a>) are 12659 created for each subdomain. The individual subdomain files differ by 12660 their name (the 12661 number of the respective subdomain is attached, e.g. 12662 PLOT1D_DATA_1). In this case the name of the file with the data of 12663 the total domain is PLOT1D_DATA_0. If no subdomains 12664 are declared (<b>statistic_regions</b> = <i>0</i>), 12665 the name 12666 PLOT1D_DATA is used (this must be considered in the 12667 respective file connection statements of the <span style="font-weight: bold;">mrun</span> configuration 12668 file).</p> 12669 12670 12671 12672 12673 12674 12675 </td> 12676 12677 12678 12679 12680 12681 12682 </tr> 12683 12684 12685 12686 12687 12688 12689 <tr> 12690 12691 12692 12693 12694 12695 12696 <td style="vertical-align: top;"> 12697 12698 12699 12700 12701 12702 12703 <p><a name="surface_heatflux"></a><b>surface_heatflux</b></p> 12704 12705 12706 12707 12708 12709 12710 12711 </td> 12712 12713 12714 12715 12716 12717 12718 <td style="vertical-align: top;">R</td> 12719 12720 12721 12722 12723 12724 12725 12726 <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br> 12727 12728 12729 12730 12731 12732 12733 12734 heatflux<br> 12735 12736 12737 12738 12739 12740 12741 </span></td> 12742 12743 12744 12745 12746 12747 12748 <td style="vertical-align: top;"> 12749 12750 12751 12752 12753 12754 12755 <p>Kinematic sensible 12756 heat flux at the bottom surface (in K m/s). </p> 12757 12758 12759 12760 12761 12762 12763 12764 12765 12766 12767 12768 12769 12770 <p>If 12771 a value is assigned to this parameter, the internal two-dimensional 12772 surface heat flux field <span style="font-style: italic;">shf</span> 12773 is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span> as 12774 bottom (horizontally homogeneous) boundary condition for the 12775 temperature equation. This additionally requires that a Neumann 12776 condition must be used for the potential temperature (see <a href="#bc_pt_b">bc_pt_b</a>), 12777 because otherwise the resolved scale may contribute to 12778 the surface flux so that a constant value cannot be guaranteed. Also, 12779 changes of the 12780 surface temperature (see <a href="#pt_surface_initial_change">pt_surface_initial_change</a>) 12781 are not allowed. The parameter <a href="#random_heatflux">random_heatflux</a> 12782 can be used to impose random perturbations on the (homogeneous) surface 12783 heat 12784 flux field <span style="font-style: italic;">shf</span>. </p> 12785 12786 12787 12788 12789 12790 12791 12792 12793 12794 12795 12796 12797 12798 <p> 12799 In case of a non-flat <a href="#topography">topography</a>, the 12800 internal two-dimensional surface heat 12801 flux field <span style="font-style: italic;">shf</span> 12802 is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span> 12803 at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a> 12804 at the topography top face. The parameter<a href="#random_heatflux"> random_heatflux</a> 12805 can be used to impose random perturbations on this combined surface 12806 heat 12807 flux field <span style="font-style: italic;">shf</span>. 12808 </p> 12809 12810 12811 12812 12813 12814 12815 12816 12817 12818 12819 12820 12821 12822 <p>If no surface heat flux is assigned, <span style="font-style: italic;">shf</span> is calculated 12823 at each timestep by u<sub>*</sub> * theta<sub>*</sub> 12824 (of course only with <a href="#prandtl_layer">prandtl_layer</a> 12825 switched on). Here, u<sub>*</sub> 12826 and theta<sub>*</sub> are calculated from the Prandtl law 12827 assuming 12828 logarithmic wind and temperature 12829 profiles between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_pt_b">bc_pt_b</a>) 12830 must be used as bottom boundary condition for the potential temperature.</p> 12831 12832 12833 12834 12835 12836 12837 12838 12839 12840 12841 12842 12843 <p>See 12844 also <a href="#top_heatflux">top_heatflux</a>.</p> 12845 12846 12847 12848 12849 12850 12851 12852 </td> 12853 12854 12855 12856 12857 12858 12859 </tr> 12860 12861 12862 12863 12864 12865 12866 <tr> 12867 12868 12869 12870 12871 12872 12873 <td style="vertical-align: top;"> 12874 12875 12876 12877 12878 12879 12880 <p><a name="surface_pressure"></a><b>surface_pressure</b></p> 12881 12882 12883 12884 12885 12886 12887 12888 </td> 12889 12890 12891 12892 12893 12894 12895 <td style="vertical-align: top;">R</td> 12896 12897 12898 12899 12900 12901 12902 12903 <td style="vertical-align: top;"><i>1013.25</i></td> 12904 12905 12906 12907 12908 12909 12910 12911 <td style="vertical-align: top;"> 12912 12913 12914 12915 12916 12917 12918 <p>Atmospheric 12919 pressure at the surface (in hPa). </p> 12920 12921 12922 12923 12924 12925 12926 12927 Starting from this surface value, the vertical pressure 12928 profile is calculated once at the beginning of the run assuming a 12929 neutrally stratified 12930 atmosphere. This is needed for 12931 converting between the liquid water potential temperature and the 12932 potential temperature (see <a href="#cloud_physics">cloud_physics</a><span style="text-decoration: underline;"></span>).</td> 12933 12934 12935 12936 12937 12938 12939 12940 </tr> 12941 12942 12943 12944 12945 12946 12947 <tr> 12948 12949 12950 12951 12952 12953 12954 <td style="vertical-align: top;"> 12955 12956 12957 12958 12959 12960 12961 <p><a name="surface_scalarflux"></a><b>surface_scalarflux</b></p> 12962 12963 12964 12965 12966 12967 12968 12969 </td> 12970 12971 12972 12973 12974 12975 12976 <td style="vertical-align: top;">R</td> 12977 12978 12979 12980 12981 12982 12983 12984 <td style="vertical-align: top;"><i>0.0</i></td> 12985 12986 12987 12988 12989 12990 12991 12992 <td style="vertical-align: top;"> 12993 12994 12995 12996 12997 12998 12999 <p>Scalar flux at 13000 the surface (in kg/(m<sup>2</sup> s)). </p> 13001 13002 13003 13004 13005 13006 13007 13008 13009 13010 13011 13012 13013 13014 <p>If a non-zero value is assigned to this parameter, the 13015 respective scalar flux value is used 13016 as bottom (horizontally homogeneous) boundary condition for the scalar 13017 concentration equation. This additionally requires that a 13018 Neumann 13019 condition must be used for the scalar concentration (see <a href="#bc_s_b">bc_s_b</a>), 13020 because otherwise the resolved scale may contribute to 13021 the surface flux so that a constant value cannot be guaranteed. Also, 13022 changes of the 13023 surface scalar concentration (see <a href="#s_surface_initial_change">s_surface_initial_change</a>) 13024 are not allowed. <br> 13025 13026 13027 13028 13029 13030 13031 </p> 13032 13033 13034 13035 13036 13037 13038 13039 13040 13041 13042 13043 13044 13045 <p>If no surface scalar 13046 flux is assigned (<b>surface_scalarflux</b> 13047 = <i>0.0</i>), 13048 it is calculated at each timestep by u<sub>*</sub> * s<sub>*</sub> 13049 (of course only with Prandtl layer switched on). Here, s<sub>*</sub> 13050 is calculated from the Prandtl law assuming a logarithmic scalar 13051 concentration 13052 profile between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_s_b">bc_s_b</a>) 13053 must be used as bottom boundary condition for the scalar concentration.</p> 13054 13055 13056 13057 13058 13059 13060 13061 </td> 13062 13063 13064 13065 13066 13067 13068 </tr> 13069 13070 13071 13072 13073 13074 13075 <tr> 13076 13077 13078 13079 13080 13081 13082 <td style="vertical-align: top;"> 13083 13084 13085 13086 13087 13088 13089 <p><a name="surface_waterflux"></a><b>surface_waterflux</b></p> 13090 13091 13092 13093 13094 13095 13096 13097 </td> 13098 13099 13100 13101 13102 13103 13104 <td style="vertical-align: top;">R</td> 13105 13106 13107 13108 13109 13110 13111 13112 <td style="vertical-align: top;"><i>0.0</i></td> 13113 13114 13115 13116 13117 13118 13119 13120 <td style="vertical-align: top;"> 13121 13122 13123 13124 13125 13126 13127 <p>Kinematic 13128 water flux near the surface (in m/s). </p> 13129 13130 13131 13132 13133 13134 13135 13136 13137 13138 13139 13140 13141 13142 <p>If 13143 a non-zero value is assigned to this parameter, the 13144 respective water flux value is used 13145 as bottom (horizontally homogeneous) boundary condition for the 13146 humidity equation. This additionally requires that a Neumann 13147 condition must be used for the specific humidity / total water content 13148 (see <a href="#bc_q_b">bc_q_b</a>), 13149 because otherwise the resolved scale may contribute to 13150 the surface flux so that a constant value cannot be guaranteed. Also, 13151 changes of the 13152 surface humidity (see <a href="#q_surface_initial_change">q_surface_initial_change</a>) 13153 are not allowed.<br> 13154 13155 13156 13157 13158 13159 13160 </p> 13161 13162 13163 13164 13165 13166 13167 13168 13169 13170 13171 13172 13173 13174 <p>If no surface water 13175 flux is assigned (<b>surface_waterflux</b> 13176 = <i>0.0</i>), 13177 it is calculated at each timestep by u<sub>*</sub> * q<sub>*</sub> 13178 (of course only with Prandtl layer switched on). Here, q<sub>*</sub> 13179 is calculated from the Prandtl law assuming a logarithmic temperature 13180 profile between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_q_b">bc_q_b</a>) 13181 must be used as the bottom boundary condition for the humidity.</p> 13182 13183 13184 13185 13186 13187 13188 13189 </td> 13190 13191 13192 13193 13194 13195 13196 </tr> 13197 13198 13199 13200 13201 13202 13203 <tr> 13204 13205 13206 13207 13208 13209 13210 <td style="vertical-align: top;"> 13211 13212 13213 13214 13215 13216 13217 <p><a name="s_surface"></a><b>s_surface</b></p> 13218 13219 13220 13221 13222 13223 13224 13225 </td> 13226 13227 13228 13229 13230 13231 13232 <td style="vertical-align: top;">R</td> 13233 13234 13235 13236 13237 13238 13239 13240 <td style="vertical-align: top;"><i>0.0</i></td> 13241 13242 13243 13244 13245 13246 13247 13248 <td style="vertical-align: top;"> 13249 13250 13251 13252 13253 13254 13255 <p>Surface value 13256 of the passive scalar (in kg/m<sup>3</sup>). <br> 13257 13258 13259 13260 13261 13262 13263 13264 </p> 13265 13266 13267 13268 13269 13270 13271 13272 This parameter assigns the value of the passive scalar s at 13273 the surface (k=0)<b>.</b> Starting from this value, the 13274 initial vertical scalar concentration profile is constructed with<a href="#s_vertical_gradient"> 13275 s_vertical_gradient</a> and <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>.</td> 13276 13277 13278 13279 13280 13281 13282 13283 </tr> 13284 13285 13286 13287 13288 13289 13290 <tr> 13291 13292 13293 13294 13295 13296 13297 <td style="vertical-align: top;"> 13298 13299 13300 13301 13302 13303 13304 <p><a name="s_surface_initial_change"></a><b>s_surface_initial</b> 13305 <br> 13306 13307 13308 13309 13310 13311 13312 <b>_change</b></p> 13313 13314 13315 13316 13317 13318 13319 </td> 13320 13321 13322 13323 13324 13325 13326 <td style="vertical-align: top;">R</td> 13327 13328 13329 13330 13331 13332 13333 <td style="vertical-align: top;"><i>0.0</i></td> 13334 13335 13336 13337 13338 13339 13340 13341 <td style="vertical-align: top;"> 13342 13343 13344 13345 13346 13347 13348 <p>Change in 13349 surface scalar concentration to be made at the 13350 beginning of the 3d run (in kg/m<sup>3</sup>). </p> 13351 13352 13353 13354 13355 13356 13357 13358 13359 13360 13361 13362 13363 13364 <p>If <b>s_surface_initial_change</b><i> </i>is 13365 set to a 13366 non-zero 13367 value, the near surface scalar flux is not allowed to be given 13368 simultaneously (see <a href="#surface_scalarflux">surface_scalarflux</a>).</p> 13369 13370 13371 13372 13373 13374 13375 13376 </td> 13377 13378 13379 13380 13381 13382 13383 </tr> 13384 13385 13386 13387 13388 13389 13390 <tr> 13391 13392 13393 13394 13395 13396 13397 <td style="vertical-align: top;"> 13398 13399 13400 13401 13402 13403 13404 <p><a name="s_vertical_gradient"></a><b>s_vertical_gradient</b></p> 13405 13406 13407 13408 13409 13410 13411 13412 </td> 13413 13414 13415 13416 13417 13418 13419 <td style="vertical-align: top;">R (10)</td> 13420 13421 13422 13423 13424 13425 13426 13427 <td style="vertical-align: top;"><i>10 * 0</i><i>.0</i></td> 13428 13429 13430 13431 13432 13433 13434 13435 <td style="vertical-align: top;"> 13436 13437 13438 13439 13440 13441 13442 <p>Scalar 13443 concentration gradient(s) of the initial scalar 13444 concentration profile (in kg/m<sup>3 </sup>/ 13445 100 m). </p> 13446 13447 13448 13449 13450 13451 13452 13453 13454 13455 13456 13457 13458 13459 <p>The scalar gradient holds 13460 starting from the height level 13461 defined by <a href="#s_vertical_gradient_level">s_vertical_gradient_level 13462 </a>(precisely: for all uv levels k, where zu(k) > 13463 s_vertical_gradient_level, s_init(k) is set: s_init(k) = s_init(k-1) + 13464 dzu(k) * <b>s_vertical_gradient</b>) up to the top 13465 boundary or up to 13466 the next height level defined by <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>. 13467 A total of 10 different gradients for 11 height intervals (10 intervals 13468 if <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>(1) 13469 = <i>0.0</i>) can be assigned. The surface scalar value is 13470 assigned 13471 via <a href="#s_surface">s_surface</a>.<br> 13472 13473 13474 13475 13476 13477 13478 </p> 13479 13480 13481 13482 13483 13484 13485 13486 13487 13488 13489 13490 13491 13492 <p>Example: </p> 13493 13494 13495 13496 13497 13498 13499 13500 13501 13502 13503 13504 13505 13506 <ul> 13507 13508 13509 13510 13511 13512 13513 13514 13515 13516 13517 13518 13519 13520 <p><b>s_vertical_gradient</b> 13521 = <i>0.1</i>, <i>0.05</i>, <br> 13522 13523 13524 13525 13526 13527 13528 13529 <b>s_vertical_gradient_level</b> = <i>500.0</i>, 13530 <i>1000.0</i>,</p> 13531 13532 13533 13534 13535 13536 13537 13538 13539 13540 13541 13542 13543 13544 </ul> 13545 13546 13547 13548 13549 13550 13551 13552 13553 13554 13555 13556 13557 13558 <p>That 13559 defines the scalar concentration to be constant with 13560 height up to z = 500.0 m with a value given by <a href="#s_surface">s_surface</a>. 13561 For 500.0 m < z <= 1000.0 m the scalar gradient is 0.1 13562 kg/m<sup>3 </sup>/ 100 m and for z > 1000.0 m up to 13563 the top 13564 boundary it is 0.05 kg/m<sup>3 </sup>/ 100 m (it is 13565 assumed that the 13566 assigned height levels 13567 correspond with uv 13568 levels).</p> 13569 13570 13571 13572 13573 13574 13575 </td> 13576 13577 13578 13579 13580 13581 13582 </tr> 13583 13584 13585 13586 13587 13588 13589 <tr> 13590 13591 13592 13593 13594 13595 13596 <td style="vertical-align: top;"> 13597 13598 13599 13600 13601 13602 13603 <p><a name="s_vertical_gradient_level"></a><b>s_vertical_gradient_</b> 13604 <br> 13605 13606 13607 13608 13609 13610 13611 <b>level</b></p> 13612 13613 13614 13615 13616 13617 13618 </td> 13619 13620 13621 13622 13623 13624 13625 <td style="vertical-align: top;">R (10)</td> 13626 13627 13628 13629 13630 13631 13632 <td style="vertical-align: top;"> 13633 13634 13635 13636 13637 13638 13639 <p><i>10 *</i> 13640 <i>0.0</i></p> 13641 13642 13643 13644 13645 13646 13647 </td> 13648 13649 13650 13651 13652 13653 13654 <td style="vertical-align: top;"> 13655 13656 13657 13658 13659 13660 13661 <p>Height level from 13662 which on the scalar gradient defined by <a href="#s_vertical_gradient">s_vertical_gradient</a> 13663 is effective (in m). </p> 13664 13665 13666 13667 13668 13669 13670 13671 13672 13673 13674 13675 13676 13677 <p>The height levels 13678 are to be assigned in ascending order. The 13679 default values result in a scalar concentration constant with height 13680 regardless of the values of <a href="#s_vertical_gradient">s_vertical_gradient</a> 13681 (unless the top boundary of the model is higher than 100000.0 m). For 13682 the 13683 piecewise construction of scalar concentration profiles see <a href="#s_vertical_gradient">s_vertical_gradient</a>.</p> 13684 13685 13686 13687 13688 13689 13690 13691 </td> 13692 13693 13694 13695 13696 13697 13698 </tr> 13699 13700 13701 13702 13703 13704 13705 <tr> 13706 13707 13708 13709 13710 13711 13712 <td style="vertical-align: top;"> 13713 13714 13715 13716 13717 13718 13719 <p><a name="timestep_scheme"></a><b>timestep_scheme</b></p> 13720 13721 13722 13723 13724 13725 13726 13727 </td> 13728 13729 13730 13731 13732 13733 13734 <td style="vertical-align: top;">C * 20</td> 13735 13736 13737 13738 13739 13740 13741 13742 <td style="vertical-align: top;"> 13743 13744 13745 13746 13747 13748 13749 <p><i>'runge</i><br> 13750 13751 13752 13753 13754 13755 13756 13757 <i>kutta-3'</i></p> 13758 13759 13760 13761 13762 13763 13764 </td> 13765 13766 13767 13768 13769 13770 13771 <td style="vertical-align: top;"> 13772 13773 13774 13775 13776 13777 13778 <p>Time step scheme to 13779 be used for the integration of the prognostic 13780 variables. </p> 13781 13782 13783 13784 13785 13786 13787 13788 13789 13790 13791 13792 13793 13794 <p>The user can choose between 13795 the following schemes:<br> 13796 13797 13798 13799 13800 13801 13802 </p> 13803 13804 13805 13806 13807 13808 13809 13810 13811 13812 13813 13814 13815 13816 <p><span style="font-style: italic;">'runge-kutta-3'</span><br> 13817 13818 13819 13820 13821 13822 13823 13824 </p> 13825 13826 13827 13828 13829 13830 13831 13832 13833 13834 13835 13836 13837 13838 <div style="margin-left: 40px;">Third order 13839 Runge-Kutta scheme.<br> 13840 13841 13842 13843 13844 13845 13846 13847 This scheme requires the use of <a href="#momentum_advec">momentum_advec</a> 13848 = <a href="#scalar_advec">scalar_advec</a> 13849 = '<i>pw-scheme'</i>. Please refer to the <a href="../tec/numerik.heiko/zeitschrittverfahren.pdf">documentation 13850 on PALM's time integration schemes (28p., in German)</a> 13851 fur further details.<br> 13852 13853 13854 13855 13856 13857 13858 </div> 13859 13860 13861 13862 13863 13864 13865 13866 13867 13868 13869 13870 13871 13872 <p><span style="font-style: italic;">'runge-kutta-2'</span><br> 13873 13874 13875 13876 13877 13878 13879 13880 </p> 13881 13882 13883 13884 13885 13886 13887 13888 13889 13890 13891 13892 13893 13894 <div style="margin-left: 40px;">Second order 13895 Runge-Kutta scheme.<br> 13896 13897 13898 13899 13900 13901 13902 13903 For special features see <b>timestep_scheme</b> = '<i>runge-kutta-3'</i>.<br> 13904 13905 13906 13907 13908 13909 13910 13911 </div> 13912 13913 13914 13915 13916 13917 13918 <br> 13919 13920 13921 13922 13923 13924 13925 <span style="font-style: italic;"><span style="font-style: italic;">'leapfrog'</span><br> 13926 13927 13928 13929 13930 13931 13932 13933 <br> 13934 13935 13936 13937 13938 13939 13940 </span> 13941 13942 13943 13944 13945 13946 13947 <div style="margin-left: 40px;">Second 13948 order leapfrog scheme.<br> 13949 13950 13951 13952 13953 13954 13955 13956 Although this scheme requires a constant timestep (because it is 13957 centered in time), is even applied in case of changes in 13958 timestep. Therefore, only small 13959 changes of the timestep are allowed (see <a href="#dt">dt</a>). 13960 However, an Euler timestep is always used as the first timestep of an 13961 initiali run. When using the Bott-Chlond scheme for scalar advection 13962 (see <a href="#scalar_advec">scalar_advec</a>), 13963 the prognostic equation for potential temperature will be calculated 13964 with the Euler scheme, although the leapfrog scheme is switched 13965 on. <br> 13966 13967 13968 13969 13970 13971 13972 13973 The leapfrog scheme must not be used together with the upstream-spline 13974 scheme for calculating the advection (see <a href="#scalar_advec">scalar_advec</a> 13975 = '<i>ups-scheme'</i> and <a href="#momentum_advec">momentum_advec</a> 13976 = '<i>ups-scheme'</i>).<br> 13977 13978 13979 13980 13981 13982 13983 </div> 13984 13985 13986 13987 13988 13989 13990 <br> 13991 13992 13993 13994 13995 13996 13997 13998 <span style="font-style: italic;">'</span><span style="font-style: italic;"><span style="font-style: italic;">leapfrog+euler'</span><br> 13999 14000 14001 14002 14003 14004 14005 14006 <br> 14007 14008 14009 14010 14011 14012 14013 </span> 14014 14015 14016 14017 14018 14019 14020 <div style="margin-left: 40px;">The 14021 leapfrog scheme is used, but 14022 after each change of a timestep an Euler timestep is carried out. 14023 Although this method is theoretically correct (because the pure 14024 leapfrog method does not allow timestep changes), the divergence of the 14025 velocity field (after applying the pressure solver) may be 14026 significantly larger than with <span style="font-style: italic;">'leapfrog'</span>.<br> 14027 14028 14029 14030 14031 14032 14033 14034 </div> 14035 14036 14037 14038 14039 14040 14041 <br> 14042 14043 14044 14045 14046 14047 14048 <span style="font-style: italic;">'euler'</span><br> 14049 14050 14051 14052 14053 14054 14055 14056 <br> 14057 14058 14059 14060 14061 14062 14063 14064 14065 14066 14067 14068 14069 14070 <div style="margin-left: 40px;">First order 14071 Euler scheme. <br> 14072 14073 14074 14075 14076 14077 14078 14079 The Euler scheme must be used when treating the advection terms with 14080 the upstream-spline scheme (see <a href="#scalar_advec">scalar_advec</a> 14081 = <span style="font-style: italic;">'ups-scheme'</span> 14082 and <a href="#momentum_advec">momentum_advec</a> 14083 = <span style="font-style: italic;">'ups-scheme'</span>).</div> 14084 14085 14086 14087 14088 14089 14090 14091 <br> 14092 14093 14094 14095 14096 14097 14098 <br> 14099 14100 14101 14102 14103 14104 14105 A differing timestep scheme can be choosed for the 14106 subgrid-scale TKE using parameter <a href="#use_upstream_for_tke">use_upstream_for_tke</a>.<br> 14107 14108 14109 14110 14111 14112 14113 14114 </td> 14115 14116 14117 14118 14119 14120 14121 </tr> 14122 14123 14124 14125 14126 14127 14128 <tr> 14129 14130 14131 14132 14133 14134 14135 <td style="text-align: left; vertical-align: top;"><span style="font-weight: bold;"><a name="topography"></a></span><span style="font-weight: bold;">topography</span></td> 14136 14137 14138 14139 14140 14141 14142 14143 <td style="vertical-align: top;">C * 40</td> 14144 14145 14146 14147 14148 14149 14150 <td style="vertical-align: top;"><span style="font-style: italic;">'flat'</span></td> 14151 14152 14153 14154 14155 14156 14157 <td> 14158 14159 14160 14161 14162 14163 14164 <p>Topography mode. </p> 14165 14166 14167 14168 14169 14170 14171 14172 14173 14174 14175 14176 14177 14178 <p>The user can 14179 choose between the following modes:<br> 14180 14181 14182 14183 14184 14185 14186 </p> 14187 14188 14189 14190 14191 14192 14193 14194 14195 14196 14197 14198 14199 14200 <p><span style="font-style: italic;">'flat'</span><br> 14201 14202 14203 14204 14205 14206 14207 </p> 14208 14209 14210 14211 14212 14213 14214 14215 14216 14217 14218 14219 14220 14221 <div style="margin-left: 40px;">Flat surface.</div> 14222 14223 14224 14225 14226 14227 14228 14229 14230 14231 14232 14233 14234 14235 <p><span style="font-style: italic;">'single_building'</span><br> 14236 14237 14238 14239 14240 14241 14242 14243 </p> 14244 14245 14246 14247 14248 14249 14250 14251 14252 14253 14254 14255 14256 14257 <div style="margin-left: 40px;">Flow 14258 around a single rectangular building mounted on a flat surface.<br> 14259 14260 14261 14262 14263 14264 14265 14266 The building size and location can be specified by the parameters <a href="#building_height">building_height</a>, <a href="#building_length_x">building_length_x</a>, <a href="#building_length_y">building_length_y</a>, <a href="#building_wall_left">building_wall_left</a> and <a href="#building_wall_south">building_wall_south</a>.<font color="#000000"><br></font></div> 14267 14268 14269 14270 14271 14272 14273 14274 <span style="font-style: italic;"></span> 14275 14276 14277 14278 14279 14280 14281 <p><span style="font-style: italic;">'single_street_canyon'</span><br> 14282 14283 14284 14285 14286 14287 14288 14289 </p> 14290 14291 14292 14293 14294 14295 14296 14297 14298 14299 14300 14301 14302 14303 <div style="margin-left: 40px;">Flow 14304 over a single, quasi-2D street canyon of infinite length oriented either in x- or in y-direction.<br> 14305 14306 14307 14308 14309 14310 14311 14312 The canyon size, orientation and location can be specified by the parameters <a href="chapter_4.1.html#canyon_height">canyon_height</a> plus <span style="font-weight: bold;">either</span> <a href="chapter_4.1.html#canyon_width_x">canyon_width_x</a> and <a href="chapter_4.1.html#canyon_wall_left">canyon_wall_left</a> <span style="font-weight: bold;">or</span> <a href="chapter_4.1.html#canyon_width_y">canyon_width_y</a> and <a href="chapter_4.1.html#canyon_wall_south">canyon_wall_south</a>.<font color="#000000"><br></font></div> 14313 14314 14315 14316 14317 14318 14319 14320 <span style="font-style: italic;"></span> <span style="font-style: italic;"></span><p><span style="font-style: italic;">'read_from_file'</span><br> 14321 14322 14323 14324 14325 14326 14327 14328 </p> 14329 14330 14331 14332 14333 14334 14335 14336 14337 14338 14339 14340 14341 14342 <div style="margin-left: 40px;">Flow around 14343 arbitrary topography.<br> 14344 14345 14346 14347 14348 14349 14350 14351 This mode requires the input file <a href="chapter_3.4.html#TOPOGRAPHY_DATA">TOPOGRAPHY_DATA</a><font color="#000000">. This file contains </font><font color="#000000"><font color="#000000">the </font></font><font color="#000000">arbitrary topography </font><font color="#000000"><font color="#000000">height 14352 information</font></font><font color="#000000"> 14353 in m. These data <span style="font-style: italic;"></span>must 14354 exactly match the horizontal grid.<br></font> </div> 14355 14356 14357 14358 14359 14360 14361 <span style="font-style: italic;"><br> 14362 14363 14364 14365 14366 14367 14368 </span><font color="#000000"> 14369 Alternatively, the user may add code to the user interface subroutine <a href="chapter_3.5.1.html#user_init_grid">user_init_grid</a> 14370 to allow further topography modes. </font>These require to explicitly set the<span style="font-weight: bold;"> </span><a href="#topography_grid_convention">topography_grid_convention</a> to either <span style="font-style: italic;">'cell_edge'</span> or <span style="font-style: italic;">'cell_center'</span>.<br> 14371 14372 <font color="#000000"> 14373 14374 14375 14376 14377 <br> 14378 14379 14380 14381 14382 14383 14384 14385 Non-flat <span style="font-weight: bold;">topography</span> 14386 modes may assign a</font> 14387 kinematic sensible<font color="#000000"> <a href="chapter_4.1.html#wall_heatflux">wall_heatflux</a> at the five topography faces.</font><br> 14388 14389 <font color="#000000"> 14390 14391 14392 14393 14394 <br> 14395 14396 14397 14398 14399 14400 14401 14402 All non-flat <span style="font-weight: bold;">topography</span> 14403 modes </font>require the use of <a href="#momentum_advec">momentum_advec</a> 14404 = <a href="#scalar_advec">scalar_advec</a> 14405 = '<i>pw-scheme'</i>, <a href="chapter_4.2.html#psolver">psolver</a> 14406 /= <i>'sor</i><i>'</i>, 14407 <i> </i><a href="#alpha_surface">alpha_surface</a> 14408 = 0.0,<span style="font-style: italic;"></span> <a style="" href="#galilei_transformation">galilei_transformation</a> 14409 = <span style="font-style: italic;">.F.</span>, <a href="#cloud_physics">cloud_physics </a> = <span style="font-style: italic;">.F.</span>, <a href="#cloud_droplets">cloud_droplets</a> = <span style="font-style: italic;">.F.</span>, <a href="#humidity">humidity</a> = <span style="font-style: italic;">.F.</span>, and <a href="#prandtl_layer">prandtl_layer</a> = .T..<br> 14410 14411 14412 14413 14414 14415 14416 14417 <font color="#000000"><br> 14418 14419 14420 14421 14422 14423 14424 14425 Note that an inclined model domain requires the use of <span style="font-weight: bold;">topography</span> = <span style="font-style: italic;">'flat'</span> and a 14426 nonzero </font><a href="#alpha_surface">alpha_surface</a>.</td> 14427 14428 14429 14430 14431 14432 14433 14434 </tr> 14435 14436 14437 14438 14439 14440 14441 <tr><td style="vertical-align: top;"><a name="topography_grid_convention"></a><span style="font-weight: bold;">topography_grid_</span><br style="font-weight: bold;"><span style="font-weight: bold;">convention</span></td><td style="vertical-align: top;">C*11</td><td style="vertical-align: top;"><span style="font-style: italic;">default depends on value of <a href="chapter_4.1.html#topography">topography</a>; see text for details</span></td><td>Convention for defining the topography grid.<br><br>Possible values are<br><ul><li><span style="font-style: italic;">'cell_edge': </span>the distance between cell edges defines the extent of topography. This setting is normally for <span style="font-style: italic;">generic topographies</span>, i.e. topographies that are constructed using length parameters. For example, <a href="chapter_4.1.html#topography">topography</a> = <span style="font-style: italic;">'single_building'</span> is constructed using <a href="chapter_4.1.html#building_length_x">building_length_x</a> and <a href="chapter_4.1.html#building_length_y">building_length_y</a>. 14442 The advantage of this setting is that the actual size of generic 14443 topography is independent of the grid size, provided that the length 14444 parameters are an integer multiple of the grid lengths <a href="chapter_4.1.html#dx">dx</a> and <a href="chapter_4.1.html#dy">dy</a>. This is convenient for resolution parameter studies.</li><li><span style="font-style: italic;">'cell_center'</span><span style="font-style: italic;">: </span>the number of topography cells define the extent of topography. This setting is normally for <span style="font-style: italic;">rastered real topographies</span> derived from digital elevation models. For example, <a href="chapter_4.1.html#topography">topography</a> = <span style="font-style: italic;">'read_from_file'</span> is constructed using the input file <a href="chapter_3.4.html#TOPOGRAPHY_DATA">TOPOGRAPHY_DATA</a><font color="#000000">. </font>The 14445 advantage of this setting is that the rastered topography cells of 14446 the input file are directly mapped to topography grid boxes in PALM. <span style="font-style: italic;"></span></li></ul>The example files <big><code>example_topo_file</code></big> and <big><code>example_building</code></big> in <big><code>trunk/EXAMPLES/</code></big> 14447 illustrate the difference between 14448 both approaches. Both examples simulate a single building and yield the 14449 same results. The former uses a rastered topography input file with <span style="font-style: italic;">'cell_center'</span> convention, the latter applies a generic topography with <span style="font-style: italic;">'cell_edge'</span> convention.<br><br>The default value is<br><ul><li><span style="font-style: italic;">'cell_edge' </span>if <a href="chapter_4.1.html#topography">topography</a> = <span style="font-style: italic;">'single_building'</span> or <span style="font-style: italic;">'single_street_canyon'</span>,</li><li><span style="font-style: italic;">'cell_center'</span><span style="font-style: italic;"></span> if <a href="chapter_4.1.html#topography">topography</a> = <span style="font-style: italic;">'read_from_file'</span>,</li><li><span style="font-style: italic;">none (' '</span> ) otherwise, leading to an abort if <span style="font-weight: bold;">topography_grid_convention</span> is not set.</li></ul>This means that <br><ul><li>For PALM simulations using a <span style="font-style: italic;">user-defined topography</span>, the<span style="font-weight: bold;"> topography_grid_convention</span> must be explicitly set to either <span style="font-style: italic;">'cell_edge'</span> or <span style="font-style: italic;">'cell_center'</span>.</li><li>For PALM simulations using a <span style="font-style: italic;">standard topography</span> <span style="font-style: italic;">('single_building'</span>, <span style="font-style: italic;">'single_street_canyon'</span> or <span style="font-style: italic;">'read_from_file')</span>, it is possible but not required to set the <span style="font-weight: bold;">topography_grid_convention</span> because appropriate default values apply.</li></ul></td></tr><tr> 14450 14451 14452 14453 14454 14455 14456 <td style="vertical-align: top;"><a name="top_heatflux"></a><span style="font-weight: bold;">top_heatflux</span></td> 14457 14458 14459 14460 14461 14462 14463 <td style="vertical-align: top;">R</td> 14464 14465 14466 14467 14468 14469 14470 <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br> 14471 14472 14473 14474 14475 14476 14477 14478 heatflux</span></td> 14479 14480 14481 14482 14483 14484 14485 <td style="vertical-align: top;"> 14486 14487 14488 14489 14490 14491 14492 <p>Kinematic 14493 sensible heat flux at the top boundary (in K m/s). </p> 14494 14495 14496 14497 14498 14499 14500 14501 14502 14503 14504 14505 14506 14507 <p>If a value is assigned to this parameter, the internal 14508 two-dimensional surface heat flux field <span style="font-family: monospace;">tswst</span> is 14509 initialized with the value of <span style="font-weight: bold;">top_heatflux</span> as 14510 top (horizontally homogeneous) boundary condition for the 14511 temperature equation. This additionally requires that a Neumann 14512 condition must be used for the potential temperature (see <a href="chapter_4.1.html#bc_pt_t">bc_pt_t</a>), 14513 because otherwise the resolved scale may contribute to 14514 the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span> </p> 14515 14516 14517 14518 14519 14520 14521 14522 14523 14524 14525 14526 14527 14528 <p><span style="font-weight: bold;">Note:</span><br> 14529 14530 14531 14532 14533 14534 14535 The 14536 application of a top heat flux additionally requires the setting of 14537 initial parameter <a href="#use_top_fluxes">use_top_fluxes</a> 14538 = .T..<span style="font-style: italic;"></span><span style="font-weight: bold;"></span> </p> 14539 14540 14541 14542 14543 14544 14545 14546 14547 14548 14549 14550 14551 <p>No 14552 Prandtl-layer is available at the top boundary so far.</p> 14553 14554 14555 14556 14557 14558 14559 14560 14561 14562 14563 14564 14565 <p>See 14566 also <a href="#surface_heatflux">surface_heatflux</a>.</p> 14567 14568 14569 14570 14571 14572 14573 14574 </td> 14575 14576 14577 14578 14579 14580 14581 </tr> 14582 14583 14584 14585 14586 14587 14588 <tr> 14589 14590 14591 14592 14593 14594 14595 <td style="vertical-align: top;"><a name="top_momentumflux_u"></a><span style="font-weight: bold;">top_momentumflux_u</span></td> 14596 14597 14598 14599 14600 14601 14602 <td style="vertical-align: top;">R</td> 14603 14604 14605 14606 14607 14608 14609 <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed momentumflux</span></td> 14610 14611 14612 14613 14614 14615 14616 <td style="vertical-align: top;">Momentum flux along x at the top boundary (in m2/s2).<br> 14617 14618 14619 14620 14621 14622 14623 14624 14625 14626 14627 14628 14629 <p>If a value is assigned to this parameter, the internal 14630 two-dimensional u-momentum flux field <span style="font-family: monospace;">uswst</span> is 14631 initialized with the value of <span style="font-weight: bold;">top_momentumflux_u</span> as 14632 top (horizontally homogeneous) boundary condition for the u-momentum equation.</p> 14633 14634 14635 14636 14637 14638 14639 14640 14641 14642 14643 14644 14645 <p><span style="font-weight: bold;">Notes:</span><br> 14646 14647 14648 14649 14650 14651 14652 The 14653 application of a top momentum flux additionally requires the setting of 14654 initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a> 14655 = .T.. Setting of <span style="font-weight: bold;">top_momentumflux_u</span> requires setting of <a href="#top_momentumflux_v">top_momentumflux_v</a> also.</p> 14656 14657 14658 14659 14660 14661 14662 14663 14664 14665 14666 14667 14668 <p>A Neumann 14669 condition should be used for the u velocity component (see <a href="chapter_4.1.html#bc_uv_t">bc_uv_t</a>), 14670 because otherwise the resolved scale may contribute to 14671 the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span> </p> 14672 14673 14674 14675 14676 14677 14678 14679 <span style="font-weight: bold;"></span> 14680 14681 14682 14683 14684 14685 14686 <p>No 14687 Prandtl-layer is available at the top boundary so far.</p> 14688 14689 14690 14691 14692 14693 14694 14695 14696 14697 14698 14699 14700 <p> The <a href="chapter_3.8.html">coupled</a> ocean parameter file <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a> should include dummy REAL value assignments to both <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> and <a href="chapter_4.1.html#top_momentumflux_v">top_momentumflux_v</a> (e.g. top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to enable the momentum flux coupling.</p> 14701 14702 14703 14704 14705 14706 14707 </td> 14708 14709 14710 14711 14712 14713 14714 </tr> 14715 14716 14717 14718 14719 14720 14721 <tr> 14722 14723 14724 14725 14726 14727 14728 <td style="vertical-align: top;"><a name="top_momentumflux_v"></a><span style="font-weight: bold;">top_momentumflux_v</span></td> 14729 14730 14731 14732 14733 14734 14735 <td style="vertical-align: top;">R</td> 14736 14737 14738 14739 14740 14741 14742 <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed momentumflux</span></td> 14743 14744 14745 14746 14747 14748 14749 <td style="vertical-align: top;">Momentum flux along y at the top boundary (in m2/s2).<br> 14750 14751 14752 14753 14754 14755 14756 14757 14758 14759 14760 14761 14762 <p>If a value is assigned to this parameter, the internal 14763 two-dimensional v-momentum flux field <span style="font-family: monospace;">vswst</span> is 14764 initialized with the value of <span style="font-weight: bold;">top_momentumflux_v</span> as 14765 top (horizontally homogeneous) boundary condition for the v-momentum equation.</p> 14766 14767 14768 14769 14770 14771 14772 14773 14774 14775 14776 14777 14778 <p><span style="font-weight: bold;">Notes:</span><br> 14779 14780 14781 14782 14783 14784 14785 The 14786 application of a top momentum flux additionally requires the setting of 14787 initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a> 14788 = .T.. Setting of <span style="font-weight: bold;">top_momentumflux_v</span> requires setting of <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> also.</p> 14789 14790 14791 14792 14793 14794 14795 14796 14797 14798 14799 14800 14801 <p>A Neumann 14802 condition should be used for the v velocity component (see <a href="chapter_4.1.html#bc_uv_t">bc_uv_t</a>), 14803 because otherwise the resolved scale may contribute to 14804 the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span> </p> 14805 14806 14807 14808 14809 14810 14811 14812 <span style="font-weight: bold;"></span> 14813 14814 14815 14816 14817 14818 14819 <p>No 14820 Prandtl-layer is available at the top boundary so far.</p> 14821 14822 14823 14824 14825 14826 14827 14828 14829 14830 14831 14832 14833 <p> The <a href="chapter_3.8.html">coupled</a> ocean parameter file <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a> should include dummy REAL value assignments to both <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> and <a href="chapter_4.1.html#top_momentumflux_v">top_momentumflux_v</a> (e.g. top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to enable the momentum flux coupling.</p> 14834 14835 14836 14837 14838 14839 14840 </td> 14841 14842 14843 14844 14845 14846 14847 </tr> 14848 14849 14850 14851 14852 14853 14854 <tr> 14855 14856 14857 14858 14859 14860 14861 <td style="vertical-align: top;"><a name="top_salinityflux"></a><span style="font-weight: bold;">top_salinityflux</span></td> 14862 14863 14864 14865 14866 14867 14868 <td style="vertical-align: top;">R</td> 14869 14870 14871 14872 14873 14874 14875 <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br> 14876 14877 14878 14879 14880 14881 14882 14883 salinityflux</span></td> 14884 14885 14886 14887 14888 14889 14890 <td style="vertical-align: top;"> 14891 14892 14893 14894 14895 14896 14897 <p>Kinematic 14898 salinity flux at the top boundary, i.e. the sea surface (in psu m/s). </p> 14899 14900 14901 14902 14903 14904 14905 14906 14907 14908 14909 14910 14911 14912 <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p> 14913 14914 14915 14916 14917 14918 14919 14920 14921 14922 14923 14924 14925 <p>If a value is assigned to this parameter, the internal 14926 two-dimensional surface heat flux field <span style="font-family: monospace;">saswst</span> is 14927 initialized with the value of <span style="font-weight: bold;">top_salinityflux</span> as 14928 top (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann 14929 condition must be used for the salinity (see <a href="chapter_4.1.html#bc_sa_t">bc_sa_t</a>), 14930 because otherwise the resolved scale may contribute to 14931 the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span> </p> 14932 14933 14934 14935 14936 14937 14938 14939 14940 14941 14942 14943 14944 14945 <p><span style="font-weight: bold;">Note:</span><br> 14946 14947 14948 14949 14950 14951 14952 The 14953 application of a salinity flux at the model top additionally requires the setting of 14954 initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a> 14955 = .T..<span style="font-style: italic;"></span><span style="font-weight: bold;"></span> </p> 14956 14957 14958 14959 14960 14961 14962 14963 14964 14965 14966 14967 14968 <p>See 14969 also <a href="chapter_4.1.html#bottom_salinityflux">bottom_salinityflux</a>.</p> 14970 14971 14972 14973 14974 14975 14976 </td> 14977 14978 14979 14980 14981 14982 14983 </tr> 14984 14985 14986 14987 14988 14989 14990 <tr><td style="vertical-align: top;"><a name="turbulent_inflow"></a><span style="font-weight: bold;">turbulent_inflow</span></td><td style="vertical-align: top;">L</td><td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td><td style="vertical-align: top;">Generates a turbulent inflow at side boundaries using a turbulence recycling method.<br><br>Turbulent inflow is realized using the turbulence recycling method from Lund et al. (1998, J. Comp. Phys., <span style="font-weight: bold;">140</span>, 233-258) modified by Kataoka and Mizuno (2002, Wind and Structures, <span style="font-weight: bold;">5</span>, 379-392).<br><br>A turbulent inflow requires Dirichlet conditions at the respective inflow boundary. <span style="font-weight: bold;">So far, a turbulent inflow is realized from the left (west) side only, i.e. </span><a style="font-weight: bold;" href="chapter_4.1.html#bc_lr">bc_lr</a><span style="font-weight: bold;"> =</span><span style="font-style: italic; font-weight: bold;"> 'dirichlet/radiation'</span><span style="font-weight: bold;"> is required!</span><br><br>The initial (quasi-stationary) turbulence field should be generated by a precursor run and used by setting <a href="chapter_4.1.html#initializing_actions">initializing_actions</a> =<span style="font-style: italic;"> 'cyclic_fill'</span>.<br><br>The distance of the recycling plane from the inflow boundary can be set with parameter <a href="chapter_4.1.html#recycling_width">recycling_width</a>. 14991 The heigth above ground above which the turbulence signal is not used 14992 for recycling and the width of the layer within the magnitude of 14993 the turbulence signal is damped from 100% to 0% can be set with 14994 parameters <a href="chapter_4.1.html#inflow_damping_height">inflow_damping_height</a> and <a href="chapter_4.1.html#inflow_damping_width">inflow_damping_width</a>.<br><br>The detailed setup for a turbulent inflow is described in <a href="chapter_3.9.html">chapter 3.9</a>.</td></tr><tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="u_bulk"></a>u_bulk</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td><td>u-component of the predefined bulk velocity (in m/s).<br><br>This parameter comes into effect if <a href="#conserve_volume_flow">conserve_volume_flow</a> = <span style="font-style: italic;">.T.</span> and <a href="#conserve_volume_flow_mode">conserve_volume_flow_mode</a> = <span style="font-style: italic;">'bulk_velocity'</span>.</td></tr><tr> 14995 14996 14997 14998 14999 15000 15001 <td style="vertical-align: top;"> 15002 15003 15004 15005 15006 15007 15008 <p><a name="ug_surface"></a><span style="font-weight: bold;">ug_surface</span></p> 15009 15010 15011 15012 15013 15014 15015 15016 </td> 15017 15018 15019 15020 15021 15022 15023 <td style="vertical-align: top;">R<br> 15024 15025 15026 15027 15028 15029 15030 </td> 15031 15032 15033 15034 15035 15036 15037 15038 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br> 15039 15040 15041 15042 15043 15044 15045 </td> 15046 15047 15048 15049 15050 15051 15052 15053 <td style="vertical-align: top;">u-component of the 15054 geostrophic 15055 wind at the surface (in m/s).<br> 15056 15057 15058 15059 15060 15061 15062 <br> 15063 15064 15065 15066 15067 15068 15069 15070 This parameter assigns the value of the u-component of the geostrophic 15071 wind (ug) at the surface (k=0). Starting from this value, the initial 15072 vertical profile of the <br> 15073 15074 15075 15076 15077 15078 15079 15080 u-component of the geostrophic wind is constructed with <a href="#ug_vertical_gradient">ug_vertical_gradient</a> 15081 and <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>. 15082 The 15083 profile constructed in that way is used for creating the initial 15084 vertical velocity profile of the 3d-model. Either it is applied, as it 15085 has been specified by the user (<a href="#initializing_actions">initializing_actions</a> 15086 = 'set_constant_profiles') or it is used for calculating a stationary 15087 boundary layer wind profile (<a href="#initializing_actions">initializing_actions</a> 15088 = 'set_1d-model_profiles'). If ug is constant with height (i.e. ug(k)=<span style="font-weight: bold;">ug_surface</span>) 15089 and has a large 15090 value, it is recommended to use a Galilei-transformation of the 15091 coordinate system, if possible (see <a href="#galilei_transformation">galilei_transformation</a>), 15092 in order to obtain larger time steps.<br> 15093 15094 15095 15096 15097 15098 15099 <br> 15100 15101 15102 15103 15104 15105 15106 <span style="font-weight: bold;">Attention:</span><br> 15107 15108 15109 15110 15111 15112 15113 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), 15114 this parameter gives the geostrophic velocity value (i.e. the pressure gradient) at the sea surface, which is 15115 at k=nzt. The profile is then constructed from the surface down to the 15116 bottom of the model.<br> 15117 15118 15119 15120 15121 15122 15123 </td> 15124 15125 15126 15127 15128 15129 15130 </tr> 15131 15132 15133 15134 15135 15136 15137 15138 <tr> 15139 15140 15141 15142 15143 15144 15145 <td style="vertical-align: top;"> 15146 15147 15148 15149 15150 15151 15152 <p><a name="ug_vertical_gradient"></a><span style="font-weight: bold;">ug_vertical_gradient</span></p> 15153 15154 15155 15156 15157 15158 15159 15160 </td> 15161 15162 15163 15164 15165 15166 15167 <td style="vertical-align: top;">R(10)<br> 15168 15169 15170 15171 15172 15173 15174 15175 </td> 15176 15177 15178 15179 15180 15181 15182 <td style="vertical-align: top;"><span style="font-style: italic;">10 15183 * 0.0</span><br> 15184 15185 15186 15187 15188 15189 15190 </td> 15191 15192 15193 15194 15195 15196 15197 <td style="vertical-align: top;">Gradient(s) of the initial 15198 profile of the u-component of the geostrophic wind (in 15199 1/100s).<br> 15200 15201 15202 15203 15204 15205 15206 <br> 15207 15208 15209 15210 15211 15212 15213 15214 The gradient holds starting from the height level defined by <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a> 15215 (precisely: for all uv levels k where zu(k) > <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>, 15216 ug(k) is set: ug(k) = ug(k-1) + dzu(k) * <span style="font-weight: bold;">ug_vertical_gradient</span>) 15217 up to the top 15218 boundary or up to the next height level defined by <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>. 15219 A 15220 total of 10 different gradients for 11 height intervals (10 15221 intervals if <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>(1) 15222 = 0.0) can be assigned. The surface geostrophic wind is assigned by <a href="#ug_surface">ug_surface</a>.<br> 15223 15224 15225 15226 15227 15228 15229 <br> 15230 15231 15232 15233 15234 15235 15236 <span style="font-weight: bold;">Attention:</span><br> 15237 15238 15239 15240 15241 15242 15243 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), 15244 the profile is constructed like described above, but starting from the 15245 sea surface (k=nzt) down to the bottom boundary of the model. Height 15246 levels have then to be given as negative values, e.g. <span style="font-weight: bold;">ug_vertical_gradient_level</span> = <span style="font-style: italic;">-500.0</span>, <span style="font-style: italic;">-1000.0</span>.<br> 15247 15248 15249 15250 15251 15252 15253 </td> 15254 15255 15256 15257 15258 15259 15260 15261 </tr> 15262 15263 15264 15265 15266 15267 15268 <tr> 15269 15270 15271 15272 15273 15274 15275 <td style="vertical-align: top;"> 15276 15277 15278 15279 15280 15281 15282 <p><a name="ug_vertical_gradient_level"></a><span style="font-weight: bold;">ug_vertical_gradient_level</span></p> 15283 15284 15285 15286 15287 15288 15289 15290 </td> 15291 15292 15293 15294 15295 15296 15297 <td style="vertical-align: top;">R(10)<br> 15298 15299 15300 15301 15302 15303 15304 15305 </td> 15306 15307 15308 15309 15310 15311 15312 <td style="vertical-align: top;"><span style="font-style: italic;">10 15313 * 0.0</span><br> 15314 15315 15316 15317 15318 15319 15320 </td> 15321 15322 15323 15324 15325 15326 15327 <td style="vertical-align: top;">Height level from which on the 15328 gradient defined by <a href="#ug_vertical_gradient">ug_vertical_gradient</a> 15329 is effective (in m).<br> 15330 15331 15332 15333 15334 15335 15336 <br> 15337 15338 15339 15340 15341 15342 15343 15344 The height levels have to be assigned in ascending order. For the 15345 piecewise construction of a profile of the u-component of the 15346 geostrophic wind component (ug) see <a href="#ug_vertical_gradient">ug_vertical_gradient</a>.<br> 15347 15348 15349 15350 15351 15352 15353 <br> 15354 15355 15356 15357 15358 15359 15360 <span style="font-weight: bold;">Attention:</span><br> 15361 15362 15363 15364 15365 15366 15367 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), the (negative) height levels have to be assigned in descending order.</td> 15368 15369 15370 15371 15372 15373 15374 </tr> 15375 15376 15377 15378 15379 15380 15381 <tr> 15382 15383 15384 15385 15386 15387 15388 <td style="vertical-align: top;"> 15389 15390 15391 15392 15393 15394 15395 <p><a name="ups_limit_e"></a><b>ups_limit_e</b></p> 15396 15397 15398 15399 15400 15401 15402 15403 </td> 15404 15405 15406 15407 15408 15409 15410 <td style="vertical-align: top;">R</td> 15411 15412 15413 15414 15415 15416 15417 15418 <td style="vertical-align: top;"><i>0.0</i></td> 15419 15420 15421 15422 15423 15424 15425 15426 <td style="vertical-align: top;"> 15427 15428 15429 15430 15431 15432 15433 <p>Subgrid-scale 15434 turbulent kinetic energy difference used as 15435 criterion for applying the upstream scheme when upstream-spline 15436 advection is switched on (in m<sup>2</sup>/s<sup>2</sup>). 15437 </p> 15438 15439 15440 15441 15442 15443 15444 15445 15446 15447 15448 15449 15450 15451 <p>This variable steers the appropriate 15452 treatment of the 15453 advection of the subgrid-scale turbulent kinetic energy in case that 15454 the uptream-spline scheme is used . For further information see <a href="#ups_limit_pt">ups_limit_pt</a>. </p> 15455 15456 15457 15458 15459 15460 15461 15462 15463 15464 15465 15466 15467 15468 <p>Only positive values are allowed for <b>ups_limit_e</b>. 15469 </p> 15470 15471 15472 15473 15474 15475 15476 </td> 15477 15478 15479 15480 15481 15482 15483 </tr> 15484 15485 15486 15487 15488 15489 15490 <tr> 15491 15492 15493 15494 15495 15496 15497 <td style="vertical-align: top;"> 15498 15499 15500 15501 15502 15503 15504 <p><a name="ups_limit_pt"></a><b>ups_limit_pt</b></p> 15505 15506 15507 15508 15509 15510 15511 15512 </td> 15513 15514 15515 15516 15517 15518 15519 <td style="vertical-align: top;">R</td> 15520 15521 15522 15523 15524 15525 15526 15527 <td style="vertical-align: top;"><i>0.0</i></td> 15528 15529 15530 15531 15532 15533 15534 15535 <td style="vertical-align: top;"> 15536 15537 15538 15539 15540 15541 15542 <p>Temperature 15543 difference used as criterion for applying 15544 the upstream scheme when upstream-spline advection is 15545 switched on 15546 (in K). </p> 15547 15548 15549 15550 15551 15552 15553 15554 15555 15556 15557 15558 15559 15560 <p>This criterion is used if the 15561 upstream-spline scheme is 15562 switched on (see <a href="#scalar_advec">scalar_advec</a>).<br> 15563 15564 15565 15566 15567 15568 15569 15570 If, for a given gridpoint, the absolute temperature difference with 15571 respect to the upstream 15572 grid point is smaller than the value given for <b>ups_limit_pt</b>, 15573 the upstream scheme is used for this gridpoint (by default, the 15574 upstream-spline scheme is always used). Reason: in case of a very small 15575 upstream gradient, the advection should cause only a very small 15576 tendency. However, in such situations the upstream-spline scheme may 15577 give wrong tendencies at a 15578 grid point due to spline overshooting, if simultaneously the downstream 15579 gradient is very large. In such cases it may be more reasonable to use 15580 the upstream scheme. The numerical diffusion caused by the upstream 15581 schme remains small as long as the upstream gradients are small.<br> 15582 15583 15584 15585 15586 15587 15588 15589 </p> 15590 15591 15592 15593 15594 15595 15596 15597 15598 15599 15600 15601 15602 15603 <p>The percentage of grid points for which the 15604 upstream 15605 scheme is actually used, can be output as a time series with respect to 15606 the 15607 three directions in space with run parameter (see <a href="chapter_4.2.html#dt_dots">dt_dots</a>, the 15608 timeseries names in the NetCDF file are <i>'splptx'</i>, <i>'splpty'</i>, 15609 <i>'splptz'</i>). The percentage 15610 of gridpoints should stay below a certain limit, however, it 15611 is 15612 not possible to give 15613 a general limit, since it depends on the respective flow. </p> 15614 15615 15616 15617 15618 15619 15620 15621 15622 15623 15624 15625 15626 15627 <p>Only positive values are permitted for <b>ups_limit_pt</b>.<br> 15628 15629 15630 15631 15632 15633 15634 15635 </p> 15636 15637 15638 15639 15640 15641 15642 15643 A more effective control of 15644 the “overshoots” can be achieved with parameter <a href="#cut_spline_overshoot">cut_spline_overshoot</a>. 15645 </td> 15646 15647 15648 15649 15650 15651 15652 </tr> 15653 15654 15655 15656 15657 15658 15659 <tr> 15660 15661 15662 15663 15664 15665 15666 <td style="vertical-align: top;"> 15667 15668 15669 15670 15671 15672 15673 <p><a name="ups_limit_u"></a><b>ups_limit_u</b></p> 15674 15675 15676 15677 15678 15679 15680 15681 </td> 15682 15683 15684 15685 15686 15687 15688 <td style="vertical-align: top;">R</td> 15689 15690 15691 15692 15693 15694 15695 15696 <td style="vertical-align: top;"><i>0.0</i></td> 15697 15698 15699 15700 15701 15702 15703 15704 <td style="vertical-align: top;"> 15705 15706 15707 15708 15709 15710 15711 <p>Velocity 15712 difference (u-component) used as criterion for 15713 applying the upstream scheme 15714 when upstream-spline advection is switched on (in m/s). </p> 15715 15716 15717 15718 15719 15720 15721 15722 15723 15724 15725 15726 15727 15728 <p>This variable steers the appropriate treatment of the 15729 advection of the u-velocity-component in case that the upstream-spline 15730 scheme is used. For further 15731 information see <a href="#ups_limit_pt">ups_limit_pt</a>. 15732 </p> 15733 15734 15735 15736 15737 15738 15739 15740 15741 15742 15743 15744 15745 15746 <p>Only positive values are permitted for <b>ups_limit_u</b>.</p> 15747 15748 15749 15750 15751 15752 15753 15754 </td> 15755 15756 15757 15758 15759 15760 15761 </tr> 15762 15763 15764 15765 15766 15767 15768 <tr> 15769 15770 15771 15772 15773 15774 15775 <td style="vertical-align: top;"> 15776 15777 15778 15779 15780 15781 15782 <p><a name="ups_limit_v"></a><b>ups_limit_v</b></p> 15783 15784 15785 15786 15787 15788 15789 15790 </td> 15791 15792 15793 15794 15795 15796 15797 <td style="vertical-align: top;">R</td> 15798 15799 15800 15801 15802 15803 15804 15805 <td style="vertical-align: top;"><i>0.0</i></td> 15806 15807 15808 15809 15810 15811 15812 15813 <td style="vertical-align: top;"> 15814 15815 15816 15817 15818 15819 15820 <p>Velocity 15821 difference (v-component) used as criterion for 15822 applying the upstream scheme 15823 when upstream-spline advection is switched on (in m/s). </p> 15824 15825 15826 15827 15828 15829 15830 15831 15832 15833 15834 15835 15836 15837 <p>This variable steers the appropriate treatment of the 15838 advection of the v-velocity-component in case that the upstream-spline 15839 scheme is used. For further 15840 information see <a href="#ups_limit_pt">ups_limit_pt</a>. 15841 </p> 15842 15843 15844 15845 15846 15847 15848 15849 15850 15851 15852 15853 15854 15855 <p>Only positive values are permitted for <b>ups_limit_v</b>.</p> 15856 15857 15858 15859 15860 15861 15862 15863 </td> 15864 15865 15866 15867 15868 15869 15870 </tr> 15871 15872 15873 15874 15875 15876 15877 <tr> 15878 15879 15880 15881 15882 15883 15884 <td style="vertical-align: top;"> 15885 15886 15887 15888 15889 15890 15891 <p><a name="ups_limit_w"></a><b>ups_limit_w</b></p> 15892 15893 15894 15895 15896 15897 15898 15899 </td> 15900 15901 15902 15903 15904 15905 15906 <td style="vertical-align: top;">R</td> 15907 15908 15909 15910 15911 15912 15913 15914 <td style="vertical-align: top;"><i>0.0</i></td> 15915 15916 15917 15918 15919 15920 15921 15922 <td style="vertical-align: top;"> 15923 15924 15925 15926 15927 15928 15929 <p>Velocity 15930 difference (w-component) used as criterion for 15931 applying the upstream scheme 15932 when upstream-spline advection is switched on (in m/s). </p> 15933 15934 15935 15936 15937 15938 15939 15940 15941 15942 15943 15944 15945 15946 <p>This variable steers the appropriate treatment of the 15947 advection of the w-velocity-component in case that the upstream-spline 15948 scheme is used. For further 15949 information see <a href="#ups_limit_pt">ups_limit_pt</a>. 15950 </p> 15951 15952 15953 15954 15955 15956 15957 15958 15959 15960 15961 15962 15963 15964 <p>Only positive values are permitted for <b>ups_limit_w</b>.</p> 15965 15966 15967 15968 15969 15970 15971 15972 </td> 15973 15974 15975 15976 15977 15978 15979 </tr> 15980 15981 15982 15983 15984 15985 15986 <tr> 15987 15988 15989 15990 15991 15992 15993 <td style="vertical-align: top;"> 15994 15995 15996 15997 15998 15999 16000 <p><a name="use_surface_fluxes"></a><b>use_surface_fluxes</b></p> 16001 16002 16003 16004 16005 16006 16007 16008 </td> 16009 16010 16011 16012 16013 16014 16015 <td style="vertical-align: top;">L</td> 16016 16017 16018 16019 16020 16021 16022 16023 <td style="vertical-align: top;"><i>.F.</i></td> 16024 16025 16026 16027 16028 16029 16030 16031 <td style="vertical-align: top;"> 16032 16033 16034 16035 16036 16037 16038 <p>Parameter to 16039 steer the treatment of the subgrid-scale vertical 16040 fluxes within the diffusion terms at k=1 (bottom boundary).<br> 16041 16042 16043 16044 16045 16046 16047 </p> 16048 16049 16050 16051 16052 16053 16054 16055 16056 16057 16058 16059 16060 16061 <p>By default, the near-surface subgrid-scale fluxes are 16062 parameterized (like in the remaining model domain) using the gradient 16063 approach. If <b>use_surface_fluxes</b> 16064 = <i>.TRUE.</i>, the user-assigned surface fluxes are used 16065 instead 16066 (see <a href="#surface_heatflux">surface_heatflux</a>, 16067 <a href="#surface_waterflux">surface_waterflux</a> 16068 and <a href="#surface_scalarflux">surface_scalarflux</a>) 16069 <span style="font-weight: bold;">or</span> the 16070 surface fluxes are 16071 calculated via the Prandtl layer relation (depends on the bottom 16072 boundary conditions, see <a href="#bc_pt_b">bc_pt_b</a>, 16073 <a href="#bc_q_b">bc_q_b</a> 16074 and <a href="#bc_s_b">bc_s_b</a>).<br> 16075 16076 16077 16078 16079 16080 16081 </p> 16082 16083 16084 16085 16086 16087 16088 16089 16090 16091 16092 16093 16094 16095 <p><b>use_surface_fluxes</b> 16096 is automatically set <i>.TRUE.</i>, if a Prandtl layer is 16097 used (see <a href="#prandtl_layer">prandtl_layer</a>). 16098 </p> 16099 16100 16101 16102 16103 16104 16105 16106 16107 16108 16109 16110 16111 16112 <p>The user may prescribe the surface fluxes at the 16113 bottom 16114 boundary without using a Prandtl layer by setting <span style="font-weight: bold;">use_surface_fluxes</span> = 16115 <span style="font-style: italic;">.T.</span> and <span style="font-weight: bold;">prandtl_layer</span> = <span style="font-style: italic;">.F.</span>. If , in this 16116 case, the 16117 momentum flux (u<sub>*</sub><sup>2</sup>) 16118 should also be prescribed, 16119 the user must assign an appropriate value within the user-defined code.</p> 16120 16121 16122 16123 16124 16125 16126 16127 </td> 16128 16129 16130 16131 16132 16133 16134 </tr> 16135 16136 16137 16138 16139 16140 16141 <tr> 16142 16143 16144 16145 16146 16147 16148 <td style="vertical-align: top;"><a name="use_top_fluxes"></a><span style="font-weight: bold;">use_top_fluxes</span></td> 16149 16150 16151 16152 16153 16154 16155 <td style="vertical-align: top;">L</td> 16156 16157 16158 16159 16160 16161 16162 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td> 16163 16164 16165 16166 16167 16168 16169 <td style="vertical-align: top;"> 16170 16171 16172 16173 16174 16175 16176 <p>Parameter to steer 16177 the treatment of the subgrid-scale vertical 16178 fluxes within the diffusion terms at k=nz (top boundary).</p> 16179 16180 16181 16182 16183 16184 16185 16186 16187 16188 16189 16190 16191 <p>By 16192 default, the fluxes at nz are calculated using the gradient approach. 16193 If <b>use_top_fluxes</b> 16194 = <i>.TRUE.</i>, the user-assigned top fluxes are used 16195 instead 16196 (see <a href="chapter_4.1.html#top_heatflux">top_heatflux</a>, <a href="#top_momentumflux_u">top_momentumflux_u</a>, <a href="#top_momentumflux_v">top_momentumflux_v</a>, <a href="#top_salinityflux">top_salinityflux</a>).</p> 16197 16198 16199 16200 16201 16202 16203 16204 16205 16206 16207 16208 16209 <p>Currently, no value for the latent heatflux can be assigned. In case of <span style="font-weight: bold;">use_top_fluxes</span> = <span style="font-style: italic;">.TRUE.</span>, the latent 16210 heat flux at the top will be automatically set to zero.</p> 16211 16212 16213 16214 16215 16216 16217 </td> 16218 16219 16220 16221 16222 16223 16224 </tr> 16225 16226 16227 16228 16229 16230 16231 <tr> 16232 16233 16234 16235 16236 16237 16238 16239 <td style="vertical-align: top;"> 16240 16241 16242 16243 16244 16245 16246 <p><a name="use_ug_for_galilei_tr"></a><b>use_ug_for_galilei_tr</b></p> 16247 16248 16249 16250 16251 16252 16253 16254 </td> 16255 16256 16257 16258 16259 16260 16261 <td style="vertical-align: top;">L</td> 16262 16263 16264 16265 16266 16267 16268 16269 <td style="vertical-align: top;"><i>.T.</i></td> 16270 16271 16272 16273 16274 16275 16276 16277 <td style="vertical-align: top;"> 16278 16279 16280 16281 16282 16283 16284 <p>Switch to 16285 determine the translation velocity in case that a 16286 Galilean transformation is used.<br> 16287 16288 16289 16290 16291 16292 16293 </p> 16294 16295 16296 16297 16298 16299 16300 16301 16302 16303 16304 16305 16306 16307 <p>In 16308 case of a Galilean transformation (see <a href="#galilei_transformation">galilei_transformation</a>), 16309 <b>use_ug_for_galilei_tr</b> 16310 = <i>.T.</i> ensures 16311 that the coordinate system is translated with the geostrophic windspeed.<br> 16312 16313 16314 16315 16316 16317 16318 16319 </p> 16320 16321 16322 16323 16324 16325 16326 16327 16328 16329 16330 16331 16332 16333 <p>Alternatively, with <b>use_ug_for_galilei_tr</b> 16334 = <i>.F</i>., 16335 the 16336 geostrophic wind can be replaced as translation speed by the (volume) 16337 averaged velocity. However, in this case the user must be aware of fast 16338 growing gravity waves, so this 16339 choice is usually not recommended!</p> 16340 16341 16342 16343 16344 16345 16346 </td> 16347 16348 16349 16350 16351 16352 16353 </tr> 16354 16355 16356 16357 16358 16359 16360 <tr> 16361 16362 16363 16364 16365 16366 16367 <td align="left" valign="top"><a name="use_upstream_for_tke"></a><span style="font-weight: bold;">use_upstream_for_tke</span></td> 16368 16369 16370 16371 16372 16373 16374 <td align="left" valign="top">L</td> 16375 16376 16377 16378 16379 16380 16381 <td align="left" valign="top"><span style="font-style: italic;">.F.</span></td> 16382 16383 16384 16385 16386 16387 16388 <td align="left" valign="top">Parameter to choose the 16389 advection/timestep scheme to be used for the subgrid-scale TKE.<br> 16390 16391 16392 16393 16394 16395 16396 <br> 16397 16398 16399 16400 16401 16402 16403 By 16404 default, the advection scheme and the timestep scheme to be used for 16405 the subgrid-scale TKE are set by the initialization parameters <a href="#scalar_advec">scalar_advec</a> and <a href="#timestep_scheme">timestep_scheme</a>, 16406 respectively. <span style="font-weight: bold;">use_upstream_for_tke</span> 16407 = <span style="font-style: italic;">.T.</span> 16408 forces the Euler-scheme and the upstream-scheme to be used as timestep 16409 scheme and advection scheme, respectively. By these methods, the strong 16410 (artificial) near-surface vertical gradients of the subgrid-scale TKE 16411 are significantly reduced. This is required when subgrid-scale 16412 velocities are used for advection of particles (see particle package 16413 parameter <a href="chapter_4.2.html#use_sgs_for_particles">use_sgs_for_particles</a>).</td> 16414 16415 16416 16417 16418 16419 16420 </tr> 16421 16422 16423 16424 16425 16426 16427 <tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="v_bulk"></a>v_bulk</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td><td>v-component of the predefined bulk velocity (in m/s).<br><br>This parameter comes into effect if <a href="chapter_4.1.html#conserve_volume_flow">conserve_volume_flow</a> = <span style="font-style: italic;">.T.</span> and <a href="chapter_4.1.html#conserve_volume_flow_mode">conserve_volume_flow_mode</a> = <span style="font-style: italic;">'bulk_velocity'</span>.</td></tr><tr> 16428 16429 16430 16431 16432 16433 16434 16435 <td style="vertical-align: top;"> 16436 16437 16438 16439 16440 16441 16442 <p><a name="vg_surface"></a><span style="font-weight: bold;">vg_surface</span></p> 16443 16444 16445 16446 16447 16448 16449 16450 </td> 16451 16452 16453 16454 16455 16456 16457 <td style="vertical-align: top;">R<br> 16458 16459 16460 16461 16462 16463 16464 </td> 16465 16466 16467 16468 16469 16470 16471 16472 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br> 16473 16474 16475 16476 16477 16478 16479 </td> 16480 16481 16482 16483 16484 16485 16486 16487 <td style="vertical-align: top;">v-component of the 16488 geostrophic 16489 wind at the surface (in m/s).<br> 16490 16491 16492 16493 16494 16495 16496 <br> 16497 16498 16499 16500 16501 16502 16503 16504 This parameter assigns the value of the v-component of the geostrophic 16505 wind (vg) at the surface (k=0). Starting from this value, the initial 16506 vertical profile of the <br> 16507 16508 16509 16510 16511 16512 16513 16514 v-component of the geostrophic wind is constructed with <a href="#vg_vertical_gradient">vg_vertical_gradient</a> 16515 and <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>. 16516 The 16517 profile 16518 constructed in that way is used for creating the initial vertical 16519 velocity profile of the 3d-model. Either it is applied, as it has been 16520 specified by the user (<a href="#initializing_actions">initializing_actions</a> 16521 = 'set_constant_profiles') 16522 or it is used for calculating a stationary boundary layer wind profile 16523 (<a href="#initializing_actions">initializing_actions</a> 16524 = 16525 'set_1d-model_profiles'). If vg is constant 16526 with height (i.e. vg(k)=<span style="font-weight: bold;">vg_surface</span>) 16527 and has a large value, it is 16528 recommended to use a Galilei-transformation of the coordinate system, 16529 if possible (see <a href="#galilei_transformation">galilei_transformation</a>), 16530 in order to obtain larger 16531 time steps.<br> 16532 16533 16534 16535 16536 16537 16538 <br> 16539 16540 16541 16542 16543 16544 16545 <span style="font-weight: bold;">Attention:</span><br> 16546 16547 16548 16549 16550 16551 16552 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), 16553 this parameter gives the geostrophic velocity value (i.e. the pressure gradient) at the sea surface, which is 16554 at k=nzt. The profile is then constructed from the surface down to the 16555 bottom of the model.</td> 16556 16557 16558 16559 16560 16561 16562 </tr> 16563 16564 16565 16566 16567 16568 16569 <tr> 16570 16571 16572 16573 16574 16575 16576 <td style="vertical-align: top;"> 16577 16578 16579 16580 16581 16582 16583 <p><a name="vg_vertical_gradient"></a><span style="font-weight: bold;">vg_vertical_gradient</span></p> 16584 16585 16586 16587 16588 16589 16590 16591 </td> 16592 16593 16594 16595 16596 16597 16598 <td style="vertical-align: top;">R(10)<br> 16599 16600 16601 16602 16603 16604 16605 16606 </td> 16607 16608 16609 16610 16611 16612 16613 <td style="vertical-align: top;"><span style="font-style: italic;">10 16614 * 0.0</span><br> 16615 16616 16617 16618 16619 16620 16621 </td> 16622 16623 16624 16625 16626 16627 16628 <td style="vertical-align: top;">Gradient(s) of the initial 16629 profile of the v-component of the geostrophic wind (in 16630 1/100s).<br> 16631 16632 16633 16634 16635 16636 16637 <br> 16638 16639 16640 16641 16642 16643 16644 16645 The gradient holds starting from the height level defined by <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a> 16646 (precisely: for all uv levels k where zu(k) 16647 > <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>, 16648 vg(k) is set: vg(k) = vg(k-1) + dzu(k) 16649 * <span style="font-weight: bold;">vg_vertical_gradient</span>) 16650 up to 16651 the top boundary or up to the next height 16652 level defined by <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>. 16653 A total of 10 different 16654 gradients for 11 height intervals (10 intervals if <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>(1) 16655 = 16656 0.0) can be assigned. The surface 16657 geostrophic wind is assigned by <a href="#vg_surface">vg_surface</a>.<br> 16658 16659 16660 16661 16662 16663 16664 <br> 16665 16666 16667 16668 16669 16670 16671 <span style="font-weight: bold;">Attention:</span><br> 16672 16673 16674 16675 16676 16677 16678 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), 16679 the profile is constructed like described above, but starting from the 16680 sea surface (k=nzt) down to the bottom boundary of the model. Height 16681 levels have then to be given as negative values, e.g. <span style="font-weight: bold;">vg_vertical_gradient_level</span> = <span style="font-style: italic;">-500.0</span>, <span style="font-style: italic;">-1000.0</span>.</td> 16682 16683 16684 16685 16686 16687 16688 16689 </tr> 16690 16691 16692 16693 16694 16695 16696 <tr> 16697 16698 16699 16700 16701 16702 16703 <td style="vertical-align: top;"> 16704 16705 16706 16707 16708 16709 16710 <p><a name="vg_vertical_gradient_level"></a><span style="font-weight: bold;">vg_vertical_gradient_level</span></p> 16711 16712 16713 16714 16715 16716 16717 16718 </td> 16719 16720 16721 16722 16723 16724 16725 <td style="vertical-align: top;">R(10)<br> 16726 16727 16728 16729 16730 16731 16732 16733 </td> 16734 16735 16736 16737 16738 16739 16740 <td style="vertical-align: top;"><span style="font-style: italic;">10 16741 * 0.0</span><br> 16742 16743 16744 16745 16746 16747 16748 </td> 16749 16750 16751 16752 16753 16754 16755 <td style="vertical-align: top;">Height level from which on the 16756 gradient defined by <a href="#vg_vertical_gradient">vg_vertical_gradient</a> 16757 is effective (in m).<br> 16758 16759 16760 16761 16762 16763 16764 <br> 16765 16766 16767 16768 16769 16770 16771 16772 The height levels have to be assigned in ascending order. For the 16773 piecewise construction of a profile of the v-component of the 16774 geostrophic wind component (vg) see <a href="#vg_vertical_gradient">vg_vertical_gradient</a>.<br> 16775 16776 16777 16778 16779 16780 16781 <br> 16782 16783 16784 16785 16786 16787 16788 <span style="font-weight: bold;">Attention:</span><br> 16789 16790 16791 16792 16793 16794 16795 In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), the (negative) height levels have to be assigned in descending order.</td> 16796 16797 16798 16799 16800 16801 16802 16803 </tr> 16804 16805 16806 16807 16808 16809 16810 <tr> 16811 16812 16813 16814 16815 16816 16817 <td style="vertical-align: top;"> 16818 16819 16820 16821 16822 16823 16824 <p><a name="wall_adjustment"></a><b>wall_adjustment</b></p> 16825 16826 16827 16828 16829 16830 16831 16832 </td> 16833 16834 16835 16836 16837 16838 16839 <td style="vertical-align: top;">L</td> 16840 16841 16842 16843 16844 16845 16846 16847 <td style="vertical-align: top;"><i>.T.</i></td> 16848 16849 16850 16851 16852 16853 16854 16855 <td style="vertical-align: top;"> 16856 16857 16858 16859 16860 16861 16862 <p>Parameter to 16863 restrict the mixing length in the vicinity of the 16864 bottom 16865 boundary (and near vertical walls of a non-flat <a href="chapter_4.1.html#topography">topography</a>). </p> 16866 16867 16868 16869 16870 16871 16872 16873 16874 16875 16876 16877 16878 16879 <p>With <b>wall_adjustment</b> 16880 = <i>.TRUE., </i>the mixing 16881 length is limited to a maximum of 1.8 * z. This condition 16882 typically affects only the 16883 first grid points above the bottom boundary.</p> 16884 16885 16886 16887 16888 <p>In case of a non-flat <a href="chapter_4.1.html#topography">topography</a> the respective horizontal distance from vertical walls is used.</p> 16889 16890 16891 16892 16893 16894 16895 </td> 16896 16897 16898 16899 16900 16901 16902 </tr> 16903 16904 16905 16906 16907 16908 16909 16910 <tr> 16911 16912 16913 16914 16915 16916 16917 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="wall_heatflux"></a>wall_heatflux</span></td> 16918 16919 16920 16921 16922 16923 16924 16925 <td style="vertical-align: top;">R(5)</td> 16926 16927 16928 16929 16930 16931 16932 <td style="vertical-align: top;"><span style="font-style: italic;">5 * 0.0</span></td> 16933 16934 16935 16936 16937 16938 16939 <td>Prescribed 16940 kinematic sensible heat flux in K m/s 16941 at the five topography faces:<br> 16942 16943 16944 16945 16946 16947 16948 <br> 16949 16950 16951 16952 16953 16954 16955 16956 16957 16958 16959 16960 16961 16962 <div style="margin-left: 40px;"><span style="font-weight: bold;">wall_heatflux(0) 16963 </span>top face<br> 16964 16965 16966 16967 16968 16969 16970 <span style="font-weight: bold;">wall_heatflux(1) 16971 </span>left face<br> 16972 16973 16974 16975 16976 16977 16978 <span style="font-weight: bold;">wall_heatflux(2) 16979 </span>right face<br> 16980 16981 16982 16983 16984 16985 16986 <span style="font-weight: bold;">wall_heatflux(3) 16987 </span>south face<br> 16988 16989 16990 16991 16992 16993 16994 <span style="font-weight: bold;">wall_heatflux(4) 16995 </span>north face</div> 16996 16997 16998 16999 17000 17001 17002 <br> 17003 17004 17005 17006 17007 17008 17009 17010 This parameter applies only in case of a non-flat <a href="#topography">topography</a>. The 17011 parameter <a href="#random_heatflux">random_heatflux</a> 17012 can be used to impose random perturbations on the internal 17013 two-dimensional surface heat 17014 flux field <span style="font-style: italic;">shf</span> 17015 that is composed of <a href="#surface_heatflux">surface_heatflux</a> 17016 at the bottom surface and <span style="font-weight: bold;">wall_heatflux(0)</span> 17017 at the topography top face. </td> 17018 17019 17020 17021 17022 17023 17024 </tr> 17025 17026 17027 17028 17029 17030 17031 17032 17033 17034 17035 17036 17037 17038 </tbody> 17039 </table> 17040 17041 17042 17043 17044 17045 17046 <br> 17047 17048 17049 17050 17051 17052 17053 17054 <p style="line-height: 100%;"><br> 17055 17056 17057 17058 17059 17060 17061 <font color="#000080"><font color="#000080"><a href="chapter_4.0.html"><font color="#000080"><img name="Grafik1" src="left.gif" align="bottom" border="2" height="32" width="32"></font></a><a href="index.html"><font color="#000080"><img name="Grafik2" src="up.gif" align="bottom" border="2" height="32" width="32"></font></a><a href="chapter_4.2.html"><font color="#000080"><img name="Grafik3" src="right.gif" align="bottom" border="2" height="32" width="32"></font></a></font></font></p> 17062 17063 17064 17065 17066 17067 17068 17069 <p style="line-height: 100%;"><i>Last 17070 change: </i> $Id$ </p> 17071 17072 17073 17074 17075 17076 17077 17078 <br> 17079 17080 17081 17082 17083 17084 17085 <br> 17086 17087 17088 17089 17090 17091 17092 17093 </body></html>
Note: See TracChangeset
for help on using the changeset viewer.
