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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 | | |