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5<meta content="Siegfried Raasch" name="AUTHOR"> <meta content="20041013;13430732" name="CREATED"> <meta content="20041117;11162734" name="CHANGED"> <meta content="parallel LES model" name="KEYWORDS"> <style>
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10<body style="direction: ltr;" lang="en-US"><h3 style="line-height: 100%;">4.4.2 A&nbsp;parameter set for ocean runs</h3>
11<p style="line-height: 100%;">... to be completed ...</p><p style="line-height: 100%;">In this chapter a brief,
12simple and
13complete parameter set is described, which can be used to carry out a
14model run. The presented example is available via <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/INSTALL/example_p3d">example
15file</a> and can be used (together with the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/INSTALL/.mrun.config">configuration
16file</a> described in <a href="chapter_3.2.html">chapter
173.2)</a> for the execution of a simple model run. </p>
18<p style="line-height: 100%;">This run simulates a
19quasi-stationary,
20convective, atmospheric boundary layer with&nbsp; <font color="#000000">zero
21mean horizontal
22wind.</font> For evaluation purposes, cross sections and
23horizontally averaged vertical
24profiles of typical boundary layer variables
25are output at the end of the run. The run shall be carried out in
26batch mode on the IBM Regatta "hanni" of the HLRN.</p>
27<p style="line-height: 100%;">The parameter file necessary
28to carry
29out a run must be provided to the model as an input file under the
30local name <a href="chapter_3.4.html#PARIN">PARIN</a>
31and has the following contents:</p>
32<pre style="line-height: 100%;">&amp;inipar <a href="chapter_4.1.html#nx">nx</a> = <span style="font-style: italic;">39</span>, <a href="chapter_4.1.html#ny">ny</a> = <span style="font-style: italic;">39</span>, <a href="chapter_4.1.html#nz">nz</a> = <span style="font-style: italic;">40</span>,<br> <a href="chapter_4.1.html#dx">dx</a> = <span style="font-style: italic;">50.0</span>, <a href="chapter_4.1.html#dy">dy</a> = <span style="font-style: italic;">50.0</span>, <a href="chapter_4.1.html#dz">dz</a> = <span style="font-style: italic;">50.0</span>,<br> <a href="chapter_4.1.html#dz_stretch_level">dz_stretch_level</a> = <span style="font-style: italic;">1200.0</span>,<br> <a href="chapter_4.1.html#fft_method">fft_method</a> = <span style="font-style: italic;">'temperton-algorithm'</span>,<br> <a href="chapter_4.1.html#initializing_actions">initializing_actions</a> = <span style="font-style: italic;">'set_constant_profiles'</span>,<br> <a href="chapter_4.1.html#ug_surface">ug_surface</a> = <span style="font-style: italic;">0.0</span>, <a href="chapter_4.1.html#vg_surface">vg_surface</a> = <span style="font-style: italic;">0.0</span>,<br> <a href="chapter_4.1.html#pt_vertical_gradient">pt_vertical_gradient</a> = <span style="font-style: italic;">0.0</span>, <span style="font-style: italic;">1.0</span>,<br> <a href="chapter_4.1.html#pt_vertical_gradient_level">pt_vertical_gradient_level</a> = <span style="font-style: italic;">0.0</span>, <span style="font-style: italic;">800.0</span>,<br> <a href="chapter_4.1.html#surface_heatflux">surface_heatflux</a> = <span style="font-style: italic;">0.1</span>, <a href="chapter_4.1.html#bc_pt_b">bc_pt_b</a> = <span style="font-style: italic;">'neumann'</span>,/<br><br>&amp;d3par <a href="chapter_4.2.html#end_time">end_time</a> = <span style="font-style: italic;">3600.0</span>,<br> <a href="chapter_4.2.html#create_disturbances">create_disturbances</a> = <span style="font-style: italic;">.T.</span>,<br> <a href="chapter_4.2.html#dt_disturb">dt_disturb</a> = <span style="font-style: italic;">150.0</span>, <a href="chapter_4.2.html#disturbance_energy_limit">disturbance_energy_limit</a> = <span style="font-style: italic;">0.01</span>,<br> <a href="chapter_4.2.html#dt_run_control">dt_run_control</a> = <span style="font-style: italic;">0.0</span>,<br> <a href="chapter_4.2.html#data_output">data_output</a> = <span style="font-style: italic;">'w_xy'</span>, <span style="font-style: italic;">'w_xz'</span>, <span style="font-style: italic;">'w_xz_av'</span>, <span style="font-style: italic;">'pt_xy'</span>, <span style="font-style: italic;">'pt_xz'</span>,<br> <a href="chapter_4.2.html#dt_data_output">dt_data_output</a> = <span style="font-style: italic;">900.0</span>,<br> <a href="chapter_4.2.html#dt_data_output_av">dt_data_output_av</a> = <span style="font-style: italic;">1800.0</span>,<br> <a href="chapter_4.2.html#averaging_interval">averaging_interval</a> = <span style="font-style: italic;">900.0</span>,<br> <a href="chapter_4.2.html#dt_averaging_input">dt_averaging_input</a> = <span style="font-style: italic;">10.0</span>,<br> <a href="chapter_4.2.html#section_xy">section_xy</a> = <span style="font-style: italic;">2</span>, <span style="font-style: italic;">10</span>, <a href="chapter_4.2.html#section_xz">section_xz</a> = <span style="font-style: italic;">20</span>,<br> <a href="chapter_4.2.html#data_output_2d_on_each_pe">data_output_2d_on_each_pe</a> = <span style="font-style: italic;">.F.</span>,<br> <a href="chapter_4.2.html#dt_dopr">dt_dopr</a> = <span style="font-style: italic;">900.0</span>, <a href="chapter_4.2.html#averaging_interval_pr">averaging_interval_pr</a> = <span style="font-style: italic;">600.0</span>,<br> <a href="chapter_4.2.html#dt_averaging_input_pr">dt_averaging_input_pr</a> = <span style="font-style: italic;">10.0</span>,<br> <a href="chapter_4.2.html#data_output_pr">data_output_pr</a> = <span style="font-style: italic;">'#pt'</span>, <span style="font-style: italic;">'w&rdquo;pt&rdquo;'</span>, <span style="font-style: italic;">'w*pt*'</span>, <span style="font-style: italic;">'wpt'</span>, <span style="font-style: italic;">'w*2'</span>, <span style="font-style: italic;">'pt*2'</span>,<br> <a href="chapter_4.2.html#cross_profiles">cross_profiles</a> = <span style="font-style: italic;">' pt '</span>, <span style="font-style: italic;">' w"pt" w*pt* wpt '</span>, <span style="font-style: italic;">' w*2 '</span>, <span style="font-style: italic;">' pt*2 '</span>,<br> <a href="chapter_4.2.html#cross_xtext">cross_xtext</a> = <span style="font-style: italic;">'pot. temperature in K'</span>,<br> <span style="font-style: italic;">'heat flux in K ms&gt;-&gt;1'</span>,<br> <span style="font-style: italic;">'velocity variance in m&gt;2s&gt;-&gt;2'</span>,<br> <span style="font-style: italic;">'temperature variance in K&gt;2'</span>,<br> <a href="chapter_4.2.html#z_max_do1d">z_max_do1d</a> = <span style="font-style: italic;">1500.0</span>, /</pre><p style="line-height: 100%;"><br><br></p>
33<p style="line-height: 100%;">The initialization
34parameters (<tt><font style="font-size: 10pt;" size="2">&amp;inipar</font></tt>)
35are located at the beginning of the file. For analysis of a
36convective boundary layer of approx. 1000 m thickness the horizontal
37size of the model domain should amount to at least 2 km x 2 km. In
38order to resolve the convective structures a grid spacing of <b>dx</b>
39=
40<b>dy</b> = <b>dz</b> = <i>50 m</i>
41is enough, since the typical
42diameter of convective plumes is more than 100 m. Thereby the
43upper array index in the two horizontal directions needs to be <b>nx</b>
44= <b>ny</b> = <i>39</i>. <font color="#000000">Since in
45each case the lower array index has the value 0, 40 grid points are
46used along both horizontal directions.</font> In the vertical
47direction
48the domain must be high enough to include the entrainment processes at
49the top of the boundary layer as well as the propagation of gravity
50waves, which were stimulated by
51the convection. However, in the stably stratified region the grid
52resolution has not necessarily to be as high as within the boundary
53layer. This can be obtained by a vertical stretching of the grid
54starting
55from 1200 m via <b>dz_stretch_level</b> = <i>1200.0
56m.</i> This saves
57grid points and computing time. <font color="#800000">T</font><font color="#000000">he
58upper boundary of the model is located at (see </font><a href="chapter_4.1.html#dz_stretch_factor"><font color="#000000">dz_stretch_factor</font></a><font color="#000000">)
59&hellip; m (computed by the model)</font>.</p><p style="line-height: 100%;">Fast Fourier transformations are
60calculated using the Temperton-algorithm, which -on the IBM Regatta- is
61faster than the default system-specific algorithm (from IBM essl
62library).</p><p style="line-height: 100%;">The
63initial profiles for
64wind and temperature can be assigned via <b>initializing_actions</b>
65= <span style="font-style: italic;">'set_constant_profiles'</span>.
66The wind speed, constant with
67height, amounts to <b>ug_surface</b> = <b>vg_surface</b>
68= <i>0.0 m/s</i>. In order
69to allow for a fast onset of convection, a neutral stratified layer up
70to z
71= 800 m capped by an inversion with dtheta/dz = 1K/100 m is given:
72<b>pt_vertical_gradient</b> = <i>0.0, 1.0</i>,
73<b>pt_vertical_gradient_level</b> = <i>0.0, 800.0.</i>
74The surface
75temperature, which by default amounts to 300 K, provides the fixed
76point for the temperature profile (see <a href="chapter_4.1.html#pt_surface">pt_surface</a>).
77Convection is driven by a given, near-surface sensible heat flux via <b>surface_heatflux</b>
78= <i>0.1 K m/s.</i> A given surface sensible heta flux
79requires the
80bottom boundary condition for potential temperature to be <b>bc_pt_b</b>
81=
82<span style="font-style: italic;">'neumann'</span> .
83Thus
84all initialization parameters are determined. These can not be
85changed during the run (also not for restart runs). </p>
86<p style="line-height: 100%;">Now the run parameters (<tt><font style="font-size: 10pt;" size="2">&amp;d3par</font></tt>)
87must be specified. To produce a quasi stationary boundary layer the
88simulated time should be at least one hour, i.e. <b>end_time</b>
89= <i>3600
90s.</i> To stimulate convection, the initially homogeneous (zero)
91wind
92field must be disturbed (<b>create_disturbances</b> = <i>.T.</i>).
93These perturbations should be repeated in a temporal interval of
94<b>dt_disturb</b> = <i>150.0 s</i> until the
95energy of the
96perturbations exceeds the value <b>disturbance_energy_limit</b>
97= 0.<i>01
98m<sup>2</sup>/s<sup>2</sup></i>. After
99each time step run time
100informations (e.g. size of the timestep, maximum velocities, etc.) are
101to be written to the local file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>
102(<b>dt_run_control</b> = <i>0.0 s</i>).</p><p style="line-height: 100%;">Instantaneous cross section data
103of vertical velocity (<span style="font-style: italic;">w</span>)
104and potential temperature (<span style="font-style: italic;">pt</span>)
105are to be output for horizontal (<span style="font-style: italic;">xy</span>)
106and vertical (<span style="font-style: italic;">xz</span>)
107cross sections, and additionally, time averaged (<span style="font-style: italic;">av</span>) vertical cross
108section data are to be output for the vertical velocity: <span style="font-weight: bold;">data_output</span> = <span style="font-style: italic;">'w_xy'</span>, <span style="font-style: italic;">'w_xz'</span>, <span style="font-style: italic;">'w_xz_av'</span>, <span style="font-style: italic;">'pt_xy'</span>, <span style="font-style: italic;">'pt_xz'</span>. Output of
109instantaneous (time averaged) data is done after each 900 (1800)s: <span style="font-weight: bold;">dt_data_output</span> = <span style="font-style: italic;">900.0</span>, <span style="font-weight: bold;">dt_data_output_av</span> = <span style="font-style: italic;">1800.0</span>. The
110averaged data are time averaged over the last 900.0 s, where the
111temporal interval of data entering the average is 10 s: <span style="font-weight: bold;">averaging_interval</span> =
112<span style="font-style: italic;">900.0</span>, <span style="font-weight: bold;">dt_averaging_input</span> =
113<span style="font-style: italic;">10.0</span>.
114Horizontal cross sections are output for vertical levels with grid
115index k=2 and k=10, vertical cross sections are output for index j=20: <span style="font-weight: bold;">section_xy</span> = <span style="font-style: italic;">2</span>, <span style="font-style: italic;">10</span>, <span style="font-weight: bold;">section_xz</span> = <span style="font-style: italic;">20</span>. For runs on
116more than one processor, cross section data are collected and output on
117PE0: <span style="font-weight: bold;">data_output_2d_on_each_pe</span>
118= <span style="font-style: italic;">.F.</span>.</p><p style="line-height: 100%;">Output
119of vertical profiles is to be done after each 900 s. The profiles shall
120be temporally averaged<font color="#000000"> over the last
121<font color="#000000">600 </font>seconds, </font>whereby
122the temporal interval of the profiles entering the average has to be
12310 s: <b>dt_dopr</b> = <i>900.0 s</i>, <b>averaging_interval_pr</b>
124=
125<i>600.0 s</i>, <b>dt_averaging_input_pr</b> =
126<i>10.0 s.</i> The temperature
127profile including the initial temperature profile (therefore <span style="font-style: italic;">'#pt'</span>),
128the subgrid scale, resolved and total vertical sensible heat flux as
129well as the variances of the vertical velocity and the potential
130temperature are to be output:&nbsp; <b>data_output_pr</b>
131= <span style="font-style: italic;">'#pt'</span><i>,
132'w"pt&rdquo;',
133'w*pt*', 'wpt', 'w*2', 'pt*2'</i>.</p><p style="line-height: 100%;">If the data output format for
134graphic software <span style="font-weight: bold;">profil</span>
135is selected (see <a href="chapter_4.2.html#data_output_format">data_output_format</a>),
136the temperature
137profile and the individual variances are to be drawn into independent
138coordinate systems, and in contrast to this all heat flux profiles are
139to
140be
141drawn into the same system: <b>cross_profiles</b> = <span style="font-style: italic;">'pt'</span><i>,
142'w"pt"w*pt*wpt', 'w*2', 'pt*2'</i>. The legend of the x
143axes of these systems is set to <b>cross_xtext</b>= <i>'pot.
144temperature in K', 'heat flux in K ms&gt;-&gt;1', 'velocity
145variance
146in m&gt;2s&gt;-&gt;2', 'temperature variance in K&gt;2'</i>.
147The profiles are to be drawn up to a height level of <b>z_max_do1d</b>
148=
149<i>1500.0 m</i>. </p>
150<p style="line-height: 100%;">Before starting the mo<font color="#000000">del
151on the parallel computer, the number of processing elements must be
152specified.</font> Since relatively few grid points are used for
153this run, choosing of e.g. 8 PEs is sufficient. By default, a 1d domain
154decomposition along x is used on the IBM-Regatta, which means that a
155virtual processor topology (grid) of 8*1 (x*y) is used. (<span style="font-weight: bold;">Note:</span> the user may
156adjust this
157default domain decomposition with the help of the parameters <a href="chapter_4.2.html#npex">npex</a>
158and <a href="chapter_4.2.html#npey">npey</a>).
159</p><p style="line-height: 100%;">Provided that the
160parameters
161file described above are set within the file </p>
162<ul> <pre style="margin-bottom: 0.5cm; line-height: 100%;"><font style="font-size: 10pt;" size="2">~/palm/current_version/JOBS/example/INPUT/example_p3d</font></pre></ul><p style="line-height: 100%;">and that the conditions
163mentioned in the
164first sections of <a href="chapter_3.2.html">chapter
1653.2</a> are met, the model run can be started with the command </p>
166<p style="line-height: 100%;"><font face="Cumberland, monospace"><font style="font-size: 10pt;" size="2">mrun
167-d example -h ibmh -K parallel -X 8 -T 8 -t 1800 -q cdev -r
168&ldquo;d3# xy# xz# pr#&rdquo;</font></font></p>
169<p style="line-height: 100%;">The output files will appear
170in the
171directories </p>
172<blockquote style="line-height: 100%;"><tt><font style="font-size: 10pt;" size="2">~/palm/current_version/JOBS/example/MONITORING</font></tt><font style="font-size: 10pt;" size="2"><br> </font><tt><font style="font-size: 10pt;" size="2">~/palm/current_version/JOBS/example/OUTPUT
173,</font></tt></blockquote>
174<p style="line-height: 100%;">while the job protocol will
175appear in
176directory <font style="font-size: 10pt;" size="2"><font face="Cumberland, monospace">~/</font></font><tt><font style="font-size: 10pt;" size="2"><font face="Cumberland, monospace">job_queue</font></font></tt>.
177<br>
178&nbsp; </p>
179<hr><p style="line-height: 100%;"><br><font color="#000080"><font color="#000080"><a href="chapter_4.4.1.html"><font color="#000080"><img style="border: 2px solid ; width: 32px; height: 32px;" alt="" name="Grafik1" src="left.gif"></font></a><a href="index.html"><font color="#000080"><img name="Grafik2" src="up.gif" align="bottom" border="2" height="32" width="32"></font></a><a href="chapter_4.5.html"><font color="#000080"><img style="border: 2px solid ; width: 32px; height: 32px;" alt="" name="Grafik3" src="right.gif"></font></a></font></font></p><p style="line-height: 100%;"><i>Last change:&nbsp;
180</i>$Id: chapter_4.4.2.html 197 2008-09-16 15:29:03Z raasch $
181<br>&nbsp; <br>
182&nbsp; </p>
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