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17  <title>PALM chapter 4.1</title></head>
18<body>
19
20
21
22<h3><a name="chapter4.1"></a>4.1
23Initialization parameters</h3>
24
25
26
27
28<br>
29
30
31
32<table style="text-align: left; width: 100%;" border="1" cellpadding="2" cellspacing="2">
33
34
35
36 <tbody>
37
38
39
40
41    <tr>
42
43
44
45 <td style="vertical-align: top;"><font size="4"><b>Parameter name</b></font></td>
46
47
48
49
50      <td style="vertical-align: top;"><font size="4"><b>Type</b></font></td>
51
52
53
54
55      <td style="vertical-align: top;"> 
56     
57     
58     
59      <p><b><font size="4">Default</font></b> <br>
60
61
62
63 <b><font size="4">value</font></b></p>
64
65
66
67 </td>
68
69
70
71
72      <td style="vertical-align: top;"><font size="4"><b>Explanation</b></font></td>
73
74
75
76
77    </tr>
78
79
80
81 <tr>
82
83
84
85 <td style="vertical-align: top;">
86     
87     
88     
89      <p><a name="adjust_mixing_length"></a><b>adjust_mixing_length</b></p>
90
91
92
93
94      </td>
95
96
97
98 <td style="vertical-align: top;">L</td>
99
100
101
102
103      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
104
105
106
107 <td style="vertical-align: top;"> 
108     
109     
110     
111      <p style="font-style: normal;">Near-surface adjustment of the
112mixing length to the Prandtl-layer law.&nbsp; </p>
113
114
115
116 
117     
118     
119     
120      <p>Usually
121the mixing length in LES models l<sub>LES</sub>
122depends (as in PALM) on the grid size and is possibly restricted
123further in case of stable stratification and near the lower wall (see
124parameter <a href="#wall_adjustment">wall_adjustment</a>).
125With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span>
126the Prandtl' mixing length l<sub>PR</sub> = kappa * z/phi
127is calculated
128and the mixing length actually used in the model is set l = MIN (l<sub>LES</sub>,
129l<sub>PR</sub>). This usually gives a decrease of the
130mixing length at
131the bottom boundary and considers the fact that eddy sizes
132decrease in the vicinity of the wall.&nbsp; </p>
133
134
135
136 
137     
138     
139     
140      <p style="font-style: normal;"><b>Warning:</b> So
141far, there is
142no good experience with <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> !&nbsp; </p>
143
144
145
146
147     
148     
149     
150      <p>With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> and the
151Prandtl-layer being
152switched on (see <a href="#prandtl_layer">prandtl_layer</a>)
153      <span style="font-style: italic;">'(u*)** 2+neumann'</span>
154should always be set as the lower boundary condition for the TKE (see <a href="#bc_e_b">bc_e_b</a>),
155otherwise the near-surface value of the TKE is not in agreement with
156the Prandtl-layer law (Prandtl-layer law and Prandtl-Kolmogorov-Ansatz
157should provide the same value for K<sub>m</sub>). A warning
158is given,
159if this is not the case.</p>
160
161
162
163 </td>
164
165
166
167 </tr>
168
169
170
171 <tr>
172
173
174
175
176      <td style="vertical-align: top;"> 
177     
178     
179     
180      <p><a name="alpha_surface"></a><b>alpha_surface</b></p>
181
182
183
184
185      </td>
186
187
188
189 <td style="vertical-align: top;">R<br>
190
191
192
193 </td>
194
195
196
197
198      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
199
200
201
202 </td>
203
204
205
206
207      <td style="vertical-align: top;"> 
208     
209     
210     
211      <p style="font-style: normal;">Inclination of the model domain
212with respect to the horizontal (in degrees).&nbsp; </p>
213
214
215
216 
217     
218     
219     
220      <p style="font-style: normal;">By means of <b>alpha_surface</b>
221the model domain can be inclined in x-direction with respect to the
222horizontal. In this way flows over inclined surfaces (e.g. drainage
223flows, gravity flows) can be simulated. In case of <b>alpha_surface
224      </b>/= <span style="font-style: italic;">0</span>
225the buoyancy term
226appears both in
227the equation of motion of the u-component and of the w-component.<br>
228
229
230
231
232      </p>
233
234
235
236 
237     
238     
239     
240      <p style="font-style: normal;">An inclination
241is only possible in
242case of cyclic horizontal boundary conditions along x AND y (see <a href="#bc_lr">bc_lr</a>
243and <a href="#bc_ns">bc_ns</a>) and <a href="#topography">topography</a> = <span style="font-style: italic;">'flat'</span>. </p>
244
245
246
247
248     
249     
250     
251      <p>Runs with inclined surface still require additional
252user-defined code as well as modifications to the default code. Please
253ask the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/PALM_group.html#0">PALM
254developer&nbsp; group</a>.</p>
255
256
257
258 </td>
259
260
261
262 </tr>
263
264
265
266
267    <tr>
268
269
270
271 <td style="vertical-align: top;"> 
272     
273     
274     
275      <p><a name="bc_e_b"></a><b>bc_e_b</b></p>
276
277
278
279 </td>
280
281
282
283
284      <td style="vertical-align: top;">C * 20</td>
285
286
287
288 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
289
290
291
292
293      <td style="vertical-align: top;"> 
294     
295     
296     
297      <p style="font-style: normal;">Bottom boundary condition of the
298TKE.&nbsp; </p>
299
300
301
302 
303     
304     
305     
306      <p><b>bc_e_b</b> may be
307set to&nbsp;<span style="font-style: italic;">'neumann'</span>
308or <span style="font-style: italic;">'(u*) ** 2+neumann'</span>.
309      <b>bc_e_b</b>
310= <span style="font-style: italic;">'neumann'</span>
311yields to
312e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is calculated
313via the prognostic TKE equation. Choice of <span style="font-style: italic;">'(u*)**2+neumann'</span>
314also yields to
315e(k=0)=e(k=1), but the TKE at the Prandtl-layer top (k=1) is calculated
316diagnostically by e(k=1)=(us/0.1)**2. However, this is only allowed if
317a Prandtl-layer is used (<a href="#prandtl_layer">prandtl_layer</a>).
318If this is not the case, a warning is given and <b>bc_e_b</b>
319is reset
320to <span style="font-style: italic;">'neumann'</span>.&nbsp;
321      </p>
322
323
324
325 
326     
327     
328     
329      <p style="font-style: normal;">At the top
330boundary a Neumann
331boundary condition is generally used: (e(nz+1) = e(nz)).</p>
332
333
334
335 </td>
336
337
338
339
340    </tr>
341
342
343
344 <tr>
345
346
347
348 <td style="vertical-align: top;">
349     
350     
351     
352      <p><a name="bc_lr"></a><b>bc_lr</b></p>
353
354
355
356
357      </td>
358
359
360
361 <td style="vertical-align: top;">C * 20</td>
362
363
364
365
366      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
367
368
369
370
371      <td style="vertical-align: top;">Boundary
372condition along x (for all quantities).<br>
373
374
375
376 <br>
377
378
379
380
381By default, a cyclic boundary condition is used along x.<br>
382
383
384
385 <br>
386
387
388
389
390      <span style="font-weight: bold;">bc_lr</span> may
391also be
392assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
393(inflow from left, outflow to the right) or <span style="font-style: italic;">'radiation/dirichlet'</span>
394(inflow from
395right, outflow to the left). This requires the multi-grid method to be
396used for solving the Poisson equation for perturbation pressure (see <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</a>)
397and it also requires cyclic boundary conditions along y (see&nbsp;<a href="#bc_ns">bc_ns</a>).<br>
398
399
400
401 <br>
402
403
404
405
406In case of these non-cyclic lateral boundaries, a Dirichlet condition
407is used at the inflow for all quantities (initial vertical profiles -
408see <a href="#initializing_actions">initializing_actions</a>
409- are fixed during the run) except u, to which a Neumann (zero
410gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
411gradient) condition is used for the scalars. For perturbation
412pressure Neumann (zero gradient) conditions are assumed both at the
413inflow and at the outflow.<br>
414
415
416
417 <br>
418
419
420
421
422When using non-cyclic lateral boundaries, a filter is applied to the
423velocity field in the vicinity of the outflow in order to suppress any
424reflections of outgoing disturbances (see <a href="#km_damp_max">km_damp_max</a>
425and <a href="#outflow_damping_width">outflow_damping_width</a>).<br>
426
427
428
429
430      <br>
431
432
433
434
435In order to maintain a turbulent state of the flow, it may be
436neccessary to continuously impose perturbations on the horizontal
437velocity field in the vicinity of the inflow throughout the whole run.
438This 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>.
439The horizontal range to which these perturbations are applied is
440controlled by the parameters <a href="#inflow_disturbance_begin">inflow_disturbance_begin</a>
441and <a href="#inflow_disturbance_end">inflow_disturbance_end</a>.
442The vertical range and the perturbation amplitude are given by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_b</a>,
443      <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_t</a>,
444and <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_amplitude</a>.
445The time interval at which perturbations are to be imposed is set by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#dt_disturb">dt_disturb</a>.<br>
446
447
448
449
450      <br>
451
452
453
454
455In 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
456at_all_substeps</a> = .T. should be used.<br>
457
458
459
460 <br>
461
462
463
464 <span style="font-weight: bold;">Note:</span><br>
465
466
467
468
469Using non-cyclic lateral boundaries requires very sensitive adjustments
470of the inflow (vertical profiles) and the bottom boundary conditions,
471e.g. a surface heating should not be applied near the inflow boundary
472because this may significantly disturb the inflow. Please check the
473model results very carefully.</td>
474
475
476
477 </tr>
478
479
480
481 <tr>
482
483
484
485 <td style="vertical-align: top;"> 
486     
487     
488     
489      <p><a name="bc_ns"></a><b>bc_ns</b></p>
490
491
492
493
494      </td>
495
496
497
498 <td style="vertical-align: top;">C * 20</td>
499
500
501
502
503      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
504
505
506
507
508      <td style="vertical-align: top;">Boundary
509condition along y (for all quantities).<br>
510
511
512
513 <br>
514
515
516
517
518By default, a cyclic boundary condition is used along y.<br>
519
520
521
522 <br>
523
524
525
526
527      <span style="font-weight: bold;">bc_ns</span> may
528also be
529assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
530(inflow from rear ("north"), outflow to the front ("south")) or <span style="font-style: italic;">'radiation/dirichlet'</span>
531(inflow from front ("south"), outflow to the rear ("north")). This
532requires the multi-grid
533method to be used for solving the Poisson equation for perturbation
534pressure (see <a href="chapter_4.2.html#psolver">psolver</a>)
535and it also requires cyclic boundary conditions along x (see<br>
536
537
538
539 <a href="#bc_lr">bc_lr</a>).<br>
540
541
542
543 <br>
544
545
546
547
548In case of these non-cyclic lateral boundaries, a Dirichlet condition
549is used at the inflow for all quantities (initial vertical profiles -
550see <a href="chapter_4.1.html#initializing_actions">initializing_actions</a>
551- are fixed during the run) except u, to which a Neumann (zero
552gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
553gradient) condition is used for the scalars. For perturbation
554pressure Neumann (zero gradient) conditions are assumed both at the
555inflow and at the outflow.<br>
556
557
558
559 <br>
560
561
562
563
564For further details regarding non-cyclic lateral boundary conditions
565see <a href="#bc_lr">bc_lr</a>.</td>
566
567
568
569 </tr>
570
571
572
573
574    <tr>
575
576
577
578 <td style="vertical-align: top;"> 
579     
580     
581     
582      <p><a name="bc_p_b"></a><b>bc_p_b</b></p>
583
584
585
586 </td>
587
588
589
590
591      <td style="vertical-align: top;">C * 20</td>
592
593
594
595 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
596
597
598
599
600      <td style="vertical-align: top;"> 
601     
602     
603     
604      <p style="font-style: normal;">Bottom boundary condition of the
605perturbation pressure.&nbsp; </p>
606
607
608
609 
610     
611     
612     
613      <p>Allowed values
614are <span style="font-style: italic;">'dirichlet'</span>,
615      <span style="font-style: italic;">'neumann'</span>
616and <span style="font-style: italic;">'neumann+inhomo'</span>.&nbsp;
617      <span style="font-style: italic;">'dirichlet'</span>
618sets
619p(k=0)=0.0,&nbsp; <span style="font-style: italic;">'neumann'</span>
620sets p(k=0)=p(k=1). <span style="font-style: italic;">'neumann+inhomo'</span>
621corresponds to an extended Neumann boundary condition where heat flux
622or temperature inhomogeneities near the
623surface (pt(k=1))&nbsp; are additionally regarded (see Shen and
624LeClerc
625(1995, Q.J.R. Meteorol. Soc.,
6261209)). This condition is only permitted with the Prandtl-layer
627switched on (<a href="#prandtl_layer">prandtl_layer</a>),
628otherwise the run is terminated.&nbsp; </p>
629
630
631
632 
633     
634     
635     
636      <p>Since
637at the bottom boundary of the model the vertical
638velocity
639disappears (w(k=0) = 0.0), the consistent Neumann condition (<span style="font-style: italic;">'neumann'</span> or <span style="font-style: italic;">'neumann+inhomo'</span>)
640dp/dz = 0 should
641be used, which leaves the vertical component w unchanged when the
642pressure solver is applied. Simultaneous use of the Neumann boundary
643conditions both at the bottom and at the top boundary (<a href="#bc_p_t">bc_p_t</a>)
644usually yields no consistent solution for the perturbation pressure and
645should be avoided.</p>
646
647
648
649 </td>
650
651
652
653 </tr>
654
655
656
657 <tr>
658
659
660
661 <td style="vertical-align: top;"> 
662     
663     
664     
665      <p><a name="bc_p_t"></a><b>bc_p_t</b></p>
666
667
668
669
670      </td>
671
672
673
674 <td style="vertical-align: top;">C * 20</td>
675
676
677
678
679      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
680
681
682
683
684      <td style="vertical-align: top;"> 
685     
686     
687     
688      <p style="font-style: normal;">Top boundary condition of the
689perturbation pressure.&nbsp; </p>
690
691
692
693 
694     
695     
696     
697      <p style="font-style: normal;">Allowed values are <span style="font-style: italic;">'dirichlet'</span>
698(p(k=nz+1)= 0.0) or <span style="font-style: italic;">'neumann'</span>
699(p(k=nz+1)=p(k=nz)).&nbsp; </p>
700
701
702
703 
704     
705     
706     
707      <p>Simultaneous use
708of Neumann boundary conditions both at the
709top and bottom boundary (<a href="#bc_p_b">bc_p_b</a>)
710usually yields no consistent solution for the perturbation pressure and
711should be avoided. Since at the bottom boundary the Neumann
712condition&nbsp; is a good choice (see <a href="#bc_p_b">bc_p_b</a>),
713a Dirichlet condition should be set at the top boundary.</p>
714
715
716
717 </td>
718
719
720
721
722    </tr>
723
724
725
726 <tr>
727
728
729
730 <td style="vertical-align: top;">
731     
732     
733     
734      <p><a name="bc_pt_b"></a><b>bc_pt_b</b></p>
735
736
737
738
739      </td>
740
741
742
743 <td style="vertical-align: top;">C*20</td>
744
745
746
747
748      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
749
750
751
752
753      <td style="vertical-align: top;"> 
754     
755     
756     
757      <p style="font-style: normal;">Bottom boundary condition of the
758potential temperature.&nbsp; </p>
759
760
761
762 
763     
764     
765     
766      <p>Allowed values
767are <span style="font-style: italic;">'dirichlet'</span>
768(pt(k=0) = const. = <a href="#pt_surface">pt_surface</a>
769+ <a href="#pt_surface_initial_change">pt_surface_initial_change</a>;
770the user may change this value during the run using user-defined code)
771and <span style="font-style: italic;">'neumann'</span>
772(pt(k=0)=pt(k=1)).&nbsp; <br>
773
774
775
776
777When a constant surface sensible heat flux is used (<a href="#surface_heatflux">surface_heatflux</a>), <b>bc_pt_b</b>
778= <span style="font-style: italic;">'neumann'</span>
779must be used, because otherwise the resolved scale may contribute to
780the surface flux so that a constant value cannot be guaranteed.</p>
781
782
783
784     
785     
786     
787      <p>In the <a href="chapter_3.8.html">coupled</a> atmosphere executable,&nbsp;<a href="chapter_4.2.html#bc_pt_b">bc_pt_b</a> is internally set and does not need to be prescribed.</p>
788
789
790
791
792      </td>
793
794
795
796 </tr>
797
798
799
800 <tr>
801
802
803
804 <td style="vertical-align: top;"> 
805     
806     
807     
808      <p><a name="pc_pt_t"></a><b>bc_pt_t</b></p>
809
810
811
812
813      </td>
814
815
816
817 <td style="vertical-align: top;">C * 20</td>
818
819
820
821
822      <td style="vertical-align: top;"><span style="font-style: italic;">'initial_ gradient'</span></td>
823
824
825
826
827      <td style="vertical-align: top;"> 
828     
829     
830     
831      <p style="font-style: normal;">Top boundary condition of the
832potential temperature.&nbsp; </p>
833
834
835
836 
837     
838     
839     
840      <p>Allowed are the
841values <span style="font-style: italic;">'dirichlet' </span>(pt(k=nz+1)
842does not change during the run), <span style="font-style: italic;">'neumann'</span>
843(pt(k=nz+1)=pt(k=nz)), and <span style="font-style: italic;">'initial_gradient'</span>.
844With the 'initial_gradient'-condition the value of the temperature
845gradient at the top is
846calculated from the initial
847temperature profile (see <a href="#pt_surface">pt_surface</a>,
848      <a href="#pt_vertical_gradient">pt_vertical_gradient</a>)
849by bc_pt_t_val = (pt_init(k=nz+1) -
850pt_init(k=nz)) / dzu(nz+1).<br>
851
852
853
854
855Using this value (assumed constant during the
856run) the temperature boundary values are calculated as&nbsp; </p>
857
858
859
860
861     
862     
863     
864      <ul>
865
866
867
868 
869       
870       
871       
872        <p style="font-style: normal;">pt(k=nz+1) =
873pt(k=nz) +
874bc_pt_t_val * dzu(nz+1)</p>
875
876
877
878 
879     
880     
881     
882      </ul>
883
884
885
886 
887     
888     
889     
890      <p style="font-style: normal;">(up to k=nz the prognostic
891equation for the temperature is solved).<br>
892
893
894
895
896When a constant sensible heat flux is used at the top boundary (<a href="chapter_4.1.html#top_heatflux">top_heatflux</a>),
897      <b>bc_pt_t</b> = <span style="font-style: italic;">'neumann'</span>
898must be used, because otherwise the resolved scale may contribute to
899the top flux so that a constant value cannot be guaranteed.</p>
900
901
902
903 </td>
904
905
906
907
908    </tr>
909
910
911
912 <tr>
913
914
915
916 <td style="vertical-align: top;">
917     
918     
919     
920      <p><a name="bc_q_b"></a><b>bc_q_b</b></p>
921
922
923
924
925      </td>
926
927
928
929 <td style="vertical-align: top;">C * 20</td>
930
931
932
933
934      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
935
936
937
938
939      <td style="vertical-align: top;"> 
940     
941     
942     
943      <p style="font-style: normal;">Bottom boundary condition of the
944specific humidity / total water content.&nbsp; </p>
945
946
947
948 
949     
950     
951     
952      <p>Allowed
953values are <span style="font-style: italic;">'dirichlet'</span>
954(q(k=0) = const. = <a href="#q_surface">q_surface</a>
955+ <a href="#q_surface_initial_change">q_surface_initial_change</a>;
956the user may change this value during the run using user-defined code)
957and <span style="font-style: italic;">'neumann'</span>
958(q(k=0)=q(k=1)).&nbsp; <br>
959
960
961
962
963When a constant surface latent heat flux is used (<a href="#surface_waterflux">surface_waterflux</a>), <b>bc_q_b</b>
964= <span style="font-style: italic;">'neumann'</span>
965must be used, because otherwise the resolved scale may contribute to
966the surface flux so that a constant value cannot be guaranteed.</p>
967
968
969
970
971      </td>
972
973
974
975 </tr>
976
977
978
979 <tr>
980
981
982
983 <td style="vertical-align: top;"> 
984     
985     
986     
987      <p><a name="bc_q_t"></a><b>bc_q_t</b></p>
988
989
990
991
992      </td>
993
994
995
996 <td style="vertical-align: top;"><span style="font-style: italic;">C
997* 20</span></td>
998
999
1000
1001 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1002
1003
1004
1005
1006      <td style="vertical-align: top;"> 
1007     
1008     
1009     
1010      <p style="font-style: normal;">Top boundary condition of the
1011specific humidity / total water content.&nbsp; </p>
1012
1013
1014
1015 
1016     
1017     
1018     
1019      <p>Allowed
1020are the values <span style="font-style: italic;">'dirichlet'</span>
1021(q(k=nz) and q(k=nz+1) do
1022not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1023With the Neumann boundary
1024condition the value of the humidity gradient at the top is calculated
1025from the
1026initial humidity profile (see <a href="#q_surface">q_surface</a>,
1027      <a href="#q_vertical_gradient">q_vertical_gradient</a>)
1028by: bc_q_t_val = ( q_init(k=nz) - q_init(k=nz-1)) / dzu(nz).<br>
1029
1030
1031
1032
1033Using this value (assumed constant during the run) the humidity
1034boundary values
1035are calculated as&nbsp; </p>
1036
1037
1038
1039 
1040     
1041     
1042     
1043      <ul>
1044
1045
1046
1047 
1048       
1049       
1050       
1051        <p style="font-style: normal;">q(k=nz+1) =q(k=nz) +
1052bc_q_t_val * dzu(nz+1)</p>
1053
1054
1055
1056 
1057     
1058     
1059     
1060      </ul>
1061
1062
1063
1064 
1065     
1066     
1067     
1068      <p style="font-style: normal;">(up tp k=nz the prognostic
1069equation for q is solved). </p>
1070
1071
1072
1073 </td>
1074
1075
1076
1077 </tr>
1078
1079
1080
1081 <tr>
1082
1083
1084
1085
1086      <td style="vertical-align: top;"> 
1087     
1088     
1089     
1090      <p><a name="bc_s_b"></a><b>bc_s_b</b></p>
1091
1092
1093
1094 </td>
1095
1096
1097
1098
1099      <td style="vertical-align: top;">C * 20</td>
1100
1101
1102
1103 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1104
1105
1106
1107
1108      <td style="vertical-align: top;"> 
1109     
1110     
1111     
1112      <p style="font-style: normal;">Bottom boundary condition of the
1113scalar concentration.&nbsp; </p>
1114
1115
1116
1117 
1118     
1119     
1120     
1121      <p>Allowed values
1122are <span style="font-style: italic;">'dirichlet'</span>
1123(s(k=0) = const. = <a href="#s_surface">s_surface</a>
1124+ <a href="#s_surface_initial_change">s_surface_initial_change</a>;
1125the user may change this value during the run using user-defined code)
1126and <span style="font-style: italic;">'neumann'</span>
1127(s(k=0) =
1128s(k=1)).&nbsp; <br>
1129
1130
1131
1132
1133When a constant surface concentration flux is used (<a href="#surface_scalarflux">surface_scalarflux</a>), <b>bc_s_b</b>
1134= <span style="font-style: italic;">'neumann'</span>
1135must be used, because otherwise the resolved scale may contribute to
1136the surface flux so that a constant value cannot be guaranteed.</p>
1137
1138
1139
1140
1141      </td>
1142
1143
1144
1145 </tr>
1146
1147
1148
1149 <tr>
1150
1151
1152
1153 <td style="vertical-align: top;"> 
1154     
1155     
1156     
1157      <p><a name="bc_s_t"></a><b>bc_s_t</b></p>
1158
1159
1160
1161
1162      </td>
1163
1164
1165
1166 <td style="vertical-align: top;">C * 20</td>
1167
1168
1169
1170
1171      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1172
1173
1174
1175
1176      <td style="vertical-align: top;"> 
1177     
1178     
1179     
1180      <p style="font-style: normal;">Top boundary condition of the
1181scalar concentration.&nbsp; </p>
1182
1183
1184
1185 
1186     
1187     
1188     
1189      <p>Allowed are the
1190values <span style="font-style: italic;">'dirichlet'</span>
1191(s(k=nz) and s(k=nz+1) do
1192not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1193With the Neumann boundary
1194condition the value of the scalar concentration gradient at the top is
1195calculated
1196from the initial scalar concentration profile (see <a href="#s_surface">s_surface</a>, <a href="#s_vertical_gradient">s_vertical_gradient</a>)
1197by: bc_s_t_val = (s_init(k=nz) - s_init(k=nz-1)) / dzu(nz).<br>
1198
1199
1200
1201
1202Using this value (assumed constant during the run) the concentration
1203boundary values
1204are calculated as </p>
1205
1206
1207
1208 
1209     
1210     
1211     
1212      <ul>
1213
1214
1215
1216 
1217       
1218       
1219       
1220        <p style="font-style: normal;">s(k=nz+1) = s(k=nz) +
1221bc_s_t_val * dzu(nz+1)</p>
1222
1223
1224
1225 
1226     
1227     
1228     
1229      </ul>
1230
1231
1232
1233 
1234     
1235     
1236     
1237      <p style="font-style: normal;">(up to k=nz the prognostic
1238equation for the scalar concentration is
1239solved).</p>
1240
1241
1242
1243 </td>
1244
1245
1246
1247 </tr>
1248
1249
1250
1251 <tr>
1252
1253
1254
1255      <td style="vertical-align: top;"><a name="bc_sa_t"></a><span style="font-weight: bold;">bc_sa_t</span></td>
1256
1257
1258
1259      <td style="vertical-align: top;">C * 20</td>
1260
1261
1262
1263      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1264
1265
1266
1267      <td style="vertical-align: top;">
1268     
1269     
1270     
1271      <p style="font-style: normal;">Top boundary condition of the salinity.&nbsp; </p>
1272
1273
1274
1275 
1276     
1277     
1278     
1279      <p>This parameter only comes into effect for ocean runs (see parameter <a href="#ocean">ocean</a>).</p>
1280
1281
1282
1283     
1284     
1285     
1286      <p style="font-style: normal;">Allowed are the
1287values <span style="font-style: italic;">'dirichlet' </span>(sa(k=nz+1)
1288does not change during the run) and <span style="font-style: italic;">'neumann'</span>
1289(sa(k=nz+1)=sa(k=nz))<span style="font-style: italic;"></span>.&nbsp;<br>
1290
1291
1292
1293      <br>
1294
1295
1296
1297
1298When a constant salinity flux is used at the top boundary (<a href="chapter_4.1.html#top_salinityflux">top_salinityflux</a>),
1299      <b>bc_sa_t</b> = <span style="font-style: italic;">'neumann'</span>
1300must be used, because otherwise the resolved scale may contribute to
1301the top flux so that a constant value cannot be guaranteed.</p>
1302
1303
1304
1305      </td>
1306
1307
1308
1309    </tr>
1310
1311
1312
1313    <tr>
1314
1315
1316
1317 <td style="vertical-align: top;"> 
1318     
1319     
1320     
1321      <p><a name="bc_uv_b"></a><b>bc_uv_b</b></p>
1322
1323
1324
1325
1326      </td>
1327
1328
1329
1330 <td style="vertical-align: top;">C * 20</td>
1331
1332
1333
1334
1335      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1336
1337
1338
1339
1340      <td style="vertical-align: top;"> 
1341     
1342     
1343     
1344      <p style="font-style: normal;">Bottom boundary condition of the
1345horizontal velocity components u and v.&nbsp; </p>
1346
1347
1348
1349 
1350     
1351     
1352     
1353      <p>Allowed
1354values are <span style="font-style: italic;">'dirichlet' </span>and
1355      <span style="font-style: italic;">'neumann'</span>. <b>bc_uv_b</b>
1356= <span style="font-style: italic;">'dirichlet'</span>
1357yields the
1358no-slip condition with u=v=0 at the bottom. Due to the staggered grid
1359u(k=0) and v(k=0) are located at z = - 0,5 * <a href="#dz">dz</a>
1360(below the bottom), while u(k=1) and v(k=1) are located at z = +0,5 *
1361dz. u=v=0 at the bottom is guaranteed using mirror boundary
1362condition:&nbsp; </p>
1363
1364
1365
1366 
1367     
1368     
1369     
1370      <ul>
1371
1372
1373
1374 
1375       
1376       
1377       
1378        <p style="font-style: normal;">u(k=0) = - u(k=1) and v(k=0) = -
1379v(k=1)</p>
1380
1381
1382
1383 
1384     
1385     
1386     
1387      </ul>
1388
1389
1390
1391 
1392     
1393     
1394     
1395      <p style="font-style: normal;">The
1396Neumann boundary condition
1397yields the free-slip condition with u(k=0) = u(k=1) and v(k=0) =
1398v(k=1).
1399With Prandtl - layer switched on, the free-slip condition is not
1400allowed (otherwise the run will be terminated)<font color="#000000">.</font></p>
1401
1402
1403
1404
1405      </td>
1406
1407
1408
1409 </tr>
1410
1411
1412
1413 <tr>
1414
1415
1416
1417 <td style="vertical-align: top;"> 
1418     
1419     
1420     
1421      <p><a name="bc_uv_t"></a><b>bc_uv_t</b></p>
1422
1423
1424
1425
1426      </td>
1427
1428
1429
1430 <td style="vertical-align: top;">C * 20</td>
1431
1432
1433
1434
1435      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1436
1437
1438
1439
1440      <td style="vertical-align: top;"> 
1441     
1442     
1443     
1444      <p style="font-style: normal;">Top boundary condition of the
1445horizontal velocity components u and v.&nbsp; </p>
1446
1447
1448
1449 
1450     
1451     
1452     
1453      <p>Allowed
1454values are <span style="font-style: italic;">'dirichlet'</span>
1455and <span style="font-style: italic;">'neumann'</span>.
1456The
1457Dirichlet condition yields u(k=nz+1) = ug(nz+1) and v(k=nz+1) =
1458vg(nz+1),
1459Neumann condition yields the free-slip condition with u(k=nz+1) =
1460u(k=nz) and v(k=nz+1) = v(k=nz) (up to k=nz the prognostic equations
1461for the velocities are solved).</p>
1462
1463
1464
1465     
1466     
1467     
1468      <p>In the <a href="chapter_3.8.html">coupled</a> ocean executable, <a href="chapter_4.2.html#bc_uv_t">bc_uv_t</a>&nbsp;is internally set ('neumann') and does not need to be prescribed.</p>
1469
1470
1471
1472 </td>
1473
1474
1475
1476 </tr>
1477
1478
1479
1480 <tr>
1481
1482
1483
1484      <td style="vertical-align: top;"><a name="bottom_salinityflux"></a><span style="font-weight: bold;">bottom_salinityflux</span></td>
1485
1486
1487
1488      <td style="vertical-align: top;">R</td>
1489
1490
1491
1492      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
1493
1494
1495
1496      <td style="vertical-align: top;">
1497     
1498     
1499     
1500      <p>Kinematic salinity flux near the surface (in psu m/s).&nbsp;</p>
1501
1502
1503
1504This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).
1505     
1506     
1507     
1508      <p>The
1509respective salinity flux value is used
1510as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
1511condition must be used for the salinity, which is currently the only available condition.<br>
1512
1513
1514
1515 </p>
1516
1517
1518
1519 </td>
1520
1521
1522
1523    </tr>
1524
1525
1526
1527    <tr>
1528
1529
1530
1531
1532      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_height"></a>building_height</span></td>
1533
1534
1535
1536
1537      <td style="vertical-align: top;">R</td>
1538
1539
1540
1541 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1542
1543
1544
1545 <td>Height
1546of a single building in m.<br>
1547
1548
1549
1550 <br>
1551
1552
1553
1554 <span style="font-weight: bold;">building_height</span> must
1555be less than the height of the model domain. This parameter requires
1556the use of&nbsp;<a href="#topography">topography</a>
1557= <span style="font-style: italic;">'single_building'</span>.</td>
1558
1559
1560
1561
1562    </tr>
1563
1564
1565
1566 <tr>
1567
1568
1569
1570 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_x"></a>building_length_x</span></td>
1571
1572
1573
1574
1575      <td style="vertical-align: top;">R</td>
1576
1577
1578
1579 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1580
1581
1582
1583 <td><span style="font-style: italic;"></span>Width of a single
1584building in m.<br>
1585
1586
1587
1588 <br>
1589
1590
1591
1592
1593Currently, <span style="font-weight: bold;">building_length_x</span>
1594must be at least <span style="font-style: italic;">3
1595*&nbsp;</span><a style="font-style: italic;" href="#dx">dx</a> and no more than <span style="font-style: italic;">(&nbsp;</span><a style="font-style: italic;" href="#nx">nx</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="#dx">dx</a>
1596      </span><span style="font-style: italic;">- <a href="#building_wall_left">building_wall_left</a></span>.
1597This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1598= <span style="font-style: italic;">'single_building'</span>.</td>
1599
1600
1601
1602
1603    </tr>
1604
1605
1606
1607 <tr>
1608
1609
1610
1611 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_y"></a>building_length_y</span></td>
1612
1613
1614
1615
1616      <td style="vertical-align: top;">R</td>
1617
1618
1619
1620 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1621
1622
1623
1624 <td>Depth
1625of a single building in m.<br>
1626
1627
1628
1629 <br>
1630
1631
1632
1633
1634Currently, <span style="font-weight: bold;">building_length_y</span>
1635must be at least <span style="font-style: italic;">3
1636*&nbsp;</span><a style="font-style: italic;" href="#dy">dy</a> and no more than <span style="font-style: italic;">(&nbsp;</span><a style="font-style: italic;" href="#ny">ny</a><span style="font-style: italic;"> - 1 )&nbsp;</span><span style="font-style: italic;"> * <a href="#dy">dy</a></span><span style="font-style: italic;"> - <a href="#building_wall_south">building_wall_south</a></span>. This parameter requires
1637the use of&nbsp;<a href="#topography">topography</a>
1638= <span style="font-style: italic;">'single_building'</span>.</td>
1639
1640
1641
1642
1643    </tr>
1644
1645
1646
1647 <tr>
1648
1649
1650
1651 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_left"></a>building_wall_left</span></td>
1652
1653
1654
1655
1656      <td style="vertical-align: top;">R</td>
1657
1658
1659
1660 <td style="vertical-align: top;"><span style="font-style: italic;">building centered in x-direction</span></td>
1661
1662
1663
1664
1665      <td>x-coordinate of the left building wall (distance between the
1666left building wall and the left border of the model domain) in m.<br>
1667
1668
1669
1670
1671      <br>
1672
1673
1674
1675
1676Currently, <span style="font-weight: bold;">building_wall_left</span>
1677must be at least <span style="font-style: italic;">1
1678*&nbsp;</span><a style="font-style: italic;" href="#dx">dx</a> and less than <span style="font-style: italic;">( <a href="#nx">nx</a>&nbsp;
1679- 1 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a></span>.
1680This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1681= <span style="font-style: italic;">'single_building'</span>.<br>
1682
1683
1684
1685
1686      <br>
1687
1688
1689
1690
1691The default value&nbsp;<span style="font-weight: bold;">building_wall_left</span>
1692= <span style="font-style: italic;">( ( <a href="#nx">nx</a>&nbsp;+
16931 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a> ) / 2</span>
1694centers the building in x-direction. </td>
1695
1696
1697
1698 </tr>
1699
1700
1701
1702 <tr>
1703
1704
1705
1706
1707      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_south"></a>building_wall_south</span></td>
1708
1709
1710
1711
1712      <td style="vertical-align: top;">R</td>
1713
1714
1715
1716 <td style="vertical-align: top;"><span style="font-style: italic;"></span><span style="font-style: italic;">building centered in y-direction</span></td>
1717
1718
1719
1720
1721      <td>y-coordinate of the South building wall (distance between the
1722South building wall and the South border of the model domain) in m.<br>
1723
1724
1725
1726
1727      <br>
1728
1729
1730
1731
1732Currently, <span style="font-weight: bold;">building_wall_south</span>
1733must be at least <span style="font-style: italic;">1
1734*&nbsp;</span><a style="font-style: italic;" href="#dy">dy</a> and less than <span style="font-style: italic;">( <a href="#ny">ny</a>&nbsp;
1735- 1 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a></span>.
1736This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1737= <span style="font-style: italic;">'single_building'</span>.<br>
1738
1739
1740
1741
1742      <br>
1743
1744
1745
1746
1747The default value&nbsp;<span style="font-weight: bold;">building_wall_south</span>
1748= <span style="font-style: italic;">( ( <a href="#ny">ny</a>&nbsp;+
17491 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a> ) / 2</span>
1750centers the building in y-direction. </td>
1751
1752
1753
1754 </tr>
1755
1756
1757
1758 <tr>
1759
1760
1761
1762
1763      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="cloud_droplets"></a>cloud_droplets</span><br>
1764
1765
1766
1767
1768      </td>
1769
1770
1771
1772 <td style="vertical-align: top;">L<br>
1773
1774
1775
1776 </td>
1777
1778
1779
1780
1781      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span><br>
1782
1783
1784
1785 </td>
1786
1787
1788
1789
1790      <td style="vertical-align: top;">Parameter to switch on
1791usage of cloud droplets.<br>
1792
1793
1794
1795 <br>
1796
1797
1798
1799
1800Cloud droplets require to use the particle package (<span style="font-weight: bold;">mrun</span>-option <span style="font-family: monospace;">-p particles</span>),
1801so in this case a particle corresponds to a droplet. The droplet
1802features (number of droplets, initial radius, etc.) can be steered with
1803the&nbsp; respective particle parameters (see e.g. <a href="#chapter_4.2.html#radius">radius</a>).
1804The real number of initial droplets in a grid cell is equal to the
1805initial number of droplets (defined by the particle source parameters <span lang="en-GB"><font face="Thorndale, serif"> </font></span><a href="chapter_4.2.html#pst"><span lang="en-GB"><font face="Thorndale, serif">pst</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psl"><span lang="en-GB"><font face="Thorndale, serif">psl</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psr"><span lang="en-GB"><font face="Thorndale, serif">psr</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pss"><span lang="en-GB"><font face="Thorndale, serif">pss</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psn"><span lang="en-GB"><font face="Thorndale, serif">psn</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psb"><span lang="en-GB"><font face="Thorndale, serif">psb</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdx"><span lang="en-GB"><font face="Thorndale, serif">pdx</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdy"><span lang="en-GB"><font face="Thorndale, serif">pdy</font></span></a>
1806      <span lang="en-GB"><font face="Thorndale, serif">and
1807      </font></span><a href="chapter_4.2.html#pdz"><span lang="en-GB"><font face="Thorndale, serif">pdz</font></span></a><span lang="en-GB"></span><span lang="en-GB"></span>)
1808times the <a href="#initial_weighting_factor">initial_weighting_factor</a>.<br>
1809
1810
1811
1812
1813      <br>
1814
1815
1816
1817
1818In case of using cloud droplets, the default condensation scheme in
1819PALM cannot be used, i.e. <a href="#cloud_physics">cloud_physics</a>
1820must be set <span style="font-style: italic;">.F.</span>.<br>
1821
1822
1823
1824
1825      </td>
1826
1827
1828
1829 </tr>
1830
1831
1832
1833 <tr>
1834
1835
1836
1837 <td style="vertical-align: top;"> 
1838     
1839     
1840     
1841      <p><a name="cloud_physics"></a><b>cloud_physics</b></p>
1842
1843
1844
1845
1846      </td>
1847
1848
1849
1850 <td style="vertical-align: top;">L<br>
1851
1852
1853
1854 </td>
1855
1856
1857
1858
1859      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
1860
1861
1862
1863 <td style="vertical-align: top;"> 
1864     
1865     
1866     
1867      <p>Parameter to switch
1868on the condensation scheme.&nbsp; </p>
1869
1870
1871
1872
1873For <b>cloud_physics =</b> <span style="font-style: italic;">.TRUE.</span>, equations
1874for the
1875liquid water&nbsp;
1876content and the liquid water potential temperature are solved instead
1877of those for specific humidity and potential temperature. Note
1878that a grid volume is assumed to be either completely saturated or
1879completely
1880unsaturated (0%-or-100%-scheme). A simple precipitation scheme can
1881additionally be switched on with parameter <a href="#precipitation">precipitation</a>.
1882Also cloud-top cooling by longwave radiation can be utilized (see <a href="#radiation">radiation</a>)<br>
1883
1884
1885
1886 <b><br>
1887
1888
1889
1890
1891cloud_physics =</b> <span style="font-style: italic;">.TRUE.
1892      </span>requires&nbsp;<a href="#humidity">humidity</a>
1893=<span style="font-style: italic;"> .TRUE.</span> .<br>
1894
1895
1896
1897
1898Detailed information about the condensation scheme is given in the
1899description of the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM-1/Dokumentationen/Cloud_physics/wolken.pdf">cloud
1900physics module</a> (pdf-file, only in German).<br>
1901
1902
1903
1904 <br>
1905
1906
1907
1908
1909This condensation scheme is not allowed if cloud droplets are simulated
1910explicitly (see <a href="#cloud_droplets">cloud_droplets</a>).<br>
1911
1912
1913
1914
1915      </td>
1916
1917
1918
1919 </tr>
1920
1921
1922
1923 <tr>
1924
1925
1926
1927 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow"></a>conserve_volume_flow</span></td>
1928
1929
1930
1931
1932      <td style="vertical-align: top;">L</td>
1933
1934
1935
1936 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
1937
1938
1939
1940 <td>Conservation
1941of volume flow in x- and y-direction.<br>
1942
1943
1944
1945 <br>
1946
1947
1948
1949 <span style="font-weight: bold;">conserve_volume_flow</span>
1950= <span style="font-style: italic;">.TRUE.</span>
1951guarantees that the volume flow through the xz- or yz-cross-section of
1952the total model domain remains constant (equal to the initial value at
1953t=0) throughout the run.<br>
1954
1955
1956
1957
1958      </td>
1959
1960
1961
1962 </tr>
1963
1964
1965
1966 <tr>
1967
1968
1969
1970 <td style="vertical-align: top;"> 
1971     
1972     
1973     
1974      <p><a name="cut_spline_overshoot"></a><b>cut_spline_overshoot</b></p>
1975
1976
1977
1978
1979      </td>
1980
1981
1982
1983 <td style="vertical-align: top;">L</td>
1984
1985
1986
1987
1988      <td style="vertical-align: top;"><span style="font-style: italic;">.T.</span></td>
1989
1990
1991
1992 <td style="vertical-align: top;"> 
1993     
1994     
1995     
1996      <p>Cuts off of
1997so-called overshoots, which can occur with the
1998upstream-spline scheme.&nbsp; </p>
1999
2000
2001
2002 
2003     
2004     
2005     
2006      <p><font color="#000000">The cubic splines tend to overshoot in
2007case of discontinuous changes of variables between neighbouring grid
2008points.</font><font color="#ff0000"> </font><font color="#000000">This
2009may lead to errors in calculating the advection tendency.</font>
2010Choice
2011of <b>cut_spline_overshoot</b> = <i>.TRUE.</i>
2012(switched on by
2013default)
2014allows variable values not to exceed an interval defined by the
2015respective adjacent grid points. This interval can be adjusted
2016seperately for every prognostic variable (see initialization parameters
2017      <a href="#overshoot_limit_e">overshoot_limit_e</a>, <a href="#overshoot_limit_pt">overshoot_limit_pt</a>, <a href="#overshoot_limit_u">overshoot_limit_u</a>,
2018etc.). This might be necessary in case that the
2019default interval has a non-tolerable effect on the model
2020results.&nbsp; </p>
2021
2022
2023
2024 
2025     
2026     
2027     
2028      <p>Overshoots may also be removed
2029using the parameters <a href="#ups_limit_e">ups_limit_e</a>,
2030      <a href="#ups_limit_pt">ups_limit_pt</a>,
2031etc. as well as by applying a long-filter (see <a href="#long_filter_factor">long_filter_factor</a>).</p>
2032
2033
2034
2035
2036      </td>
2037
2038
2039
2040 </tr>
2041
2042
2043
2044 <tr>
2045
2046
2047
2048 <td style="vertical-align: top;"> 
2049     
2050     
2051     
2052      <p><a name="damp_level_1d"></a><b>damp_level_1d</b></p>
2053
2054
2055
2056
2057      </td>
2058
2059
2060
2061 <td style="vertical-align: top;">R</td>
2062
2063
2064
2065
2066      <td style="vertical-align: top;"><span style="font-style: italic;">zu(nz+1)</span></td>
2067
2068
2069
2070
2071      <td style="vertical-align: top;"> 
2072     
2073     
2074     
2075      <p>Height where
2076the damping layer begins in the 1d-model
2077(in m).&nbsp; </p>
2078
2079
2080
2081 
2082     
2083     
2084     
2085      <p>This parameter is used to
2086switch on a damping layer for the
20871d-model, which is generally needed for the damping of inertia
2088oscillations. Damping is done by gradually increasing the value
2089of the eddy diffusivities about 10% per vertical grid level
2090(starting with the value at the height given by <b>damp_level_1d</b>,
2091or possibly from the next grid pint above), i.e. K<sub>m</sub>(k+1)
2092=
20931.1 * K<sub>m</sub>(k).
2094The values of K<sub>m</sub> are limited to 10 m**2/s at
2095maximum.&nbsp; <br>
2096
2097
2098
2099
2100This parameter only comes into effect if the 1d-model is switched on
2101for
2102the initialization of the 3d-model using <a href="#initializing_actions">initializing_actions</a>
2103= <span style="font-style: italic;">'set_1d-model_profiles'</span>.
2104      <br>
2105
2106
2107
2108 </p>
2109
2110
2111
2112 </td>
2113
2114
2115
2116 </tr>
2117
2118
2119
2120 <tr>
2121
2122
2123
2124 <td style="vertical-align: top;"><a name="dissipation_1d"></a><span style="font-weight: bold;">dissipation_1d</span><br>
2125
2126
2127
2128
2129      </td>
2130
2131
2132
2133 <td style="vertical-align: top;">C*20<br>
2134
2135
2136
2137
2138      </td>
2139
2140
2141
2142 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
2143
2144
2145
2146 <span style="font-style: italic;">model'</span><br>
2147
2148
2149
2150 </td>
2151
2152
2153
2154
2155      <td style="vertical-align: top;">Calculation method for
2156the energy dissipation term in the TKE equation of the 1d-model.<br>
2157
2158
2159
2160
2161      <br>
2162
2163
2164
2165
2166By default the dissipation is calculated as in the 3d-model using diss
2167= (0.19 + 0.74 * l / l_grid) * e**1.5 / l.<br>
2168
2169
2170
2171 <br>
2172
2173
2174
2175
2176Setting <span style="font-weight: bold;">dissipation_1d</span>
2177= <span style="font-style: italic;">'detering'</span>
2178forces the dissipation to be calculated as diss = 0.064 * e**1.5 / l.<br>
2179
2180
2181
2182
2183      </td>
2184
2185
2186
2187 </tr>
2188
2189
2190
2191
2192    <tr>
2193
2194
2195
2196 <td style="vertical-align: top;"> 
2197     
2198     
2199     
2200      <p><a name="dt"></a><b>dt</b></p>
2201
2202
2203
2204 </td>
2205
2206
2207
2208
2209      <td style="vertical-align: top;">R</td>
2210
2211
2212
2213 <td style="vertical-align: top;"><span style="font-style: italic;">variable</span></td>
2214
2215
2216
2217
2218      <td style="vertical-align: top;"> 
2219     
2220     
2221     
2222      <p>Time step for
2223the 3d-model (in s).&nbsp; </p>
2224
2225
2226
2227 
2228     
2229     
2230     
2231      <p>By default, (i.e.
2232if a Runge-Kutta scheme is used, see <a href="#timestep_scheme">timestep_scheme</a>)
2233the value of the time step is calculating after each time step
2234(following the time step criteria) and
2235used for the next step.</p>
2236
2237
2238
2239 
2240     
2241     
2242     
2243      <p>If the user assigns <b>dt</b>
2244a value, then the time step is
2245fixed to this value throughout the whole run (whether it fulfills the
2246time step
2247criteria or not). However, changes are allowed for restart runs,
2248because <b>dt</b> can also be used as a <a href="chapter_4.2.html#dt_laufparameter">run
2249parameter</a>.&nbsp; </p>
2250
2251
2252
2253 
2254     
2255     
2256     
2257      <p>In case that the
2258calculated time step meets the condition<br>
2259
2260
2261
2262 </p>
2263
2264
2265
2266 
2267     
2268     
2269     
2270      <ul>
2271
2272
2273
2274
2275       
2276       
2277       
2278        <p><b>dt</b> &lt; 0.00001 * <a href="chapter_4.2.html#dt_max">dt_max</a> (with dt_max
2279= 20.0)</p>
2280
2281
2282
2283 
2284     
2285     
2286     
2287      </ul>
2288
2289
2290
2291 
2292     
2293     
2294     
2295      <p>the simulation will be
2296aborted. Such situations usually arise
2297in case of any numerical problem / instability which causes a
2298non-realistic increase of the wind speed.&nbsp; </p>
2299
2300
2301
2302 
2303     
2304     
2305     
2306      <p>A
2307small time step due to a large mean horizontal windspeed
2308speed may be enlarged by using a coordinate transformation (see <a href="#galilei_transformation">galilei_transformation</a>),
2309in order to spare CPU time.<br>
2310
2311
2312
2313 </p>
2314
2315
2316
2317 
2318     
2319     
2320     
2321      <p>If the
2322leapfrog timestep scheme is used (see <a href="#timestep_scheme">timestep_scheme</a>)
2323a temporary time step value dt_new is calculated first, with dt_new = <a href="chapter_4.2.html#fcl_factor">cfl_factor</a>
2324* dt_crit where dt_crit is the maximum timestep allowed by the CFL and
2325diffusion condition. Next it is examined whether dt_new exceeds or
2326falls below the
2327value of the previous timestep by at
2328least +5 % / -2%. If it is smaller, <span style="font-weight: bold;">dt</span>
2329= dt_new is immediately used for the next timestep. If it is larger,
2330then <span style="font-weight: bold;">dt </span>=
23311.02 * dt_prev
2332(previous timestep) is used as the new timestep, however the time
2333step is only increased if the last change of the time step is dated
2334back at
2335least 30 iterations. If dt_new is located in the interval mentioned
2336above, then dt
2337does not change at all. By doing so, permanent time step changes as
2338well as large
2339sudden changes (increases) in the time step are avoided.</p>
2340
2341
2342
2343 </td>
2344
2345
2346
2347
2348    </tr>
2349
2350
2351
2352 <tr>
2353
2354
2355
2356 <td style="vertical-align: top;">
2357     
2358     
2359     
2360      <p><a name="dt_pr_1d"></a><b>dt_pr_1d</b></p>
2361
2362
2363
2364
2365      </td>
2366
2367
2368
2369 <td style="vertical-align: top;">R</td>
2370
2371
2372
2373
2374      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
2375
2376
2377
2378
2379      <td style="vertical-align: top;"> 
2380     
2381     
2382     
2383      <p>Temporal
2384interval of vertical profile output of the 1D-model
2385(in s).&nbsp; </p>
2386
2387
2388
2389 
2390     
2391     
2392     
2393      <p>Data are written in ASCII
2394format to file <a href="chapter_3.4.html#LIST_PROFIL_1D">LIST_PROFIL_1D</a>.
2395This parameter is only in effect if the 1d-model has been switched on
2396for the
2397initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
2398= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
2399
2400
2401
2402
2403      </td>
2404
2405
2406
2407 </tr>
2408
2409
2410
2411 <tr>
2412
2413
2414
2415 <td style="vertical-align: top;"> 
2416     
2417     
2418     
2419      <p><a name="dt_run_control_1d"></a><b>dt_run_control_1d</b></p>
2420
2421
2422
2423
2424      </td>
2425
2426
2427
2428 <td style="vertical-align: top;">R</td>
2429
2430
2431
2432
2433      <td style="vertical-align: top;"><span style="font-style: italic;">60.0</span></td>
2434
2435
2436
2437 <td style="vertical-align: top;"> 
2438     
2439     
2440     
2441      <p>Temporal interval of
2442runtime control output of the 1d-model
2443(in s).&nbsp; </p>
2444
2445
2446
2447 
2448     
2449     
2450     
2451      <p>Data are written in ASCII
2452format to file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.
2453This parameter is only in effect if the 1d-model is switched on for the
2454initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
2455= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
2456
2457
2458
2459
2460      </td>
2461
2462
2463
2464 </tr>
2465
2466
2467
2468 <tr>
2469
2470
2471
2472 <td style="vertical-align: top;"> 
2473     
2474     
2475     
2476      <p><a name="dx"></a><b>dx</b></p>
2477
2478
2479
2480
2481      </td>
2482
2483
2484
2485 <td style="vertical-align: top;">R</td>
2486
2487
2488
2489
2490      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
2491
2492
2493
2494 <td style="vertical-align: top;"> 
2495     
2496     
2497     
2498      <p>Horizontal grid
2499spacing along the x-direction (in m).&nbsp; </p>
2500
2501
2502
2503 
2504     
2505     
2506     
2507      <p>Along
2508x-direction only a constant grid spacing is allowed.</p>
2509
2510
2511
2512     
2513     
2514     
2515      <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be&nbsp;equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a>
2516and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
2517
2518
2519
2520 </td>
2521
2522
2523
2524
2525    </tr>
2526
2527
2528
2529 <tr>
2530
2531
2532
2533 <td style="vertical-align: top;">
2534     
2535     
2536     
2537      <p><a name="dy"></a><b>dy</b></p>
2538
2539
2540
2541
2542      </td>
2543
2544
2545
2546 <td style="vertical-align: top;">R</td>
2547
2548
2549
2550
2551      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
2552
2553
2554
2555 <td style="vertical-align: top;"> 
2556     
2557     
2558     
2559      <p>Horizontal grid
2560spacing along the y-direction (in m).&nbsp; </p>
2561
2562
2563
2564 
2565     
2566     
2567     
2568      <p>Along y-direction only a constant grid spacing is allowed.</p>
2569
2570
2571
2572     
2573     
2574     
2575      <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be&nbsp;equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a>
2576and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
2577
2578
2579
2580 </td>
2581
2582
2583
2584
2585    </tr>
2586
2587
2588
2589 <tr>
2590
2591
2592
2593 <td style="vertical-align: top;">
2594     
2595     
2596     
2597      <p><a name="dz"></a><b>dz</b></p>
2598
2599
2600
2601
2602      </td>
2603
2604
2605
2606 <td style="vertical-align: top;">R</td>
2607
2608
2609
2610
2611      <td style="vertical-align: top;"><br>
2612
2613
2614
2615 </td>
2616
2617
2618
2619 <td style="vertical-align: top;"> 
2620     
2621     
2622     
2623      <p>Vertical grid
2624spacing (in m).&nbsp; </p>
2625
2626
2627
2628 
2629     
2630     
2631     
2632      <p>This parameter must be
2633assigned by the user, because no
2634default value is given.<br>
2635
2636
2637
2638 </p>
2639
2640
2641
2642 
2643     
2644     
2645     
2646      <p>By default, the
2647model uses constant grid spacing along z-direction, but it can be
2648stretched using the parameters <a href="#dz_stretch_level">dz_stretch_level</a>
2649and <a href="#dz_stretch_factor">dz_stretch_factor</a>.
2650In case of stretching, a maximum allowed grid spacing can be given by <a href="#dz_max">dz_max</a>.<br>
2651
2652
2653
2654 </p>
2655
2656
2657
2658 
2659     
2660     
2661     
2662      <p>Assuming
2663a constant <span style="font-weight: bold;">dz</span>,
2664the scalar levels (zu) are calculated directly by:&nbsp; </p>
2665
2666
2667
2668
2669     
2670     
2671     
2672      <ul>
2673
2674
2675
2676 
2677       
2678       
2679       
2680        <p>zu(0) = - dz * 0.5&nbsp; <br>
2681
2682
2683
2684
2685zu(1) = dz * 0.5</p>
2686
2687
2688
2689 
2690     
2691     
2692     
2693      </ul>
2694
2695
2696
2697 
2698     
2699     
2700     
2701      <p>The w-levels lie
2702half between them:&nbsp; </p>
2703
2704
2705
2706 
2707     
2708     
2709     
2710      <ul>
2711
2712
2713
2714 
2715       
2716       
2717       
2718        <p>zw(k) =
2719( zu(k) + zu(k+1) ) * 0.5</p>
2720
2721
2722
2723 
2724     
2725     
2726     
2727      </ul>
2728
2729
2730
2731 </td>
2732
2733
2734
2735 </tr>
2736
2737
2738
2739
2740    <tr>
2741
2742
2743
2744      <td style="vertical-align: top;"><a name="dz_max"></a><span style="font-weight: bold;">dz_max</span></td>
2745
2746
2747
2748      <td style="vertical-align: top;">R</td>
2749
2750
2751
2752      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
2753
2754
2755
2756      <td style="vertical-align: top;">Allowed maximum vertical grid
2757spacing (in m).<br>
2758
2759
2760
2761      <br>
2762
2763
2764
2765If the vertical grid is stretched
2766(see <a href="#dz_stretch_factor">dz_stretch_factor</a>
2767and <a href="#dz_stretch_level">dz_stretch_level</a>),
2768      <span style="font-weight: bold;">dz_max</span> can
2769be used to limit the vertical grid spacing.</td>
2770
2771
2772
2773    </tr>
2774
2775
2776
2777    <tr>
2778
2779
2780
2781
2782      <td style="vertical-align: top;"> 
2783     
2784     
2785     
2786      <p><a name="dz_stretch_factor"></a><b>dz_stretch_factor</b></p>
2787
2788
2789
2790
2791      </td>
2792
2793
2794
2795 <td style="vertical-align: top;">R</td>
2796
2797
2798
2799
2800      <td style="vertical-align: top;"><span style="font-style: italic;">1.08</span></td>
2801
2802
2803
2804 <td style="vertical-align: top;"> 
2805     
2806     
2807     
2808      <p>Stretch factor for a
2809vertically stretched grid (see <a href="#dz_stretch_level">dz_stretch_level</a>).&nbsp;
2810      </p>
2811
2812
2813
2814 
2815     
2816     
2817     
2818      <p>The stretch factor should not exceed a value of
2819approx. 1.10 -
28201.12, otherwise the discretization errors due to the stretched grid not
2821negligible any more. (refer Kalnay de Rivas)</p>
2822
2823
2824
2825 </td>
2826
2827
2828
2829 </tr>
2830
2831
2832
2833
2834    <tr>
2835
2836
2837
2838 <td style="vertical-align: top;"> 
2839     
2840     
2841     
2842      <p><a name="dz_stretch_level"></a><b>dz_stretch_level</b></p>
2843
2844
2845
2846
2847      </td>
2848
2849
2850
2851 <td style="vertical-align: top;">R</td>
2852
2853
2854
2855
2856      <td style="vertical-align: top;"><span style="font-style: italic;">100000.0</span><br>
2857
2858
2859
2860 </td>
2861
2862
2863
2864
2865      <td style="vertical-align: top;"> 
2866     
2867     
2868     
2869      <p>Height level
2870above/below which the grid is to be stretched
2871vertically (in m).&nbsp; </p>
2872
2873
2874
2875 
2876     
2877     
2878     
2879      <p>For <a href="chapter_4.1.html#ocean">ocean</a> = .F., <b>dz_stretch_level </b>is the height level (in m)&nbsp;<span style="font-weight: bold;">above </span>which the grid is to be stretched
2880vertically. The vertical grid
2881spacings <a href="#dz">dz</a>
2882above this level are calculated as&nbsp; </p>
2883
2884
2885
2886 
2887     
2888     
2889     
2890      <ul>
2891
2892
2893
2894 
2895       
2896       
2897       
2898        <p><b>dz</b>(k+1)
2899= <b>dz</b>(k) * <a href="#dz_stretch_factor">dz_stretch_factor</a></p>
2900
2901
2902
2903
2904     
2905     
2906     
2907      </ul>
2908
2909
2910
2911 
2912     
2913     
2914     
2915      <p>and used as spacings for the scalar levels (zu).
2916The
2917w-levels are then defined as:&nbsp; </p>
2918
2919
2920
2921 
2922     
2923     
2924     
2925      <ul>
2926
2927
2928
2929 
2930       
2931       
2932       
2933        <p>zw(k)
2934= ( zu(k) + zu(k+1) ) * 0.5.
2935
2936 
2937     
2938      </p>
2939
2940     
2941      </ul>
2942
2943     
2944      <p>For <a href="#ocean">ocean</a> = .T., <b>dz_stretch_level </b>is the height level (in m, negative) <span style="font-weight: bold;">below</span> which the grid is to be stretched
2945vertically. The vertical grid
2946spacings <a href="chapter_4.1.html#dz">dz</a> below this level are calculated correspondingly as
2947
2948 
2949     
2950      </p>
2951
2952     
2953      <ul>
2954
2955       
2956        <p><b>dz</b>(k-1)
2957= <b>dz</b>(k) * <a href="chapter_4.1.html#dz_stretch_factor">dz_stretch_factor</a>.</p>
2958
2959     
2960      </ul>
2961
2962
2963
2964 </td>
2965
2966
2967
2968 </tr>
2969
2970
2971
2972
2973    <tr>
2974
2975
2976      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_init"></a>e_init</span></td>
2977
2978
2979      <td style="vertical-align: top;">R</td>
2980
2981
2982      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
2983
2984
2985      <td>Initial subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
2986
2987
2988
2989
2990      <br>
2991
2992
2993
2994This
2995option prescribes an initial&nbsp;subgrid-scale TKE from which the initial diffusion coefficients K<sub>m</sub> and K<sub>h</sub> will be calculated if <span style="font-weight: bold;">e_init</span> is positive. This option only has an effect if&nbsp;<a href="#km_constant">km_constant</a> is not set.</td>
2996
2997
2998    </tr>
2999
3000
3001    <tr>
3002
3003
3004
3005 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_min"></a>e_min</span></td>
3006
3007
3008
3009
3010      <td style="vertical-align: top;">R</td>
3011
3012
3013
3014 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
3015
3016
3017
3018 <td>Minimum
3019subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
3020
3021
3022
3023
3024      <br>
3025
3026
3027
3028This
3029option&nbsp;adds artificial viscosity to the flow by ensuring that
3030the
3031subgrid-scale TKE does not fall below the minimum threshold <span style="font-weight: bold;">e_min</span>.</td>
3032
3033
3034
3035 </tr>
3036
3037
3038
3039
3040    <tr>
3041
3042
3043
3044 <td style="vertical-align: top;"> 
3045     
3046     
3047     
3048      <p><a name="end_time_1d"></a><b>end_time_1d</b></p>
3049
3050
3051
3052
3053      </td>
3054
3055
3056
3057 <td style="vertical-align: top;">R</td>
3058
3059
3060
3061
3062      <td style="vertical-align: top;"><span style="font-style: italic;">864000.0</span><br>
3063
3064
3065
3066 </td>
3067
3068
3069
3070
3071      <td style="vertical-align: top;"> 
3072     
3073     
3074     
3075      <p>Time to be
3076simulated for the 1d-model (in s).&nbsp; </p>
3077
3078
3079
3080 
3081     
3082     
3083     
3084      <p>The
3085default value corresponds to a simulated time of 10 days.
3086Usually, after such a period the inertia oscillations have completely
3087decayed and the solution of the 1d-model can be regarded as stationary
3088(see <a href="#damp_level_1d">damp_level_1d</a>).
3089This parameter is only in effect if the 1d-model is switched on for the
3090initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
3091= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
3092
3093
3094
3095
3096      </td>
3097
3098
3099
3100 </tr>
3101
3102
3103
3104 <tr>
3105
3106
3107
3108 <td style="vertical-align: top;"> 
3109     
3110     
3111     
3112      <p><a name="fft_method"></a><b>fft_method</b></p>
3113
3114
3115
3116
3117      </td>
3118
3119
3120
3121 <td style="vertical-align: top;">C * 20</td>
3122
3123
3124
3125
3126      <td style="vertical-align: top;"><span style="font-style: italic;">'system-</span><br style="font-style: italic;">
3127
3128
3129
3130 <span style="font-style: italic;">specific'</span></td>
3131
3132
3133
3134
3135      <td style="vertical-align: top;"> 
3136     
3137     
3138     
3139      <p>FFT-method to
3140be used.<br>
3141
3142
3143
3144 </p>
3145
3146
3147
3148 
3149     
3150     
3151     
3152      <p><br>
3153
3154
3155
3156
3157The fast fourier transformation (FFT) is used for solving the
3158perturbation pressure equation with a direct method (see <a href="chapter_4.2.html#psolver">psolver</a>)
3159and for calculating power spectra (see optional software packages,
3160section <a href="chapter_4.2.html#spectra_package">4.2</a>).</p>
3161
3162
3163
3164
3165     
3166     
3167     
3168      <p><br>
3169
3170
3171
3172
3173By default, system-specific, optimized routines from external
3174vendor libraries are used. However, these are available only on certain
3175computers and there are more or less severe restrictions concerning the
3176number of gridpoints to be used with them.<br>
3177
3178
3179
3180 </p>
3181
3182
3183
3184 
3185     
3186     
3187     
3188      <p>There
3189are two other PALM internal methods available on every
3190machine (their respective source code is part of the PALM source code):</p>
3191
3192
3193
3194
3195     
3196     
3197     
3198      <p>1.: The <span style="font-weight: bold;">Temperton</span>-method
3199from Clive Temperton (ECWMF) which is computationally very fast and
3200switched on with <b>fft_method</b> = <span style="font-style: italic;">'temperton-algorithm'</span>.
3201The number of horizontal gridpoints (nx+1, ny+1) to be used with this
3202method must be composed of prime factors 2, 3 and 5.<br>
3203
3204
3205
3206 </p>
3207
3208
3209
3210
32112.: The <span style="font-weight: bold;">Singleton</span>-method
3212which is very slow but has no restrictions concerning the number of
3213gridpoints to be used with, switched on with <b>fft_method</b>
3214= <span style="font-style: italic;">'singleton-algorithm'</span>.
3215      </td>
3216
3217
3218
3219 </tr>
3220
3221
3222
3223 <tr>
3224
3225
3226
3227 <td style="vertical-align: top;"> 
3228     
3229     
3230     
3231      <p><a name="galilei_transformation"></a><b>galilei_transformation</b></p>
3232
3233
3234
3235
3236      </td>
3237
3238
3239
3240 <td style="vertical-align: top;">L</td>
3241
3242
3243
3244
3245      <td style="vertical-align: top;"><i>.F.</i></td>
3246
3247
3248
3249
3250      <td style="vertical-align: top;">Application of a
3251Galilei-transformation to the
3252coordinate
3253system of the model.<br>
3254
3255
3256
3257     
3258     
3259     
3260      <p>With <b>galilei_transformation</b>
3261= <i>.T.,</i> a so-called
3262Galilei-transformation is switched on which ensures that the coordinate
3263system of the model is moved along with the geostrophical wind.
3264Alternatively, the model domain can be moved along with the averaged
3265horizontal wind (see <a href="#use_ug_for_galilei_tr">use_ug_for_galilei_tr</a>,
3266this can and will naturally change in time). With this method,
3267numerical inaccuracies of the Piascek - Williams - scheme (concerns in
3268particular the momentum advection) are minimized. Beyond that, in the
3269majority of cases the lower relative velocities in the moved system
3270permit a larger time step (<a href="#dt">dt</a>).
3271Switching the transformation on is only worthwhile if the geostrophical
3272wind (ug, vg)
3273and the averaged horizontal wind clearly deviate from the value 0. In
3274each case, the distance the coordinate system has been moved is written
3275to the file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.&nbsp;
3276      </p>
3277
3278
3279
3280 
3281     
3282     
3283     
3284      <p>Non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
3285and <a href="#bc_ns">bc_ns</a>), the specification
3286of a gestrophic
3287wind that is not constant with height
3288as well as e.g. stationary inhomogeneities at the bottom boundary do
3289not allow the use of this transformation.</p>
3290
3291
3292
3293 </td>
3294
3295
3296
3297 </tr>
3298
3299
3300
3301
3302    <tr>
3303
3304
3305
3306 <td style="vertical-align: top;"> 
3307     
3308     
3309     
3310      <p><a name="grid_matching"></a><b>grid_matching</b></p>
3311
3312
3313
3314
3315      </td>
3316
3317
3318
3319 <td style="vertical-align: top;">C * 6</td>
3320
3321
3322
3323
3324      <td style="vertical-align: top;"><span style="font-style: italic;">'match'</span></td>
3325
3326
3327
3328 <td style="vertical-align: top;">Variable to adjust the
3329subdomain
3330sizes in parallel runs.<br>
3331
3332
3333
3334 <br>
3335
3336
3337
3338
3339For <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>,
3340the subdomains are forced to have an identical
3341size on all processors. In this case the processor numbers in the
3342respective directions of the virtual processor net must fulfill certain
3343divisor conditions concerning the grid point numbers in the three
3344directions (see <a href="#nx">nx</a>, <a href="#ny">ny</a>
3345and <a href="#nz">nz</a>).
3346Advantage of this method is that all PEs bear the same computational
3347load.<br>
3348
3349
3350
3351 <br>
3352
3353
3354
3355
3356There is no such restriction by default, because then smaller
3357subdomains are allowed on those processors which
3358form the right and/or north boundary of the virtual processor grid. On
3359all other processors the subdomains are of same size. Whether smaller
3360subdomains are actually used, depends on the number of processors and
3361the grid point numbers used. Information about the respective settings
3362are given in file <a href="file:///home/raasch/public_html/PALM_group/home/raasch/public_html/PALM_group/doc/app/chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.<br>
3363
3364
3365
3366
3367      <br>
3368
3369
3370
3371
3372When using a multi-grid method for solving the Poisson equation (see <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">psolver</a>)
3373only <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>
3374is allowed.<br>
3375
3376
3377
3378 <br>
3379
3380
3381
3382 <b>Note:</b><br>
3383
3384
3385
3386
3387In some cases for small processor numbers there may be a very bad load
3388balancing among the
3389processors which may reduce the performance of the code.</td>
3390
3391
3392
3393 </tr>
3394
3395
3396
3397
3398    <tr>
3399
3400
3401
3402 <td style="vertical-align: top;"><a name="inflow_disturbance_begin"></a><b>inflow_disturbance_<br>
3403
3404
3405
3406
3407begin</b></td>
3408
3409
3410
3411 <td style="vertical-align: top;">I</td>
3412
3413
3414
3415
3416      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(10,</span><br style="font-style: italic;">
3417
3418
3419
3420 <span style="font-style: italic;">nx/2 or ny/2)</span></td>
3421
3422
3423
3424
3425      <td style="vertical-align: top;">Lower
3426limit of the horizontal range for which random perturbations are to be
3427imposed on the horizontal velocity field (gridpoints).<br>
3428
3429
3430
3431 <br>
3432
3433
3434
3435
3436If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
3437or <a href="#bc_ns">bc_ns</a>),
3438this parameter gives the gridpoint number (counted horizontally from
3439the inflow)&nbsp; from which on perturbations are imposed on the
3440horizontal velocity field. Perturbations must be switched on with
3441parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
3442
3443
3444
3445
3446    </tr>
3447
3448
3449
3450 <tr>
3451
3452
3453
3454 <td style="vertical-align: top;"><a name="inflow_disturbance_end"></a><b>inflow_disturbance_<br>
3455
3456
3457
3458
3459end</b></td>
3460
3461
3462
3463 <td style="vertical-align: top;">I</td>
3464
3465
3466
3467
3468      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(100,</span><br style="font-style: italic;">
3469
3470
3471
3472 <span style="font-style: italic;">3/4*nx or</span><br style="font-style: italic;">
3473
3474
3475
3476 <span style="font-style: italic;">3/4*ny)</span></td>
3477
3478
3479
3480 <td style="vertical-align: top;">Upper
3481limit of the horizontal range for which random perturbations are
3482to be imposed on the horizontal velocity field (gridpoints).<br>
3483
3484
3485
3486 <br>
3487
3488
3489
3490
3491If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
3492or <a href="#bc_ns">bc_ns</a>),
3493this parameter gives the gridpoint number (counted horizontally from
3494the inflow)&nbsp; unto which perturbations are imposed on the
3495horizontal
3496velocity field. Perturbations must be switched on with parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
3497
3498
3499
3500
3501    </tr>
3502
3503
3504
3505 <tr>
3506
3507
3508
3509 <td style="vertical-align: top;">
3510     
3511     
3512     
3513      <p><a name="initializing_actions"></a><b>initializing_actions</b></p>
3514
3515
3516
3517
3518      </td>
3519
3520
3521
3522 <td style="vertical-align: top;">C * 100</td>
3523
3524
3525
3526
3527      <td style="vertical-align: top;"><br>
3528
3529
3530
3531 </td>
3532
3533
3534
3535 <td style="vertical-align: top;"> 
3536     
3537     
3538     
3539      <p style="font-style: normal;">Initialization actions
3540to be carried out.&nbsp; </p>
3541
3542
3543
3544 
3545     
3546     
3547     
3548      <p style="font-style: normal;">This parameter does not have a
3549default value and therefore must be assigned with each model run. For
3550restart runs <b>initializing_actions</b> = <span style="font-style: italic;">'read_restart_data'</span>
3551must be set. For the initial run of a job chain the following values
3552are allowed:&nbsp; </p>
3553
3554
3555
3556 
3557     
3558     
3559     
3560      <p style="font-style: normal;"><span style="font-style: italic;">'set_constant_profiles'</span>
3561      </p>
3562
3563
3564
3565 
3566     
3567     
3568     
3569      <ul>
3570
3571
3572
3573 
3574       
3575       
3576       
3577        <p>A horizontal wind profile consisting
3578of linear sections (see <a href="#ug_surface">ug_surface</a>,
3579        <a href="#ug_vertical_gradient">ug_vertical_gradient</a>,
3580        <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>
3581and <a href="#vg_surface">vg_surface</a>, <a href="#vg_vertical_gradient">vg_vertical_gradient</a>,
3582        <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>,
3583respectively) as well as a vertical temperature (humidity) profile
3584consisting of
3585linear sections (see <a href="#pt_surface">pt_surface</a>,
3586        <a href="#pt_vertical_gradient">pt_vertical_gradient</a>,
3587        <a href="#q_surface">q_surface</a>
3588and <a href="#q_vertical_gradient">q_vertical_gradient</a>)
3589are assumed as initial profiles. The subgrid-scale TKE is set to 0 but K<sub>m</sub>
3590and K<sub>h</sub> are set to very small values because
3591otherwise no TKE
3592would be generated.</p>
3593
3594
3595
3596 
3597     
3598     
3599     
3600      </ul>
3601
3602
3603
3604 
3605     
3606     
3607     
3608      <p style="font-style: italic;">'set_1d-model_profiles' </p>
3609
3610
3611
3612
3613     
3614     
3615     
3616      <ul>
3617
3618
3619
3620 
3621       
3622       
3623       
3624        <p>The arrays of the 3d-model are initialized with
3625the
3626(stationary) solution of the 1d-model. These are the variables e, kh,
3627km, u, v and with Prandtl layer switched on rif, us, usws, vsws. The
3628temperature (humidity) profile consisting of linear sections is set as
3629for 'set_constant_profiles' and assumed as constant in time within the
36301d-model. For steering of the 1d-model a set of parameters with suffix
3631"_1d" (e.g. <a href="#end_time_1d">end_time_1d</a>,
3632        <a href="#damp_level_1d">damp_level_1d</a>)
3633is available.</p>
3634
3635
3636
3637 
3638     
3639     
3640     
3641      </ul>
3642
3643
3644
3645 
3646     
3647     
3648     
3649      <p><span style="font-style: italic;">'by_user'</span></p>
3650
3651
3652
3653     
3654     
3655     
3656      <p style="margin-left: 40px;">The initialization of the arrays
3657of the 3d-model is under complete control of the user and has to be
3658done in routine <a href="chapter_3.5.1.html#user_init_3d_model">user_init_3d_model</a>
3659of the user-interface.<span style="font-style: italic;"></span></p>
3660
3661
3662
3663     
3664     
3665     
3666      <p><span style="font-style: italic;">'initialize_vortex'</span>
3667      </p>
3668
3669
3670
3671 
3672     
3673     
3674     
3675      <div style="margin-left: 40px;">The initial
3676velocity field of the
36773d-model corresponds to a
3678Rankine-vortex with vertical axis. This setting may be used to test
3679advection schemes. Free-slip boundary conditions for u and v (see <a href="#bc_uv_b">bc_uv_b</a>, <a href="#bc_uv_t">bc_uv_t</a>)
3680are necessary. In order not to distort the vortex, an initial
3681horizontal wind profile constant
3682with height is necessary (to be set by <b>initializing_actions</b>
3683= <span style="font-style: italic;">'set_constant_profiles'</span>)
3684and some other conditions have to be met (neutral stratification,
3685diffusion must be
3686switched off, see <a href="#km_constant">km_constant</a>).
3687The center of the vortex is located at jc = (nx+1)/2. It
3688extends from k = 0 to k = nz+1. Its radius is 8 * <a href="#dx">dx</a>
3689and the exponentially decaying part ranges to 32 * <a href="#dx">dx</a>
3690(see init_rankine.f90). </div>
3691
3692
3693
3694 
3695     
3696     
3697     
3698      <p><span style="font-style: italic;">'initialize_ptanom'</span>
3699      </p>
3700
3701
3702
3703 
3704     
3705     
3706     
3707      <ul>
3708
3709
3710
3711 
3712       
3713       
3714       
3715        <p>A 2d-Gauss-like shape disturbance
3716(x,y) is added to the
3717initial temperature field with radius 10.0 * <a href="#dx">dx</a>
3718and center at jc = (nx+1)/2. This may be used for tests of scalar
3719advection schemes
3720(see <a href="#scalar_advec">scalar_advec</a>).
3721Such tests require a horizontal wind profile constant with hight and
3722diffusion
3723switched off (see <span style="font-style: italic;">'initialize_vortex'</span>).
3724Additionally, the buoyancy term
3725must be switched of in the equation of motion&nbsp; for w (this
3726requires the user to comment out the call of <span style="font-family: monospace;">buoyancy</span> in the
3727source code of <span style="font-family: monospace;">prognostic_equations.f90</span>).</p>
3728
3729
3730
3731
3732     
3733     
3734     
3735      </ul>
3736
3737
3738
3739 
3740     
3741     
3742     
3743      <p style="font-style: normal;">Values may be
3744combined, e.g. <b>initializing_actions</b> = <span style="font-style: italic;">'set_constant_profiles
3745initialize_vortex'</span>, but the values of <span style="font-style: italic;">'set_constant_profiles'</span>,
3746      <span style="font-style: italic;">'set_1d-model_profiles'</span>
3747, and <span style="font-style: italic;">'by_user'</span>
3748must not be given at the same time.</p>
3749
3750
3751
3752 
3753     
3754     
3755     
3756      <p style="font-style: italic;"> </p>
3757
3758
3759
3760 </td>
3761
3762
3763
3764 </tr>
3765
3766
3767
3768
3769    <tr>
3770
3771
3772
3773 <td style="vertical-align: top;"> 
3774     
3775     
3776     
3777      <p><a name="km_constant"></a><b>km_constant</b></p>
3778
3779
3780
3781
3782      </td>
3783
3784
3785
3786 <td style="vertical-align: top;">R</td>
3787
3788
3789
3790
3791      <td style="vertical-align: top;"><i>variable<br>
3792
3793
3794
3795
3796(computed from TKE)</i></td>
3797
3798
3799
3800 <td style="vertical-align: top;"> 
3801     
3802     
3803     
3804      <p>Constant eddy
3805diffusivities are used (laminar
3806simulations).&nbsp; </p>
3807
3808
3809
3810 
3811     
3812     
3813     
3814      <p>If this parameter is
3815specified, both in the 1d and in the
38163d-model constant values for the eddy diffusivities are used in
3817space and time with K<sub>m</sub> = <b>km_constant</b>
3818and K<sub>h</sub> = K<sub>m</sub> / <a href="chapter_4.2.html#prandtl_number">prandtl_number</a>.
3819The prognostic equation for the subgrid-scale TKE is switched off.
3820Constant eddy diffusivities are only allowed with the Prandtl layer (<a href="#prandtl_layer">prandtl_layer</a>)
3821switched off.</p>
3822
3823
3824
3825 </td>
3826
3827
3828
3829 </tr>
3830
3831
3832
3833 <tr>
3834
3835
3836
3837 <td style="vertical-align: top;"> 
3838     
3839     
3840     
3841      <p><a name="km_damp_max"></a><b>km_damp_max</b></p>
3842
3843
3844
3845
3846      </td>
3847
3848
3849
3850 <td style="vertical-align: top;">R</td>
3851
3852
3853
3854
3855      <td style="vertical-align: top;"><span style="font-style: italic;">0.5*(dx
3856or dy)</span></td>
3857
3858
3859
3860 <td style="vertical-align: top;">Maximum
3861diffusivity used for filtering the velocity field in the vicinity of
3862the outflow (in m<sup>2</sup>/s).<br>
3863
3864
3865
3866 <br>
3867
3868
3869
3870
3871When using non-cyclic lateral boundaries (see <a href="#bc_lr">bc_lr</a>
3872or <a href="#bc_ns">bc_ns</a>),
3873a smoothing has to be applied to the
3874velocity field in the vicinity of the outflow in order to suppress any
3875reflections of outgoing disturbances. Smoothing is done by increasing
3876the eddy diffusivity along the horizontal direction which is
3877perpendicular to the outflow boundary. Only velocity components
3878parallel to the outflow boundary are filtered (e.g. v and w, if the
3879outflow is along x). Damping is applied from the bottom to the top of
3880the domain.<br>
3881
3882
3883
3884 <br>
3885
3886
3887
3888
3889The horizontal range of the smoothing is controlled by <a href="#outflow_damping_width">outflow_damping_width</a>
3890which defines the number of gridpoints (counted from the outflow
3891boundary) from where on the smoothing is applied. Starting from that
3892point, the eddy diffusivity is linearly increased (from zero to its
3893maximum value given by <span style="font-weight: bold;">km_damp_max</span>)
3894until half of the damping range width, from where it remains constant
3895up to the outflow boundary. If at a certain grid point the eddy
3896diffusivity calculated from the flow field is larger than as described
3897above, it is used instead.<br>
3898
3899
3900
3901 <br>
3902
3903
3904
3905
3906The default value of <span style="font-weight: bold;">km_damp_max</span>
3907has been empirically proven to be sufficient.</td>
3908
3909
3910
3911 </tr>
3912
3913
3914
3915 <tr>
3916
3917
3918
3919
3920      <td style="vertical-align: top;"> 
3921     
3922     
3923     
3924      <p><a name="long_filter_factor"></a><b>long_filter_factor</b></p>
3925
3926
3927
3928
3929      </td>
3930
3931
3932
3933 <td style="vertical-align: top;">R</td>
3934
3935
3936
3937
3938      <td style="vertical-align: top;"><i>0.0</i></td>
3939
3940
3941
3942
3943      <td style="vertical-align: top;"> 
3944     
3945     
3946     
3947      <p>Filter factor
3948for the so-called Long-filter.<br>
3949
3950
3951
3952 </p>
3953
3954
3955
3956 
3957     
3958     
3959     
3960      <p><br>
3961
3962
3963
3964
3965This filter very efficiently
3966eliminates 2-delta-waves sometimes cauesed by the upstream-spline
3967scheme (see Mahrer and
3968Pielke, 1978: Mon. Wea. Rev., 106, 818-830). It works in all three
3969directions in space. A value of <b>long_filter_factor</b>
3970= <i>0.01</i>
3971sufficiently removes the small-scale waves without affecting the
3972longer waves.<br>
3973
3974
3975
3976 </p>
3977
3978
3979
3980 
3981     
3982     
3983     
3984      <p>By default, the filter is
3985switched off (= <i>0.0</i>).
3986It is exclusively applied to the tendencies calculated by the
3987upstream-spline scheme (see <a href="#momentum_advec">momentum_advec</a>
3988and <a href="#scalar_advec">scalar_advec</a>),
3989not to the prognostic variables themselves. At the bottom and top
3990boundary of the model domain the filter effect for vertical
39912-delta-waves is reduced. There, the amplitude of these waves is only
3992reduced by approx. 50%, otherwise by nearly 100%.&nbsp; <br>
3993
3994
3995
3996
3997Filter factors with values &gt; <i>0.01</i> also
3998reduce the amplitudes
3999of waves with wavelengths longer than 2-delta (see the paper by Mahrer
4000and
4001Pielke, quoted above). </p>
4002
4003
4004
4005 </td>
4006
4007
4008
4009 </tr>
4010
4011
4012
4013 <tr>
4014
4015
4016
4017      <td style="vertical-align: top;"><a name="loop_optimization"></a><span style="font-weight: bold;">loop_optimization</span></td>
4018
4019
4020
4021      <td style="vertical-align: top;">C*16</td>
4022
4023
4024
4025      <td style="vertical-align: top;"><span style="font-style: italic;">see right</span></td>
4026
4027
4028
4029      <td>Method used to optimize loops for solving the prognostic equations .<br>
4030
4031
4032
4033      <br>
4034
4035
4036
4037By
4038default, the optimization method depends on the host on which PALM is
4039running. On machines with vector-type CPUs, single 3d-loops are used to
4040calculate each tendency term of each prognostic equation, while on all
4041other machines, all prognostic equations are solved within one big loop
4042over the two horizontal indices<span style="font-family: Courier New,Courier,monospace;"> i </span>and<span style="font-family: Courier New,Courier,monospace;"> j </span>(giving a good cache uitilization).<br>
4043
4044
4045
4046      <br>
4047
4048
4049
4050The default behaviour can be changed by setting either <span style="font-weight: bold;">loop_optimization</span> = <span style="font-style: italic;">'vector'</span> or <span style="font-weight: bold;">loop_optimization</span> = <span style="font-style: italic;">'cache'</span>.</td>
4051
4052
4053
4054    </tr>
4055
4056
4057
4058    <tr>
4059
4060
4061
4062
4063      <td style="vertical-align: top;"><a name="mixing_length_1d"></a><span style="font-weight: bold;">mixing_length_1d</span><br>
4064
4065
4066
4067
4068      </td>
4069
4070
4071
4072 <td style="vertical-align: top;">C*20<br>
4073
4074
4075
4076
4077      </td>
4078
4079
4080
4081 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
4082
4083
4084
4085 <span style="font-style: italic;">model'</span><br>
4086
4087
4088
4089 </td>
4090
4091
4092
4093
4094      <td style="vertical-align: top;">Mixing length used in the
40951d-model.<br>
4096
4097
4098
4099 <br>
4100
4101
4102
4103
4104By default the mixing length is calculated as in the 3d-model (i.e. it
4105depends on the grid spacing).<br>
4106
4107
4108
4109 <br>
4110
4111
4112
4113
4114By setting <span style="font-weight: bold;">mixing_length_1d</span>
4115= <span style="font-style: italic;">'blackadar'</span>,
4116the so-called Blackadar mixing length is used (l = kappa * z / ( 1 +
4117kappa * z / lambda ) with the limiting value lambda = 2.7E-4 * u_g / f).<br>
4118
4119
4120
4121
4122      </td>
4123
4124
4125
4126 </tr>
4127
4128
4129
4130 <tr>
4131
4132
4133
4134 <td style="vertical-align: top;"> 
4135     
4136     
4137     
4138      <p><a name="humidity"></a><b>humidity</b></p>
4139
4140
4141
4142
4143      </td>
4144
4145
4146
4147 <td style="vertical-align: top;">L</td>
4148
4149
4150
4151
4152      <td style="vertical-align: top;"><i>.F.</i></td>
4153
4154
4155
4156
4157      <td style="vertical-align: top;"> 
4158     
4159     
4160     
4161      <p>Parameter to
4162switch on the prognostic equation for specific
4163humidity q.<br>
4164
4165
4166
4167 </p>
4168
4169
4170
4171 
4172     
4173     
4174     
4175      <p>The initial vertical
4176profile of q can be set via parameters <a href="chapter_4.1.html#q_surface">q_surface</a>, <a href="chapter_4.1.html#q_vertical_gradient">q_vertical_gradient</a>
4177and <a href="chapter_4.1.html#q_vertical_gradient_level">q_vertical_gradient_level</a>.&nbsp;
4178Boundary conditions can be set via <a href="chapter_4.1.html#q_surface_initial_change">q_surface_initial_change</a>
4179and <a href="chapter_4.1.html#surface_waterflux">surface_waterflux</a>.<br>
4180
4181
4182
4183
4184      </p>
4185
4186
4187
4188
4189If the condensation scheme is switched on (<a href="chapter_4.1.html#cloud_physics">cloud_physics</a>
4190= .TRUE.), q becomes the total liquid water content (sum of specific
4191humidity and liquid water content).</td>
4192
4193
4194
4195 </tr>
4196
4197
4198
4199
4200    <tr>
4201
4202
4203
4204 <td style="vertical-align: top;"> 
4205     
4206     
4207     
4208      <p><a name="momentum_advec"></a><b>momentum_advec</b></p>
4209
4210
4211
4212
4213      </td>
4214
4215
4216
4217 <td style="vertical-align: top;">C * 10</td>
4218
4219
4220
4221
4222      <td style="vertical-align: top;"><i>'pw-scheme'</i></td>
4223
4224
4225
4226
4227      <td style="vertical-align: top;"> 
4228     
4229     
4230     
4231      <p>Advection
4232scheme to be used for the momentum equations.<br>
4233
4234
4235
4236 <br>
4237
4238
4239
4240
4241The user can choose between the following schemes:<br>
4242
4243
4244
4245
4246&nbsp;<br>
4247
4248
4249
4250 <br>
4251
4252
4253
4254 <span style="font-style: italic;">'pw-scheme'</span><br>
4255
4256
4257
4258
4259      </p>
4260
4261
4262
4263 
4264     
4265     
4266     
4267      <div style="margin-left: 40px;">The scheme of
4268Piascek and
4269Williams (1970, J. Comp. Phys., 6,
4270392-405) with central differences in the form C3 is used.<br>
4271
4272
4273
4274
4275If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a>
4276= <span style="font-style: italic;">'leapfrog+euler'</span>
4277the
4278advection scheme is - for the Euler-timestep - automatically switched
4279to an upstream-scheme.<br>
4280
4281
4282
4283 </div>
4284
4285
4286
4287 
4288     
4289     
4290     
4291      <p> </p>
4292
4293
4294
4295 
4296     
4297     
4298     
4299      <p><span style="font-style: italic;">'ups-scheme'</span><br>
4300
4301
4302
4303
4304      </p>
4305
4306
4307
4308 
4309     
4310     
4311     
4312      <div style="margin-left: 40px;">The
4313upstream-spline scheme is
4314used
4315(see Mahrer and Pielke,
43161978: Mon. Wea. Rev., 106, 818-830). In opposite to the
4317Piascek-Williams scheme, this is characterized by much better numerical
4318features (less numerical diffusion, better preservation of flow
4319structures, e.g. vortices), but computationally it is much more
4320expensive. In
4321addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a>
4322= <span style="font-style: italic;">'</span><i>euler'</i>),
4323i.e. the
4324timestep accuracy is only of first order.
4325For this reason the advection of scalar variables (see <a href="#scalar_advec">scalar_advec</a>)
4326should then also be carried out with the upstream-spline scheme,
4327because otherwise the scalar variables would
4328be subject to large numerical diffusion due to the upstream
4329scheme.&nbsp; </div>
4330
4331
4332
4333 
4334     
4335     
4336     
4337      <p style="margin-left: 40px;">Since
4338the cubic splines used tend
4339to overshoot under
4340certain circumstances, this effect must be adjusted by suitable
4341filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>,
4342      <a href="#long_filter_factor">long_filter_factor</a>,
4343      <a href="#ups_limit_pt">ups_limit_pt</a>, <a href="#ups_limit_u">ups_limit_u</a>, <a href="#ups_limit_v">ups_limit_v</a>, <a href="#ups_limit_w">ups_limit_w</a>).
4344This is always neccessary for runs with stable stratification,
4345even if this stratification appears only in parts of the model domain.<br>
4346
4347
4348
4349
4350      </p>
4351
4352
4353
4354 
4355     
4356     
4357     
4358      <div style="margin-left: 40px;">With stable
4359stratification the
4360upstream-spline scheme also
4361produces gravity waves with large amplitude, which must be
4362suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br>
4363
4364
4365
4366
4367      <br>
4368
4369
4370
4371 <span style="font-weight: bold;">Important: </span>The&nbsp;
4372upstream-spline scheme is not implemented for humidity and passive
4373scalars (see&nbsp;<a href="#humidity">humidity</a>
4374and <a href="#passive_scalar">passive_scalar</a>)
4375and requires the use of a 2d-domain-decomposition. The last conditions
4376severely restricts code optimization on several machines leading to
4377very long execution times! The scheme is also not allowed for
4378non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
4379and <a href="#bc_ns">bc_ns</a>).</div>
4380
4381
4382
4383 </td>
4384
4385
4386
4387
4388    </tr>
4389
4390
4391
4392 <tr>
4393
4394
4395
4396 <td style="vertical-align: top;"><a name="netcdf_precision"></a><span style="font-weight: bold;">netcdf_precision</span><br>
4397
4398
4399
4400
4401      </td>
4402
4403
4404
4405 <td style="vertical-align: top;">C*20<br>
4406
4407
4408
4409
4410(10)<br>
4411
4412
4413
4414 </td>
4415
4416
4417
4418 <td style="vertical-align: top;"><span style="font-style: italic;">single preci-</span><br style="font-style: italic;">
4419
4420
4421
4422 <span style="font-style: italic;">sion for all</span><br style="font-style: italic;">
4423
4424
4425
4426 <span style="font-style: italic;">output quan-</span><br style="font-style: italic;">
4427
4428
4429
4430 <span style="font-style: italic;">tities</span><br>
4431
4432
4433
4434 </td>
4435
4436
4437
4438
4439      <td style="vertical-align: top;">Defines the accuracy of
4440the NetCDF output.<br>
4441
4442
4443
4444 <br>
4445
4446
4447
4448
4449By default, all NetCDF output data (see <a href="chapter_4.2.html#data_output_format">data_output_format</a>)
4450have single precision&nbsp; (4 byte) accuracy. Double precision (8
4451byte) can be choosen alternatively.<br>
4452
4453
4454
4455
4456Accuracy for the different output data (cross sections, 3d-volume data,
4457spectra, etc.) can be set independently.<br>
4458
4459
4460
4461 <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL4'</span>
4462(single precision) or <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL8'</span>
4463(double precision) are the two principally allowed values for <span style="font-weight: bold;">netcdf_precision</span>,
4464where the string <span style="font-style: italic;">'&lt;out&gt;'
4465      </span>can be chosen out of the following list:<br>
4466
4467
4468
4469 <br>
4470
4471
4472
4473
4474     
4475     
4476     
4477      <table style="text-align: left; width: 284px; height: 234px;" border="1" cellpadding="2" cellspacing="2">
4478
4479
4480
4481 <tbody>
4482
4483
4484
4485
4486          <tr>
4487
4488
4489
4490 <td style="vertical-align: top;"><span style="font-style: italic;">'xy'</span><br>
4491
4492
4493
4494 </td>
4495
4496
4497
4498
4499            <td style="vertical-align: top;">horizontal cross section<br>
4500
4501
4502
4503
4504            </td>
4505
4506
4507
4508 </tr>
4509
4510
4511
4512 <tr>
4513
4514
4515
4516 <td style="vertical-align: top;"><span style="font-style: italic;">'xz'</span><br>
4517
4518
4519
4520 </td>
4521
4522
4523
4524
4525            <td style="vertical-align: top;">vertical (xz) cross
4526section<br>
4527
4528
4529
4530 </td>
4531
4532
4533
4534 </tr>
4535
4536
4537
4538 <tr>
4539
4540
4541
4542 <td style="vertical-align: top;"><span style="font-style: italic;">'yz'</span><br>
4543
4544
4545
4546 </td>
4547
4548
4549
4550
4551            <td style="vertical-align: top;">vertical (yz) cross
4552section<br>
4553
4554
4555
4556 </td>
4557
4558
4559
4560 </tr>
4561
4562
4563
4564 <tr>
4565
4566
4567
4568 <td style="vertical-align: top;"><span style="font-style: italic;">'2d'</span><br>
4569
4570
4571
4572 </td>
4573
4574
4575
4576
4577            <td style="vertical-align: top;">all cross sections<br>
4578
4579
4580
4581
4582            </td>
4583
4584
4585
4586 </tr>
4587
4588
4589
4590 <tr>
4591
4592
4593
4594 <td style="vertical-align: top;"><span style="font-style: italic;">'3d'</span><br>
4595
4596
4597
4598 </td>
4599
4600
4601
4602
4603            <td style="vertical-align: top;">volume data<br>
4604
4605
4606
4607 </td>
4608
4609
4610
4611
4612          </tr>
4613
4614
4615
4616 <tr>
4617
4618
4619
4620 <td style="vertical-align: top;"><span style="font-style: italic;">'pr'</span><br>
4621
4622
4623
4624 </td>
4625
4626
4627
4628
4629            <td style="vertical-align: top;">vertical profiles<br>
4630
4631
4632
4633
4634            </td>
4635
4636
4637
4638 </tr>
4639
4640
4641
4642 <tr>
4643
4644
4645
4646 <td style="vertical-align: top;"><span style="font-style: italic;">'ts'</span><br>
4647
4648
4649
4650 </td>
4651
4652
4653
4654
4655            <td style="vertical-align: top;">time series, particle
4656time series<br>
4657
4658
4659
4660 </td>
4661
4662
4663
4664 </tr>
4665
4666
4667
4668 <tr>
4669
4670
4671
4672 <td style="vertical-align: top;"><span style="font-style: italic;">'sp'</span><br>
4673
4674
4675
4676 </td>
4677
4678
4679
4680
4681            <td style="vertical-align: top;">spectra<br>
4682
4683
4684
4685 </td>
4686
4687
4688
4689
4690          </tr>
4691
4692
4693
4694 <tr>
4695
4696
4697
4698 <td style="vertical-align: top;"><span style="font-style: italic;">'prt'</span><br>
4699
4700
4701
4702 </td>
4703
4704
4705
4706
4707            <td style="vertical-align: top;">particles<br>
4708
4709
4710
4711 </td>
4712
4713
4714
4715
4716          </tr>
4717
4718
4719
4720 <tr>
4721
4722
4723
4724 <td style="vertical-align: top;"><span style="font-style: italic;">'all'</span><br>
4725
4726
4727
4728 </td>
4729
4730
4731
4732
4733            <td style="vertical-align: top;">all output quantities<br>
4734
4735
4736
4737
4738            </td>
4739
4740
4741
4742 </tr>
4743
4744
4745
4746 
4747       
4748       
4749       
4750        </tbody> 
4751     
4752     
4753     
4754      </table>
4755
4756
4757
4758 <br>
4759
4760
4761
4762 <span style="font-weight: bold;">Example:</span><br>
4763
4764
4765
4766
4767If all cross section data and the particle data shall be output in
4768double precision and all other quantities in single precision, then <span style="font-weight: bold;">netcdf_precision</span> = <span style="font-style: italic;">'2d_NF90_REAL8'</span>, <span style="font-style: italic;">'prt_NF90_REAL8'</span>
4769has to be assigned.<br>
4770
4771
4772
4773 </td>
4774
4775
4776
4777 </tr>
4778
4779
4780
4781
4782    <tr>
4783
4784
4785
4786 <td style="vertical-align: top;"> 
4787     
4788     
4789     
4790      <p><a name="npex"></a><b>npex</b></p>
4791
4792
4793
4794 </td>
4795
4796
4797
4798
4799      <td style="vertical-align: top;">I</td>
4800
4801
4802
4803 <td style="vertical-align: top;"><br>
4804
4805
4806
4807 </td>
4808
4809
4810
4811 <td style="vertical-align: top;"> 
4812     
4813     
4814     
4815      <p>Number of processors
4816along x-direction of the virtual
4817processor
4818net.&nbsp; </p>
4819
4820
4821
4822 
4823     
4824     
4825     
4826      <p>For parallel runs, the total
4827number of processors to be used
4828is given by
4829the <span style="font-weight: bold;">mrun</span>
4830option <a href="http://www.muk.uni-hannover.de/software/mrun_beschreibung.html#Opt-X">-X</a>.
4831By default, depending on the type of the parallel computer, PALM
4832generates a 1d processor
4833net (domain decomposition along x, <span style="font-weight: bold;">npey</span>
4834= <span style="font-style: italic;">1</span>) or a
48352d-net (this is
4836favored on machines with fast communication network). In case of a
48372d-net, it is tried to make it more or less square-shaped. If, for
4838example, 16 processors are assigned (-X 16), a 4 * 4 processor net is
4839generated (<span style="font-weight: bold;">npex</span>
4840= <span style="font-style: italic;">4</span>, <span style="font-weight: bold;">npey</span>
4841= <span style="font-style: italic;">4</span>).
4842This choice is optimal for square total domains (<a href="#nx">nx</a>
4843= <a href="#ny">ny</a>),
4844since then the number of ghost points at the lateral boundarys of
4845the subdomains is minimal. If <span style="font-weight: bold;">nx</span>
4846nd <span style="font-weight: bold;">ny</span>
4847differ extremely, the
4848processor net should be manually adjusted using adequate values for <span style="font-weight: bold;">npex</span> and <span style="font-weight: bold;">npey</span>.&nbsp; </p>
4849
4850
4851
4852
4853     
4854     
4855     
4856      <p><b>Important:</b> The value of <span style="font-weight: bold;">npex</span> * <span style="font-weight: bold;">npey</span> must exactly
4857correspond to the
4858value assigned by the <span style="font-weight: bold;">mrun</span>-option
4859      <tt>-X</tt>.
4860Otherwise the model run will abort with a corresponding error
4861message.&nbsp; <br>
4862
4863
4864
4865
4866Additionally, the specification of <span style="font-weight: bold;">npex</span>
4867and <span style="font-weight: bold;">npey</span>
4868may of course
4869override the default setting for the domain decomposition (1d or 2d)
4870which may have a significant (negative) effect on the code performance.
4871      </p>
4872
4873
4874
4875 </td>
4876
4877
4878
4879 </tr>
4880
4881
4882
4883 <tr>
4884
4885
4886
4887 <td style="vertical-align: top;"> 
4888     
4889     
4890     
4891      <p><a name="npey"></a><b>npey</b></p>
4892
4893
4894
4895
4896      </td>
4897
4898
4899
4900 <td style="vertical-align: top;">I</td>
4901
4902
4903
4904
4905      <td style="vertical-align: top;"><br>
4906
4907
4908
4909 </td>
4910
4911
4912
4913 <td style="vertical-align: top;"> 
4914     
4915     
4916     
4917      <p>Number of processors
4918along y-direction of the virtual
4919processor
4920net.&nbsp; </p>
4921
4922
4923
4924 
4925     
4926     
4927     
4928      <p>For further information see <a href="#npex">npex</a>.</p>
4929
4930
4931
4932 </td>
4933
4934
4935
4936 </tr>
4937
4938
4939
4940
4941    <tr>
4942
4943
4944
4945 <td style="vertical-align: top;"> 
4946     
4947     
4948     
4949      <p><a name="nsor_ini"></a><b>nsor_ini</b></p>
4950
4951
4952
4953
4954      </td>
4955
4956
4957
4958 <td style="vertical-align: top;">I</td>
4959
4960
4961
4962
4963      <td style="vertical-align: top;"><i>100</i></td>
4964
4965
4966
4967
4968      <td style="vertical-align: top;"> 
4969     
4970     
4971     
4972      <p>Initial number
4973of iterations with the SOR algorithm.&nbsp; </p>
4974
4975
4976
4977 
4978     
4979     
4980     
4981      <p>This
4982parameter is only effective if the SOR algorithm was
4983selected as the pressure solver scheme (<a href="chapter_4.2.html#psolver">psolver</a>
4984= <span style="font-style: italic;">'sor'</span>)
4985and specifies the
4986number of initial iterations of the SOR
4987scheme (at t = 0). The number of subsequent iterations at the following
4988timesteps is determined
4989with the parameter <a href="#nsor">nsor</a>.
4990Usually <b>nsor</b> &lt; <b>nsor_ini</b>,
4991since in each case
4992subsequent calls to <a href="chapter_4.2.html#psolver">psolver</a>
4993use the solution of the previous call as initial value. Suitable
4994test runs should determine whether sufficient convergence of the
4995solution is obtained with the default value and if necessary the value
4996of <b>nsor_ini</b> should be changed.</p>
4997
4998
4999
5000 </td>
5001
5002
5003
5004
5005    </tr>
5006
5007
5008
5009 <tr>
5010
5011
5012
5013 <td style="vertical-align: top;">
5014     
5015     
5016     
5017      <p><a name="nx"></a><b>nx</b></p>
5018
5019
5020
5021
5022      </td>
5023
5024
5025
5026 <td style="vertical-align: top;">I</td>
5027
5028
5029
5030
5031      <td style="vertical-align: top;"><br>
5032
5033
5034
5035 </td>
5036
5037
5038
5039 <td style="vertical-align: top;"> 
5040     
5041     
5042     
5043      <p>Number of grid
5044points in x-direction.&nbsp; </p>
5045
5046
5047
5048 
5049     
5050     
5051     
5052      <p>A value for this
5053parameter must be assigned. Since the lower
5054array bound in PALM
5055starts with i = 0, the actual number of grid points is equal to <b>nx+1</b>.
5056In case of cyclic boundary conditions along x, the domain size is (<b>nx+1</b>)*
5057      <a href="#dx">dx</a>.</p>
5058
5059
5060
5061 
5062     
5063     
5064     
5065      <p>For
5066parallel runs, in case of <a href="#grid_matching">grid_matching</a>
5067= <span style="font-style: italic;">'strict'</span>,
5068      <b>nx+1</b> must
5069be an integral multiple
5070of the processor numbers (see <a href="#npex">npex</a>
5071and <a href="#npey">npey</a>)
5072along x- as well as along y-direction (due to data
5073transposition restrictions).</p>
5074
5075
5076
5077     
5078     
5079     
5080      <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be&nbsp;equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a>
5081and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
5082
5083
5084
5085 </td>
5086
5087
5088
5089 </tr>
5090
5091
5092
5093 <tr>
5094
5095
5096
5097
5098      <td style="vertical-align: top;"> 
5099     
5100     
5101     
5102      <p><a name="ny"></a><b>ny</b></p>
5103
5104
5105
5106
5107      </td>
5108
5109
5110
5111 <td style="vertical-align: top;">I</td>
5112
5113
5114
5115
5116      <td style="vertical-align: top;"><br>
5117
5118
5119
5120 </td>
5121
5122
5123
5124 <td style="vertical-align: top;"> 
5125     
5126     
5127     
5128      <p>Number of grid
5129points in y-direction.&nbsp; </p>
5130
5131
5132
5133 
5134     
5135     
5136     
5137      <p>A value for this
5138parameter must be assigned. Since the lower
5139array bound in PALM starts with j = 0, the actual number of grid points
5140is equal to <b>ny+1</b>. In case of cyclic boundary
5141conditions along
5142y, the domain size is (<b>ny+1</b>) * <a href="#dy">dy</a>.</p>
5143
5144
5145
5146
5147     
5148     
5149     
5150      <p>For parallel runs, in case of <a href="#grid_matching">grid_matching</a>
5151= <span style="font-style: italic;">'strict'</span>,
5152      <b>ny+1</b> must
5153be an integral multiple
5154of the processor numbers (see <a href="#npex">npex</a>
5155and <a href="#npey">npey</a>)&nbsp;
5156along y- as well as along x-direction (due to data
5157transposition restrictions).</p>
5158
5159
5160
5161     
5162     
5163     
5164      <p>For <a href="chapter_3.8.html">coupled runs</a> this parameter must be&nbsp;equal in both parameter files <a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2"><span style="font-family: mon;"></span>PARIN</font></a>
5165and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
5166
5167
5168
5169 </td>
5170
5171
5172
5173 </tr>
5174
5175
5176
5177 <tr>
5178
5179
5180
5181
5182      <td style="vertical-align: top;"> 
5183     
5184     
5185     
5186      <p><a name="nz"></a><b>nz</b></p>
5187
5188
5189
5190
5191      </td>
5192
5193
5194
5195 <td style="vertical-align: top;">I</td>
5196
5197
5198
5199
5200      <td style="vertical-align: top;"><br>
5201
5202
5203
5204 </td>
5205
5206
5207
5208 <td style="vertical-align: top;"> 
5209     
5210     
5211     
5212      <p>Number of grid
5213points in z-direction.&nbsp; </p>
5214
5215
5216
5217 
5218     
5219     
5220     
5221      <p>A value for this
5222parameter must be assigned. Since the lower
5223array bound in PALM
5224starts with k = 0 and since one additional grid point is added at the
5225top boundary (k = <b>nz+1</b>), the actual number of grid
5226points is <b>nz+2</b>.
5227However, the prognostic equations are only solved up to <b>nz</b>
5228(u,
5229v)
5230or up to <b>nz-1</b> (w, scalar quantities). The top
5231boundary for u
5232and v is at k = <b>nz+1</b> (u, v) while at k = <b>nz</b>
5233for all
5234other quantities.&nbsp; </p>
5235
5236
5237
5238 
5239     
5240     
5241     
5242      <p>For parallel
5243runs,&nbsp; in case of <a href="#grid_matching">grid_matching</a>
5244= <span style="font-style: italic;">'strict'</span>,
5245      <b>nz</b> must
5246be an integral multiple of
5247the number of processors in x-direction (due to data transposition
5248restrictions).</p>
5249
5250
5251
5252 </td>
5253
5254
5255
5256 </tr>
5257
5258
5259
5260 <tr>
5261
5262
5263
5264      <td style="vertical-align: top;"><a name="ocean"></a><span style="font-weight: bold;">ocean</span></td>
5265
5266
5267
5268      <td style="vertical-align: top;">L</td>
5269
5270
5271
5272      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
5273
5274
5275
5276      <td style="vertical-align: top;">Parameter to switch on&nbsp;ocean runs.<br>
5277
5278
5279
5280      <br>
5281
5282
5283
5284By default PALM is configured to simulate&nbsp;atmospheric flows. However, starting from version 3.3, <span style="font-weight: bold;">ocean</span> = <span style="font-style: italic;">.T.</span> allows&nbsp;simulation of ocean turbulent flows. Setting this switch has several effects:<br>
5285
5286
5287
5288      <br>
5289
5290
5291
5292     
5293     
5294     
5295      <ul>
5296
5297
5298
5299        <li>An additional prognostic equation for salinity is solved.</li>
5300
5301
5302
5303        <li>Potential temperature in buoyancy and stability-related terms is replaced by potential density.</li>
5304
5305
5306
5307        <li>Potential
5308density is calculated from the equation of state for seawater after
5309each timestep, using the algorithm proposed by Jackett et al. (2006, J.
5310Atmos. Oceanic Technol., <span style="font-weight: bold;">23</span>, 1709-1728).<br>
5311
5312
5313
5314So far, only the initial hydrostatic pressure is entered into this equation.</li>
5315
5316
5317
5318        <li>z=0 (sea surface) is assumed at the model top (vertical grid index <span style="font-family: Courier New,Courier,monospace;">k=nzt</span> on the w-grid), with negative values of z indicating the depth.</li>
5319
5320
5321
5322        <li>Initial profiles are constructed (e.g. from <a href="#pt_vertical_gradient">pt_vertical_gradient</a> / <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>) starting from the sea surface, using surface values&nbsp;given by <a href="#pt_surface">pt_surface</a>, <a href="#sa_surface">sa_surface</a>, <a href="#ug_surface">ug_surface</a>, and <a href="#vg_surface">vg_surface</a>.</li>
5323
5324
5325
5326        <li>Zero salinity flux is used as default boundary condition at the bottom of the sea.</li>
5327
5328
5329
5330        <li>If switched on, random perturbations are by default imposed to the upper model domain from zu(nzt*2/3) to zu(nzt-3).</li>
5331
5332
5333
5334     
5335     
5336     
5337      </ul>
5338
5339
5340
5341      <br>
5342
5343
5344
5345Relevant parameters to be exclusively used for steering ocean runs are <a href="#bc_sa_t">bc_sa_t</a>, <a href="#bottom_salinityflux">bottom_salinityflux</a>, <a href="#sa_surface">sa_surface</a>, <a href="#sa_vertical_gradient">sa_vertical_gradient</a>, <a href="#sa_vertical_gradient_level">sa_vertical_gradient_level</a>, and <a href="#top_salinityflux">top_salinityflux</a>.<br>
5346
5347
5348
5349      <br>
5350
5351
5352
5353Section <a href="chapter_4.2.2.html">4.4.2</a> gives an example for appropriate settings of these and other parameters neccessary for ocean runs.<br>
5354
5355
5356
5357      <br>
5358
5359
5360
5361      <span style="font-weight: bold;">ocean</span> = <span style="font-style: italic;">.T.</span> does not allow settings of <a href="#timestep_scheme">timestep_scheme</a> = <span style="font-style: italic;">'leapfrog'</span> or <span style="font-style: italic;">'leapfrog+euler'</span> as well as <a href="#scalar_advec">scalar_advec</a> = <span style="font-style: italic;">'ups-scheme'</span>.<span style="font-weight: bold;"></span><br>
5362      </td>
5363
5364
5365
5366    </tr>
5367
5368
5369
5370    <tr>
5371
5372
5373
5374 <td style="vertical-align: top;"> 
5375     
5376     
5377     
5378      <p><a name="omega"></a><b>omega</b></p>
5379
5380
5381
5382
5383      </td>
5384
5385
5386
5387 <td style="vertical-align: top;">R</td>
5388
5389
5390
5391
5392      <td style="vertical-align: top;"><i>7.29212E-5</i></td>
5393
5394
5395
5396
5397      <td style="vertical-align: top;"> 
5398     
5399     
5400     
5401      <p>Angular
5402velocity of the rotating system (in rad s<sup>-1</sup>).&nbsp;
5403      </p>
5404
5405
5406
5407 
5408     
5409     
5410     
5411      <p>The angular velocity of the earth is set by
5412default. The
5413values
5414of the Coriolis parameters are calculated as:&nbsp; </p>
5415
5416
5417
5418 
5419     
5420     
5421     
5422      <ul>
5423
5424
5425
5426
5427       
5428       
5429       
5430        <p>f = 2.0 * <b>omega</b> * sin(<a href="#phi">phi</a>)&nbsp;
5431        <br>
5432
5433
5434
5435f* = 2.0 * <b>omega</b> * cos(<a href="#phi">phi</a>)</p>
5436
5437
5438
5439
5440     
5441     
5442     
5443      </ul>
5444
5445
5446
5447 </td>
5448
5449
5450
5451 </tr>
5452
5453
5454
5455 <tr>
5456
5457
5458
5459 <td style="vertical-align: top;"> 
5460     
5461     
5462     
5463      <p><a name="outflow_damping_width"></a><b>outflow_damping_width</b></p>
5464
5465
5466
5467
5468      </td>
5469
5470
5471
5472 <td style="vertical-align: top;">I</td>
5473
5474
5475
5476
5477      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(20,
5478nx/2</span> or <span style="font-style: italic;">ny/2)</span></td>
5479
5480
5481
5482
5483      <td style="vertical-align: top;">Width of
5484the damping range in the vicinity of the outflow (gridpoints).<br>
5485
5486
5487
5488
5489      <br>
5490
5491
5492
5493
5494When using non-cyclic lateral boundaries (see <a href="chapter_4.1.html#bc_lr">bc_lr</a>
5495or <a href="chapter_4.1.html#bc_ns">bc_ns</a>),
5496a smoothing has to be applied to the
5497velocity field in the vicinity of the outflow in order to suppress any
5498reflections of outgoing disturbances. This parameter controlls the
5499horizontal range to which the smoothing is applied. The range is given
5500in gridpoints counted from the respective outflow boundary. For further
5501details about the smoothing see parameter <a href="chapter_4.1.html#km_damp_max">km_damp_max</a>,
5502which defines the magnitude of the damping.</td>
5503
5504
5505
5506 </tr>
5507
5508
5509
5510
5511    <tr>
5512
5513
5514
5515 <td style="vertical-align: top;"> 
5516     
5517     
5518     
5519      <p><a name="overshoot_limit_e"></a><b>overshoot_limit_e</b></p>
5520
5521
5522
5523
5524      </td>
5525
5526
5527
5528 <td style="vertical-align: top;">R</td>
5529
5530
5531
5532
5533      <td style="vertical-align: top;"><i>0.0</i></td>
5534
5535
5536
5537
5538      <td style="vertical-align: top;"> 
5539     
5540     
5541     
5542      <p>Allowed limit
5543for the overshooting of subgrid-scale TKE in
5544case that the upstream-spline scheme is switched on (in m<sup>2</sup>/s<sup>2</sup>).&nbsp;
5545      </p>
5546
5547
5548
5549 
5550     
5551     
5552     
5553      <p>By deafult, if cut-off of overshoots is switched
5554on for the
5555upstream-spline scheme (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>),
5556no overshoots are permitted at all. If <b>overshoot_limit_e</b>
5557is given a non-zero value, overshoots with the respective
5558amplitude (both upward and downward) are allowed.&nbsp; </p>
5559
5560
5561
5562
5563     
5564     
5565     
5566      <p>Only positive values are allowed for <b>overshoot_limit_e</b>.</p>
5567
5568
5569
5570
5571      </td>
5572
5573
5574
5575 </tr>
5576
5577
5578
5579 <tr>
5580
5581
5582
5583 <td style="vertical-align: top;"> 
5584     
5585     
5586     
5587      <p><a name="overshoot_limit_pt"></a><b>overshoot_limit_pt</b></p>
5588
5589
5590
5591
5592      </td>
5593
5594
5595
5596 <td style="vertical-align: top;">R</td>
5597
5598
5599
5600
5601      <td style="vertical-align: top;"><i>0.0</i></td>
5602
5603
5604
5605
5606      <td style="vertical-align: top;"> 
5607     
5608     
5609     
5610      <p>Allowed limit
5611for the overshooting of potential temperature in
5612case that the upstream-spline scheme is switched on (in K).&nbsp; </p>
5613
5614
5615
5616
5617     
5618     
5619     
5620      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5621      </p>
5622
5623
5624
5625 
5626     
5627     
5628     
5629      <p>Only positive values are allowed for <b>overshoot_limit_pt</b>.</p>
5630
5631
5632
5633
5634      </td>
5635
5636
5637
5638 </tr>
5639
5640
5641
5642 <tr>
5643
5644
5645
5646 <td style="vertical-align: top;"> 
5647     
5648     
5649     
5650      <p><a name="overshoot_limit_u"></a><b>overshoot_limit_u</b></p>
5651
5652
5653
5654
5655      </td>
5656
5657
5658
5659 <td style="vertical-align: top;">R</td>
5660
5661
5662
5663
5664      <td style="vertical-align: top;"><i>0.0</i></td>
5665
5666
5667
5668
5669      <td style="vertical-align: top;">Allowed limit for the
5670overshooting of
5671the u-component of velocity in case that the upstream-spline scheme is
5672switched on (in m/s).
5673     
5674     
5675     
5676      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5677      </p>
5678
5679
5680
5681 
5682     
5683     
5684     
5685      <p>Only positive values are allowed for <b>overshoot_limit_u</b>.</p>
5686
5687
5688
5689
5690      </td>
5691
5692
5693
5694 </tr>
5695
5696
5697
5698 <tr>
5699
5700
5701
5702 <td style="vertical-align: top;"> 
5703     
5704     
5705     
5706      <p><a name="overshoot_limit_v"></a><b>overshoot_limit_v</b></p>
5707
5708
5709
5710
5711      </td>
5712
5713
5714
5715 <td style="vertical-align: top;">R</td>
5716
5717
5718
5719
5720      <td style="vertical-align: top;"><i>0.0</i></td>
5721
5722
5723
5724
5725      <td style="vertical-align: top;"> 
5726     
5727     
5728     
5729      <p>Allowed limit
5730for the overshooting of the v-component of
5731velocity in case that the upstream-spline scheme is switched on
5732(in m/s).&nbsp; </p>
5733
5734
5735
5736 
5737     
5738     
5739     
5740      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5741      </p>
5742
5743
5744
5745 
5746     
5747     
5748     
5749      <p>Only positive values are allowed for <b>overshoot_limit_v</b>.</p>
5750
5751
5752
5753
5754      </td>
5755
5756
5757
5758 </tr>
5759
5760
5761
5762 <tr>
5763
5764
5765
5766 <td style="vertical-align: top;"> 
5767     
5768     
5769     
5770      <p><a name="overshoot_limit_w"></a><b>overshoot_limit_w</b></p>
5771
5772
5773
5774
5775      </td>
5776
5777
5778
5779 <td style="vertical-align: top;">R</td>
5780
5781
5782
5783
5784      <td style="vertical-align: top;"><i>0.0</i></td>
5785
5786
5787
5788
5789      <td style="vertical-align: top;"> 
5790     
5791     
5792     
5793      <p>Allowed limit
5794for the overshooting of the w-component of
5795velocity in case that the upstream-spline scheme is switched on
5796(in m/s).&nbsp; </p>
5797
5798
5799
5800 
5801     
5802     
5803     
5804      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5805      </p>
5806
5807
5808
5809 
5810     
5811     
5812     
5813      <p>Only positive values are permitted for <b>overshoot_limit_w</b>.</p>
5814
5815
5816
5817
5818      </td>
5819
5820
5821
5822 </tr>
5823
5824
5825
5826 <tr>
5827
5828
5829
5830 <td style="vertical-align: top;"> 
5831     
5832     
5833     
5834      <p><a name="passive_scalar"></a><b>passive_scalar</b></p>
5835
5836
5837
5838
5839      </td>
5840
5841
5842
5843 <td style="vertical-align: top;">L</td>
5844
5845
5846
5847
5848      <td style="vertical-align: top;"><i>.F.</i></td>
5849
5850
5851
5852
5853      <td style="vertical-align: top;"> 
5854     
5855     
5856     
5857      <p>Parameter to
5858switch on the prognostic equation for a passive
5859scalar. <br>
5860
5861
5862
5863 </p>
5864
5865
5866
5867 
5868     
5869     
5870     
5871      <p>The initial vertical profile
5872of s can be set via parameters <a href="#s_surface">s_surface</a>,
5873      <a href="#s_vertical_gradient">s_vertical_gradient</a>
5874and&nbsp; <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>.
5875Boundary conditions can be set via <a href="#s_surface_initial_change">s_surface_initial_change</a>
5876and <a href="#surface_scalarflux">surface_scalarflux</a>.&nbsp;
5877      </p>
5878
5879
5880
5881 
5882     
5883     
5884     
5885      <p><b>Note:</b> <br>
5886
5887
5888
5889
5890With <span style="font-weight: bold;">passive_scalar</span>
5891switched
5892on, the simultaneous use of humidity (see&nbsp;<a href="#humidity">humidity</a>)
5893is impossible.</p>
5894
5895
5896
5897 </td>
5898
5899
5900
5901 </tr>
5902
5903
5904
5905 <tr>
5906
5907
5908
5909 <td style="vertical-align: top;"> 
5910     
5911     
5912     
5913      <p><a name="phi"></a><b>phi</b></p>
5914
5915
5916
5917
5918      </td>
5919
5920
5921
5922 <td style="vertical-align: top;">R</td>
5923
5924
5925
5926
5927      <td style="vertical-align: top;"><i>55.0</i></td>
5928
5929
5930
5931
5932      <td style="vertical-align: top;"> 
5933     
5934     
5935     
5936      <p>Geographical
5937latitude (in degrees).&nbsp; </p>
5938
5939
5940
5941 
5942     
5943     
5944     
5945      <p>The value of
5946this parameter determines the value of the
5947Coriolis parameters f and f*, provided that the angular velocity (see <a href="#omega">omega</a>)
5948is non-zero.</p>
5949
5950
5951
5952 </td>
5953
5954
5955
5956 </tr>
5957
5958
5959
5960 <tr>
5961
5962
5963
5964 <td style="vertical-align: top;"> 
5965     
5966     
5967     
5968      <p><a name="prandtl_layer"></a><b>prandtl_layer</b></p>
5969
5970
5971
5972
5973      </td>
5974
5975
5976
5977 <td style="vertical-align: top;">L</td>
5978
5979
5980
5981
5982      <td style="vertical-align: top;"><i>.T.</i></td>
5983
5984
5985
5986
5987      <td style="vertical-align: top;"> 
5988     
5989     
5990     
5991      <p>Parameter to
5992switch on a Prandtl layer.&nbsp; </p>
5993
5994
5995
5996 
5997     
5998     
5999     
6000      <p>By default,
6001a Prandtl layer is switched on at the bottom
6002boundary between z = 0 and z = 0.5 * <a href="#dz">dz</a>
6003(the first computational grid point above ground for u, v and the
6004scalar quantities).
6005In this case, at the bottom boundary, free-slip conditions for u and v
6006(see <a href="#bc_uv_b">bc_uv_b</a>)
6007are not allowed. Likewise, laminar
6008simulations with constant eddy diffusivities (<a href="#km_constant">km_constant</a>)
6009are forbidden.&nbsp; </p>
6010
6011
6012
6013 
6014     
6015     
6016     
6017      <p>With Prandtl-layer
6018switched off, the TKE boundary condition <a href="#bc_e_b">bc_e_b</a>
6019= '<i>(u*)**2+neumann'</i> must not be used and is
6020automatically
6021changed to <i>'neumann'</i> if necessary.&nbsp; Also,
6022the pressure
6023boundary condition <a href="#bc_p_b">bc_p_b</a>
6024= <i>'neumann+inhomo'</i>&nbsp; is not allowed. </p>
6025
6026
6027
6028
6029     
6030     
6031     
6032      <p>The roughness length is declared via the parameter <a href="#roughness_length">roughness_length</a>.</p>
6033
6034
6035
6036
6037      </td>
6038
6039
6040
6041 </tr>
6042
6043
6044
6045 <tr>
6046
6047
6048
6049 <td style="vertical-align: top;"> 
6050     
6051     
6052     
6053      <p><a name="precipitation"></a><b>precipitation</b></p>
6054
6055
6056
6057
6058      </td>
6059
6060
6061
6062 <td style="vertical-align: top;">L</td>
6063
6064
6065
6066
6067      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
6068
6069
6070
6071 <td style="vertical-align: top;"> 
6072     
6073     
6074     
6075      <p>Parameter to switch
6076on the precipitation scheme.<br>
6077
6078
6079
6080 </p>
6081
6082
6083
6084 
6085     
6086     
6087     
6088      <p>For
6089precipitation processes PALM uses a simplified Kessler
6090scheme. This scheme only considers the
6091so-called autoconversion, that means the generation of rain water by
6092coagulation of cloud drops among themselves. Precipitation begins and
6093is immediately removed from the flow as soon as the liquid water
6094content exceeds the critical value of 0.5 g/kg.</p>
6095
6096
6097
6098     
6099     
6100     
6101      <p>The precipitation rate and amount can be output by assigning the runtime parameter <a href="chapter_4.2.html#data_output">data_output</a> = <span style="font-style: italic;">'prr*'</span> or <span style="font-style: italic;">'pra*'</span>, respectively. The time interval on which the precipitation amount is defined can be controlled via runtime parameter <a href="chapter_4.2.html#precipitation_amount_interval">precipitation_amount_interval</a>.</p>
6102
6103
6104
6105 </td>
6106
6107
6108
6109 </tr>
6110
6111
6112
6113
6114    <tr>
6115
6116
6117
6118      <td style="vertical-align: top;"><a name="pt_reference"></a><span style="font-weight: bold;">pt_reference</span></td>
6119
6120
6121
6122      <td style="vertical-align: top;">R</td>
6123
6124
6125
6126      <td style="vertical-align: top;"><span style="font-style: italic;">use horizontal average as
6127refrence</span></td>
6128
6129
6130
6131      <td style="vertical-align: top;">Reference
6132temperature to be used in all buoyancy terms (in K).<br>
6133
6134
6135
6136      <br>
6137
6138
6139
6140By
6141default, the instantaneous horizontal average over the total model
6142domain is used.<br>
6143
6144
6145
6146      <br>
6147
6148
6149
6150      <span style="font-weight: bold;">Attention:</span><br>
6151
6152
6153
6154In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>), always a reference temperature is used in the buoyancy terms with a default value of <span style="font-weight: bold;">pt_reference</span> = <a href="#pt_surface">pt_surface</a>.</td>
6155
6156
6157
6158    </tr>
6159
6160
6161
6162    <tr>
6163
6164
6165
6166 <td style="vertical-align: top;"> 
6167     
6168     
6169     
6170      <p><a name="pt_surface"></a><b>pt_surface</b></p>
6171
6172
6173
6174
6175      </td>
6176
6177
6178
6179 <td style="vertical-align: top;">R</td>
6180
6181
6182
6183
6184      <td style="vertical-align: top;"><i>300.0</i></td>
6185
6186
6187
6188
6189      <td style="vertical-align: top;"> 
6190     
6191     
6192     
6193      <p>Surface
6194potential temperature (in K).&nbsp; </p>
6195
6196
6197
6198 
6199     
6200     
6201     
6202      <p>This
6203parameter assigns the value of the potential temperature
6204      <span style="font-weight: bold;">pt</span> at the surface (k=0)<b>.</b> Starting from this value,
6205the
6206initial vertical temperature profile is constructed with <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6207and <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level
6208      </a>.
6209This profile is also used for the 1d-model as a stationary profile.</p>
6210
6211
6212
6213     
6214     
6215     
6216      <p><span style="font-weight: bold;">Attention:</span><br>
6217
6218
6219
6220In case of ocean runs (see <a href="#ocean">ocean</a>),
6221this parameter gives the temperature value at the sea surface, which is
6222at k=nzt. The profile is then constructed from the surface down to the
6223bottom of the model.</p>
6224
6225
6226
6227
6228      </td>
6229
6230
6231
6232 </tr>
6233
6234
6235
6236 <tr>
6237
6238
6239
6240 <td style="vertical-align: top;"> 
6241     
6242     
6243     
6244      <p><a name="pt_surface_initial_change"></a><b>pt_surface_initial</b>
6245      <br>
6246
6247
6248
6249 <b>_change</b></p>
6250
6251
6252
6253 </td>
6254
6255
6256
6257 <td style="vertical-align: top;">R</td>
6258
6259
6260
6261 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
6262
6263
6264
6265 </td>
6266
6267
6268
6269
6270      <td style="vertical-align: top;"> 
6271     
6272     
6273     
6274      <p>Change in
6275surface temperature to be made at the beginning of
6276the 3d run
6277(in K).&nbsp; </p>
6278
6279
6280
6281 
6282     
6283     
6284     
6285      <p>If <b>pt_surface_initial_change</b>
6286is set to a non-zero
6287value, the near surface sensible heat flux is not allowed to be given
6288simultaneously (see <a href="#surface_heatflux">surface_heatflux</a>).</p>
6289
6290
6291
6292
6293      </td>
6294
6295
6296
6297 </tr>
6298
6299
6300
6301 <tr>
6302
6303
6304
6305 <td style="vertical-align: top;"> 
6306     
6307     
6308     
6309      <p><a name="pt_vertical_gradient"></a><b>pt_vertical_gradient</b></p>
6310
6311
6312
6313
6314      </td>
6315
6316
6317
6318 <td style="vertical-align: top;">R (10)</td>
6319
6320
6321
6322
6323      <td style="vertical-align: top;"><i>10 * 0.0</i></td>
6324
6325
6326
6327
6328      <td style="vertical-align: top;"> 
6329     
6330     
6331     
6332      <p>Temperature
6333gradient(s) of the initial temperature profile (in
6334K
6335/ 100 m).&nbsp; </p>
6336
6337
6338
6339 
6340     
6341     
6342     
6343      <p>This temperature gradient
6344holds starting from the height&nbsp;
6345level defined by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>
6346(precisely: for all uv levels k where zu(k) &gt;
6347pt_vertical_gradient_level,
6348pt_init(k) is set: pt_init(k) = pt_init(k-1) + dzu(k) * <b>pt_vertical_gradient</b>)
6349up to the top boundary or up to the next height level defined
6350by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>.
6351A total of 10 different gradients for 11 height intervals (10 intervals
6352if <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>(1)
6353= <i>0.0</i>) can be assigned. The surface temperature is
6354assigned via <a href="#pt_surface">pt_surface</a>.&nbsp;
6355      </p>
6356
6357
6358
6359 
6360     
6361     
6362     
6363      <p>Example:&nbsp; </p>
6364
6365
6366
6367 
6368     
6369     
6370     
6371      <ul>
6372
6373
6374
6375 
6376       
6377       
6378       
6379        <p><b>pt_vertical_gradient</b>
6380= <i>1.0</i>, <i>0.5</i>,&nbsp; <br>
6381
6382
6383
6384
6385        <b>pt_vertical_gradient_level</b> = <i>500.0</i>,
6386        <i>1000.0</i>,</p>
6387
6388
6389
6390 
6391     
6392     
6393     
6394      </ul>
6395
6396
6397
6398 
6399     
6400     
6401     
6402      <p>That
6403defines the temperature profile to be neutrally
6404stratified
6405up to z = 500.0 m with a temperature given by <a href="#pt_surface">pt_surface</a>.
6406For 500.0 m &lt; z &lt;= 1000.0 m the temperature gradient is
64071.0 K /
6408100 m and for z &gt; 1000.0 m up to the top boundary it is
64090.5 K / 100 m (it is assumed that the assigned height levels correspond
6410with uv levels).</p>
6411
6412
6413
6414     
6415     
6416     
6417      <p><span style="font-weight: bold;">Attention:</span><br>
6418
6419
6420
6421In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>),
6422the profile is constructed like described above, but starting from the
6423sea surface (k=nzt) down to the bottom boundary of the model. Height
6424levels have then to be given as negative values, e.g. <span style="font-weight: bold;">pt_vertical_gradient_level</span> = <span style="font-style: italic;">-500.0</span>, <span style="font-style: italic;">-1000.0</span>.</p>
6425
6426
6427
6428 </td>
6429
6430
6431
6432 </tr>
6433
6434
6435
6436 <tr>
6437
6438
6439
6440 <td style="vertical-align: top;"> 
6441     
6442     
6443     
6444      <p><a name="pt_vertical_gradient_level"></a><b>pt_vertical_gradient</b>
6445      <br>
6446
6447
6448
6449 <b>_level</b></p>
6450
6451
6452
6453 </td>
6454
6455
6456
6457 <td style="vertical-align: top;">R (10)</td>
6458
6459
6460
6461 <td style="vertical-align: top;"> 
6462     
6463     
6464     
6465      <p><i>10 *</i>&nbsp;
6466      <span style="font-style: italic;">0.0</span><br>
6467
6468
6469
6470
6471      </p>
6472
6473
6474
6475 </td>
6476
6477
6478
6479 <td style="vertical-align: top;">
6480     
6481     
6482     
6483      <p>Height level from which on the temperature gradient defined by
6484      <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6485is effective (in m).&nbsp; </p>
6486
6487
6488
6489 
6490     
6491     
6492     
6493      <p>The height levels have to be assigned in ascending order. The
6494default values result in a neutral stratification regardless of the
6495values of <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6496(unless the top boundary of the model is higher than 100000.0 m).
6497For the piecewise construction of temperature profiles see <a href="#pt_vertical_gradient">pt_vertical_gradient</a>.</p>
6498
6499
6500
6501      <span style="font-weight: bold;">Attention:</span><br>
6502
6503
6504
6505In case of ocean runs&nbsp;(see <a href="chapter_4.1.html#ocean">ocean</a>), the (negative) height levels have to be assigned in descending order.
6506      </td>
6507
6508
6509
6510 </tr>
6511
6512
6513
6514 <tr>
6515
6516
6517
6518 <td style="vertical-align: top;"> 
6519     
6520     
6521     
6522      <p><a name="q_surface"></a><b>q_surface</b></p>
6523
6524
6525
6526
6527      </td>
6528
6529
6530
6531 <td style="vertical-align: top;">R</td>
6532
6533
6534
6535
6536      <td style="vertical-align: top;"><i>0.0</i></td>
6537
6538
6539
6540
6541      <td style="vertical-align: top;"> 
6542     
6543     
6544     
6545      <p>Surface
6546specific humidity / total water content (kg/kg).&nbsp; </p>
6547
6548
6549
6550 
6551     
6552     
6553     
6554      <p>This
6555parameter assigns the value of the specific humidity q at
6556the surface (k=0).&nbsp; Starting from this value, the initial
6557humidity
6558profile is constructed with&nbsp; <a href="#q_vertical_gradient">q_vertical_gradient</a>
6559and <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>.
6560This profile is also used for the 1d-model as a stationary profile.</p>
6561
6562
6563
6564
6565      </td>
6566
6567
6568
6569 </tr>
6570
6571
6572
6573 <tr>
6574
6575
6576
6577 <td style="vertical-align: top;"> 
6578     
6579     
6580     
6581      <p><a name="q_surface_initial_change"></a><b>q_surface_initial</b>
6582      <br>
6583
6584
6585
6586 <b>_change</b></p>
6587
6588
6589
6590 </td>
6591
6592
6593
6594 <td style="vertical-align: top;">R<br>
6595
6596
6597
6598 </td>
6599
6600
6601
6602 <td style="vertical-align: top;"><i>0.0</i></td>
6603
6604
6605
6606
6607      <td style="vertical-align: top;"> 
6608     
6609     
6610     
6611      <p>Change in
6612surface specific humidity / total water content to
6613be made at the beginning
6614of the 3d run (kg/kg).&nbsp; </p>
6615
6616
6617
6618 
6619     
6620     
6621     
6622      <p>If <b>q_surface_initial_change</b><i>
6623      </i>is set to a
6624non-zero value the
6625near surface latent heat flux (water flux) is not allowed to be given
6626simultaneously (see <a href="#surface_waterflux">surface_waterflux</a>).</p>
6627
6628
6629
6630
6631      </td>
6632
6633
6634
6635 </tr>
6636
6637
6638
6639 <tr>
6640
6641
6642
6643 <td style="vertical-align: top;"> 
6644     
6645     
6646     
6647      <p><a name="q_vertical_gradient"></a><b>q_vertical_gradient</b></p>
6648
6649
6650
6651
6652      </td>
6653
6654
6655
6656 <td style="vertical-align: top;">R (10)</td>
6657
6658
6659
6660
6661      <td style="vertical-align: top;"><i>10 * 0.0</i></td>
6662
6663
6664
6665
6666      <td style="vertical-align: top;"> 
6667     
6668     
6669     
6670      <p>Humidity
6671gradient(s) of the initial humidity profile
6672(in 1/100 m).&nbsp; </p>
6673
6674
6675
6676 
6677     
6678     
6679     
6680      <p>This humidity gradient
6681holds starting from the height
6682level&nbsp; defined by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>
6683(precisely: for all uv levels k, where zu(k) &gt;
6684q_vertical_gradient_level,
6685q_init(k) is set: q_init(k) = q_init(k-1) + dzu(k) * <b>q_vertical_gradient</b>)
6686up to the top boundary or up to the next height level defined
6687by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>.
6688A total of 10 different gradients for 11 height intervals (10 intervals
6689if <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>(1)
6690= <i>0.0</i>) can be asigned. The surface humidity is
6691assigned
6692via <a href="#q_surface">q_surface</a>. </p>
6693
6694
6695
6696
6697     
6698     
6699     
6700      <p>Example:&nbsp; </p>
6701
6702
6703
6704 
6705     
6706     
6707     
6708      <ul>
6709
6710
6711
6712 
6713       
6714       
6715       
6716        <p><b>q_vertical_gradient</b>
6717= <i>0.001</i>, <i>0.0005</i>,&nbsp; <br>
6718
6719
6720
6721
6722        <b>q_vertical_gradient_level</b> = <i>500.0</i>,
6723        <i>1000.0</i>,</p>
6724
6725
6726
6727 
6728     
6729     
6730     
6731      </ul>
6732
6733
6734
6735
6736That defines the humidity to be constant with height up to z =
6737500.0
6738m with a
6739value given by <a href="#q_surface">q_surface</a>.
6740For 500.0 m &lt; z &lt;= 1000.0 m the humidity gradient is
67410.001 / 100
6742m and for z &gt; 1000.0 m up to the top boundary it is
67430.0005 / 100 m (it is assumed that the assigned height levels
6744correspond with uv
6745levels). </td>
6746
6747
6748
6749 </tr>
6750
6751
6752
6753 <tr>
6754
6755
6756
6757 <td style="vertical-align: top;"> 
6758     
6759     
6760     
6761      <p><a name="q_vertical_gradient_level"></a><b>q_vertical_gradient</b>
6762      <br>
6763
6764
6765
6766 <b>_level</b></p>
6767
6768
6769
6770 </td>
6771
6772
6773
6774 <td style="vertical-align: top;">R (10)</td>
6775
6776
6777
6778 <td style="vertical-align: top;"> 
6779     
6780     
6781     
6782      <p><i>10 *</i>&nbsp;
6783      <i>0.0</i></p>
6784
6785
6786
6787 </td>
6788
6789
6790
6791 <td style="vertical-align: top;"> 
6792     
6793     
6794     
6795      <p>Height level from
6796which on the humidity gradient defined by <a href="#q_vertical_gradient">q_vertical_gradient</a>
6797is effective (in m).&nbsp; </p>
6798
6799
6800
6801 
6802     
6803     
6804     
6805      <p>The height levels
6806are to be assigned in ascending order. The
6807default values result in a humidity constant with height regardless of
6808the values of <a href="#q_vertical_gradient">q_vertical_gradient</a>
6809(unless the top boundary of the model is higher than 100000.0 m). For
6810the piecewise construction of humidity profiles see <a href="#q_vertical_gradient">q_vertical_gradient</a>.</p>
6811
6812
6813
6814
6815      </td>
6816
6817
6818
6819 </tr>
6820
6821
6822
6823 <tr>
6824
6825
6826
6827 <td style="vertical-align: top;"> 
6828     
6829     
6830     
6831      <p><a name="radiation"></a><b>radiation</b></p>
6832
6833
6834
6835
6836      </td>
6837
6838
6839
6840 <td style="vertical-align: top;">L</td>
6841
6842
6843
6844
6845      <td style="vertical-align: top;"><i>.F.</i></td>
6846
6847
6848
6849
6850      <td style="vertical-align: top;"> 
6851     
6852     
6853     
6854      <p>Parameter to
6855switch on longwave radiation cooling at
6856cloud-tops.&nbsp; </p>
6857
6858
6859
6860 
6861     
6862     
6863     
6864      <p>Long-wave radiation
6865processes are parameterized by the
6866effective emissivity, which considers only the absorption and emission
6867of long-wave radiation at cloud droplets. The radiation scheme can be
6868used only with <a href="#cloud_physics">cloud_physics</a>
6869= .TRUE. .</p>
6870
6871
6872
6873 </td>
6874
6875
6876
6877 </tr>
6878
6879
6880
6881 <tr>
6882
6883
6884
6885 <td style="vertical-align: top;"> 
6886     
6887     
6888     
6889      <p><a name="random_generator"></a><b>random_generator</b></p>
6890
6891
6892
6893
6894      </td>
6895
6896
6897
6898 <td style="vertical-align: top;">C * 20</td>
6899
6900
6901
6902
6903      <td style="vertical-align: top;"> 
6904     
6905     
6906     
6907      <p><i>'numerical</i><br>
6908
6909
6910
6911
6912      <i>recipes'</i></p>
6913
6914
6915
6916 </td>
6917
6918
6919
6920 <td style="vertical-align: top;"> 
6921     
6922     
6923     
6924      <p>Random number
6925generator to be used for creating uniformly
6926distributed random numbers. <br>
6927
6928
6929
6930 </p>
6931
6932
6933
6934 
6935     
6936     
6937     
6938      <p>It is
6939used if random perturbations are to be imposed on the
6940velocity field or on the surface heat flux field (see <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>
6941and <a href="chapter_4.2.html#random_heatflux">random_heatflux</a>).
6942By default, the "Numerical Recipes" random number generator is used.
6943This one provides exactly the same order of random numbers on all
6944different machines and should be used in particular for comparison runs.<br>
6945
6946
6947
6948
6949      <br>
6950
6951
6952
6953
6954Besides, a system-specific generator is available ( <b>random_generator</b>
6955= <i>'system-specific')</i> which should particularly be
6956used for runs
6957on vector parallel computers (NEC), because the default generator
6958cannot be vectorized and therefore significantly drops down the code
6959performance on these machines.<br>
6960
6961
6962
6963 </p>
6964
6965
6966
6967 <span style="font-weight: bold;">Note:</span><br>
6968
6969
6970
6971
6972Results from two otherwise identical model runs will not be comparable
6973one-to-one if they used different random number generators.</td>
6974
6975
6976
6977 </tr>
6978
6979
6980
6981
6982    <tr>
6983
6984
6985
6986 <td style="vertical-align: top;"> 
6987     
6988     
6989     
6990      <p><a name="random_heatflux"></a><b>random_heatflux</b></p>
6991
6992
6993
6994
6995      </td>
6996
6997
6998
6999 <td style="vertical-align: top;">L</td>
7000
7001
7002
7003
7004      <td style="vertical-align: top;"><i>.F.</i></td>
7005
7006
7007
7008
7009      <td style="vertical-align: top;"> 
7010     
7011     
7012     
7013      <p>Parameter to
7014impose random perturbations on the internal two-dimensional near
7015surface heat flux field <span style="font-style: italic;">shf</span>.
7016      <br>
7017
7018
7019
7020 </p>
7021
7022
7023
7024If a near surface heat flux is used as bottom
7025boundary
7026condition (see <a href="#surface_heatflux">surface_heatflux</a>),
7027it is by default assumed to be horizontally homogeneous. Random
7028perturbations can be imposed on the internal
7029two-dimensional&nbsp;heat flux field <span style="font-style: italic;">shf</span> by assigning <b>random_heatflux</b>
7030= <i>.T.</i>. The disturbed heat flux field is calculated
7031by
7032multiplying the
7033values at each mesh point with a normally distributed random number
7034with a mean value and standard deviation of 1. This is repeated after
7035every timestep.<br>
7036
7037
7038
7039 <br>
7040
7041
7042
7043
7044In case of a non-flat <a href="#topography">topography</a>,&nbsp;assigning
7045      <b>random_heatflux</b>
7046= <i>.T.</i> imposes random perturbations on the
7047combined&nbsp;heat
7048flux field <span style="font-style: italic;">shf</span>
7049composed of <a href="#surface_heatflux">surface_heatflux</a>
7050at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a>
7051at the topography top face.</td>
7052
7053
7054
7055 </tr>
7056
7057
7058
7059 <tr>
7060
7061
7062
7063 <td style="vertical-align: top;"> 
7064     
7065     
7066     
7067      <p><a name="rif_max"></a><b>rif_max</b></p>
7068
7069
7070
7071
7072      </td>
7073
7074
7075
7076 <td style="vertical-align: top;">R</td>
7077
7078
7079
7080
7081      <td style="vertical-align: top;"><i>1.0</i></td>
7082
7083
7084
7085
7086      <td style="vertical-align: top;"> 
7087     
7088     
7089     
7090      <p>Upper limit of
7091the flux-Richardson number.&nbsp; </p>
7092
7093
7094
7095 
7096     
7097     
7098     
7099      <p>With the
7100Prandtl layer switched on (see <a href="#prandtl_layer">prandtl_layer</a>),
7101flux-Richardson numbers (rif) are calculated for z=z<sub>p</sub>
7102(k=1)
7103in the 3d-model (in the 1d model for all heights). Their values in
7104particular determine the
7105values of the friction velocity (1d- and 3d-model) and the values of
7106the eddy diffusivity (1d-model). With small wind velocities at the
7107Prandtl layer top or small vertical wind shears in the 1d-model, rif
7108can take up unrealistic large values. They are limited by an upper (<span style="font-weight: bold;">rif_max</span>) and lower
7109limit (see <a href="#rif_min">rif_min</a>)
7110for the flux-Richardson number. The condition <b>rif_max</b>
7111&gt; <b>rif_min</b>
7112must be met.</p>
7113
7114
7115
7116 </td>
7117
7118
7119
7120 </tr>
7121
7122
7123
7124 <tr>
7125
7126
7127
7128 <td style="vertical-align: top;"> 
7129     
7130     
7131     
7132      <p><a name="rif_min"></a><b>rif_min</b></p>
7133
7134
7135
7136
7137      </td>
7138
7139
7140
7141 <td style="vertical-align: top;">R</td>
7142
7143
7144
7145
7146      <td style="vertical-align: top;"><i>- 5.0</i></td>
7147
7148
7149
7150
7151      <td style="vertical-align: top;"> 
7152     
7153     
7154     
7155      <p>Lower limit of
7156the flux-Richardson number.&nbsp; </p>
7157
7158
7159
7160 
7161     
7162     
7163     
7164      <p>For further
7165explanations see <a href="#rif_max">rif_max</a>.
7166The condition <b>rif_max</b> &gt; <b>rif_min </b>must
7167be met.</p>
7168
7169
7170
7171 </td>
7172
7173
7174
7175 </tr>
7176
7177
7178
7179 <tr>
7180
7181
7182
7183 <td style="vertical-align: top;"> 
7184     
7185     
7186     
7187      <p><a name="roughness_length"></a><b>roughness_length</b></p>
7188
7189
7190
7191
7192      </td>
7193
7194
7195
7196 <td style="vertical-align: top;">R</td>
7197
7198
7199
7200
7201      <td style="vertical-align: top;"><i>0.1</i></td>
7202
7203
7204
7205
7206      <td style="vertical-align: top;"> 
7207     
7208     
7209     
7210      <p>Roughness
7211length (in m).&nbsp; </p>
7212
7213
7214
7215 
7216     
7217     
7218     
7219      <p>This parameter is
7220effective only in case that a Prandtl layer
7221is switched
7222on (see <a href="#prandtl_layer">prandtl_layer</a>).</p>
7223
7224
7225
7226
7227      </td>
7228
7229
7230
7231 </tr>
7232
7233
7234
7235 <tr>
7236
7237
7238
7239      <td style="vertical-align: top;"><a name="sa_surface"></a><span style="font-weight: bold;">sa_surface</span></td>
7240
7241
7242
7243      <td style="vertical-align: top;">R</td>
7244
7245
7246
7247      <td style="vertical-align: top;"><span style="font-style: italic;">35.0</span></td>
7248
7249
7250
7251      <td style="vertical-align: top;"> 
7252     
7253     
7254     
7255      <p>Surface salinity (in psu).&nbsp;</p>
7256
7257
7258
7259This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).
7260     
7261     
7262     
7263      <p>This
7264parameter assigns the value of the salinity <span style="font-weight: bold;">sa</span> at the sea surface (k=nzt)<b>.</b> Starting from this value,
7265the
7266initial vertical salinity profile is constructed from the surface down to the bottom of the model (k=0) by using&nbsp;<a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>
7267and&nbsp;<a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level
7268      </a>.</p>
7269
7270
7271
7272      </td>
7273
7274
7275
7276    </tr>
7277
7278
7279
7280    <tr>
7281
7282
7283
7284      <td style="vertical-align: top;"><a name="sa_vertical_gradient"></a><span style="font-weight: bold;">sa_vertical_gradient</span></td>
7285
7286
7287
7288      <td style="vertical-align: top;">R(10)</td>
7289
7290
7291
7292      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
7293
7294
7295
7296      <td style="vertical-align: top;">
7297     
7298     
7299     
7300      <p>Salinity gradient(s) of the initial salinity profile (in psu
7301/ 100 m).&nbsp; </p>
7302
7303
7304
7305 
7306     
7307     
7308     
7309      <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p>
7310
7311
7312
7313     
7314     
7315     
7316      <p>This salinity gradient
7317holds starting from the height&nbsp;
7318level defined by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>
7319(precisely: for all uv levels k where zu(k) &lt;
7320sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) =
7321sa_init(k+1) - dzu(k+1) * <b>sa_vertical_gradient</b>) down to the bottom boundary or down to the next height level defined
7322by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>.
7323A total of 10 different gradients for 11 height intervals (10 intervals
7324if <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>(1)
7325= <i>0.0</i>) can be assigned. The surface salinity at k=nzt is
7326assigned via <a href="chapter_4.1.html#sa_surface">sa_surface</a>.&nbsp;
7327      </p>
7328
7329
7330
7331 
7332     
7333     
7334     
7335      <p>Example:&nbsp; </p>
7336
7337
7338
7339 
7340     
7341     
7342     
7343      <ul>
7344
7345
7346
7347       
7348       
7349       
7350        <p><b>sa_vertical_gradient</b>
7351= <i>1.0</i>, <i>0.5</i>,&nbsp; <br>
7352
7353
7354
7355
7356        <b>sa_vertical_gradient_level</b> = <i>-500.0</i>,
7357-<i>1000.0</i>,</p>
7358
7359
7360
7361     
7362     
7363     
7364      </ul>
7365
7366
7367
7368 
7369     
7370     
7371     
7372      <p>That
7373defines the salinity to be constant down to z = -500.0 m with a salinity given by <a href="chapter_4.1.html#sa_surface">sa_surface</a>.
7374For -500.0 m &lt; z &lt;= -1000.0 m the salinity gradient is
73751.0 psu /
7376100 m and for z &lt; -1000.0 m down to the bottom boundary it is
73770.5 psu / 100 m (it is assumed that the assigned height levels correspond
7378with uv levels).</p>
7379
7380
7381
7382      </td>
7383
7384
7385
7386    </tr>
7387
7388
7389
7390    <tr>
7391
7392
7393
7394      <td style="vertical-align: top;"><a name="sa_vertical_gradient_level"></a><span style="font-weight: bold;">sa_vertical_gradient_level</span></td>
7395
7396
7397
7398      <td style="vertical-align: top;">R(10)</td>
7399
7400
7401
7402      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
7403
7404
7405
7406      <td style="vertical-align: top;">
7407     
7408     
7409     
7410      <p>Height level from which on the salinity gradient defined by <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>
7411is effective (in m).&nbsp; </p>
7412
7413
7414
7415 
7416     
7417     
7418     
7419      <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p>
7420
7421
7422
7423     
7424     
7425     
7426      <p>The height levels have to be assigned in descending order. The
7427default values result in a constant salinity profile regardless of the
7428values of <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>
7429(unless the bottom boundary of the model is lower than -100000.0 m).
7430For the piecewise construction of salinity profiles see <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>.</p>
7431
7432
7433
7434      </td>
7435
7436
7437
7438    </tr>
7439
7440
7441
7442    <tr>
7443
7444
7445
7446 <td style="vertical-align: top;"> 
7447     
7448     
7449     
7450      <p><a name="scalar_advec"></a><b>scalar_advec</b></p>
7451
7452
7453
7454
7455      </td>
7456
7457
7458
7459 <td style="vertical-align: top;">C * 10</td>
7460
7461
7462
7463
7464      <td style="vertical-align: top;"><i>'pw-scheme'</i></td>
7465
7466
7467
7468
7469      <td style="vertical-align: top;"> 
7470     
7471     
7472     
7473      <p>Advection
7474scheme to be used for the scalar quantities.&nbsp; </p>
7475
7476
7477
7478 
7479     
7480     
7481     
7482      <p>The
7483user can choose between the following schemes:<br>
7484
7485
7486
7487 </p>
7488
7489
7490
7491 
7492     
7493     
7494     
7495      <p><span style="font-style: italic;">'pw-scheme'</span><br>
7496
7497
7498
7499
7500      </p>
7501
7502
7503
7504 
7505     
7506     
7507     
7508      <div style="margin-left: 40px;">The scheme of
7509Piascek and
7510Williams (1970, J. Comp. Phys., 6,
7511392-405) with central differences in the form C3 is used.<br>
7512
7513
7514
7515
7516If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a>
7517= <span style="font-style: italic;">'leapfrog+euler'</span>
7518the
7519advection scheme is - for the Euler-timestep - automatically switched
7520to an upstream-scheme. <br>
7521
7522
7523
7524 </div>
7525
7526
7527
7528 <br>
7529
7530
7531
7532 
7533     
7534     
7535     
7536      <p><span style="font-style: italic;">'bc-scheme'</span><br>
7537
7538
7539
7540
7541      </p>
7542
7543
7544
7545 
7546     
7547     
7548     
7549      <div style="margin-left: 40px;">The Bott
7550scheme modified by
7551Chlond (1994, Mon.
7552Wea. Rev., 122, 111-125). This is a conservative monotonous scheme with
7553very small numerical diffusion and therefore very good conservation of
7554scalar flow features. The scheme however, is computationally very
7555expensive both because it is expensive itself and because it does (so
7556far) not allow specific code optimizations (e.g. cache optimization).
7557Choice of this
7558scheme forces the Euler timestep scheme to be used for the scalar
7559quantities. For output of horizontally averaged
7560profiles of the resolved / total heat flux, <a href="chapter_4.2.html#data_output_pr">data_output_pr</a>
7561= <i>'w*pt*BC'</i> / <i>'wptBC' </i>should
7562be used, instead of the
7563standard profiles (<span style="font-style: italic;">'w*pt*'</span>
7564and <span style="font-style: italic;">'wpt'</span>)
7565because these are
7566too inaccurate with this scheme. However, for subdomain analysis (see <a href="#statistic_regions">statistic_regions</a>)
7567exactly the reverse holds: here <i>'w*pt*BC'</i> and <i>'wptBC'</i>
7568show very large errors and should not be used.<br>
7569
7570
7571
7572 <br>
7573
7574
7575
7576
7577This scheme is not allowed for non-cyclic lateral boundary conditions
7578(see <a href="#bc_lr">bc_lr</a>
7579and <a href="#bc_ns">bc_ns</a>).<br>
7580
7581
7582
7583 <br>
7584
7585
7586
7587
7588      </div>
7589
7590
7591
7592 <span style="font-style: italic;">'ups-scheme'</span><br>
7593
7594
7595
7596
7597     
7598     
7599     
7600      <p style="margin-left: 40px;">The upstream-spline-scheme
7601is used
7602(see Mahrer and Pielke,
76031978: Mon. Wea. Rev., 106, 818-830). In opposite to the Piascek
7604Williams scheme, this is characterized by much better numerical
7605features (less numerical diffusion, better preservation of flux
7606structures, e.g. vortices), but computationally it is much more
7607expensive. In
7608addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a>
7609= <span style="font-style: italic;">'</span><i>euler'</i>),
7610i.e. the
7611timestep accuracy is only first order. For this reason the advection of
7612momentum (see <a href="#momentum_advec">momentum_advec</a>)
7613should then also be carried out with the upstream-spline scheme,
7614because otherwise the momentum would
7615be subject to large numerical diffusion due to the upstream
7616scheme.&nbsp; </p>
7617
7618
7619
7620 
7621     
7622     
7623     
7624      <p style="margin-left: 40px;">Since
7625the cubic splines used tend
7626to overshoot under
7627certain circumstances, this effect must be adjusted by suitable
7628filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>,
7629      <a href="#long_filter_factor">long_filter_factor</a>,
7630      <a href="#ups_limit_pt">ups_limit_pt</a>, <a href="#ups_limit_u">ups_limit_u</a>, <a href="#ups_limit_v">ups_limit_v</a>, <a href="#ups_limit_w">ups_limit_w</a>).
7631This is always neccesssary for runs with stable stratification,
7632even if this stratification appears only in parts of the model
7633domain.&nbsp; </p>
7634
7635
7636
7637 
7638     
7639     
7640     
7641      <p style="margin-left: 40px;">With
7642stable stratification the
7643upstream-upline scheme also produces gravity waves with large
7644amplitude, which must be
7645suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br>
7646
7647
7648
7649
7650      </p>
7651
7652
7653
7654 
7655     
7656     
7657     
7658      <p style="margin-left: 40px;"><span style="font-weight: bold;">Important: </span>The&nbsp;
7659upstream-spline scheme is not implemented for humidity and passive
7660scalars (see&nbsp;<a href="#humidity">humidity</a>
7661and <a href="#passive_scalar">passive_scalar</a>)
7662and requires the use of a 2d-domain-decomposition. The last conditions
7663severely restricts code optimization on several machines leading to
7664very long execution times! This scheme is also not allowed for
7665non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
7666and <a href="#bc_ns">bc_ns</a>).</p>
7667
7668
7669
7670      <br>
7671
7672
7673
7674A
7675differing advection scheme can be choosed for the subgrid-scale TKE
7676using parameter <a href="chapter_4.1.html#use_upstream_for_tke">use_upstream_for_tke</a>.</td>
7677
7678
7679
7680
7681    </tr>
7682
7683
7684
7685 <tr>
7686
7687
7688
7689 <td style="vertical-align: top;">
7690     
7691     
7692     
7693      <p><a name="statistic_regions"></a><b>statistic_regions</b></p>
7694
7695
7696
7697
7698      </td>
7699
7700
7701
7702 <td style="vertical-align: top;">I</td>
7703
7704
7705
7706
7707      <td style="vertical-align: top;"><i>0</i></td>
7708
7709
7710
7711
7712      <td style="vertical-align: top;"> 
7713     
7714     
7715     
7716      <p>Number of
7717additional user-defined subdomains for which
7718statistical analysis
7719and corresponding output (profiles, time series) shall be
7720made.&nbsp; </p>
7721
7722
7723
7724 
7725     
7726     
7727     
7728      <p>By default, vertical profiles and
7729other statistical quantities
7730are calculated as horizontal and/or volume average of the total model
7731domain. Beyond that, these calculations can also be carried out for
7732subdomains which can be defined using the field <a href="chapter_3.5.3.html">rmask </a>within the
7733user-defined software
7734(see <a href="chapter_3.5.3.html">chapter
77353.5.3</a>). The number of these subdomains is determined with the
7736parameter <b>statistic_regions</b>. Maximum 9 additional
7737subdomains
7738are allowed. The parameter <a href="chapter_4.3.html#region">region</a>
7739can be used to assigned names (identifier) to these subdomains which
7740are then used in the headers
7741of the output files and plots.</p>
7742
7743
7744
7745     
7746     
7747     
7748      <p>If the default NetCDF
7749output format is selected (see parameter <a href="chapter_4.2.html#data_output_format">data_output_format</a>),
7750data for the total domain and all defined subdomains are output to the
7751same file(s) (<a href="chapter_3.4.html#DATA_1D_PR_NETCDF">DATA_1D_PR_NETCDF</a>,
7752      <a href="chapter_3.4.html#DATA_1D_TS_NETCDF">DATA_1D_TS_NETCDF</a>).
7753In case of <span style="font-weight: bold;">statistic_regions</span>
7754&gt; <span style="font-style: italic;">0</span>,
7755data on the file for the different domains can be distinguished by a
7756suffix which is appended to the quantity names. Suffix 0 means data for
7757the total domain, suffix 1 means data for subdomain 1, etc.</p>
7758
7759
7760
7761     
7762     
7763     
7764      <p>In
7765case of <span style="font-weight: bold;">data_output_format</span>
7766= <span style="font-style: italic;">'profil'</span>,
7767individual local files for profiles (<a href="chapter_3.4.html#PLOT1D_DATA">PLOT1D_DATA</a>)&nbsp;are
7768created for each subdomain. The individual subdomain files differ by
7769their name (the
7770number of the respective subdomain is attached, e.g.
7771PLOT1D_DATA_1). In this case the name of the file with the data of
7772the total domain is PLOT1D_DATA_0. If no subdomains
7773are declared (<b>statistic_regions</b> = <i>0</i>),
7774the name
7775PLOT1D_DATA is used (this must be considered in the
7776respective file connection statements of the <span style="font-weight: bold;">mrun</span> configuration
7777file).</p>
7778
7779
7780
7781 </td>
7782
7783
7784
7785 </tr>
7786
7787
7788
7789 <tr>
7790
7791
7792
7793 <td style="vertical-align: top;"> 
7794     
7795     
7796     
7797      <p><a name="surface_heatflux"></a><b>surface_heatflux</b></p>
7798
7799
7800
7801
7802      </td>
7803
7804
7805
7806 <td style="vertical-align: top;">R</td>
7807
7808
7809
7810
7811      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br>
7812
7813
7814
7815
7816heatflux<br>
7817
7818
7819
7820 </span></td>
7821
7822
7823
7824 <td style="vertical-align: top;"> 
7825     
7826     
7827     
7828      <p>Kinematic sensible
7829heat flux at the bottom surface (in K m/s).&nbsp; </p>
7830
7831
7832
7833 
7834     
7835     
7836     
7837      <p>If
7838a value is assigned to this parameter, the internal two-dimensional
7839surface heat flux field <span style="font-style: italic;">shf</span>
7840is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span>&nbsp;as
7841bottom (horizontally homogeneous) boundary condition for the
7842temperature equation. This additionally requires that a Neumann
7843condition must be used for the potential temperature (see <a href="#bc_pt_b">bc_pt_b</a>),
7844because otherwise the resolved scale may contribute to
7845the surface flux so that a constant value cannot be guaranteed. Also,
7846changes of the
7847surface temperature (see <a href="#pt_surface_initial_change">pt_surface_initial_change</a>)
7848are not allowed. The parameter <a href="#random_heatflux">random_heatflux</a>
7849can be used to impose random perturbations on the (homogeneous) surface
7850heat
7851flux field <span style="font-style: italic;">shf</span>.&nbsp;</p>
7852
7853
7854
7855
7856     
7857     
7858     
7859      <p>
7860In case of a non-flat <a href="#topography">topography</a>,&nbsp;the
7861internal two-dimensional&nbsp;surface heat
7862flux field <span style="font-style: italic;">shf</span>
7863is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span>
7864at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a>
7865at the topography top face.&nbsp;The parameter<a href="#random_heatflux"> random_heatflux</a>
7866can be used to impose random perturbations on this combined surface
7867heat
7868flux field <span style="font-style: italic;">shf</span>.&nbsp;
7869      </p>
7870
7871
7872
7873 
7874     
7875     
7876     
7877      <p>If no surface heat flux is assigned, <span style="font-style: italic;">shf</span> is calculated
7878at each timestep by u<sub>*</sub> * theta<sub>*</sub>
7879(of course only with <a href="#prandtl_layer">prandtl_layer</a>
7880switched on). Here, u<sub>*</sub>
7881and theta<sub>*</sub> are calculated from the Prandtl law
7882assuming
7883logarithmic wind and temperature
7884profiles between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_pt_b">bc_pt_b</a>)
7885must be used as bottom boundary condition for the potential temperature.</p>
7886
7887
7888
7889     
7890     
7891     
7892      <p>See
7893also <a href="#top_heatflux">top_heatflux</a>.</p>
7894
7895
7896
7897
7898      </td>
7899
7900
7901
7902 </tr>
7903
7904
7905
7906 <tr>
7907
7908
7909
7910 <td style="vertical-align: top;"> 
7911     
7912     
7913     
7914      <p><a name="surface_pressure"></a><b>surface_pressure</b></p>
7915
7916
7917
7918
7919      </td>
7920
7921
7922
7923 <td style="vertical-align: top;">R</td>
7924
7925
7926
7927
7928      <td style="vertical-align: top;"><i>1013.25</i></td>
7929
7930
7931
7932
7933      <td style="vertical-align: top;"> 
7934     
7935     
7936     
7937      <p>Atmospheric
7938pressure at the surface (in hPa).&nbsp; </p>
7939
7940
7941
7942
7943Starting from this surface value, the vertical pressure
7944profile is calculated once at the beginning of the run assuming a
7945neutrally stratified
7946atmosphere. This is needed for
7947converting between the liquid water potential temperature and the
7948potential temperature (see <a href="#cloud_physics">cloud_physics</a><span style="text-decoration: underline;"></span>).</td>
7949
7950
7951
7952
7953    </tr>
7954
7955
7956
7957 <tr>
7958
7959
7960
7961 <td style="vertical-align: top;">
7962     
7963     
7964     
7965      <p><a name="surface_scalarflux"></a><b>surface_scalarflux</b></p>
7966
7967
7968
7969
7970      </td>
7971
7972
7973
7974 <td style="vertical-align: top;">R</td>
7975
7976
7977
7978
7979      <td style="vertical-align: top;"><i>0.0</i></td>
7980
7981
7982
7983
7984      <td style="vertical-align: top;"> 
7985     
7986     
7987     
7988      <p>Scalar flux at
7989the surface (in kg/(m<sup>2</sup> s)).&nbsp; </p>
7990
7991
7992
7993
7994     
7995     
7996     
7997      <p>If a non-zero value is assigned to this parameter, the
7998respective scalar flux value is used
7999as bottom (horizontally homogeneous) boundary condition for the scalar
8000concentration equation.&nbsp;This additionally requires that a
8001Neumann
8002condition must be used for the scalar concentration&nbsp;(see <a href="#bc_s_b">bc_s_b</a>),
8003because otherwise the resolved scale may contribute to
8004the surface flux so that a constant value cannot be guaranteed. Also,
8005changes of the
8006surface scalar concentration (see <a href="#s_surface_initial_change">s_surface_initial_change</a>)
8007are not allowed. <br>
8008
8009
8010
8011 </p>
8012
8013
8014
8015 
8016     
8017     
8018     
8019      <p>If no surface scalar
8020flux is assigned (<b>surface_scalarflux</b>
8021= <i>0.0</i>),
8022it is calculated at each timestep by u<sub>*</sub> * s<sub>*</sub>
8023(of course only with Prandtl layer switched on). Here, s<sub>*</sub>
8024is calculated from the Prandtl law assuming a logarithmic scalar
8025concentration
8026profile between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_s_b">bc_s_b</a>)
8027must be used as bottom boundary condition for the scalar concentration.</p>
8028
8029
8030
8031
8032      </td>
8033
8034
8035
8036 </tr>
8037
8038
8039
8040 <tr>
8041
8042
8043
8044 <td style="vertical-align: top;"> 
8045     
8046     
8047     
8048      <p><a name="surface_waterflux"></a><b>surface_waterflux</b></p>
8049
8050
8051
8052
8053      </td>
8054
8055
8056
8057 <td style="vertical-align: top;">R</td>
8058
8059
8060
8061
8062      <td style="vertical-align: top;"><i>0.0</i></td>
8063
8064
8065
8066
8067      <td style="vertical-align: top;"> 
8068     
8069     
8070     
8071      <p>Kinematic
8072water flux near the surface (in m/s).&nbsp; </p>
8073
8074
8075
8076 
8077     
8078     
8079     
8080      <p>If
8081a non-zero value is assigned to this parameter, the
8082respective water flux value is used
8083as bottom (horizontally homogeneous) boundary condition for the
8084humidity equation. This additionally requires that a Neumann
8085condition must be used for the specific humidity / total water content
8086(see <a href="#bc_q_b">bc_q_b</a>),
8087because otherwise the resolved scale may contribute to
8088the surface flux so that a constant value cannot be guaranteed. Also,
8089changes of the
8090surface humidity (see <a href="#q_surface_initial_change">q_surface_initial_change</a>)
8091are not allowed.<br>
8092
8093
8094
8095 </p>
8096
8097
8098
8099 
8100     
8101     
8102     
8103      <p>If no surface water
8104flux is assigned (<b>surface_waterflux</b>
8105= <i>0.0</i>),
8106it is calculated at each timestep by u<sub>*</sub> * q<sub>*</sub>
8107(of course only with Prandtl layer switched on). Here, q<sub>*</sub>
8108is calculated from the Prandtl law assuming a logarithmic temperature
8109profile between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_q_b">bc_q_b</a>)
8110must be used as the bottom boundary condition for the humidity.</p>
8111
8112
8113
8114
8115      </td>
8116
8117
8118
8119 </tr>
8120
8121
8122
8123 <tr>
8124
8125
8126
8127 <td style="vertical-align: top;"> 
8128     
8129     
8130     
8131      <p><a name="s_surface"></a><b>s_surface</b></p>
8132
8133
8134
8135
8136      </td>
8137
8138
8139
8140 <td style="vertical-align: top;">R</td>
8141
8142
8143
8144
8145      <td style="vertical-align: top;"><i>0.0</i></td>
8146
8147
8148
8149
8150      <td style="vertical-align: top;"> 
8151     
8152     
8153     
8154      <p>Surface value
8155of the passive scalar (in kg/m<sup>3</sup>).&nbsp;<br>
8156
8157
8158
8159
8160      </p>
8161
8162
8163
8164
8165This parameter assigns the value of the passive scalar s at
8166the surface (k=0)<b>.</b> Starting from this value, the
8167initial vertical scalar concentration profile is constructed with<a href="#s_vertical_gradient">
8168s_vertical_gradient</a> and <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>.</td>
8169
8170
8171
8172
8173    </tr>
8174
8175
8176
8177 <tr>
8178
8179
8180
8181 <td style="vertical-align: top;">
8182     
8183     
8184     
8185      <p><a name="s_surface_initial_change"></a><b>s_surface_initial</b>
8186      <br>
8187
8188
8189
8190 <b>_change</b></p>
8191
8192
8193
8194 </td>
8195
8196
8197
8198 <td style="vertical-align: top;">R</td>
8199
8200
8201
8202 <td style="vertical-align: top;"><i>0.0</i></td>
8203
8204
8205
8206
8207      <td style="vertical-align: top;"> 
8208     
8209     
8210     
8211      <p>Change in
8212surface scalar concentration to be made at the
8213beginning of the 3d run (in kg/m<sup>3</sup>).&nbsp; </p>
8214
8215
8216
8217
8218     
8219     
8220     
8221      <p>If <b>s_surface_initial_change</b><i>&nbsp;</i>is
8222set to a
8223non-zero
8224value, the near surface scalar flux is not allowed to be given
8225simultaneously (see <a href="#surface_scalarflux">surface_scalarflux</a>).</p>
8226
8227
8228
8229
8230      </td>
8231
8232
8233
8234 </tr>
8235
8236
8237
8238 <tr>
8239
8240
8241
8242 <td style="vertical-align: top;"> 
8243     
8244     
8245     
8246      <p><a name="s_vertical_gradient"></a><b>s_vertical_gradient</b></p>
8247
8248
8249
8250
8251      </td>
8252
8253
8254
8255 <td style="vertical-align: top;">R (10)</td>
8256
8257
8258
8259
8260      <td style="vertical-align: top;"><i>10 * 0</i><i>.0</i></td>
8261
8262
8263
8264
8265      <td style="vertical-align: top;"> 
8266     
8267     
8268     
8269      <p>Scalar
8270concentration gradient(s) of the initial scalar
8271concentration profile (in kg/m<sup>3 </sup>/
8272100 m).&nbsp; </p>
8273
8274
8275
8276 
8277     
8278     
8279     
8280      <p>The scalar gradient holds
8281starting from the height level
8282defined by <a href="#s_vertical_gradient_level">s_vertical_gradient_level
8283      </a>(precisely: for all uv levels k, where zu(k) &gt;
8284s_vertical_gradient_level, s_init(k) is set: s_init(k) = s_init(k-1) +
8285dzu(k) * <b>s_vertical_gradient</b>) up to the top
8286boundary or up to
8287the next height level defined by <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>.
8288A total of 10 different gradients for 11 height intervals (10 intervals
8289if <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>(1)
8290= <i>0.0</i>) can be assigned. The surface scalar value is
8291assigned
8292via <a href="#s_surface">s_surface</a>.<br>
8293
8294
8295
8296 </p>
8297
8298
8299
8300
8301     
8302     
8303     
8304      <p>Example:&nbsp; </p>
8305
8306
8307
8308 
8309     
8310     
8311     
8312      <ul>
8313
8314
8315
8316 
8317       
8318       
8319       
8320        <p><b>s_vertical_gradient</b>
8321= <i>0.1</i>, <i>0.05</i>,&nbsp; <br>
8322
8323
8324
8325
8326        <b>s_vertical_gradient_level</b> = <i>500.0</i>,
8327        <i>1000.0</i>,</p>
8328
8329
8330
8331 
8332     
8333     
8334     
8335      </ul>
8336
8337
8338
8339 
8340     
8341     
8342     
8343      <p>That
8344defines the scalar concentration to be constant with
8345height up to z = 500.0 m with a value given by <a href="#s_surface">s_surface</a>.
8346For 500.0 m &lt; z &lt;= 1000.0 m the scalar gradient is 0.1
8347kg/m<sup>3 </sup>/ 100 m and for z &gt; 1000.0 m up to
8348the top
8349boundary it is 0.05 kg/m<sup>3 </sup>/ 100 m (it is
8350assumed that the
8351assigned height levels
8352correspond with uv
8353levels).</p>
8354
8355
8356
8357 </td>
8358
8359
8360
8361 </tr>
8362
8363
8364
8365 <tr>
8366
8367
8368
8369 <td style="vertical-align: top;"> 
8370     
8371     
8372     
8373      <p><a name="s_vertical_gradient_level"></a><b>s_vertical_gradient_</b>
8374      <br>
8375
8376
8377
8378 <b>level</b></p>
8379
8380
8381
8382 </td>
8383
8384
8385
8386 <td style="vertical-align: top;">R (10)</td>
8387
8388
8389
8390 <td style="vertical-align: top;"> 
8391     
8392     
8393     
8394      <p><i>10 *</i>
8395      <i>0.0</i></p>
8396
8397
8398
8399 </td>
8400
8401
8402
8403 <td style="vertical-align: top;"> 
8404     
8405     
8406     
8407      <p>Height level from
8408which on the scalar gradient defined by <a href="#s_vertical_gradient">s_vertical_gradient</a>
8409is effective (in m).&nbsp; </p>
8410
8411
8412
8413 
8414     
8415     
8416     
8417      <p>The height levels
8418are to be assigned in ascending order. The
8419default values result in a scalar concentration constant with height
8420regardless of the values of <a href="#s_vertical_gradient">s_vertical_gradient</a>
8421(unless the top boundary of the model is higher than 100000.0 m). For
8422the
8423piecewise construction of scalar concentration profiles see <a href="#s_vertical_gradient">s_vertical_gradient</a>.</p>
8424
8425
8426
8427
8428      </td>
8429
8430
8431
8432 </tr>
8433
8434
8435
8436 <tr>
8437
8438
8439
8440 <td style="vertical-align: top;"> 
8441     
8442     
8443     
8444      <p><a name="timestep_scheme"></a><b>timestep_scheme</b></p>
8445
8446
8447
8448
8449      </td>
8450
8451
8452
8453 <td style="vertical-align: top;">C * 20</td>
8454
8455
8456
8457
8458      <td style="vertical-align: top;"> 
8459     
8460     
8461     
8462      <p><i>'runge</i><br>
8463
8464
8465
8466
8467      <i>kutta-3'</i></p>
8468
8469
8470
8471 </td>
8472
8473
8474
8475 <td style="vertical-align: top;"> 
8476     
8477     
8478     
8479      <p>Time step scheme to
8480be used for the integration of the prognostic
8481variables.&nbsp; </p>
8482
8483
8484
8485 
8486     
8487     
8488     
8489      <p>The user can choose between
8490the following schemes:<br>
8491
8492
8493
8494 </p>
8495
8496
8497
8498 
8499     
8500     
8501     
8502      <p><span style="font-style: italic;">'runge-kutta-3'</span><br>
8503
8504
8505
8506
8507      </p>
8508
8509
8510
8511 
8512     
8513     
8514     
8515      <div style="margin-left: 40px;">Third order
8516Runge-Kutta scheme.<br>
8517
8518
8519
8520
8521This scheme requires the use of <a href="#momentum_advec">momentum_advec</a>
8522= <a href="#scalar_advec">scalar_advec</a>
8523= '<i>pw-scheme'</i>. Please refer to the&nbsp;<a href="../tec/numerik.heiko/zeitschrittverfahren.pdf">documentation
8524on PALM's time integration schemes&nbsp;(28p., in German)</a>
8525fur further details.<br>
8526
8527
8528
8529 </div>
8530
8531
8532
8533 
8534     
8535     
8536     
8537      <p><span style="font-style: italic;">'runge-kutta-2'</span><br>
8538
8539
8540
8541
8542      </p>
8543
8544
8545
8546 
8547     
8548     
8549     
8550      <div style="margin-left: 40px;">Second order
8551Runge-Kutta scheme.<br>
8552
8553
8554
8555
8556For special features see <b>timestep_scheme</b> = '<i>runge-kutta-3'</i>.<br>
8557
8558
8559
8560
8561      </div>
8562
8563
8564
8565 <br>
8566
8567
8568
8569 <span style="font-style: italic;"><span style="font-style: italic;">'leapfrog'</span><br>
8570
8571
8572
8573
8574      <br>
8575
8576
8577
8578 </span> 
8579     
8580     
8581     
8582      <div style="margin-left: 40px;">Second
8583order leapfrog scheme.<br>
8584
8585
8586
8587
8588Although this scheme requires a constant timestep (because it is
8589centered in time),&nbsp; is even applied in case of changes in
8590timestep. Therefore, only small
8591changes of the timestep are allowed (see <a href="#dt">dt</a>).
8592However, an Euler timestep is always used as the first timestep of an
8593initiali run. When using the Bott-Chlond scheme for scalar advection
8594(see <a href="#scalar_advec">scalar_advec</a>),
8595the prognostic equation for potential temperature will be calculated
8596with the Euler scheme, although the leapfrog scheme is switched
8597on.&nbsp; <br>
8598
8599
8600
8601
8602The leapfrog scheme must not be used together with the upstream-spline
8603scheme for calculating the advection (see <a href="#scalar_advec">scalar_advec</a>
8604= '<i>ups-scheme'</i> and <a href="#momentum_advec">momentum_advec</a>
8605= '<i>ups-scheme'</i>).<br>
8606
8607
8608
8609 </div>
8610
8611
8612
8613 <br>
8614
8615
8616
8617
8618      <span style="font-style: italic;">'</span><span style="font-style: italic;"><span style="font-style: italic;">leapfrog+euler'</span><br>
8619
8620
8621
8622
8623      <br>
8624
8625
8626
8627 </span> 
8628     
8629     
8630     
8631      <div style="margin-left: 40px;">The
8632leapfrog scheme is used, but
8633after each change of a timestep an Euler timestep is carried out.
8634Although this method is theoretically correct (because the pure
8635leapfrog method does not allow timestep changes), the divergence of the
8636velocity field (after applying the pressure solver) may be
8637significantly larger than with <span style="font-style: italic;">'leapfrog'</span>.<br>
8638
8639
8640
8641
8642      </div>
8643
8644
8645
8646 <br>
8647
8648
8649
8650 <span style="font-style: italic;">'euler'</span><br>
8651
8652
8653
8654
8655      <br>
8656
8657
8658
8659 
8660     
8661     
8662     
8663      <div style="margin-left: 40px;">First order
8664Euler scheme.&nbsp; <br>
8665
8666
8667
8668
8669The Euler scheme must be used when treating the advection terms with
8670the upstream-spline scheme (see <a href="#scalar_advec">scalar_advec</a>
8671= <span style="font-style: italic;">'ups-scheme'</span>
8672and <a href="#momentum_advec">momentum_advec</a>
8673= <span style="font-style: italic;">'ups-scheme'</span>).</div>
8674
8675
8676
8677
8678      <br>
8679
8680
8681
8682      <br>
8683
8684
8685
8686A differing timestep scheme can be choosed for the
8687subgrid-scale TKE using parameter <a href="#use_upstream_for_tke">use_upstream_for_tke</a>.<br>
8688
8689
8690
8691
8692      </td>
8693
8694
8695
8696 </tr>
8697
8698
8699
8700 <tr>
8701
8702
8703
8704 <td style="text-align: left; vertical-align: top;"><span style="font-weight: bold;"><a name="topography"></a></span><span style="font-weight: bold;">topography</span></td>
8705
8706
8707
8708
8709      <td style="vertical-align: top;">C * 40</td>
8710
8711
8712
8713 <td style="vertical-align: top;"><span style="font-style: italic;">'flat'</span></td>
8714
8715
8716
8717 <td>
8718     
8719     
8720     
8721      <p>Topography mode.&nbsp; </p>
8722
8723
8724
8725 
8726     
8727     
8728     
8729      <p>The user can
8730choose between the following modes:<br>
8731
8732
8733
8734 </p>
8735
8736
8737
8738 
8739     
8740     
8741     
8742      <p><span style="font-style: italic;">'flat'</span><br>
8743
8744
8745
8746 </p>
8747
8748
8749
8750
8751     
8752     
8753     
8754      <div style="margin-left: 40px;">Flat surface.</div>
8755
8756
8757
8758 
8759     
8760     
8761     
8762      <p><span style="font-style: italic;">'single_building'</span><br>
8763
8764
8765
8766
8767      </p>
8768
8769
8770
8771 
8772     
8773     
8774     
8775      <div style="margin-left: 40px;">Flow
8776around&nbsp;a single rectangular building mounted on a flat surface.<br>
8777
8778
8779
8780
8781The building size and location can be specified with the parameters <a href="#building_height">building_height</a>, <a href="#building_length_x">building_length_x</a>, <a href="#building_length_y">building_length_y</a>, <a href="#building_wall_left">building_wall_left</a> and <a href="#building_wall_south">building_wall_south</a>.</div>
8782
8783
8784
8785
8786      <span style="font-style: italic;"></span> 
8787     
8788     
8789     
8790      <p><span style="font-style: italic;">'read_from_file'</span><br>
8791
8792
8793
8794
8795      </p>
8796
8797
8798
8799 
8800     
8801     
8802     
8803      <div style="margin-left: 40px;">Flow around
8804arbitrary topography.<br>
8805
8806
8807
8808
8809This mode requires the input file <a href="chapter_3.4.html#TOPOGRAPHY_DATA">TOPOGRAPHY_DATA</a><font color="#000000">. This file contains </font><font color="#000000"><font color="#000000">the&nbsp;</font></font><font color="#000000">arbitrary topography </font><font color="#000000"><font color="#000000">height
8810information</font></font><font color="#000000">
8811in m. These data&nbsp;<span style="font-style: italic;"></span>must
8812exactly match the horizontal grid.</font> </div>
8813
8814
8815
8816 <span style="font-style: italic;"><br>
8817
8818
8819
8820 </span><font color="#000000">
8821Alternatively, the user may add code to the user interface subroutine <a href="chapter_3.5.1.html#user_init_grid">user_init_grid</a>
8822to allow further topography modes.<br>
8823
8824
8825
8826 <br>
8827
8828
8829
8830
8831All non-flat <span style="font-weight: bold;">topography</span>
8832modes </font>require the use of <a href="#momentum_advec">momentum_advec</a>
8833= <a href="#scalar_advec">scalar_advec</a>
8834= '<i>pw-scheme'</i>, <a href="chapter_4.2.html#psolver">psolver</a>
8835= <i>'poisfft'</i> or '<i>poisfft_hybrid'</i>,
8836      <i>&nbsp;</i><a href="#alpha_surface">alpha_surface</a>
8837= 0.0, <a href="#bc_lr">bc_lr</a> = <a href="#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>,&nbsp;<a style="" href="#galilei_transformation">galilei_transformation</a>
8838= <span style="font-style: italic;">.F.</span>,&nbsp;<a href="#cloud_physics">cloud_physics&nbsp;</a> = <span style="font-style: italic;">.F.</span>,&nbsp; <a href="#cloud_droplets">cloud_droplets</a> = <span style="font-style: italic;">.F.</span>,&nbsp;&nbsp;<a href="#humidity">humidity</a> = <span style="font-style: italic;">.F.</span>, and <a href="#prandtl_layer">prandtl_layer</a> = .T..<br>
8839
8840
8841
8842
8843      <font color="#000000"><br>
8844
8845
8846
8847
8848Note that an inclined model domain requires the use of <span style="font-weight: bold;">topography</span> = <span style="font-style: italic;">'flat'</span> and a
8849nonzero </font><a href="#alpha_surface">alpha_surface</a>.</td>
8850
8851
8852
8853
8854    </tr>
8855
8856
8857
8858 <tr>
8859
8860
8861
8862      <td style="vertical-align: top;"><a name="top_heatflux"></a><span style="font-weight: bold;">top_heatflux</span></td>
8863
8864
8865
8866      <td style="vertical-align: top;">R</td>
8867
8868
8869
8870      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br>
8871
8872
8873
8874
8875heatflux</span></td>
8876
8877
8878
8879      <td style="vertical-align: top;">
8880     
8881     
8882     
8883      <p>Kinematic
8884sensible heat flux at the top boundary (in K m/s).&nbsp; </p>
8885
8886
8887
8888
8889     
8890     
8891     
8892      <p>If a value is assigned to this parameter, the internal
8893two-dimensional surface heat flux field <span style="font-family: monospace;">tswst</span> is
8894initialized with the value of <span style="font-weight: bold;">top_heatflux</span>&nbsp;as
8895top (horizontally homogeneous) boundary condition for the
8896temperature equation. This additionally requires that a Neumann
8897condition must be used for the potential temperature (see <a href="chapter_4.1.html#bc_pt_t">bc_pt_t</a>),
8898because otherwise the resolved scale may contribute to
8899the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span>&nbsp;</p>
8900
8901
8902
8903
8904     
8905     
8906     
8907      <p><span style="font-weight: bold;">Note:</span><br>
8908
8909
8910
8911The
8912application of a top heat flux additionally requires the setting of
8913initial parameter <a href="#use_top_fluxes">use_top_fluxes</a>
8914= .T..<span style="font-style: italic;"></span><span style="font-weight: bold;"></span> </p>
8915
8916
8917
8918     
8919     
8920     
8921      <p>No
8922Prandtl-layer is available at the top boundary so far.</p>
8923
8924
8925
8926     
8927     
8928     
8929      <p>See
8930also <a href="#surface_heatflux">surface_heatflux</a>.</p>
8931
8932
8933
8934
8935      </td>
8936
8937
8938
8939    </tr>
8940
8941
8942
8943    <tr>
8944
8945
8946
8947      <td style="vertical-align: top;"><a name="top_momentumflux_u"></a><span style="font-weight: bold;">top_momentumflux_u</span></td>
8948
8949
8950
8951      <td style="vertical-align: top;">R</td>
8952
8953
8954
8955      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed momentumflux</span></td>
8956
8957
8958
8959      <td style="vertical-align: top;">Momentum flux along x at the top boundary (in m2/s2).<br>
8960
8961
8962
8963     
8964     
8965     
8966      <p>If a value is assigned to this parameter, the internal
8967two-dimensional u-momentum flux field <span style="font-family: monospace;">uswst</span> is
8968initialized with the value of <span style="font-weight: bold;">top_momentumflux_u</span> as
8969top (horizontally homogeneous) boundary condition for the u-momentum equation.</p>
8970
8971
8972
8973     
8974     
8975     
8976      <p><span style="font-weight: bold;">Notes:</span><br>
8977
8978
8979
8980The
8981application of a top momentum flux additionally requires the setting of
8982initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a>
8983= .T.. Setting of <span style="font-weight: bold;">top_momentumflux_u</span> requires setting of <a href="#top_momentumflux_v">top_momentumflux_v</a> also.</p>
8984
8985
8986
8987     
8988     
8989     
8990      <p>A&nbsp;Neumann
8991condition should be used for the u velocity component (see <a href="chapter_4.1.html#bc_uv_t">bc_uv_t</a>),
8992because otherwise the resolved scale may contribute to
8993the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span>&nbsp;</p>
8994
8995
8996
8997
8998      <span style="font-weight: bold;"></span>
8999     
9000     
9001     
9002      <p>No
9003Prandtl-layer is available at the top boundary so far.</p>
9004
9005
9006
9007     
9008     
9009     
9010      <p> The <a href="chapter_3.8.html">coupled</a> ocean parameter file&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a> should include dummy REAL value assignments to both <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> and&nbsp;<a href="chapter_4.1.html#top_momentumflux_v">top_momentumflux_v</a> (e.g.&nbsp;top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to enable the momentum flux coupling.</p>
9011
9012
9013
9014      </td>
9015
9016
9017
9018    </tr>
9019
9020
9021
9022    <tr>
9023
9024
9025
9026      <td style="vertical-align: top;"><a name="top_momentumflux_v"></a><span style="font-weight: bold;">top_momentumflux_v</span></td>
9027
9028
9029
9030      <td style="vertical-align: top;">R</td>
9031
9032
9033
9034      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed momentumflux</span></td>
9035
9036
9037
9038      <td style="vertical-align: top;">Momentum flux along y at the top boundary (in m2/s2).<br>
9039
9040
9041
9042     
9043     
9044     
9045      <p>If a value is assigned to this parameter, the internal
9046two-dimensional v-momentum flux field <span style="font-family: monospace;">vswst</span> is
9047initialized with the value of <span style="font-weight: bold;">top_momentumflux_v</span> as
9048top (horizontally homogeneous) boundary condition for the v-momentum equation.</p>
9049
9050
9051
9052     
9053     
9054     
9055      <p><span style="font-weight: bold;">Notes:</span><br>
9056
9057
9058
9059The
9060application of a top momentum flux additionally requires the setting of
9061initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a>
9062= .T.. Setting of <span style="font-weight: bold;">top_momentumflux_v</span> requires setting of <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> also.</p>
9063
9064
9065
9066     
9067     
9068     
9069      <p>A&nbsp;Neumann
9070condition should be used for the v velocity component (see <a href="chapter_4.1.html#bc_uv_t">bc_uv_t</a>),
9071because otherwise the resolved scale may contribute to
9072the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span>&nbsp;</p>
9073
9074
9075
9076
9077      <span style="font-weight: bold;"></span>
9078     
9079     
9080     
9081      <p>No
9082Prandtl-layer is available at the top boundary so far.</p>
9083
9084
9085
9086     
9087     
9088     
9089      <p> The <a href="chapter_3.8.html">coupled</a> ocean parameter file&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a> should include dummy REAL value assignments to both <a href="chapter_4.1.html#top_momentumflux_u">top_momentumflux_u</a> and&nbsp;<a href="chapter_4.1.html#top_momentumflux_v">top_momentumflux_v</a> (e.g.&nbsp;top_momentumflux_u = 0.0, top_momentumflux_v = 0.0) to enable the momentum flux coupling.</p>
9090
9091
9092
9093      </td>
9094
9095
9096
9097    </tr>
9098
9099
9100
9101    <tr>
9102
9103
9104
9105      <td style="vertical-align: top;"><a name="top_salinityflux"></a><span style="font-weight: bold;">top_salinityflux</span></td>
9106
9107
9108
9109      <td style="vertical-align: top;">R</td>
9110
9111
9112
9113      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br>
9114
9115
9116
9117
9118salinityflux</span></td>
9119
9120
9121
9122      <td style="vertical-align: top;">
9123     
9124     
9125     
9126      <p>Kinematic
9127salinity flux at the top boundary, i.e. the sea surface (in psu m/s).&nbsp; </p>
9128
9129
9130
9131
9132     
9133     
9134     
9135      <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p>
9136
9137
9138
9139     
9140     
9141     
9142      <p>If a value is assigned to this parameter, the internal
9143two-dimensional surface heat flux field <span style="font-family: monospace;">saswst</span> is
9144initialized with the value of <span style="font-weight: bold;">top_salinityflux</span>&nbsp;as
9145top (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
9146condition must be used for the salinity (see <a href="chapter_4.1.html#bc_sa_t">bc_sa_t</a>),
9147because otherwise the resolved scale may contribute to
9148the top flux so that a constant flux value cannot be guaranteed.<span style="font-style: italic;"></span>&nbsp;</p>
9149
9150
9151
9152
9153     
9154     
9155     
9156      <p><span style="font-weight: bold;">Note:</span><br>
9157
9158
9159
9160The
9161application of a salinity flux at the model top additionally requires the setting of
9162initial parameter <a href="chapter_4.1.html#use_top_fluxes">use_top_fluxes</a>
9163= .T..<span style="font-style: italic;"></span><span style="font-weight: bold;"></span> </p>
9164
9165
9166
9167     
9168     
9169     
9170      <p>See
9171also <a href="chapter_4.1.html#bottom_salinityflux">bottom_salinityflux</a>.</p>
9172
9173
9174
9175      </td>
9176
9177
9178
9179    </tr>
9180
9181
9182
9183    <tr>
9184
9185
9186
9187 <td style="vertical-align: top;">
9188     
9189     
9190     
9191      <p><a name="ug_surface"></a><span style="font-weight: bold;">ug_surface</span></p>
9192
9193
9194
9195
9196      </td>
9197
9198
9199
9200 <td style="vertical-align: top;">R<br>
9201
9202
9203
9204 </td>
9205
9206
9207
9208
9209      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
9210
9211
9212
9213 </td>
9214
9215
9216
9217
9218      <td style="vertical-align: top;">u-component of the
9219geostrophic
9220wind at the surface (in m/s).<br>
9221
9222
9223
9224 <br>
9225
9226
9227
9228
9229This parameter assigns the value of the u-component of the geostrophic
9230wind (ug) at the surface (k=0). Starting from this value, the initial
9231vertical profile of the <br>
9232
9233
9234
9235
9236u-component of the geostrophic wind is constructed with <a href="#ug_vertical_gradient">ug_vertical_gradient</a>
9237and <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>.
9238The
9239profile constructed in that way is used for creating the initial
9240vertical velocity profile of the 3d-model. Either it is applied, as it
9241has been specified by the user (<a href="#initializing_actions">initializing_actions</a>
9242= 'set_constant_profiles') or it is used for calculating a stationary
9243boundary layer wind profile (<a href="#initializing_actions">initializing_actions</a>
9244= 'set_1d-model_profiles'). If ug is constant with height (i.e. ug(k)=<span style="font-weight: bold;">ug_surface</span>)
9245and&nbsp; has a large
9246value, it is recommended to use a Galilei-transformation of the
9247coordinate system, if possible (see <a href="#galilei_transformation">galilei_transformation</a>),
9248in order to obtain larger time steps.<br>
9249
9250
9251
9252      <br>
9253
9254
9255
9256      <span style="font-weight: bold;">Attention:</span><br>
9257
9258
9259
9260In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>),
9261this parameter gives the geostrophic velocity value (i.e. the pressure gradient) at the sea surface, which is
9262at k=nzt. The profile is then constructed from the surface down to the
9263bottom of the model.<br>
9264
9265
9266
9267 </td>
9268
9269
9270
9271 </tr>
9272
9273
9274
9275
9276    <tr>
9277
9278
9279
9280 <td style="vertical-align: top;"> 
9281     
9282     
9283     
9284      <p><a name="ug_vertical_gradient"></a><span style="font-weight: bold;">ug_vertical_gradient</span></p>
9285
9286
9287
9288
9289      </td>
9290
9291
9292
9293 <td style="vertical-align: top;">R(10)<br>
9294
9295
9296
9297
9298      </td>
9299
9300
9301
9302 <td style="vertical-align: top;"><span style="font-style: italic;">10
9303* 0.0</span><br>
9304
9305
9306
9307 </td>
9308
9309
9310
9311 <td style="vertical-align: top;">Gradient(s) of the initial
9312profile of the&nbsp; u-component of the geostrophic wind (in
93131/100s).<br>
9314
9315
9316
9317 <br>
9318
9319
9320
9321
9322The gradient holds starting from the height level defined by <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>
9323(precisely: for all uv levels k where zu(k) &gt; <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>,
9324ug(k) is set: ug(k) = ug(k-1) + dzu(k) * <span style="font-weight: bold;">ug_vertical_gradient</span>)
9325up to the top
9326boundary or up to the next height level defined by <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>.
9327A
9328total of 10 different gradients for 11 height intervals (10
9329intervals&nbsp; if <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>(1)
9330= 0.0) can be assigned. The surface geostrophic wind is assigned by <a href="#ug_surface">ug_surface</a>.<br>
9331
9332
9333
9334      <br>
9335
9336
9337
9338      <span style="font-weight: bold;">Attention:</span><br>
9339
9340
9341
9342In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>),
9343the profile is constructed like described above, but starting from the
9344sea surface (k=nzt) down to the bottom boundary of the model. Height
9345levels have then to be given as negative values, e.g. <span style="font-weight: bold;">ug_vertical_gradient_level</span> = <span style="font-style: italic;">-500.0</span>, <span style="font-style: italic;">-1000.0</span>.<br>
9346
9347
9348
9349 </td>
9350
9351
9352
9353
9354    </tr>
9355
9356
9357
9358 <tr>
9359
9360
9361
9362 <td style="vertical-align: top;">
9363     
9364     
9365     
9366      <p><a name="ug_vertical_gradient_level"></a><span style="font-weight: bold;">ug_vertical_gradient_level</span></p>
9367
9368
9369
9370
9371      </td>
9372
9373
9374
9375 <td style="vertical-align: top;">R(10)<br>
9376
9377
9378
9379
9380      </td>
9381
9382
9383
9384 <td style="vertical-align: top;"><span style="font-style: italic;">10
9385* 0.0</span><br>
9386
9387
9388
9389 </td>
9390
9391
9392
9393 <td style="vertical-align: top;">Height level from which on the
9394gradient defined by <a href="#ug_vertical_gradient">ug_vertical_gradient</a>
9395is effective (in m).<br>
9396
9397
9398
9399 <br>
9400
9401
9402
9403
9404The height levels have to be assigned in ascending order. For the
9405piecewise construction of a profile of the u-component of the
9406geostrophic wind component (ug) see <a href="#ug_vertical_gradient">ug_vertical_gradient</a>.<br>
9407
9408
9409
9410      <br>
9411
9412
9413
9414      <span style="font-weight: bold;">Attention:</span><br>
9415
9416
9417
9418In case of ocean runs&nbsp;(see <a href="chapter_4.1.html#ocean">ocean</a>), the (negative) height levels have to be assigned in descending order.</td>
9419
9420
9421
9422 </tr>
9423
9424
9425
9426 <tr>
9427
9428
9429
9430 <td style="vertical-align: top;"> 
9431     
9432     
9433     
9434      <p><a name="ups_limit_e"></a><b>ups_limit_e</b></p>
9435
9436
9437
9438
9439      </td>
9440
9441
9442
9443 <td style="vertical-align: top;">R</td>
9444
9445
9446
9447
9448      <td style="vertical-align: top;"><i>0.0</i></td>
9449
9450
9451
9452
9453      <td style="vertical-align: top;"> 
9454     
9455     
9456     
9457      <p>Subgrid-scale
9458turbulent kinetic energy difference used as
9459criterion for applying the upstream scheme when upstream-spline
9460advection is switched on (in m<sup>2</sup>/s<sup>2</sup>).
9461&nbsp; </p>
9462
9463
9464
9465 
9466     
9467     
9468     
9469      <p>This variable steers the appropriate
9470treatment of the
9471advection of the subgrid-scale turbulent kinetic energy in case that
9472the uptream-spline scheme is used . For further information see <a href="#ups_limit_pt">ups_limit_pt</a>.&nbsp; </p>
9473
9474
9475
9476
9477     
9478     
9479     
9480      <p>Only positive values are allowed for <b>ups_limit_e</b>.
9481      </p>
9482
9483
9484
9485 </td>
9486
9487
9488
9489 </tr>
9490
9491
9492
9493 <tr>
9494
9495
9496
9497 <td style="vertical-align: top;"> 
9498     
9499     
9500     
9501      <p><a name="ups_limit_pt"></a><b>ups_limit_pt</b></p>
9502
9503
9504
9505
9506      </td>
9507
9508
9509
9510 <td style="vertical-align: top;">R</td>
9511
9512
9513
9514
9515      <td style="vertical-align: top;"><i>0.0</i></td>
9516
9517
9518
9519
9520      <td style="vertical-align: top;"> 
9521     
9522     
9523     
9524      <p>Temperature
9525difference used as criterion for applying&nbsp;
9526the upstream scheme when upstream-spline advection&nbsp; is
9527switched on
9528(in K).&nbsp; </p>
9529
9530
9531
9532 
9533     
9534     
9535     
9536      <p>This criterion is used if the
9537upstream-spline scheme is
9538switched on (see <a href="#scalar_advec">scalar_advec</a>).<br>
9539
9540
9541
9542
9543If, for a given gridpoint, the absolute temperature difference with
9544respect to the upstream
9545grid point is smaller than the value given for <b>ups_limit_pt</b>,
9546the upstream scheme is used for this gridpoint (by default, the
9547upstream-spline scheme is always used). Reason: in case of a very small
9548upstream gradient, the advection should cause only a very small
9549tendency. However, in such situations the upstream-spline scheme may
9550give wrong tendencies at a
9551grid point due to spline overshooting, if simultaneously the downstream
9552gradient is very large. In such cases it may be more reasonable to use
9553the upstream scheme. The numerical diffusion caused by the upstream
9554schme remains small as long as the upstream gradients are small.<br>
9555
9556
9557
9558
9559      </p>
9560
9561
9562
9563 
9564     
9565     
9566     
9567      <p>The percentage of grid points for which the
9568upstream
9569scheme is actually used, can be output as a time series with respect to
9570the
9571three directions in space with run parameter (see <a href="chapter_4.2.html#dt_dots">dt_dots</a>, the
9572timeseries names in the NetCDF file are <i>'splptx'</i>, <i>'splpty'</i>,
9573      <i>'splptz'</i>). The percentage
9574of gridpoints&nbsp; should stay below a certain limit, however, it
9575is
9576not possible to give
9577a general limit, since it depends on the respective flow.&nbsp; </p>
9578
9579
9580
9581
9582     
9583     
9584     
9585      <p>Only positive values are permitted for <b>ups_limit_pt</b>.<br>
9586
9587
9588
9589
9590      </p>
9591
9592
9593
9594
9595A more effective control of
9596the &ldquo;overshoots&rdquo; can be achieved with parameter <a href="#cut_spline_overshoot">cut_spline_overshoot</a>.
9597      </td>
9598
9599
9600
9601 </tr>
9602
9603
9604
9605 <tr>
9606
9607
9608
9609 <td style="vertical-align: top;"> 
9610     
9611     
9612     
9613      <p><a name="ups_limit_u"></a><b>ups_limit_u</b></p>
9614
9615
9616
9617
9618      </td>
9619
9620
9621
9622 <td style="vertical-align: top;">R</td>
9623
9624
9625
9626
9627      <td style="vertical-align: top;"><i>0.0</i></td>
9628
9629
9630
9631
9632      <td style="vertical-align: top;"> 
9633     
9634     
9635     
9636      <p>Velocity
9637difference (u-component) used as criterion for
9638applying the upstream scheme
9639when upstream-spline advection is switched on (in m/s).&nbsp; </p>
9640
9641
9642
9643
9644     
9645     
9646     
9647      <p>This variable steers the appropriate treatment of the
9648advection of the u-velocity-component in case that the upstream-spline
9649scheme is used. For further
9650information see <a href="#ups_limit_pt">ups_limit_pt</a>.&nbsp;
9651      </p>
9652
9653
9654
9655 
9656     
9657     
9658     
9659      <p>Only positive values are permitted for <b>ups_limit_u</b>.</p>
9660
9661
9662
9663
9664      </td>
9665
9666
9667
9668 </tr>
9669
9670
9671
9672 <tr>
9673
9674
9675
9676 <td style="vertical-align: top;"> 
9677     
9678     
9679     
9680      <p><a name="ups_limit_v"></a><b>ups_limit_v</b></p>
9681
9682
9683
9684
9685      </td>
9686
9687
9688
9689 <td style="vertical-align: top;">R</td>
9690
9691
9692
9693
9694      <td style="vertical-align: top;"><i>0.0</i></td>
9695
9696
9697
9698
9699      <td style="vertical-align: top;"> 
9700     
9701     
9702     
9703      <p>Velocity
9704difference (v-component) used as criterion for
9705applying the upstream scheme
9706when upstream-spline advection is switched on (in m/s).&nbsp; </p>
9707
9708
9709
9710
9711     
9712     
9713     
9714      <p>This variable steers the appropriate treatment of the
9715advection of the v-velocity-component in case that the upstream-spline
9716scheme is used. For further
9717information see <a href="#ups_limit_pt">ups_limit_pt</a>.&nbsp;
9718      </p>
9719
9720
9721
9722 
9723     
9724     
9725     
9726      <p>Only positive values are permitted for <b>ups_limit_v</b>.</p>
9727
9728
9729
9730
9731      </td>
9732
9733
9734
9735 </tr>
9736
9737
9738
9739 <tr>
9740
9741
9742
9743 <td style="vertical-align: top;"> 
9744     
9745     
9746     
9747      <p><a name="ups_limit_w"></a><b>ups_limit_w</b></p>
9748
9749
9750
9751
9752      </td>
9753
9754
9755
9756 <td style="vertical-align: top;">R</td>
9757
9758
9759
9760
9761      <td style="vertical-align: top;"><i>0.0</i></td>
9762
9763
9764
9765
9766      <td style="vertical-align: top;"> 
9767     
9768     
9769     
9770      <p>Velocity
9771difference (w-component) used as criterion for
9772applying the upstream scheme
9773when upstream-spline advection is switched on (in m/s).&nbsp; </p>
9774
9775
9776
9777
9778     
9779     
9780     
9781      <p>This variable steers the appropriate treatment of the
9782advection of the