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17  <title>PALM chapter 4.1</title></head>
18
19<body>
20
21
22
23<h3><a name="chapter4.1"></a>4.1
24Initialization parameters</h3>
25
26
27
28
29<br>
30
31
32
33<table style="text-align: left; width: 100%;" border="1" cellpadding="2" cellspacing="2">
34
35
36
37 <tbody>
38
39
40
41
42    <tr>
43
44
45
46 <td style="vertical-align: top;"><font size="4"><b>Parameter name</b></font></td>
47
48
49
50
51      <td style="vertical-align: top;"><font size="4"><b>Type</b></font></td>
52
53
54
55
56      <td style="vertical-align: top;"> 
57     
58     
59     
60      <p><b><font size="4">Default</font></b> <br>
61
62
63
64 <b><font size="4">value</font></b></p>
65
66
67
68 </td>
69
70
71
72
73      <td style="vertical-align: top;"><font size="4"><b>Explanation</b></font></td>
74
75
76
77
78    </tr>
79
80
81
82 <tr>
83
84
85
86 <td style="vertical-align: top;">
87     
88     
89     
90      <p><a name="adjust_mixing_length"></a><b>adjust_mixing_length</b></p>
91
92
93
94
95      </td>
96
97
98
99 <td style="vertical-align: top;">L</td>
100
101
102
103
104      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
105
106
107
108 <td style="vertical-align: top;"> 
109     
110     
111     
112      <p style="font-style: normal;">Near-surface adjustment of the
113mixing length to the Prandtl-layer law.&nbsp; </p>
114
115
116
117 
118     
119     
120     
121      <p>Usually
122the mixing length in LES models l<sub>LES</sub>
123depends (as in PALM) on the grid size and is possibly restricted
124further in case of stable stratification and near the lower wall (see
125parameter <a href="#wall_adjustment">wall_adjustment</a>).
126With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span>
127the Prandtl' mixing length l<sub>PR</sub> = kappa * z/phi
128is calculated
129and the mixing length actually used in the model is set l = MIN (l<sub>LES</sub>,
130l<sub>PR</sub>). This usually gives a decrease of the
131mixing length at
132the bottom boundary and considers the fact that eddy sizes
133decrease in the vicinity of the wall.&nbsp; </p>
134
135
136
137 
138     
139     
140     
141      <p style="font-style: normal;"><b>Warning:</b> So
142far, there is
143no good experience with <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> !&nbsp; </p>
144
145
146
147
148     
149     
150     
151      <p>With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> and the
152Prandtl-layer being
153switched on (see <a href="#prandtl_layer">prandtl_layer</a>)
154      <span style="font-style: italic;">'(u*)** 2+neumann'</span>
155should always be set as the lower boundary condition for the TKE (see <a href="#bc_e_b">bc_e_b</a>),
156otherwise the near-surface value of the TKE is not in agreement with
157the Prandtl-layer law (Prandtl-layer law and Prandtl-Kolmogorov-Ansatz
158should provide the same value for K<sub>m</sub>). A warning
159is given,
160if this is not the case.</p>
161
162
163
164 </td>
165
166
167
168 </tr>
169
170
171
172 <tr>
173
174
175
176
177      <td style="vertical-align: top;"> 
178     
179     
180     
181      <p><a name="alpha_surface"></a><b>alpha_surface</b></p>
182
183
184
185
186      </td>
187
188
189
190 <td style="vertical-align: top;">R<br>
191
192
193
194 </td>
195
196
197
198
199      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
200
201
202
203 </td>
204
205
206
207
208      <td style="vertical-align: top;"> 
209     
210     
211     
212      <p style="font-style: normal;">Inclination of the model domain
213with respect to the horizontal (in degrees).&nbsp; </p>
214
215
216
217 
218     
219     
220     
221      <p style="font-style: normal;">By means of <b>alpha_surface</b>
222the model domain can be inclined in x-direction with respect to the
223horizontal. In this way flows over inclined surfaces (e.g. drainage
224flows, gravity flows) can be simulated. In case of <b>alpha_surface
225      </b>/= <span style="font-style: italic;">0</span>
226the buoyancy term
227appears both in
228the equation of motion of the u-component and of the w-component.<br>
229
230
231
232
233      </p>
234
235
236
237 
238     
239     
240     
241      <p style="font-style: normal;">An inclination
242is only possible in
243case of cyclic horizontal boundary conditions along x AND y (see <a href="#bc_lr">bc_lr</a>
244and <a href="#bc_ns">bc_ns</a>) and <a href="#topography">topography</a> = <span style="font-style: italic;">'flat'</span>. </p>
245
246
247
248
249     
250     
251     
252      <p>Runs with inclined surface still require additional
253user-defined code as well as modifications to the default code. Please
254ask the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/PALM_group.html#0">PALM
255developer&nbsp; group</a>.</p>
256
257
258
259 </td>
260
261
262
263 </tr>
264
265
266
267
268    <tr>
269
270
271
272 <td style="vertical-align: top;"> 
273     
274     
275     
276      <p><a name="bc_e_b"></a><b>bc_e_b</b></p>
277
278
279
280 </td>
281
282
283
284
285      <td style="vertical-align: top;">C * 20</td>
286
287
288
289 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
290
291
292
293
294      <td style="vertical-align: top;"> 
295     
296     
297     
298      <p style="font-style: normal;">Bottom boundary condition of the
299TKE.&nbsp; </p>
300
301
302
303 
304     
305     
306     
307      <p><b>bc_e_b</b> may be
308set to&nbsp;<span style="font-style: italic;">'neumann'</span>
309or <span style="font-style: italic;">'(u*) ** 2+neumann'</span>.
310      <b>bc_e_b</b>
311= <span style="font-style: italic;">'neumann'</span>
312yields to
313e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is calculated
314via the prognostic TKE equation. Choice of <span style="font-style: italic;">'(u*)**2+neumann'</span>
315also yields to
316e(k=0)=e(k=1), but the TKE at the Prandtl-layer top (k=1) is calculated
317diagnostically by e(k=1)=(us/0.1)**2. However, this is only allowed if
318a Prandtl-layer is used (<a href="#prandtl_layer">prandtl_layer</a>).
319If this is not the case, a warning is given and <b>bc_e_b</b>
320is reset
321to <span style="font-style: italic;">'neumann'</span>.&nbsp;
322      </p>
323
324
325
326 
327     
328     
329     
330      <p style="font-style: normal;">At the top
331boundary a Neumann
332boundary condition is generally used: (e(nz+1) = e(nz)).</p>
333
334
335
336 </td>
337
338
339
340
341    </tr>
342
343
344
345 <tr>
346
347
348
349 <td style="vertical-align: top;">
350     
351     
352     
353      <p><a name="bc_lr"></a><b>bc_lr</b></p>
354
355
356
357
358      </td>
359
360
361
362 <td style="vertical-align: top;">C * 20</td>
363
364
365
366
367      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
368
369
370
371
372      <td style="vertical-align: top;">Boundary
373condition along x (for all quantities).<br>
374
375
376
377 <br>
378
379
380
381
382By default, a cyclic boundary condition is used along x.<br>
383
384
385
386 <br>
387
388
389
390
391      <span style="font-weight: bold;">bc_lr</span> may
392also be
393assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
394(inflow from left, outflow to the right) or <span style="font-style: italic;">'radiation/dirichlet'</span>
395(inflow from
396right, outflow to the left). This requires the multi-grid method to be
397used 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>)
398and it also requires cyclic boundary conditions along y (see&nbsp;<a href="#bc_ns">bc_ns</a>).<br>
399
400
401
402 <br>
403
404
405
406
407In case of these non-cyclic lateral boundaries, a Dirichlet condition
408is used at the inflow for all quantities (initial vertical profiles -
409see <a href="#initializing_actions">initializing_actions</a>
410- are fixed during the run) except u, to which a Neumann (zero
411gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
412gradient) condition is used for the scalars. For perturbation
413pressure Neumann (zero gradient) conditions are assumed both at the
414inflow and at the outflow.<br>
415
416
417
418 <br>
419
420
421
422
423When using non-cyclic lateral boundaries, a filter is applied to the
424velocity field in the vicinity of the outflow in order to suppress any
425reflections of outgoing disturbances (see <a href="#km_damp_max">km_damp_max</a>
426and <a href="#outflow_damping_width">outflow_damping_width</a>).<br>
427
428
429
430
431      <br>
432
433
434
435
436In order to maintain a turbulent state of the flow, it may be
437neccessary to continuously impose perturbations on the horizontal
438velocity field in the vicinity of the inflow throughout the whole run.
439This 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>.
440The horizontal range to which these perturbations are applied is
441controlled by the parameters <a href="#inflow_disturbance_begin">inflow_disturbance_begin</a>
442and <a href="#inflow_disturbance_end">inflow_disturbance_end</a>.
443The 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>,
444      <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_t</a>,
445and <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_amplitude</a>.
446The 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>
447
448
449
450
451      <br>
452
453
454
455
456In 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
457at_all_substeps</a> = .T. should be used.<br>
458
459
460
461 <br>
462
463
464
465 <span style="font-weight: bold;">Note:</span><br>
466
467
468
469
470Using non-cyclic lateral boundaries requires very sensitive adjustments
471of the inflow (vertical profiles) and the bottom boundary conditions,
472e.g. a surface heating should not be applied near the inflow boundary
473because this may significantly disturb the inflow. Please check the
474model results very carefully.</td>
475
476
477
478 </tr>
479
480
481
482 <tr>
483
484
485
486 <td style="vertical-align: top;"> 
487     
488     
489     
490      <p><a name="bc_ns"></a><b>bc_ns</b></p>
491
492
493
494
495      </td>
496
497
498
499 <td style="vertical-align: top;">C * 20</td>
500
501
502
503
504      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
505
506
507
508
509      <td style="vertical-align: top;">Boundary
510condition along y (for all quantities).<br>
511
512
513
514 <br>
515
516
517
518
519By default, a cyclic boundary condition is used along y.<br>
520
521
522
523 <br>
524
525
526
527
528      <span style="font-weight: bold;">bc_ns</span> may
529also be
530assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
531(inflow from rear ("north"), outflow to the front ("south")) or <span style="font-style: italic;">'radiation/dirichlet'</span>
532(inflow from front ("south"), outflow to the rear ("north")). This
533requires the multi-grid
534method to be used for solving the Poisson equation for perturbation
535pressure (see <a href="chapter_4.2.html#psolver">psolver</a>)
536and it also requires cyclic boundary conditions along x (see<br>
537
538
539
540 <a href="#bc_lr">bc_lr</a>).<br>
541
542
543
544 <br>
545
546
547
548
549In case of these non-cyclic lateral boundaries, a Dirichlet condition
550is used at the inflow for all quantities (initial vertical profiles -
551see <a href="chapter_4.1.html#initializing_actions">initializing_actions</a>
552- are fixed during the run) except u, to which a Neumann (zero
553gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
554gradient) condition is used for the scalars. For perturbation
555pressure Neumann (zero gradient) conditions are assumed both at the
556inflow and at the outflow.<br>
557
558
559
560 <br>
561
562
563
564
565For further details regarding non-cyclic lateral boundary conditions
566see <a href="#bc_lr">bc_lr</a>.</td>
567
568
569
570 </tr>
571
572
573
574
575    <tr>
576
577
578
579 <td style="vertical-align: top;"> 
580     
581     
582     
583      <p><a name="bc_p_b"></a><b>bc_p_b</b></p>
584
585
586
587 </td>
588
589
590
591
592      <td style="vertical-align: top;">C * 20</td>
593
594
595
596 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
597
598
599
600
601      <td style="vertical-align: top;"> 
602     
603     
604     
605      <p style="font-style: normal;">Bottom boundary condition of the
606perturbation pressure.&nbsp; </p>
607
608
609
610 
611     
612     
613     
614      <p>Allowed values
615are <span style="font-style: italic;">'dirichlet'</span>,
616      <span style="font-style: italic;">'neumann'</span>
617and <span style="font-style: italic;">'neumann+inhomo'</span>.&nbsp;
618      <span style="font-style: italic;">'dirichlet'</span>
619sets
620p(k=0)=0.0,&nbsp; <span style="font-style: italic;">'neumann'</span>
621sets p(k=0)=p(k=1). <span style="font-style: italic;">'neumann+inhomo'</span>
622corresponds to an extended Neumann boundary condition where heat flux
623or temperature inhomogeneities near the
624surface (pt(k=1))&nbsp; are additionally regarded (see Shen and
625LeClerc
626(1995, Q.J.R. Meteorol. Soc.,
6271209)). This condition is only permitted with the Prandtl-layer
628switched on (<a href="#prandtl_layer">prandtl_layer</a>),
629otherwise the run is terminated.&nbsp; </p>
630
631
632
633 
634     
635     
636     
637      <p>Since
638at the bottom boundary of the model the vertical
639velocity
640disappears (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>)
641dp/dz = 0 should
642be used, which leaves the vertical component w unchanged when the
643pressure solver is applied. Simultaneous use of the Neumann boundary
644conditions both at the bottom and at the top boundary (<a href="#bc_p_t">bc_p_t</a>)
645usually yields no consistent solution for the perturbation pressure and
646should be avoided.</p>
647
648
649
650 </td>
651
652
653
654 </tr>
655
656
657
658 <tr>
659
660
661
662 <td style="vertical-align: top;"> 
663     
664     
665     
666      <p><a name="bc_p_t"></a><b>bc_p_t</b></p>
667
668
669
670
671      </td>
672
673
674
675 <td style="vertical-align: top;">C * 20</td>
676
677
678
679
680      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
681
682
683
684
685      <td style="vertical-align: top;"> 
686     
687     
688     
689      <p style="font-style: normal;">Top boundary condition of the
690perturbation pressure.&nbsp; </p>
691
692
693
694 
695     
696     
697     
698      <p style="font-style: normal;">Allowed values are <span style="font-style: italic;">'dirichlet'</span>
699(p(k=nz+1)= 0.0) or <span style="font-style: italic;">'neumann'</span>
700(p(k=nz+1)=p(k=nz)).&nbsp; </p>
701
702
703
704 
705     
706     
707     
708      <p>Simultaneous use
709of Neumann boundary conditions both at the
710top and bottom boundary (<a href="#bc_p_b">bc_p_b</a>)
711usually yields no consistent solution for the perturbation pressure and
712should be avoided. Since at the bottom boundary the Neumann
713condition&nbsp; is a good choice (see <a href="#bc_p_b">bc_p_b</a>),
714a Dirichlet condition should be set at the top boundary.</p>
715
716
717
718 </td>
719
720
721
722
723    </tr>
724
725
726
727 <tr>
728
729
730
731 <td style="vertical-align: top;">
732     
733     
734     
735      <p><a name="bc_pt_b"></a><b>bc_pt_b</b></p>
736
737
738
739
740      </td>
741
742
743
744 <td style="vertical-align: top;">C*20</td>
745
746
747
748
749      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
750
751
752
753
754      <td style="vertical-align: top;"> 
755     
756     
757     
758      <p style="font-style: normal;">Bottom boundary condition of the
759potential temperature.&nbsp; </p>
760
761
762
763 
764     
765     
766     
767      <p>Allowed values
768are <span style="font-style: italic;">'dirichlet'</span>
769(pt(k=0) = const. = <a href="#pt_surface">pt_surface</a>
770+ <a href="#pt_surface_initial_change">pt_surface_initial_change</a>;
771the user may change this value during the run using user-defined code)
772and <span style="font-style: italic;">'neumann'</span>
773(pt(k=0)=pt(k=1)).&nbsp; <br>
774
775
776
777
778When a constant surface sensible heat flux is used (<a href="#surface_heatflux">surface_heatflux</a>), <b>bc_pt_b</b>
779= <span style="font-style: italic;">'neumann'</span>
780must be used, because otherwise the resolved scale may contribute to
781the surface flux so that a constant value cannot be guaranteed.</p>
782
783
784
785     
786     
787     
788      <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>
789
790
791
792
793      </td>
794
795
796
797 </tr>
798
799
800
801 <tr>
802
803
804
805 <td style="vertical-align: top;"> 
806     
807     
808     
809      <p><a name="pc_pt_t"></a><b>bc_pt_t</b></p>
810
811
812
813
814      </td>
815
816
817
818 <td style="vertical-align: top;">C * 20</td>
819
820
821
822
823      <td style="vertical-align: top;"><span style="font-style: italic;">'initial_ gradient'</span></td>
824
825
826
827
828      <td style="vertical-align: top;"> 
829     
830     
831     
832      <p style="font-style: normal;">Top boundary condition of the
833potential temperature.&nbsp; </p>
834
835
836
837 
838     
839     
840     
841      <p>Allowed are the
842values <span style="font-style: italic;">'dirichlet' </span>(pt(k=nz+1)
843does not change during the run), <span style="font-style: italic;">'neumann'</span>
844(pt(k=nz+1)=pt(k=nz)), and <span style="font-style: italic;">'initial_gradient'</span>.
845With the 'initial_gradient'-condition the value of the temperature
846gradient at the top is
847calculated from the initial
848temperature profile (see <a href="#pt_surface">pt_surface</a>,
849      <a href="#pt_vertical_gradient">pt_vertical_gradient</a>)
850by bc_pt_t_val = (pt_init(k=nz+1) -
851pt_init(k=nz)) / dzu(nz+1).<br>
852
853
854
855
856Using this value (assumed constant during the
857run) the temperature boundary values are calculated as&nbsp; </p>
858
859
860
861
862     
863     
864     
865      <ul>
866
867
868
869 
870       
871       
872       
873        <p style="font-style: normal;">pt(k=nz+1) =
874pt(k=nz) +
875bc_pt_t_val * dzu(nz+1)</p>
876
877
878
879 
880     
881     
882     
883      </ul>
884
885
886
887 
888     
889     
890     
891      <p style="font-style: normal;">(up to k=nz the prognostic
892equation for the temperature is solved).<br>
893
894
895
896
897When a constant sensible heat flux is used at the top boundary (<a href="chapter_4.1.html#top_heatflux">top_heatflux</a>),
898      <b>bc_pt_t</b> = <span style="font-style: italic;">'neumann'</span>
899must be used, because otherwise the resolved scale may contribute to
900the top flux so that a constant value cannot be guaranteed.</p>
901
902
903
904 </td>
905
906
907
908
909    </tr>
910
911
912
913 <tr>
914
915
916
917 <td style="vertical-align: top;">
918     
919     
920     
921      <p><a name="bc_q_b"></a><b>bc_q_b</b></p>
922
923
924
925
926      </td>
927
928
929
930 <td style="vertical-align: top;">C * 20</td>
931
932
933
934
935      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
936
937
938
939
940      <td style="vertical-align: top;"> 
941     
942     
943     
944      <p style="font-style: normal;">Bottom boundary condition of the
945specific humidity / total water content.&nbsp; </p>
946
947
948
949 
950     
951     
952     
953      <p>Allowed
954values are <span style="font-style: italic;">'dirichlet'</span>
955(q(k=0) = const. = <a href="#q_surface">q_surface</a>
956+ <a href="#q_surface_initial_change">q_surface_initial_change</a>;
957the user may change this value during the run using user-defined code)
958and <span style="font-style: italic;">'neumann'</span>
959(q(k=0)=q(k=1)).&nbsp; <br>
960
961
962
963
964When a constant surface latent heat flux is used (<a href="#surface_waterflux">surface_waterflux</a>), <b>bc_q_b</b>
965= <span style="font-style: italic;">'neumann'</span>
966must be used, because otherwise the resolved scale may contribute to
967the surface flux so that a constant value cannot be guaranteed.</p>
968
969
970
971
972      </td>
973
974
975
976 </tr>
977
978
979
980 <tr>
981
982
983
984 <td style="vertical-align: top;"> 
985     
986     
987     
988      <p><a name="bc_q_t"></a><b>bc_q_t</b></p>
989
990
991
992
993      </td>
994
995
996
997 <td style="vertical-align: top;"><span style="font-style: italic;">C
998* 20</span></td>
999
1000
1001
1002 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1003
1004
1005
1006
1007      <td style="vertical-align: top;"> 
1008     
1009     
1010     
1011      <p style="font-style: normal;">Top boundary condition of the
1012specific humidity / total water content.&nbsp; </p>
1013
1014
1015
1016 
1017     
1018     
1019     
1020      <p>Allowed
1021are the values <span style="font-style: italic;">'dirichlet'</span>
1022(q(k=nz) and q(k=nz+1) do
1023not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1024With the Neumann boundary
1025condition the value of the humidity gradient at the top is calculated
1026from the
1027initial humidity profile (see <a href="#q_surface">q_surface</a>,
1028      <a href="#q_vertical_gradient">q_vertical_gradient</a>)
1029by: bc_q_t_val = ( q_init(k=nz) - q_init(k=nz-1)) / dzu(nz).<br>
1030
1031
1032
1033
1034Using this value (assumed constant during the run) the humidity
1035boundary values
1036are calculated as&nbsp; </p>
1037
1038
1039
1040 
1041     
1042     
1043     
1044      <ul>
1045
1046
1047
1048 
1049       
1050       
1051       
1052        <p style="font-style: normal;">q(k=nz+1) =q(k=nz) +
1053bc_q_t_val * dzu(nz+1)</p>
1054
1055
1056
1057 
1058     
1059     
1060     
1061      </ul>
1062
1063
1064
1065 
1066     
1067     
1068     
1069      <p style="font-style: normal;">(up tp k=nz the prognostic
1070equation for q is solved). </p>
1071
1072
1073
1074 </td>
1075
1076
1077
1078 </tr>
1079
1080
1081
1082 <tr>
1083
1084
1085
1086
1087      <td style="vertical-align: top;"> 
1088     
1089     
1090     
1091      <p><a name="bc_s_b"></a><b>bc_s_b</b></p>
1092
1093
1094
1095 </td>
1096
1097
1098
1099
1100      <td style="vertical-align: top;">C * 20</td>
1101
1102
1103
1104 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1105
1106
1107
1108
1109      <td style="vertical-align: top;"> 
1110     
1111     
1112     
1113      <p style="font-style: normal;">Bottom boundary condition of the
1114scalar concentration.&nbsp; </p>
1115
1116
1117
1118 
1119     
1120     
1121     
1122      <p>Allowed values
1123are <span style="font-style: italic;">'dirichlet'</span>
1124(s(k=0) = const. = <a href="#s_surface">s_surface</a>
1125+ <a href="#s_surface_initial_change">s_surface_initial_change</a>;
1126the user may change this value during the run using user-defined code)
1127and <span style="font-style: italic;">'neumann'</span>
1128(s(k=0) =
1129s(k=1)).&nbsp; <br>
1130
1131
1132
1133
1134When a constant surface concentration flux is used (<a href="#surface_scalarflux">surface_scalarflux</a>), <b>bc_s_b</b>
1135= <span style="font-style: italic;">'neumann'</span>
1136must be used, because otherwise the resolved scale may contribute to
1137the surface flux so that a constant value cannot be guaranteed.</p>
1138
1139
1140
1141
1142      </td>
1143
1144
1145
1146 </tr>
1147
1148
1149
1150 <tr>
1151
1152
1153
1154 <td style="vertical-align: top;"> 
1155     
1156     
1157     
1158      <p><a name="bc_s_t"></a><b>bc_s_t</b></p>
1159
1160
1161
1162
1163      </td>
1164
1165
1166
1167 <td style="vertical-align: top;">C * 20</td>
1168
1169
1170
1171
1172      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1173
1174
1175
1176
1177      <td style="vertical-align: top;"> 
1178     
1179     
1180     
1181      <p style="font-style: normal;">Top boundary condition of the
1182scalar concentration.&nbsp; </p>
1183
1184
1185
1186 
1187     
1188     
1189     
1190      <p>Allowed are the
1191values <span style="font-style: italic;">'dirichlet'</span>
1192(s(k=nz) and s(k=nz+1) do
1193not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1194With the Neumann boundary
1195condition the value of the scalar concentration gradient at the top is
1196calculated
1197from the initial scalar concentration profile (see <a href="#s_surface">s_surface</a>, <a href="#s_vertical_gradient">s_vertical_gradient</a>)
1198by: bc_s_t_val = (s_init(k=nz) - s_init(k=nz-1)) / dzu(nz).<br>
1199
1200
1201
1202
1203Using this value (assumed constant during the run) the concentration
1204boundary values
1205are calculated as </p>
1206
1207
1208
1209 
1210     
1211     
1212     
1213      <ul>
1214
1215
1216
1217 
1218       
1219       
1220       
1221        <p style="font-style: normal;">s(k=nz+1) = s(k=nz) +
1222bc_s_t_val * dzu(nz+1)</p>
1223
1224
1225
1226 
1227     
1228     
1229     
1230      </ul>
1231
1232
1233
1234 
1235     
1236     
1237     
1238      <p style="font-style: normal;">(up to k=nz the prognostic
1239equation for the scalar concentration is
1240solved).</p>
1241
1242
1243
1244 </td>
1245
1246
1247
1248 </tr>
1249
1250
1251
1252 <tr>
1253
1254
1255
1256      <td style="vertical-align: top;"><a name="bc_sa_t"></a><span style="font-weight: bold;">bc_sa_t</span></td>
1257
1258
1259
1260      <td style="vertical-align: top;">C * 20</td>
1261
1262
1263
1264      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1265
1266
1267
1268      <td style="vertical-align: top;">
1269     
1270     
1271     
1272      <p style="font-style: normal;">Top boundary condition of the salinity.&nbsp; </p>
1273
1274
1275
1276 
1277     
1278     
1279     
1280      <p>This parameter only comes into effect for ocean runs (see parameter <a href="#ocean">ocean</a>).</p>
1281
1282
1283
1284     
1285     
1286     
1287      <p style="font-style: normal;">Allowed are the
1288values <span style="font-style: italic;">'dirichlet' </span>(sa(k=nz+1)
1289does not change during the run) and <span style="font-style: italic;">'neumann'</span>
1290(sa(k=nz+1)=sa(k=nz))<span style="font-style: italic;"></span>.&nbsp;<br>
1291
1292
1293
1294      <br>
1295
1296
1297
1298
1299When a constant salinity flux is used at the top boundary (<a href="chapter_4.1.html#top_salinityflux">top_salinityflux</a>),
1300      <b>bc_sa_t</b> = <span style="font-style: italic;">'neumann'</span>
1301must be used, because otherwise the resolved scale may contribute to
1302the top flux so that a constant value cannot be guaranteed.</p>
1303
1304
1305
1306      </td>
1307
1308
1309
1310    </tr>
1311
1312
1313
1314    <tr>
1315
1316
1317
1318 <td style="vertical-align: top;"> 
1319     
1320     
1321     
1322      <p><a name="bc_uv_b"></a><b>bc_uv_b</b></p>
1323
1324
1325
1326
1327      </td>
1328
1329
1330
1331 <td style="vertical-align: top;">C * 20</td>
1332
1333
1334
1335
1336      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1337
1338
1339
1340
1341      <td style="vertical-align: top;"> 
1342     
1343     
1344     
1345      <p style="font-style: normal;">Bottom boundary condition of the
1346horizontal velocity components u and v.&nbsp; </p>
1347
1348
1349
1350 
1351     
1352     
1353     
1354      <p>Allowed
1355values are <span style="font-style: italic;">'dirichlet' </span>and
1356      <span style="font-style: italic;">'neumann'</span>. <b>bc_uv_b</b>
1357= <span style="font-style: italic;">'dirichlet'</span>
1358yields the
1359no-slip condition with u=v=0 at the bottom. Due to the staggered grid
1360u(k=0) and v(k=0) are located at z = - 0,5 * <a href="#dz">dz</a>
1361(below the bottom), while u(k=1) and v(k=1) are located at z = +0,5 *
1362dz. u=v=0 at the bottom is guaranteed using mirror boundary
1363condition:&nbsp; </p>
1364
1365
1366
1367 
1368     
1369     
1370     
1371      <ul>
1372
1373
1374
1375 
1376       
1377       
1378       
1379        <p style="font-style: normal;">u(k=0) = - u(k=1) and v(k=0) = -
1380v(k=1)</p>
1381
1382
1383
1384 
1385     
1386     
1387     
1388      </ul>
1389
1390
1391
1392 
1393     
1394     
1395     
1396      <p style="font-style: normal;">The
1397Neumann boundary condition
1398yields the free-slip condition with u(k=0) = u(k=1) and v(k=0) =
1399v(k=1).
1400With Prandtl - layer switched on, the free-slip condition is not
1401allowed (otherwise the run will be terminated)<font color="#000000">.</font></p>
1402
1403
1404
1405
1406      </td>
1407
1408
1409
1410 </tr>
1411
1412
1413
1414 <tr>
1415
1416
1417
1418 <td style="vertical-align: top;"> 
1419     
1420     
1421     
1422      <p><a name="bc_uv_t"></a><b>bc_uv_t</b></p>
1423
1424
1425
1426
1427      </td>
1428
1429
1430
1431 <td style="vertical-align: top;">C * 20</td>
1432
1433
1434
1435
1436      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1437
1438
1439
1440
1441      <td style="vertical-align: top;"> 
1442     
1443     
1444     
1445      <p style="font-style: normal;">Top boundary condition of the
1446horizontal velocity components u and v.&nbsp; </p>
1447
1448
1449
1450 
1451     
1452     
1453     
1454      <p>Allowed
1455values are <span style="font-style: italic;">'dirichlet'</span>
1456and <span style="font-style: italic;">'neumann'</span>.
1457The
1458Dirichlet condition yields u(k=nz+1) = ug(nz+1) and v(k=nz+1) =
1459vg(nz+1),
1460Neumann condition yields the free-slip condition with u(k=nz+1) =
1461u(k=nz) and v(k=nz+1) = v(k=nz) (up to k=nz the prognostic equations
1462for the velocities are solved).</p>
1463
1464
1465
1466     
1467     
1468     
1469      <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>
1470
1471
1472
1473 </td>
1474
1475
1476
1477 </tr>
1478
1479
1480
1481 <tr>
1482
1483
1484
1485      <td style="vertical-align: top;"><a name="bottom_salinityflux"></a><span style="font-weight: bold;">bottom_salinityflux</span></td>
1486
1487
1488
1489      <td style="vertical-align: top;">R</td>
1490
1491
1492
1493      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
1494
1495
1496
1497      <td style="vertical-align: top;">
1498     
1499     
1500     
1501      <p>Kinematic salinity flux near the surface (in psu m/s).&nbsp;</p>
1502
1503
1504
1505This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).
1506     
1507     
1508     
1509      <p>The
1510respective salinity flux value is used
1511as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
1512condition must be used for the salinity, which is currently the only available condition.<br>
1513
1514
1515
1516 </p>
1517
1518
1519
1520 </td>
1521
1522
1523
1524    </tr>
1525
1526
1527
1528    <tr>
1529
1530
1531
1532
1533      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_height"></a>building_height</span></td>
1534
1535
1536
1537
1538      <td style="vertical-align: top;">R</td>
1539
1540
1541
1542 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1543
1544
1545
1546 <td>Height
1547of a single building in m.<br>
1548
1549
1550
1551 <br>
1552
1553
1554
1555 <span style="font-weight: bold;">building_height</span> must
1556be less than the height of the model domain. This parameter requires
1557the use of&nbsp;<a href="#topography">topography</a>
1558= <span style="font-style: italic;">'single_building'</span>.</td>
1559
1560
1561
1562
1563    </tr>
1564
1565
1566
1567 <tr>
1568
1569
1570
1571 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_x"></a>building_length_x</span></td>
1572
1573
1574
1575
1576      <td style="vertical-align: top;">R</td>
1577
1578
1579
1580 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1581
1582
1583
1584 <td><span style="font-style: italic;"></span>Width of a single
1585building in m.<br>
1586
1587
1588
1589 <br>
1590
1591
1592
1593
1594Currently, <span style="font-weight: bold;">building_length_x</span>
1595must be at least <span style="font-style: italic;">3
1596*&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>
1597      </span><span style="font-style: italic;">- <a href="#building_wall_left">building_wall_left</a></span>.
1598This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1599= <span style="font-style: italic;">'single_building'</span>.</td>
1600
1601
1602
1603
1604    </tr>
1605
1606
1607
1608 <tr>
1609
1610
1611
1612 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_y"></a>building_length_y</span></td>
1613
1614
1615
1616
1617      <td style="vertical-align: top;">R</td>
1618
1619
1620
1621 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
1622
1623
1624
1625 <td>Depth
1626of a single building in m.<br>
1627
1628
1629
1630 <br>
1631
1632
1633
1634
1635Currently, <span style="font-weight: bold;">building_length_y</span>
1636must be at least <span style="font-style: italic;">3
1637*&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
1638the use of&nbsp;<a href="#topography">topography</a>
1639= <span style="font-style: italic;">'single_building'</span>.</td>
1640
1641
1642
1643
1644    </tr>
1645
1646
1647
1648 <tr>
1649
1650
1651
1652 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_left"></a>building_wall_left</span></td>
1653
1654
1655
1656
1657      <td style="vertical-align: top;">R</td>
1658
1659
1660
1661 <td style="vertical-align: top;"><span style="font-style: italic;">building centered in x-direction</span></td>
1662
1663
1664
1665
1666      <td>x-coordinate of the left building wall (distance between the
1667left building wall and the left border of the model domain) in m.<br>
1668
1669
1670
1671
1672      <br>
1673
1674
1675
1676
1677Currently, <span style="font-weight: bold;">building_wall_left</span>
1678must be at least <span style="font-style: italic;">1
1679*&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;
1680- 1 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a></span>.
1681This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1682= <span style="font-style: italic;">'single_building'</span>.<br>
1683
1684
1685
1686
1687      <br>
1688
1689
1690
1691
1692The default value&nbsp;<span style="font-weight: bold;">building_wall_left</span>
1693= <span style="font-style: italic;">( ( <a href="#nx">nx</a>&nbsp;+
16941 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a> ) / 2</span>
1695centers the building in x-direction. </td>
1696
1697
1698
1699 </tr>
1700
1701
1702
1703 <tr>
1704
1705
1706
1707
1708      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_south"></a>building_wall_south</span></td>
1709
1710
1711
1712
1713      <td style="vertical-align: top;">R</td>
1714
1715
1716
1717 <td style="vertical-align: top;"><span style="font-style: italic;"></span><span style="font-style: italic;">building centered in y-direction</span></td>
1718
1719
1720
1721
1722      <td>y-coordinate of the South building wall (distance between the
1723South building wall and the South border of the model domain) in m.<br>
1724
1725
1726
1727
1728      <br>
1729
1730
1731
1732
1733Currently, <span style="font-weight: bold;">building_wall_south</span>
1734must be at least <span style="font-style: italic;">1
1735*&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;
1736- 1 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a></span>.
1737This parameter requires the use of&nbsp;<a href="#topography">topography</a>
1738= <span style="font-style: italic;">'single_building'</span>.<br>
1739
1740
1741
1742
1743      <br>
1744
1745
1746
1747
1748The default value&nbsp;<span style="font-weight: bold;">building_wall_south</span>
1749= <span style="font-style: italic;">( ( <a href="#ny">ny</a>&nbsp;+
17501 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a> ) / 2</span>
1751centers the building in y-direction. </td>
1752
1753
1754
1755 </tr>
1756
1757
1758
1759 <tr>
1760
1761
1762
1763
1764      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="cloud_droplets"></a>cloud_droplets</span><br>
1765
1766
1767
1768
1769      </td>
1770
1771
1772
1773 <td style="vertical-align: top;">L<br>
1774
1775
1776
1777 </td>
1778
1779
1780
1781
1782      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span><br>
1783
1784
1785
1786 </td>
1787
1788
1789
1790
1791      <td style="vertical-align: top;">Parameter to switch on
1792usage of cloud droplets.<br>
1793
1794
1795
1796 <br>
1797
1798
1799
1800
1801Cloud droplets require to use the particle package (<span style="font-weight: bold;">mrun</span>-option <span style="font-family: monospace;">-p particles</span>),
1802so in this case a particle corresponds to a droplet. The droplet
1803features (number of droplets, initial radius, etc.) can be steered with
1804the&nbsp; respective particle parameters (see e.g. <a href="#chapter_4.2.html#radius">radius</a>).
1805The real number of initial droplets in a grid cell is equal to the
1806initial 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>
1807      <span lang="en-GB"><font face="Thorndale, serif">and
1808      </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>)
1809times the <a href="#initial_weighting_factor">initial_weighting_factor</a>.<br>
1810
1811
1812
1813
1814      <br>
1815
1816
1817
1818
1819In case of using cloud droplets, the default condensation scheme in
1820PALM cannot be used, i.e. <a href="#cloud_physics">cloud_physics</a>
1821must be set <span style="font-style: italic;">.F.</span>.<br>
1822
1823
1824
1825
1826      </td>
1827
1828
1829
1830 </tr>
1831
1832
1833
1834 <tr>
1835
1836
1837
1838 <td style="vertical-align: top;"> 
1839     
1840     
1841     
1842      <p><a name="cloud_physics"></a><b>cloud_physics</b></p>
1843
1844
1845
1846
1847      </td>
1848
1849
1850
1851 <td style="vertical-align: top;">L<br>
1852
1853
1854
1855 </td>
1856
1857
1858
1859
1860      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
1861
1862
1863
1864 <td style="vertical-align: top;"> 
1865     
1866     
1867     
1868      <p>Parameter to switch
1869on the condensation scheme.&nbsp; </p>
1870
1871
1872
1873
1874For <b>cloud_physics =</b> <span style="font-style: italic;">.TRUE.</span>, equations
1875for the
1876liquid water&nbsp;
1877content and the liquid water potential temperature are solved instead
1878of those for specific humidity and potential temperature. Note
1879that a grid volume is assumed to be either completely saturated or
1880completely
1881unsaturated (0%-or-100%-scheme). A simple precipitation scheme can
1882additionally be switched on with parameter <a href="#precipitation">precipitation</a>.
1883Also cloud-top cooling by longwave radiation can be utilized (see <a href="#radiation">radiation</a>)<br>
1884
1885
1886
1887 <b><br>
1888
1889
1890
1891
1892cloud_physics =</b> <span style="font-style: italic;">.TRUE.
1893      </span>requires&nbsp;<a href="#humidity">humidity</a>
1894=<span style="font-style: italic;"> .TRUE.</span> .<br>
1895
1896
1897
1898
1899Detailed information about the condensation scheme is given in the
1900description of the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM-1/Dokumentationen/Cloud_physics/wolken.pdf">cloud
1901physics module</a> (pdf-file, only in German).<br>
1902
1903
1904
1905 <br>
1906
1907
1908
1909
1910This condensation scheme is not allowed if cloud droplets are simulated
1911explicitly (see <a href="#cloud_droplets">cloud_droplets</a>).<br>
1912
1913
1914
1915
1916      </td>
1917
1918
1919
1920 </tr>
1921
1922
1923
1924 <tr>
1925
1926
1927
1928 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow"></a>conserve_volume_flow</span></td>
1929
1930
1931
1932
1933      <td style="vertical-align: top;">L</td>
1934
1935
1936
1937 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
1938
1939
1940
1941 <td>Conservation
1942of volume flow in x- and y-direction.<br>
1943
1944
1945
1946 <br>
1947
1948
1949
1950 <span style="font-weight: bold;">conserve_volume_flow</span>
1951= <span style="font-style: italic;">.TRUE.</span>
1952guarantees that the volume flow through the xz- or yz-cross-section of
1953the total model domain remains constant (equal to the initial value at
1954t=0) throughout the run.<br>
1955
1956
1957
1958
1959      </td>
1960
1961
1962
1963 </tr>
1964
1965
1966
1967 <tr>
1968
1969
1970
1971 <td style="vertical-align: top;"> 
1972     
1973     
1974     
1975      <p><a name="cut_spline_overshoot"></a><b>cut_spline_overshoot</b></p>
1976
1977
1978
1979
1980      </td>
1981
1982
1983
1984 <td style="vertical-align: top;">L</td>
1985
1986
1987
1988
1989      <td style="vertical-align: top;"><span style="font-style: italic;">.T.</span></td>
1990
1991
1992
1993 <td style="vertical-align: top;"> 
1994     
1995     
1996     
1997      <p>Cuts off of
1998so-called overshoots, which can occur with the
1999upstream-spline scheme.&nbsp; </p>
2000
2001
2002
2003 
2004     
2005     
2006     
2007      <p><font color="#000000">The cubic splines tend to overshoot in
2008case of discontinuous changes of variables between neighbouring grid
2009points.</font><font color="#ff0000"> </font><font color="#000000">This
2010may lead to errors in calculating the advection tendency.</font>
2011Choice
2012of <b>cut_spline_overshoot</b> = <i>.TRUE.</i>
2013(switched on by
2014default)
2015allows variable values not to exceed an interval defined by the
2016respective adjacent grid points. This interval can be adjusted
2017seperately for every prognostic variable (see initialization parameters
2018      <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>,
2019etc.). This might be necessary in case that the
2020default interval has a non-tolerable effect on the model
2021results.&nbsp; </p>
2022
2023
2024
2025 
2026     
2027     
2028     
2029      <p>Overshoots may also be removed
2030using the parameters <a href="#ups_limit_e">ups_limit_e</a>,
2031      <a href="#ups_limit_pt">ups_limit_pt</a>,
2032etc. as well as by applying a long-filter (see <a href="#long_filter_factor">long_filter_factor</a>).</p>
2033
2034
2035
2036
2037      </td>
2038
2039
2040
2041 </tr>
2042
2043
2044
2045 <tr>
2046
2047
2048
2049 <td style="vertical-align: top;"> 
2050     
2051     
2052     
2053      <p><a name="damp_level_1d"></a><b>damp_level_1d</b></p>
2054
2055
2056
2057
2058      </td>
2059
2060
2061
2062 <td style="vertical-align: top;">R</td>
2063
2064
2065
2066
2067      <td style="vertical-align: top;"><span style="font-style: italic;">zu(nz+1)</span></td>
2068
2069
2070
2071
2072      <td style="vertical-align: top;"> 
2073     
2074     
2075     
2076      <p>Height where
2077the damping layer begins in the 1d-model
2078(in m).&nbsp; </p>
2079
2080
2081
2082 
2083     
2084     
2085     
2086      <p>This parameter is used to
2087switch on a damping layer for the
20881d-model, which is generally needed for the damping of inertia
2089oscillations. Damping is done by gradually increasing the value
2090of the eddy diffusivities about 10% per vertical grid level
2091(starting with the value at the height given by <b>damp_level_1d</b>,
2092or possibly from the next grid pint above), i.e. K<sub>m</sub>(k+1)
2093=
20941.1 * K<sub>m</sub>(k).
2095The values of K<sub>m</sub> are limited to 10 m**2/s at
2096maximum.&nbsp; <br>
2097
2098
2099
2100
2101This parameter only comes into effect if the 1d-model is switched on
2102for
2103the initialization of the 3d-model using <a href="#initializing_actions">initializing_actions</a>
2104= <span style="font-style: italic;">'set_1d-model_profiles'</span>.
2105      <br>
2106
2107
2108
2109 </p>
2110
2111
2112
2113 </td>
2114
2115
2116
2117 </tr>
2118
2119
2120
2121 <tr>
2122
2123
2124
2125 <td style="vertical-align: top;"><a name="dissipation_1d"></a><span style="font-weight: bold;">dissipation_1d</span><br>
2126
2127
2128
2129
2130      </td>
2131
2132
2133
2134 <td style="vertical-align: top;">C*20<br>
2135
2136
2137
2138
2139      </td>
2140
2141
2142
2143 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
2144
2145
2146
2147 <span style="font-style: italic;">model'</span><br>
2148
2149
2150
2151 </td>
2152
2153
2154
2155
2156      <td style="vertical-align: top;">Calculation method for
2157the energy dissipation term in the TKE equation of the 1d-model.<br>
2158
2159
2160
2161
2162      <br>
2163
2164
2165
2166
2167By default the dissipation is calculated as in the 3d-model using diss
2168= (0.19 + 0.74 * l / l_grid) * e**1.5 / l.<br>
2169
2170
2171
2172 <br>
2173
2174
2175
2176
2177Setting <span style="font-weight: bold;">dissipation_1d</span>
2178= <span style="font-style: italic;">'detering'</span>
2179forces the dissipation to be calculated as diss = 0.064 * e**1.5 / l.<br>
2180
2181
2182
2183
2184      </td>
2185
2186
2187
2188 </tr>
2189
2190
2191
2192
2193    <tr>
2194
2195
2196
2197 <td style="vertical-align: top;"> 
2198     
2199     
2200     
2201      <p><a name="dt"></a><b>dt</b></p>
2202
2203
2204
2205 </td>
2206
2207
2208
2209
2210      <td style="vertical-align: top;">R</td>
2211
2212
2213
2214 <td style="vertical-align: top;"><span style="font-style: italic;">variable</span></td>
2215
2216
2217
2218
2219      <td style="vertical-align: top;"> 
2220     
2221     
2222     
2223      <p>Time step for
2224the 3d-model (in s).&nbsp; </p>
2225
2226
2227
2228 
2229     
2230     
2231     
2232      <p>By default, (i.e.
2233if a Runge-Kutta scheme is used, see <a href="#timestep_scheme">timestep_scheme</a>)
2234the value of the time step is calculating after each time step
2235(following the time step criteria) and
2236used for the next step.</p>
2237
2238
2239
2240 
2241     
2242     
2243     
2244      <p>If the user assigns <b>dt</b>
2245a value, then the time step is
2246fixed to this value throughout the whole run (whether it fulfills the
2247time step
2248criteria or not). However, changes are allowed for restart runs,
2249because <b>dt</b> can also be used as a <a href="chapter_4.2.html#dt_laufparameter">run
2250parameter</a>.&nbsp; </p>
2251
2252
2253
2254 
2255     
2256     
2257     
2258      <p>In case that the
2259calculated time step meets the condition<br>
2260
2261
2262
2263 </p>
2264
2265
2266
2267 
2268     
2269     
2270     
2271      <ul>
2272
2273
2274
2275
2276       
2277       
2278       
2279        <p><b>dt</b> &lt; 0.00001 * <a href="chapter_4.2.html#dt_max">dt_max</a> (with dt_max
2280= 20.0)</p>
2281
2282
2283
2284 
2285     
2286     
2287     
2288      </ul>
2289
2290
2291
2292 
2293     
2294     
2295     
2296      <p>the simulation will be
2297aborted. Such situations usually arise
2298in case of any numerical problem / instability which causes a
2299non-realistic increase of the wind speed.&nbsp; </p>
2300
2301
2302
2303 
2304     
2305     
2306     
2307      <p>A
2308small time step due to a large mean horizontal windspeed
2309speed may be enlarged by using a coordinate transformation (see <a href="#galilei_transformation">galilei_transformation</a>),
2310in order to spare CPU time.<br>
2311
2312
2313
2314 </p>
2315
2316
2317
2318 
2319     
2320     
2321     
2322      <p>If the
2323leapfrog timestep scheme is used (see <a href="#timestep_scheme">timestep_scheme</a>)
2324a temporary time step value dt_new is calculated first, with dt_new = <a href="chapter_4.2.html#fcl_factor">cfl_factor</a>
2325* dt_crit where dt_crit is the maximum timestep allowed by the CFL and
2326diffusion condition. Next it is examined whether dt_new exceeds or
2327falls below the
2328value of the previous timestep by at
2329least +5 % / -2%. If it is smaller, <span style="font-weight: bold;">dt</span>
2330= dt_new is immediately used for the next timestep. If it is larger,
2331then <span style="font-weight: bold;">dt </span>=
23321.02 * dt_prev
2333(previous timestep) is used as the new timestep, however the time
2334step is only increased if the last change of the time step is dated
2335back at
2336least 30 iterations. If dt_new is located in the interval mentioned
2337above, then dt
2338does not change at all. By doing so, permanent time step changes as
2339well as large
2340sudden changes (increases) in the time step are avoided.</p>
2341
2342
2343
2344 </td>
2345
2346
2347
2348
2349    </tr>
2350
2351
2352
2353 <tr>
2354
2355
2356
2357 <td style="vertical-align: top;">
2358     
2359     
2360     
2361      <p><a name="dt_pr_1d"></a><b>dt_pr_1d</b></p>
2362
2363
2364
2365
2366      </td>
2367
2368
2369
2370 <td style="vertical-align: top;">R</td>
2371
2372
2373
2374
2375      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
2376
2377
2378
2379
2380      <td style="vertical-align: top;"> 
2381     
2382     
2383     
2384      <p>Temporal
2385interval of vertical profile output of the 1D-model
2386(in s).&nbsp; </p>
2387
2388
2389
2390 
2391     
2392     
2393     
2394      <p>Data are written in ASCII
2395format to file <a href="chapter_3.4.html#LIST_PROFIL_1D">LIST_PROFIL_1D</a>.
2396This parameter is only in effect if the 1d-model has been switched on
2397for the
2398initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
2399= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
2400
2401
2402
2403
2404      </td>
2405
2406
2407
2408 </tr>
2409
2410
2411
2412 <tr>
2413
2414
2415
2416 <td style="vertical-align: top;"> 
2417     
2418     
2419     
2420      <p><a name="dt_run_control_1d"></a><b>dt_run_control_1d</b></p>
2421
2422
2423
2424
2425      </td>
2426
2427
2428
2429 <td style="vertical-align: top;">R</td>
2430
2431
2432
2433
2434      <td style="vertical-align: top;"><span style="font-style: italic;">60.0</span></td>
2435
2436
2437
2438 <td style="vertical-align: top;"> 
2439     
2440     
2441     
2442      <p>Temporal interval of
2443runtime control output of the 1d-model
2444(in s).&nbsp; </p>
2445
2446
2447
2448 
2449     
2450     
2451     
2452      <p>Data are written in ASCII
2453format to file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.
2454This parameter is only in effect if the 1d-model is switched on for the
2455initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
2456= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
2457
2458
2459
2460
2461      </td>
2462
2463
2464
2465 </tr>
2466
2467
2468
2469 <tr>
2470
2471
2472
2473 <td style="vertical-align: top;"> 
2474     
2475     
2476     
2477      <p><a name="dx"></a><b>dx</b></p>
2478
2479
2480
2481
2482      </td>
2483
2484
2485
2486 <td style="vertical-align: top;">R</td>
2487
2488
2489
2490
2491      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
2492
2493
2494
2495 <td style="vertical-align: top;"> 
2496     
2497     
2498     
2499      <p>Horizontal grid
2500spacing along the x-direction (in m).&nbsp; </p>
2501
2502
2503
2504 
2505     
2506     
2507     
2508      <p>Along
2509x-direction only a constant grid spacing is allowed.</p>
2510
2511
2512
2513     
2514     
2515     
2516      <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>
2517and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
2518
2519
2520
2521 </td>
2522
2523
2524
2525
2526    </tr>
2527
2528
2529
2530 <tr>
2531
2532
2533
2534 <td style="vertical-align: top;">
2535     
2536     
2537     
2538      <p><a name="dy"></a><b>dy</b></p>
2539
2540
2541
2542
2543      </td>
2544
2545
2546
2547 <td style="vertical-align: top;">R</td>
2548
2549
2550
2551
2552      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
2553
2554
2555
2556 <td style="vertical-align: top;"> 
2557     
2558     
2559     
2560      <p>Horizontal grid
2561spacing along the y-direction (in m).&nbsp; </p>
2562
2563
2564
2565 
2566     
2567     
2568     
2569      <p>Along y-direction only a constant grid spacing is allowed.</p>
2570
2571
2572
2573     
2574     
2575     
2576      <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>
2577and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
2578
2579
2580
2581 </td>
2582
2583
2584
2585
2586    </tr>
2587
2588
2589
2590 <tr>
2591
2592
2593
2594 <td style="vertical-align: top;">
2595     
2596     
2597     
2598      <p><a name="dz"></a><b>dz</b></p>
2599
2600
2601
2602
2603      </td>
2604
2605
2606
2607 <td style="vertical-align: top;">R</td>
2608
2609
2610
2611
2612      <td style="vertical-align: top;"><br>
2613
2614
2615
2616 </td>
2617
2618
2619
2620 <td style="vertical-align: top;"> 
2621     
2622     
2623     
2624      <p>Vertical grid
2625spacing (in m).&nbsp; </p>
2626
2627
2628
2629 
2630     
2631     
2632     
2633      <p>This parameter must be
2634assigned by the user, because no
2635default value is given.<br>
2636
2637
2638
2639 </p>
2640
2641
2642
2643 
2644     
2645     
2646     
2647      <p>By default, the
2648model uses constant grid spacing along z-direction, but it can be
2649stretched using the parameters <a href="#dz_stretch_level">dz_stretch_level</a>
2650and <a href="#dz_stretch_factor">dz_stretch_factor</a>.
2651In case of stretching, a maximum allowed grid spacing can be given by <a href="#dz_max">dz_max</a>.<br>
2652
2653
2654
2655 </p>
2656
2657
2658
2659 
2660     
2661     
2662     
2663      <p>Assuming
2664a constant <span style="font-weight: bold;">dz</span>,
2665the scalar levels (zu) are calculated directly by:&nbsp; </p>
2666
2667
2668
2669
2670     
2671     
2672     
2673      <ul>
2674
2675
2676
2677 
2678       
2679       
2680       
2681        <p>zu(0) = - dz * 0.5&nbsp; <br>
2682
2683
2684
2685
2686zu(1) = dz * 0.5</p>
2687
2688
2689
2690 
2691     
2692     
2693     
2694      </ul>
2695
2696
2697
2698 
2699     
2700     
2701     
2702      <p>The w-levels lie
2703half between them:&nbsp; </p>
2704
2705
2706
2707 
2708     
2709     
2710     
2711      <ul>
2712
2713
2714
2715 
2716       
2717       
2718       
2719        <p>zw(k) =
2720( zu(k) + zu(k+1) ) * 0.5</p>
2721
2722
2723
2724 
2725     
2726     
2727     
2728      </ul>
2729
2730
2731
2732 </td>
2733
2734
2735
2736 </tr>
2737
2738
2739
2740
2741    <tr>
2742
2743
2744
2745      <td style="vertical-align: top;"><a name="dz_max"></a><span style="font-weight: bold;">dz_max</span></td>
2746
2747
2748
2749      <td style="vertical-align: top;">R</td>
2750
2751
2752
2753      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
2754
2755
2756
2757      <td style="vertical-align: top;">Allowed maximum vertical grid
2758spacing (in m).<br>
2759
2760
2761
2762      <br>
2763
2764
2765
2766If the vertical grid is stretched
2767(see <a href="#dz_stretch_factor">dz_stretch_factor</a>
2768and <a href="#dz_stretch_level">dz_stretch_level</a>),
2769      <span style="font-weight: bold;">dz_max</span> can
2770be used to limit the vertical grid spacing.</td>
2771
2772
2773
2774    </tr>
2775
2776
2777
2778    <tr>
2779
2780
2781
2782
2783      <td style="vertical-align: top;"> 
2784     
2785     
2786     
2787      <p><a name="dz_stretch_factor"></a><b>dz_stretch_factor</b></p>
2788
2789
2790
2791
2792      </td>
2793
2794
2795
2796 <td style="vertical-align: top;">R</td>
2797
2798
2799
2800
2801      <td style="vertical-align: top;"><span style="font-style: italic;">1.08</span></td>
2802
2803
2804
2805 <td style="vertical-align: top;"> 
2806     
2807     
2808     
2809      <p>Stretch factor for a
2810vertically stretched grid (see <a href="#dz_stretch_level">dz_stretch_level</a>).&nbsp;
2811      </p>
2812
2813
2814
2815 
2816     
2817     
2818     
2819      <p>The stretch factor should not exceed a value of
2820approx. 1.10 -
28211.12, otherwise the discretization errors due to the stretched grid not
2822negligible any more. (refer Kalnay de Rivas)</p>
2823
2824
2825
2826 </td>
2827
2828
2829
2830 </tr>
2831
2832
2833
2834
2835    <tr>
2836
2837
2838
2839 <td style="vertical-align: top;"> 
2840     
2841     
2842     
2843      <p><a name="dz_stretch_level"></a><b>dz_stretch_level</b></p>
2844
2845
2846
2847
2848      </td>
2849
2850
2851
2852 <td style="vertical-align: top;">R</td>
2853
2854
2855
2856
2857      <td style="vertical-align: top;"><span style="font-style: italic;">100000.0</span><br>
2858
2859
2860
2861 </td>
2862
2863
2864
2865
2866      <td style="vertical-align: top;"> 
2867     
2868     
2869     
2870      <p>Height level
2871above/below which the grid is to be stretched
2872vertically (in m).&nbsp; </p>
2873
2874
2875
2876 
2877     
2878     
2879     
2880      <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
2881vertically. The vertical grid
2882spacings <a href="#dz">dz</a>
2883above this level are calculated as&nbsp; </p>
2884
2885
2886
2887 
2888     
2889     
2890     
2891      <ul>
2892
2893
2894
2895 
2896       
2897       
2898       
2899        <p><b>dz</b>(k+1)
2900= <b>dz</b>(k) * <a href="#dz_stretch_factor">dz_stretch_factor</a></p>
2901
2902
2903
2904
2905     
2906     
2907     
2908      </ul>
2909
2910
2911
2912 
2913     
2914     
2915     
2916      <p>and used as spacings for the scalar levels (zu).
2917The
2918w-levels are then defined as:&nbsp; </p>
2919
2920
2921
2922 
2923     
2924     
2925     
2926      <ul>
2927
2928
2929
2930 
2931       
2932       
2933       
2934        <p>zw(k)
2935= ( zu(k) + zu(k+1) ) * 0.5.
2936
2937 
2938     
2939      </p>
2940
2941     
2942      </ul>
2943
2944     
2945      <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
2946vertically. The vertical grid
2947spacings <a href="chapter_4.1.html#dz">dz</a> below this level are calculated correspondingly as
2948
2949 
2950     
2951      </p>
2952
2953     
2954      <ul>
2955
2956       
2957        <p><b>dz</b>(k-1)
2958= <b>dz</b>(k) * <a href="chapter_4.1.html#dz_stretch_factor">dz_stretch_factor</a>.</p>
2959
2960     
2961      </ul>
2962
2963
2964
2965 </td>
2966
2967
2968
2969 </tr>
2970
2971
2972
2973
2974    <tr>
2975
2976
2977      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_init"></a>e_init</span></td>
2978
2979
2980      <td style="vertical-align: top;">R</td>
2981
2982
2983      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
2984
2985
2986      <td>Initial subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
2987
2988
2989
2990
2991      <br>
2992
2993
2994
2995This
2996option 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>
2997
2998
2999    </tr>
3000
3001
3002    <tr>
3003
3004
3005
3006 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_min"></a>e_min</span></td>
3007
3008
3009
3010
3011      <td style="vertical-align: top;">R</td>
3012
3013
3014
3015 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
3016
3017
3018
3019 <td>Minimum
3020subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
3021
3022
3023
3024
3025      <br>
3026
3027
3028
3029This
3030option&nbsp;adds artificial viscosity to the flow by ensuring that
3031the
3032subgrid-scale TKE does not fall below the minimum threshold <span style="font-weight: bold;">e_min</span>.</td>
3033
3034
3035
3036 </tr>
3037
3038
3039
3040
3041    <tr>
3042
3043
3044
3045 <td style="vertical-align: top;"> 
3046     
3047     
3048     
3049      <p><a name="end_time_1d"></a><b>end_time_1d</b></p>
3050
3051
3052
3053
3054      </td>
3055
3056
3057
3058 <td style="vertical-align: top;">R</td>
3059
3060
3061
3062
3063      <td style="vertical-align: top;"><span style="font-style: italic;">864000.0</span><br>
3064
3065
3066
3067 </td>
3068
3069
3070
3071
3072      <td style="vertical-align: top;"> 
3073     
3074     
3075     
3076      <p>Time to be
3077simulated for the 1d-model (in s).&nbsp; </p>
3078
3079
3080
3081 
3082     
3083     
3084     
3085      <p>The
3086default value corresponds to a simulated time of 10 days.
3087Usually, after such a period the inertia oscillations have completely
3088decayed and the solution of the 1d-model can be regarded as stationary
3089(see <a href="#damp_level_1d">damp_level_1d</a>).
3090This parameter is only in effect if the 1d-model is switched on for the
3091initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
3092= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
3093
3094
3095
3096
3097      </td>
3098
3099
3100
3101 </tr>
3102
3103
3104
3105 <tr>
3106
3107
3108
3109 <td style="vertical-align: top;"> 
3110     
3111     
3112     
3113      <p><a name="fft_method"></a><b>fft_method</b></p>
3114
3115
3116
3117
3118      </td>
3119
3120
3121
3122 <td style="vertical-align: top;">C * 20</td>
3123
3124
3125
3126
3127      <td style="vertical-align: top;"><span style="font-style: italic;">'system-</span><br style="font-style: italic;">
3128
3129
3130
3131 <span style="font-style: italic;">specific'</span></td>
3132
3133
3134
3135
3136      <td style="vertical-align: top;"> 
3137     
3138     
3139     
3140      <p>FFT-method to
3141be used.<br>
3142
3143
3144
3145 </p>
3146
3147
3148
3149 
3150     
3151     
3152     
3153      <p><br>
3154
3155
3156
3157
3158The fast fourier transformation (FFT) is used for solving the
3159perturbation pressure equation with a direct method (see <a href="chapter_4.2.html#psolver">psolver</a>)
3160and for calculating power spectra (see optional software packages,
3161section <a href="chapter_4.2.html#spectra_package">4.2</a>).</p>
3162
3163
3164
3165
3166     
3167     
3168     
3169      <p><br>
3170
3171
3172
3173
3174By default, system-specific, optimized routines from external
3175vendor libraries are used. However, these are available only on certain
3176computers and there are more or less severe restrictions concerning the
3177number of gridpoints to be used with them.<br>
3178
3179
3180
3181 </p>
3182
3183
3184
3185 
3186     
3187     
3188     
3189      <p>There
3190are two other PALM internal methods available on every
3191machine (their respective source code is part of the PALM source code):</p>
3192
3193
3194
3195
3196     
3197     
3198     
3199      <p>1.: The <span style="font-weight: bold;">Temperton</span>-method
3200from Clive Temperton (ECWMF) which is computationally very fast and
3201switched on with <b>fft_method</b> = <span style="font-style: italic;">'temperton-algorithm'</span>.
3202The number of horizontal gridpoints (nx+1, ny+1) to be used with this
3203method must be composed of prime factors 2, 3 and 5.<br>
3204
3205
3206
3207 </p>
3208
3209
3210
3211
32122.: The <span style="font-weight: bold;">Singleton</span>-method
3213which is very slow but has no restrictions concerning the number of
3214gridpoints to be used with, switched on with <b>fft_method</b>
3215= <span style="font-style: italic;">'singleton-algorithm'</span>.
3216      </td>
3217
3218
3219
3220 </tr>
3221
3222
3223
3224 <tr>
3225
3226
3227
3228 <td style="vertical-align: top;"> 
3229     
3230     
3231     
3232      <p><a name="galilei_transformation"></a><b>galilei_transformation</b></p>
3233
3234
3235
3236
3237      </td>
3238
3239
3240
3241 <td style="vertical-align: top;">L</td>
3242
3243
3244
3245
3246      <td style="vertical-align: top;"><i>.F.</i></td>
3247
3248
3249
3250
3251      <td style="vertical-align: top;">Application of a
3252Galilei-transformation to the
3253coordinate
3254system of the model.<br>
3255
3256
3257
3258     
3259     
3260     
3261      <p>With <b>galilei_transformation</b>
3262= <i>.T.,</i> a so-called
3263Galilei-transformation is switched on which ensures that the coordinate
3264system of the model is moved along with the geostrophical wind.
3265Alternatively, the model domain can be moved along with the averaged
3266horizontal wind (see <a href="#use_ug_for_galilei_tr">use_ug_for_galilei_tr</a>,
3267this can and will naturally change in time). With this method,
3268numerical inaccuracies of the Piascek - Williams - scheme (concerns in
3269particular the momentum advection) are minimized. Beyond that, in the
3270majority of cases the lower relative velocities in the moved system
3271permit a larger time step (<a href="#dt">dt</a>).
3272Switching the transformation on is only worthwhile if the geostrophical
3273wind (ug, vg)
3274and the averaged horizontal wind clearly deviate from the value 0. In
3275each case, the distance the coordinate system has been moved is written
3276to the file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.&nbsp;
3277      </p>
3278
3279
3280
3281 
3282     
3283     
3284     
3285      <p>Non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
3286and <a href="#bc_ns">bc_ns</a>), the specification
3287of a gestrophic
3288wind that is not constant with height
3289as well as e.g. stationary inhomogeneities at the bottom boundary do
3290not allow the use of this transformation.</p>
3291
3292
3293
3294 </td>
3295
3296
3297
3298 </tr>
3299
3300
3301
3302
3303    <tr>
3304
3305
3306
3307 <td style="vertical-align: top;"> 
3308     
3309     
3310     
3311      <p><a name="grid_matching"></a><b>grid_matching</b></p>
3312
3313
3314
3315
3316      </td>
3317
3318
3319
3320 <td style="vertical-align: top;">C * 6</td>
3321
3322
3323
3324
3325      <td style="vertical-align: top;"><span style="font-style: italic;">'match'</span></td>
3326
3327
3328
3329 <td style="vertical-align: top;">Variable to adjust the
3330subdomain
3331sizes in parallel runs.<br>
3332
3333
3334
3335 <br>
3336
3337
3338
3339
3340For <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>,
3341the subdomains are forced to have an identical
3342size on all processors. In this case the processor numbers in the
3343respective directions of the virtual processor net must fulfill certain
3344divisor conditions concerning the grid point numbers in the three
3345directions (see <a href="#nx">nx</a>, <a href="#ny">ny</a>
3346and <a href="#nz">nz</a>).
3347Advantage of this method is that all PEs bear the same computational
3348load.<br>
3349
3350
3351
3352 <br>
3353
3354
3355
3356
3357There is no such restriction by default, because then smaller
3358subdomains are allowed on those processors which
3359form the right and/or north boundary of the virtual processor grid. On
3360all other processors the subdomains are of same size. Whether smaller
3361subdomains are actually used, depends on the number of processors and
3362the grid point numbers used. Information about the respective settings
3363are 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>
3364
3365
3366
3367
3368      <br>
3369
3370
3371
3372
3373When 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>)
3374only <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>
3375is allowed.<br>
3376
3377
3378
3379 <br>
3380
3381
3382
3383 <b>Note:</b><br>
3384
3385
3386
3387
3388In some cases for small processor numbers there may be a very bad load
3389balancing among the
3390processors which may reduce the performance of the code.</td>
3391
3392
3393
3394 </tr>
3395
3396
3397
3398
3399    <tr>
3400
3401
3402
3403 <td style="vertical-align: top;"><a name="inflow_disturbance_begin"></a><b>inflow_disturbance_<br>
3404
3405
3406
3407
3408begin</b></td>
3409
3410
3411
3412 <td style="vertical-align: top;">I</td>
3413
3414
3415
3416
3417      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(10,</span><br style="font-style: italic;">
3418
3419
3420
3421 <span style="font-style: italic;">nx/2 or ny/2)</span></td>
3422
3423
3424
3425
3426      <td style="vertical-align: top;">Lower
3427limit of the horizontal range for which random perturbations are to be
3428imposed on the horizontal velocity field (gridpoints).<br>
3429
3430
3431
3432 <br>
3433
3434
3435
3436
3437If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
3438or <a href="#bc_ns">bc_ns</a>),
3439this parameter gives the gridpoint number (counted horizontally from
3440the inflow)&nbsp; from which on perturbations are imposed on the
3441horizontal velocity field. Perturbations must be switched on with
3442parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
3443
3444
3445
3446
3447    </tr>
3448
3449
3450
3451 <tr>
3452
3453
3454
3455 <td style="vertical-align: top;"><a name="inflow_disturbance_end"></a><b>inflow_disturbance_<br>
3456
3457
3458
3459
3460end</b></td>
3461
3462
3463
3464 <td style="vertical-align: top;">I</td>
3465
3466
3467
3468
3469      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(100,</span><br style="font-style: italic;">
3470
3471
3472
3473 <span style="font-style: italic;">3/4*nx or</span><br style="font-style: italic;">
3474
3475
3476
3477 <span style="font-style: italic;">3/4*ny)</span></td>
3478
3479
3480
3481 <td style="vertical-align: top;">Upper
3482limit of the horizontal range for which random perturbations are
3483to be imposed on the horizontal velocity field (gridpoints).<br>
3484
3485
3486
3487 <br>
3488
3489
3490
3491
3492If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
3493or <a href="#bc_ns">bc_ns</a>),
3494this parameter gives the gridpoint number (counted horizontally from
3495the inflow)&nbsp; unto which perturbations are imposed on the
3496horizontal
3497velocity field. Perturbations must be switched on with parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
3498
3499
3500
3501
3502    </tr>
3503
3504
3505
3506 <tr>
3507
3508
3509
3510 <td style="vertical-align: top;">
3511     
3512     
3513     
3514      <p><a name="initializing_actions"></a><b>initializing_actions</b></p>
3515
3516
3517
3518
3519      </td>
3520
3521
3522
3523 <td style="vertical-align: top;">C * 100</td>
3524
3525
3526
3527
3528      <td style="vertical-align: top;"><br>
3529
3530
3531
3532 </td>
3533
3534
3535
3536 <td style="vertical-align: top;"> 
3537     
3538     
3539     
3540      <p style="font-style: normal;">Initialization actions
3541to be carried out.&nbsp; </p>
3542
3543
3544
3545 
3546     
3547     
3548     
3549      <p style="font-style: normal;">This parameter does not have a
3550default value and therefore must be assigned with each model run. For
3551restart runs <b>initializing_actions</b> = <span style="font-style: italic;">'read_restart_data'</span>
3552must be set. For the initial run of a job chain the following values
3553are allowed:&nbsp; </p>
3554
3555
3556
3557 
3558     
3559     
3560     
3561      <p style="font-style: normal;"><span style="font-style: italic;">'set_constant_profiles'</span>
3562      </p>
3563
3564
3565
3566 
3567     
3568     
3569     
3570      <ul>
3571
3572
3573
3574 
3575       
3576       
3577       
3578        <p>A horizontal wind profile consisting
3579of linear sections (see <a href="#ug_surface">ug_surface</a>,
3580        <a href="#ug_vertical_gradient">ug_vertical_gradient</a>,
3581        <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>
3582and <a href="#vg_surface">vg_surface</a>, <a href="#vg_vertical_gradient">vg_vertical_gradient</a>,
3583        <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>,
3584respectively) as well as a vertical temperature (humidity) profile
3585consisting of
3586linear sections (see <a href="#pt_surface">pt_surface</a>,
3587        <a href="#pt_vertical_gradient">pt_vertical_gradient</a>,
3588        <a href="#q_surface">q_surface</a>
3589and <a href="#q_vertical_gradient">q_vertical_gradient</a>)
3590are assumed as initial profiles. The subgrid-scale TKE is set to 0 but K<sub>m</sub>
3591and K<sub>h</sub> are set to very small values because
3592otherwise no TKE
3593would be generated.</p>
3594
3595
3596
3597 
3598     
3599     
3600     
3601      </ul>
3602
3603
3604
3605 
3606     
3607     
3608     
3609      <p style="font-style: italic;">'set_1d-model_profiles' </p>
3610
3611
3612
3613
3614     
3615     
3616     
3617      <ul>
3618
3619
3620
3621 
3622       
3623       
3624       
3625        <p>The arrays of the 3d-model are initialized with
3626the
3627(stationary) solution of the 1d-model. These are the variables e, kh,
3628km, u, v and with Prandtl layer switched on rif, us, usws, vsws. The
3629temperature (humidity) profile consisting of linear sections is set as
3630for 'set_constant_profiles' and assumed as constant in time within the
36311d-model. For steering of the 1d-model a set of parameters with suffix
3632"_1d" (e.g. <a href="#end_time_1d">end_time_1d</a>,
3633        <a href="#damp_level_1d">damp_level_1d</a>)
3634is available.</p>
3635
3636
3637
3638 
3639     
3640     
3641     
3642      </ul>
3643
3644
3645
3646 
3647     
3648     
3649     
3650      <p><span style="font-style: italic;">'by_user'</span></p>
3651
3652
3653
3654     
3655     
3656     
3657      <p style="margin-left: 40px;">The initialization of the arrays
3658of the 3d-model is under complete control of the user and has to be
3659done in routine <a href="chapter_3.5.1.html#user_init_3d_model">user_init_3d_model</a>
3660of the user-interface.<span style="font-style: italic;"></span></p>
3661
3662
3663
3664     
3665     
3666     
3667      <p><span style="font-style: italic;">'initialize_vortex'</span>
3668      </p>
3669
3670
3671
3672 
3673     
3674     
3675     
3676      <div style="margin-left: 40px;">The initial
3677velocity field of the
36783d-model corresponds to a
3679Rankine-vortex with vertical axis. This setting may be used to test
3680advection 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>)
3681are necessary. In order not to distort the vortex, an initial
3682horizontal wind profile constant
3683with height is necessary (to be set by <b>initializing_actions</b>
3684= <span style="font-style: italic;">'set_constant_profiles'</span>)
3685and some other conditions have to be met (neutral stratification,
3686diffusion must be
3687switched off, see <a href="#km_constant">km_constant</a>).
3688The center of the vortex is located at jc = (nx+1)/2. It
3689extends from k = 0 to k = nz+1. Its radius is 8 * <a href="#dx">dx</a>
3690and the exponentially decaying part ranges to 32 * <a href="#dx">dx</a>
3691(see init_rankine.f90). </div>
3692
3693
3694
3695 
3696     
3697     
3698     
3699      <p><span style="font-style: italic;">'initialize_ptanom'</span>
3700      </p>
3701
3702
3703
3704 
3705     
3706     
3707     
3708      <ul>
3709
3710
3711
3712 
3713       
3714       
3715       
3716        <p>A 2d-Gauss-like shape disturbance
3717(x,y) is added to the
3718initial temperature field with radius 10.0 * <a href="#dx">dx</a>
3719and center at jc = (nx+1)/2. This may be used for tests of scalar
3720advection schemes
3721(see <a href="#scalar_advec">scalar_advec</a>).
3722Such tests require a horizontal wind profile constant with hight and
3723diffusion
3724switched off (see <span style="font-style: italic;">'initialize_vortex'</span>).
3725Additionally, the buoyancy term
3726must be switched of in the equation of motion&nbsp; for w (this
3727requires the user to comment out the call of <span style="font-family: monospace;">buoyancy</span> in the
3728source code of <span style="font-family: monospace;">prognostic_equations.f90</span>).</p>
3729
3730
3731
3732
3733     
3734     
3735     
3736      </ul>
3737
3738
3739
3740 
3741     
3742     
3743     
3744      <p style="font-style: normal;">Values may be
3745combined, e.g. <b>initializing_actions</b> = <span style="font-style: italic;">'set_constant_profiles
3746initialize_vortex'</span>, but the values of <span style="font-style: italic;">'set_constant_profiles'</span>,
3747      <span style="font-style: italic;">'set_1d-model_profiles'</span>
3748, and <span style="font-style: italic;">'by_user'</span>
3749must not be given at the same time.</p>
3750
3751
3752
3753 
3754     
3755     
3756     
3757      <p style="font-style: italic;"> </p>
3758
3759
3760
3761 </td>
3762
3763
3764
3765 </tr>
3766
3767
3768
3769
3770    <tr>
3771
3772
3773
3774 <td style="vertical-align: top;"> 
3775     
3776     
3777     
3778      <p><a name="km_constant"></a><b>km_constant</b></p>
3779
3780
3781
3782
3783      </td>
3784
3785
3786
3787 <td style="vertical-align: top;">R</td>
3788
3789
3790
3791
3792      <td style="vertical-align: top;"><i>variable<br>
3793
3794
3795
3796
3797(computed from TKE)</i></td>
3798
3799
3800
3801 <td style="vertical-align: top;"> 
3802     
3803     
3804     
3805      <p>Constant eddy
3806diffusivities are used (laminar
3807simulations).&nbsp; </p>
3808
3809
3810
3811 
3812     
3813     
3814     
3815      <p>If this parameter is
3816specified, both in the 1d and in the
38173d-model constant values for the eddy diffusivities are used in
3818space and time with K<sub>m</sub> = <b>km_constant</b>
3819and K<sub>h</sub> = K<sub>m</sub> / <a href="chapter_4.2.html#prandtl_number">prandtl_number</a>.
3820The prognostic equation for the subgrid-scale TKE is switched off.
3821Constant eddy diffusivities are only allowed with the Prandtl layer (<a href="#prandtl_layer">prandtl_layer</a>)
3822switched off.</p>
3823
3824
3825
3826 </td>
3827
3828
3829
3830 </tr>
3831
3832
3833
3834 <tr>
3835
3836
3837
3838 <td style="vertical-align: top;"> 
3839     
3840     
3841     
3842      <p><a name="km_damp_max"></a><b>km_damp_max</b></p>
3843
3844
3845
3846
3847      </td>
3848
3849
3850
3851 <td style="vertical-align: top;">R</td>
3852
3853
3854
3855
3856      <td style="vertical-align: top;"><span style="font-style: italic;">0.5*(dx
3857or dy)</span></td>
3858
3859
3860
3861 <td style="vertical-align: top;">Maximum
3862diffusivity used for filtering the velocity field in the vicinity of
3863the outflow (in m<sup>2</sup>/s).<br>
3864
3865
3866
3867 <br>
3868
3869
3870
3871
3872When using non-cyclic lateral boundaries (see <a href="#bc_lr">bc_lr</a>
3873or <a href="#bc_ns">bc_ns</a>),
3874a smoothing has to be applied to the
3875velocity field in the vicinity of the outflow in order to suppress any
3876reflections of outgoing disturbances. Smoothing is done by increasing
3877the eddy diffusivity along the horizontal direction which is
3878perpendicular to the outflow boundary. Only velocity components
3879parallel to the outflow boundary are filtered (e.g. v and w, if the
3880outflow is along x). Damping is applied from the bottom to the top of
3881the domain.<br>
3882
3883
3884
3885 <br>
3886
3887
3888
3889
3890The horizontal range of the smoothing is controlled by <a href="#outflow_damping_width">outflow_damping_width</a>
3891which defines the number of gridpoints (counted from the outflow
3892boundary) from where on the smoothing is applied. Starting from that
3893point, the eddy diffusivity is linearly increased (from zero to its
3894maximum value given by <span style="font-weight: bold;">km_damp_max</span>)
3895until half of the damping range width, from where it remains constant
3896up to the outflow boundary. If at a certain grid point the eddy
3897diffusivity calculated from the flow field is larger than as described
3898above, it is used instead.<br>
3899
3900
3901
3902 <br>
3903
3904
3905
3906
3907The default value of <span style="font-weight: bold;">km_damp_max</span>
3908has been empirically proven to be sufficient.</td>
3909
3910
3911
3912 </tr>
3913
3914
3915
3916 <tr>
3917
3918
3919
3920
3921      <td style="vertical-align: top;"> 
3922     
3923     
3924     
3925      <p><a name="long_filter_factor"></a><b>long_filter_factor</b></p>
3926
3927
3928
3929
3930      </td>
3931
3932
3933
3934 <td style="vertical-align: top;">R</td>
3935
3936
3937
3938
3939      <td style="vertical-align: top;"><i>0.0</i></td>
3940
3941
3942
3943
3944      <td style="vertical-align: top;"> 
3945     
3946     
3947     
3948      <p>Filter factor
3949for the so-called Long-filter.<br>
3950
3951
3952
3953 </p>
3954
3955
3956
3957 
3958     
3959     
3960     
3961      <p><br>
3962
3963
3964
3965
3966This filter very efficiently
3967eliminates 2-delta-waves sometimes cauesed by the upstream-spline
3968scheme (see Mahrer and
3969Pielke, 1978: Mon. Wea. Rev., 106, 818-830). It works in all three
3970directions in space. A value of <b>long_filter_factor</b>
3971= <i>0.01</i>
3972sufficiently removes the small-scale waves without affecting the
3973longer waves.<br>
3974
3975
3976
3977 </p>
3978
3979
3980
3981 
3982     
3983     
3984     
3985      <p>By default, the filter is
3986switched off (= <i>0.0</i>).
3987It is exclusively applied to the tendencies calculated by the
3988upstream-spline scheme (see <a href="#momentum_advec">momentum_advec</a>
3989and <a href="#scalar_advec">scalar_advec</a>),
3990not to the prognostic variables themselves. At the bottom and top
3991boundary of the model domain the filter effect for vertical
39922-delta-waves is reduced. There, the amplitude of these waves is only
3993reduced by approx. 50%, otherwise by nearly 100%.&nbsp; <br>
3994
3995
3996
3997
3998Filter factors with values &gt; <i>0.01</i> also
3999reduce the amplitudes
4000of waves with wavelengths longer than 2-delta (see the paper by Mahrer
4001and
4002Pielke, quoted above). </p>
4003
4004
4005
4006 </td>
4007
4008
4009
4010 </tr>
4011
4012
4013
4014 <tr>
4015
4016
4017
4018      <td style="vertical-align: top;"><a name="loop_optimization"></a><span style="font-weight: bold;">loop_optimization</span></td>
4019
4020
4021
4022      <td style="vertical-align: top;">C*16</td>
4023
4024
4025
4026      <td style="vertical-align: top;"><span style="font-style: italic;">see right</span></td>
4027
4028
4029
4030      <td>Method used to optimize loops for solving the prognostic equations .<br>
4031
4032
4033
4034      <br>
4035
4036
4037
4038By
4039default, the optimization method depends on the host on which PALM is
4040running. On machines with vector-type CPUs, single 3d-loops are used to
4041calculate each tendency term of each prognostic equation, while on all
4042other machines, all prognostic equations are solved within one big loop
4043over 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>
4044
4045
4046
4047      <br>
4048
4049
4050
4051The 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>
4052
4053
4054
4055    </tr>
4056
4057
4058
4059    <tr>
4060
4061
4062
4063
4064      <td style="vertical-align: top;"><a name="mixing_length_1d"></a><span style="font-weight: bold;">mixing_length_1d</span><br>
4065
4066
4067
4068
4069      </td>
4070
4071
4072
4073 <td style="vertical-align: top;">C*20<br>
4074
4075
4076
4077
4078      </td>
4079
4080
4081
4082 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
4083
4084
4085
4086 <span style="font-style: italic;">model'</span><br>
4087
4088
4089
4090 </td>
4091
4092
4093
4094
4095      <td style="vertical-align: top;">Mixing length used in the
40961d-model.<br>
4097
4098
4099
4100 <br>
4101
4102
4103
4104
4105By default the mixing length is calculated as in the 3d-model (i.e. it
4106depends on the grid spacing).<br>
4107
4108
4109
4110 <br>
4111
4112
4113
4114
4115By setting <span style="font-weight: bold;">mixing_length_1d</span>
4116= <span style="font-style: italic;">'blackadar'</span>,
4117the so-called Blackadar mixing length is used (l = kappa * z / ( 1 +
4118kappa * z / lambda ) with the limiting value lambda = 2.7E-4 * u_g / f).<br>
4119
4120
4121
4122
4123      </td>
4124
4125
4126
4127 </tr>
4128
4129
4130
4131 <tr>
4132
4133
4134
4135 <td style="vertical-align: top;"> 
4136     
4137     
4138     
4139      <p><a name="humidity"></a><b>humidity</b></p>
4140
4141
4142
4143
4144      </td>
4145
4146
4147
4148 <td style="vertical-align: top;">L</td>
4149
4150
4151
4152
4153      <td style="vertical-align: top;"><i>.F.</i></td>
4154
4155
4156
4157
4158      <td style="vertical-align: top;"> 
4159     
4160     
4161     
4162      <p>Parameter to
4163switch on the prognostic equation for specific
4164humidity q.<br>
4165
4166
4167
4168 </p>
4169
4170
4171
4172 
4173     
4174     
4175     
4176      <p>The initial vertical
4177profile 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>
4178and <a href="chapter_4.1.html#q_vertical_gradient_level">q_vertical_gradient_level</a>.&nbsp;
4179Boundary conditions can be set via <a href="chapter_4.1.html#q_surface_initial_change">q_surface_initial_change</a>
4180and <a href="chapter_4.1.html#surface_waterflux">surface_waterflux</a>.<br>
4181
4182
4183
4184
4185      </p>
4186
4187
4188
4189
4190If the condensation scheme is switched on (<a href="chapter_4.1.html#cloud_physics">cloud_physics</a>
4191= .TRUE.), q becomes the total liquid water content (sum of specific
4192humidity and liquid water content).</td>
4193
4194
4195
4196 </tr>
4197
4198
4199
4200
4201    <tr>
4202
4203
4204
4205 <td style="vertical-align: top;"> 
4206     
4207     
4208     
4209      <p><a name="momentum_advec"></a><b>momentum_advec</b></p>
4210
4211
4212
4213
4214      </td>
4215
4216
4217
4218 <td style="vertical-align: top;">C * 10</td>
4219
4220
4221
4222
4223      <td style="vertical-align: top;"><i>'pw-scheme'</i></td>
4224
4225
4226
4227
4228      <td style="vertical-align: top;"> 
4229     
4230     
4231     
4232      <p>Advection
4233scheme to be used for the momentum equations.<br>
4234
4235
4236
4237 <br>
4238
4239
4240
4241
4242The user can choose between the following schemes:<br>
4243
4244
4245
4246
4247&nbsp;<br>
4248
4249
4250
4251 <br>
4252
4253
4254
4255 <span style="font-style: italic;">'pw-scheme'</span><br>
4256
4257
4258
4259
4260      </p>
4261
4262
4263
4264 
4265     
4266     
4267     
4268      <div style="margin-left: 40px;">The scheme of
4269Piascek and
4270Williams (1970, J. Comp. Phys., 6,
4271392-405) with central differences in the form C3 is used.<br>
4272
4273
4274
4275
4276If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a>
4277= <span style="font-style: italic;">'leapfrog+euler'</span>
4278the
4279advection scheme is - for the Euler-timestep - automatically switched
4280to an upstream-scheme.<br>
4281
4282
4283
4284 </div>
4285
4286
4287
4288 
4289     
4290     
4291     
4292      <p> </p>
4293
4294
4295
4296 
4297     
4298     
4299     
4300      <p><span style="font-style: italic;">'ups-scheme'</span><br>
4301
4302
4303
4304
4305      </p>
4306
4307
4308
4309 
4310     
4311     
4312     
4313      <div style="margin-left: 40px;">The
4314upstream-spline scheme is
4315used
4316(see Mahrer and Pielke,
43171978: Mon. Wea. Rev., 106, 818-830). In opposite to the
4318Piascek-Williams scheme, this is characterized by much better numerical
4319features (less numerical diffusion, better preservation of flow
4320structures, e.g. vortices), but computationally it is much more
4321expensive. In
4322addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a>
4323= <span style="font-style: italic;">'</span><i>euler'</i>),
4324i.e. the
4325timestep accuracy is only of first order.
4326For this reason the advection of scalar variables (see <a href="#scalar_advec">scalar_advec</a>)
4327should then also be carried out with the upstream-spline scheme,
4328because otherwise the scalar variables would
4329be subject to large numerical diffusion due to the upstream
4330scheme.&nbsp; </div>
4331
4332
4333
4334 
4335     
4336     
4337     
4338      <p style="margin-left: 40px;">Since
4339the cubic splines used tend
4340to overshoot under
4341certain circumstances, this effect must be adjusted by suitable
4342filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>,
4343      <a href="#long_filter_factor">long_filter_factor</a>,
4344      <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>).
4345This is always neccessary for runs with stable stratification,
4346even if this stratification appears only in parts of the model domain.<br>
4347
4348
4349
4350
4351      </p>
4352
4353
4354
4355 
4356     
4357     
4358     
4359      <div style="margin-left: 40px;">With stable
4360stratification the
4361upstream-spline scheme also
4362produces gravity waves with large amplitude, which must be
4363suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br>
4364
4365
4366
4367
4368      <br>
4369
4370
4371
4372 <span style="font-weight: bold;">Important: </span>The&nbsp;
4373upstream-spline scheme is not implemented for humidity and passive
4374scalars (see&nbsp;<a href="#humidity">humidity</a>
4375and <a href="#passive_scalar">passive_scalar</a>)
4376and requires the use of a 2d-domain-decomposition. The last conditions
4377severely restricts code optimization on several machines leading to
4378very long execution times! The scheme is also not allowed for
4379non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
4380and <a href="#bc_ns">bc_ns</a>).</div>
4381
4382
4383
4384 </td>
4385
4386
4387
4388
4389    </tr>
4390
4391
4392
4393 <tr>
4394
4395
4396
4397 <td style="vertical-align: top;"><a name="netcdf_precision"></a><span style="font-weight: bold;">netcdf_precision</span><br>
4398
4399
4400
4401
4402      </td>
4403
4404
4405
4406 <td style="vertical-align: top;">C*20<br>
4407
4408
4409
4410
4411(10)<br>
4412
4413
4414
4415 </td>
4416
4417
4418
4419 <td style="vertical-align: top;"><span style="font-style: italic;">single preci-</span><br style="font-style: italic;">
4420
4421
4422
4423 <span style="font-style: italic;">sion for all</span><br style="font-style: italic;">
4424
4425
4426
4427 <span style="font-style: italic;">output quan-</span><br style="font-style: italic;">
4428
4429
4430
4431 <span style="font-style: italic;">tities</span><br>
4432
4433
4434
4435 </td>
4436
4437
4438
4439
4440      <td style="vertical-align: top;">Defines the accuracy of
4441the NetCDF output.<br>
4442
4443
4444
4445 <br>
4446
4447
4448
4449
4450By default, all NetCDF output data (see <a href="chapter_4.2.html#data_output_format">data_output_format</a>)
4451have single precision&nbsp; (4 byte) accuracy. Double precision (8
4452byte) can be choosen alternatively.<br>
4453
4454
4455
4456
4457Accuracy for the different output data (cross sections, 3d-volume data,
4458spectra, etc.) can be set independently.<br>
4459
4460
4461
4462 <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL4'</span>
4463(single precision) or <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL8'</span>
4464(double precision) are the two principally allowed values for <span style="font-weight: bold;">netcdf_precision</span>,
4465where the string <span style="font-style: italic;">'&lt;out&gt;'
4466      </span>can be chosen out of the following list:<br>
4467
4468
4469
4470 <br>
4471
4472
4473
4474
4475     
4476     
4477     
4478      <table style="text-align: left; width: 284px; height: 234px;" border="1" cellpadding="2" cellspacing="2">
4479
4480
4481
4482 <tbody>
4483
4484
4485
4486
4487          <tr>
4488
4489
4490
4491 <td style="vertical-align: top;"><span style="font-style: italic;">'xy'</span><br>
4492
4493
4494
4495 </td>
4496
4497
4498
4499
4500            <td style="vertical-align: top;">horizontal cross section<br>
4501
4502
4503
4504
4505            </td>
4506
4507
4508
4509 </tr>
4510
4511
4512
4513 <tr>
4514
4515
4516
4517 <td style="vertical-align: top;"><span style="font-style: italic;">'xz'</span><br>
4518
4519
4520
4521 </td>
4522
4523
4524
4525
4526            <td style="vertical-align: top;">vertical (xz) cross
4527section<br>
4528
4529
4530
4531 </td>
4532
4533
4534
4535 </tr>
4536
4537
4538
4539 <tr>
4540
4541
4542
4543 <td style="vertical-align: top;"><span style="font-style: italic;">'yz'</span><br>
4544
4545
4546
4547 </td>
4548
4549
4550
4551
4552            <td style="vertical-align: top;">vertical (yz) cross
4553section<br>
4554
4555
4556
4557 </td>
4558
4559
4560
4561 </tr>
4562
4563
4564
4565 <tr>
4566
4567
4568
4569 <td style="vertical-align: top;"><span style="font-style: italic;">'2d'</span><br>
4570
4571
4572
4573 </td>
4574
4575
4576
4577
4578            <td style="vertical-align: top;">all cross sections<br>
4579
4580
4581
4582
4583            </td>
4584
4585
4586
4587 </tr>
4588
4589
4590
4591 <tr>
4592
4593
4594
4595 <td style="vertical-align: top;"><span style="font-style: italic;">'3d'</span><br>
4596
4597
4598
4599 </td>
4600
4601
4602
4603
4604            <td style="vertical-align: top;">volume data<br>
4605
4606
4607
4608 </td>
4609
4610
4611
4612
4613          </tr>
4614
4615
4616
4617 <tr>
4618
4619
4620
4621 <td style="vertical-align: top;"><span style="font-style: italic;">'pr'</span><br>
4622
4623
4624
4625 </td>
4626
4627
4628
4629
4630            <td style="vertical-align: top;">vertical profiles<br>
4631
4632
4633
4634
4635            </td>
4636
4637
4638
4639 </tr>
4640
4641
4642
4643 <tr>
4644
4645
4646
4647 <td style="vertical-align: top;"><span style="font-style: italic;">'ts'</span><br>
4648
4649
4650
4651 </td>
4652
4653
4654
4655
4656            <td style="vertical-align: top;">time series, particle
4657time series<br>
4658
4659
4660
4661 </td>
4662
4663
4664
4665 </tr>
4666
4667
4668
4669 <tr>
4670
4671
4672
4673 <td style="vertical-align: top;"><span style="font-style: italic;">'sp'</span><br>
4674
4675
4676
4677 </td>
4678
4679
4680
4681
4682            <td style="vertical-align: top;">spectra<br>
4683
4684
4685
4686 </td>
4687
4688
4689
4690
4691          </tr>
4692
4693
4694
4695 <tr>
4696
4697
4698
4699 <td style="vertical-align: top;"><span style="font-style: italic;">'prt'</span><br>
4700
4701
4702
4703 </td>
4704
4705
4706
4707
4708            <td style="vertical-align: top;">particles<br>
4709
4710
4711
4712 </td>
4713
4714
4715
4716
4717          </tr>
4718
4719
4720
4721 <tr>
4722
4723
4724
4725 <td style="vertical-align: top;"><span style="font-style: italic;">'all'</span><br>
4726
4727
4728
4729 </td>
4730
4731
4732
4733
4734            <td style="vertical-align: top;">all output quantities<br>
4735
4736
4737
4738
4739            </td>
4740
4741
4742
4743 </tr>
4744
4745
4746
4747 
4748       
4749       
4750       
4751        </tbody> 
4752     
4753     
4754     
4755      </table>
4756
4757
4758
4759 <br>
4760
4761
4762
4763 <span style="font-weight: bold;">Example:</span><br>
4764
4765
4766
4767
4768If all cross section data and the particle data shall be output in
4769double 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>
4770has to be assigned.<br>
4771
4772
4773
4774 </td>
4775
4776
4777
4778 </tr>
4779
4780
4781
4782
4783    <tr>
4784
4785
4786
4787 <td style="vertical-align: top;"> 
4788     
4789     
4790     
4791      <p><a name="npex"></a><b>npex</b></p>
4792
4793
4794
4795 </td>
4796
4797
4798
4799
4800      <td style="vertical-align: top;">I</td>
4801
4802
4803
4804 <td style="vertical-align: top;"><br>
4805
4806
4807
4808 </td>
4809
4810
4811
4812 <td style="vertical-align: top;"> 
4813     
4814     
4815     
4816      <p>Number of processors
4817along x-direction of the virtual
4818processor
4819net.&nbsp; </p>
4820
4821
4822
4823 
4824     
4825     
4826     
4827      <p>For parallel runs, the total
4828number of processors to be used
4829is given by
4830the <span style="font-weight: bold;">mrun</span>
4831option <a href="http://www.muk.uni-hannover.de/software/mrun_beschreibung.html#Opt-X">-X</a>.
4832By default, depending on the type of the parallel computer, PALM
4833generates a 1d processor
4834net (domain decomposition along x, <span style="font-weight: bold;">npey</span>
4835= <span style="font-style: italic;">1</span>) or a
48362d-net (this is
4837favored on machines with fast communication network). In case of a
48382d-net, it is tried to make it more or less square-shaped. If, for
4839example, 16 processors are assigned (-X 16), a 4 * 4 processor net is
4840generated (<span style="font-weight: bold;">npex</span>
4841= <span style="font-style: italic;">4</span>, <span style="font-weight: bold;">npey</span>
4842= <span style="font-style: italic;">4</span>).
4843This choice is optimal for square total domains (<a href="#nx">nx</a>
4844= <a href="#ny">ny</a>),
4845since then the number of ghost points at the lateral boundarys of
4846the subdomains is minimal. If <span style="font-weight: bold;">nx</span>
4847nd <span style="font-weight: bold;">ny</span>
4848differ extremely, the
4849processor 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>
4850
4851
4852
4853
4854     
4855     
4856     
4857      <p><b>Important:</b> The value of <span style="font-weight: bold;">npex</span> * <span style="font-weight: bold;">npey</span> must exactly
4858correspond to the
4859value assigned by the <span style="font-weight: bold;">mrun</span>-option
4860      <tt>-X</tt>.
4861Otherwise the model run will abort with a corresponding error
4862message.&nbsp; <br>
4863
4864
4865
4866
4867Additionally, the specification of <span style="font-weight: bold;">npex</span>
4868and <span style="font-weight: bold;">npey</span>
4869may of course
4870override the default setting for the domain decomposition (1d or 2d)
4871which may have a significant (negative) effect on the code performance.
4872      </p>
4873
4874
4875
4876 </td>
4877
4878
4879
4880 </tr>
4881
4882
4883
4884 <tr>
4885
4886
4887
4888 <td style="vertical-align: top;"> 
4889     
4890     
4891     
4892      <p><a name="npey"></a><b>npey</b></p>
4893
4894
4895
4896
4897      </td>
4898
4899
4900
4901 <td style="vertical-align: top;">I</td>
4902
4903
4904
4905
4906      <td style="vertical-align: top;"><br>
4907
4908
4909
4910 </td>
4911
4912
4913
4914 <td style="vertical-align: top;"> 
4915     
4916     
4917     
4918      <p>Number of processors
4919along y-direction of the virtual
4920processor
4921net.&nbsp; </p>
4922
4923
4924
4925 
4926     
4927     
4928     
4929      <p>For further information see <a href="#npex">npex</a>.</p>
4930
4931
4932
4933 </td>
4934
4935
4936
4937 </tr>
4938
4939
4940
4941
4942    <tr>
4943
4944
4945
4946 <td style="vertical-align: top;"> 
4947     
4948     
4949     
4950      <p><a name="nsor_ini"></a><b>nsor_ini</b></p>
4951
4952
4953
4954
4955      </td>
4956
4957
4958
4959 <td style="vertical-align: top;">I</td>
4960
4961
4962
4963
4964      <td style="vertical-align: top;"><i>100</i></td>
4965
4966
4967
4968
4969      <td style="vertical-align: top;"> 
4970     
4971     
4972     
4973      <p>Initial number
4974of iterations with the SOR algorithm.&nbsp; </p>
4975
4976
4977
4978 
4979     
4980     
4981     
4982      <p>This
4983parameter is only effective if the SOR algorithm was
4984selected as the pressure solver scheme (<a href="chapter_4.2.html#psolver">psolver</a>
4985= <span style="font-style: italic;">'sor'</span>)
4986and specifies the
4987number of initial iterations of the SOR
4988scheme (at t = 0). The number of subsequent iterations at the following
4989timesteps is determined
4990with the parameter <a href="#nsor">nsor</a>.
4991Usually <b>nsor</b> &lt; <b>nsor_ini</b>,
4992since in each case
4993subsequent calls to <a href="chapter_4.2.html#psolver">psolver</a>
4994use the solution of the previous call as initial value. Suitable
4995test runs should determine whether sufficient convergence of the
4996solution is obtained with the default value and if necessary the value
4997of <b>nsor_ini</b> should be changed.</p>
4998
4999
5000
5001 </td>
5002
5003
5004
5005
5006    </tr>
5007
5008
5009
5010 <tr>
5011
5012
5013
5014 <td style="vertical-align: top;">
5015     
5016     
5017     
5018      <p><a name="nx"></a><b>nx</b></p>
5019
5020
5021
5022
5023      </td>
5024
5025
5026
5027 <td style="vertical-align: top;">I</td>
5028
5029
5030
5031
5032      <td style="vertical-align: top;"><br>
5033
5034
5035
5036 </td>
5037
5038
5039
5040 <td style="vertical-align: top;"> 
5041     
5042     
5043     
5044      <p>Number of grid
5045points in x-direction.&nbsp; </p>
5046
5047
5048
5049 
5050     
5051     
5052     
5053      <p>A value for this
5054parameter must be assigned. Since the lower
5055array bound in PALM
5056starts with i = 0, the actual number of grid points is equal to <b>nx+1</b>.
5057In case of cyclic boundary conditions along x, the domain size is (<b>nx+1</b>)*
5058      <a href="#dx">dx</a>.</p>
5059
5060
5061
5062 
5063     
5064     
5065     
5066      <p>For
5067parallel runs, in case of <a href="#grid_matching">grid_matching</a>
5068= <span style="font-style: italic;">'strict'</span>,
5069      <b>nx+1</b> must
5070be an integral multiple
5071of the processor numbers (see <a href="#npex">npex</a>
5072and <a href="#npey">npey</a>)
5073along x- as well as along y-direction (due to data
5074transposition restrictions).</p>
5075
5076
5077
5078     
5079     
5080     
5081      <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>
5082and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
5083
5084
5085
5086 </td>
5087
5088
5089
5090 </tr>
5091
5092
5093
5094 <tr>
5095
5096
5097
5098
5099      <td style="vertical-align: top;"> 
5100     
5101     
5102     
5103      <p><a name="ny"></a><b>ny</b></p>
5104
5105
5106
5107
5108      </td>
5109
5110
5111
5112 <td style="vertical-align: top;">I</td>
5113
5114
5115
5116
5117      <td style="vertical-align: top;"><br>
5118
5119
5120
5121 </td>
5122
5123
5124
5125 <td style="vertical-align: top;"> 
5126     
5127     
5128     
5129      <p>Number of grid
5130points in y-direction.&nbsp; </p>
5131
5132
5133
5134 
5135     
5136     
5137     
5138      <p>A value for this
5139parameter must be assigned. Since the lower
5140array bound in PALM starts with j = 0, the actual number of grid points
5141is equal to <b>ny+1</b>. In case of cyclic boundary
5142conditions along
5143y, the domain size is (<b>ny+1</b>) * <a href="#dy">dy</a>.</p>
5144
5145
5146
5147
5148     
5149     
5150     
5151      <p>For parallel runs, in case of <a href="#grid_matching">grid_matching</a>
5152= <span style="font-style: italic;">'strict'</span>,
5153      <b>ny+1</b> must
5154be an integral multiple
5155of the processor numbers (see <a href="#npex">npex</a>
5156and <a href="#npey">npey</a>)&nbsp;
5157along y- as well as along x-direction (due to data
5158transposition restrictions).</p>
5159
5160
5161
5162     
5163     
5164     
5165      <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>
5166and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
5167
5168
5169
5170 </td>
5171
5172
5173
5174 </tr>
5175
5176
5177
5178 <tr>
5179
5180
5181
5182
5183      <td style="vertical-align: top;"> 
5184     
5185     
5186     
5187      <p><a name="nz"></a><b>nz</b></p>
5188
5189
5190
5191
5192      </td>
5193
5194
5195
5196 <td style="vertical-align: top;">I</td>
5197
5198
5199
5200
5201      <td style="vertical-align: top;"><br>
5202
5203
5204
5205 </td>
5206
5207
5208
5209 <td style="vertical-align: top;"> 
5210     
5211     
5212     
5213      <p>Number of grid
5214points in z-direction.&nbsp; </p>
5215
5216
5217
5218 
5219     
5220     
5221     
5222      <p>A value for this
5223parameter must be assigned. Since the lower
5224array bound in PALM
5225starts with k = 0 and since one additional grid point is added at the
5226top boundary (k = <b>nz+1</b>), the actual number of grid
5227points is <b>nz+2</b>.
5228However, the prognostic equations are only solved up to <b>nz</b>
5229(u,
5230v)
5231or up to <b>nz-1</b> (w, scalar quantities). The top
5232boundary for u
5233and v is at k = <b>nz+1</b> (u, v) while at k = <b>nz</b>
5234for all
5235other quantities.&nbsp; </p>
5236
5237
5238
5239 
5240     
5241     
5242     
5243      <p>For parallel
5244runs,&nbsp; in case of <a href="#grid_matching">grid_matching</a>
5245= <span style="font-style: italic;">'strict'</span>,
5246      <b>nz</b> must
5247be an integral multiple of
5248the number of processors in x-direction (due to data transposition
5249restrictions).</p>
5250
5251
5252
5253 </td>
5254
5255
5256
5257 </tr>
5258
5259
5260
5261 <tr>
5262
5263
5264
5265      <td style="vertical-align: top;"><a name="ocean"></a><span style="font-weight: bold;">ocean</span></td>
5266
5267
5268
5269      <td style="vertical-align: top;">L</td>
5270
5271
5272
5273      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
5274
5275
5276
5277      <td style="vertical-align: top;">Parameter to switch on&nbsp;ocean runs.<br>
5278
5279
5280
5281      <br>
5282
5283
5284
5285By 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>
5286
5287
5288
5289      <br>
5290
5291
5292
5293     
5294     
5295     
5296      <ul>
5297
5298
5299
5300        <li>An additional prognostic equation for salinity is solved.</li>
5301
5302
5303
5304        <li>Potential temperature in buoyancy and stability-related terms is replaced by potential density.</li>
5305
5306
5307
5308        <li>Potential
5309density is calculated from the equation of state for seawater after
5310each timestep, using the algorithm proposed by Jackett et al. (2006, J.
5311Atmos. Oceanic Technol., <span style="font-weight: bold;">23</span>, 1709-1728).<br>
5312
5313
5314
5315So far, only the initial hydrostatic pressure is entered into this equation.</li>
5316
5317
5318
5319        <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>
5320
5321
5322
5323        <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>
5324
5325
5326
5327        <li>Zero salinity flux is used as default boundary condition at the bottom of the sea.</li>
5328
5329
5330
5331        <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>
5332
5333
5334
5335     
5336     
5337     
5338      </ul>
5339
5340
5341
5342      <br>
5343
5344
5345
5346Relevant 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>
5347
5348
5349
5350      <br>
5351
5352
5353
5354Section <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>
5355
5356
5357
5358      <br>
5359
5360
5361
5362      <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>
5363      </td>
5364
5365
5366
5367    </tr>
5368
5369
5370
5371    <tr>
5372
5373
5374
5375 <td style="vertical-align: top;"> 
5376     
5377     
5378     
5379      <p><a name="omega"></a><b>omega</b></p>
5380
5381
5382
5383
5384      </td>
5385
5386
5387
5388 <td style="vertical-align: top;">R</td>
5389
5390
5391
5392
5393      <td style="vertical-align: top;"><i>7.29212E-5</i></td>
5394
5395
5396
5397
5398      <td style="vertical-align: top;"> 
5399     
5400     
5401     
5402      <p>Angular
5403velocity of the rotating system (in rad s<sup>-1</sup>).&nbsp;
5404      </p>
5405
5406
5407
5408 
5409     
5410     
5411     
5412      <p>The angular velocity of the earth is set by
5413default. The
5414values
5415of the Coriolis parameters are calculated as:&nbsp; </p>
5416
5417
5418
5419 
5420     
5421     
5422     
5423      <ul>
5424
5425
5426
5427
5428       
5429       
5430       
5431        <p>f = 2.0 * <b>omega</b> * sin(<a href="#phi">phi</a>)&nbsp;
5432        <br>
5433
5434
5435
5436f* = 2.0 * <b>omega</b> * cos(<a href="#phi">phi</a>)</p>
5437
5438
5439
5440
5441     
5442     
5443     
5444      </ul>
5445
5446
5447
5448 </td>
5449
5450
5451
5452 </tr>
5453
5454
5455
5456 <tr>
5457
5458
5459
5460 <td style="vertical-align: top;"> 
5461     
5462     
5463     
5464      <p><a name="outflow_damping_width"></a><b>outflow_damping_width</b></p>
5465
5466
5467
5468
5469      </td>
5470
5471
5472
5473 <td style="vertical-align: top;">I</td>
5474
5475
5476
5477
5478      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(20,
5479nx/2</span> or <span style="font-style: italic;">ny/2)</span></td>
5480
5481
5482
5483
5484      <td style="vertical-align: top;">Width of
5485the damping range in the vicinity of the outflow (gridpoints).<br>
5486
5487
5488
5489
5490      <br>
5491
5492
5493
5494
5495When using non-cyclic lateral boundaries (see <a href="chapter_4.1.html#bc_lr">bc_lr</a>
5496or <a href="chapter_4.1.html#bc_ns">bc_ns</a>),
5497a smoothing has to be applied to the
5498velocity field in the vicinity of the outflow in order to suppress any
5499reflections of outgoing disturbances. This parameter controlls the
5500horizontal range to which the smoothing is applied. The range is given
5501in gridpoints counted from the respective outflow boundary. For further
5502details about the smoothing see parameter <a href="chapter_4.1.html#km_damp_max">km_damp_max</a>,
5503which defines the magnitude of the damping.</td>
5504
5505
5506
5507 </tr>
5508
5509
5510
5511
5512    <tr>
5513
5514
5515
5516 <td style="vertical-align: top;"> 
5517     
5518     
5519     
5520      <p><a name="overshoot_limit_e"></a><b>overshoot_limit_e</b></p>
5521
5522
5523
5524
5525      </td>
5526
5527
5528
5529 <td style="vertical-align: top;">R</td>
5530
5531
5532
5533
5534      <td style="vertical-align: top;"><i>0.0</i></td>
5535
5536
5537
5538
5539      <td style="vertical-align: top;"> 
5540     
5541     
5542     
5543      <p>Allowed limit
5544for the overshooting of subgrid-scale TKE in
5545case that the upstream-spline scheme is switched on (in m<sup>2</sup>/s<sup>2</sup>).&nbsp;
5546      </p>
5547
5548
5549
5550 
5551     
5552     
5553     
5554      <p>By deafult, if cut-off of overshoots is switched
5555on for the
5556upstream-spline scheme (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>),
5557no overshoots are permitted at all. If <b>overshoot_limit_e</b>
5558is given a non-zero value, overshoots with the respective
5559amplitude (both upward and downward) are allowed.&nbsp; </p>
5560
5561
5562
5563
5564     
5565     
5566     
5567      <p>Only positive values are allowed for <b>overshoot_limit_e</b>.</p>
5568
5569
5570
5571
5572      </td>
5573
5574
5575
5576 </tr>
5577
5578
5579
5580 <tr>
5581
5582
5583
5584 <td style="vertical-align: top;"> 
5585     
5586     
5587     
5588      <p><a name="overshoot_limit_pt"></a><b>overshoot_limit_pt</b></p>
5589
5590
5591
5592
5593      </td>
5594
5595
5596
5597 <td style="vertical-align: top;">R</td>
5598
5599
5600
5601
5602      <td style="vertical-align: top;"><i>0.0</i></td>
5603
5604
5605
5606
5607      <td style="vertical-align: top;"> 
5608     
5609     
5610     
5611      <p>Allowed limit
5612for the overshooting of potential temperature in
5613case that the upstream-spline scheme is switched on (in K).&nbsp; </p>
5614
5615
5616
5617
5618     
5619     
5620     
5621      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5622      </p>
5623
5624
5625
5626 
5627     
5628     
5629     
5630      <p>Only positive values are allowed for <b>overshoot_limit_pt</b>.</p>
5631
5632
5633
5634
5635      </td>
5636
5637
5638
5639 </tr>
5640
5641
5642
5643 <tr>
5644
5645
5646
5647 <td style="vertical-align: top;"> 
5648     
5649     
5650     
5651      <p><a name="overshoot_limit_u"></a><b>overshoot_limit_u</b></p>
5652
5653
5654
5655
5656      </td>
5657
5658
5659
5660 <td style="vertical-align: top;">R</td>
5661
5662
5663
5664
5665      <td style="vertical-align: top;"><i>0.0</i></td>
5666
5667
5668
5669
5670      <td style="vertical-align: top;">Allowed limit for the
5671overshooting of
5672the u-component of velocity in case that the upstream-spline scheme is
5673switched on (in m/s).
5674     
5675     
5676     
5677      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5678      </p>
5679
5680
5681
5682 
5683     
5684     
5685     
5686      <p>Only positive values are allowed for <b>overshoot_limit_u</b>.</p>
5687
5688
5689
5690
5691      </td>
5692
5693
5694
5695 </tr>
5696
5697
5698
5699 <tr>
5700
5701
5702
5703 <td style="vertical-align: top;"> 
5704     
5705     
5706     
5707      <p><a name="overshoot_limit_v"></a><b>overshoot_limit_v</b></p>
5708
5709
5710
5711
5712      </td>
5713
5714
5715
5716 <td style="vertical-align: top;">R</td>
5717
5718
5719
5720
5721      <td style="vertical-align: top;"><i>0.0</i></td>
5722
5723
5724
5725
5726      <td style="vertical-align: top;"> 
5727     
5728     
5729     
5730      <p>Allowed limit
5731for the overshooting of the v-component of
5732velocity in case that the upstream-spline scheme is switched on
5733(in m/s).&nbsp; </p>
5734
5735
5736
5737 
5738     
5739     
5740     
5741      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5742      </p>
5743
5744
5745
5746 
5747     
5748     
5749     
5750      <p>Only positive values are allowed for <b>overshoot_limit_v</b>.</p>
5751
5752
5753
5754
5755      </td>
5756
5757
5758
5759 </tr>
5760
5761
5762
5763 <tr>
5764
5765
5766
5767 <td style="vertical-align: top;"> 
5768     
5769     
5770     
5771      <p><a name="overshoot_limit_w"></a><b>overshoot_limit_w</b></p>
5772
5773
5774
5775
5776      </td>
5777
5778
5779
5780 <td style="vertical-align: top;">R</td>
5781
5782
5783
5784
5785      <td style="vertical-align: top;"><i>0.0</i></td>
5786
5787
5788
5789
5790      <td style="vertical-align: top;"> 
5791     
5792     
5793     
5794      <p>Allowed limit
5795for the overshooting of the w-component of
5796velocity in case that the upstream-spline scheme is switched on
5797(in m/s).&nbsp; </p>
5798
5799
5800
5801 
5802     
5803     
5804     
5805      <p>For further information see <a href="#overshoot_limit_e">overshoot_limit_e</a>.&nbsp;
5806      </p>
5807
5808
5809
5810 
5811     
5812     
5813     
5814      <p>Only positive values are permitted for <b>overshoot_limit_w</b>.</p>
5815
5816
5817
5818
5819      </td>
5820
5821
5822
5823 </tr>
5824
5825
5826
5827 <tr>
5828
5829
5830
5831 <td style="vertical-align: top;"> 
5832     
5833     
5834     
5835      <p><a name="passive_scalar"></a><b>passive_scalar</b></p>
5836
5837
5838
5839
5840      </td>
5841
5842
5843
5844 <td style="vertical-align: top;">L</td>
5845
5846
5847
5848
5849      <td style="vertical-align: top;"><i>.F.</i></td>
5850
5851
5852
5853
5854      <td style="vertical-align: top;"> 
5855     
5856     
5857     
5858      <p>Parameter to
5859switch on the prognostic equation for a passive
5860scalar. <br>
5861
5862
5863
5864 </p>
5865
5866
5867
5868 
5869     
5870     
5871     
5872      <p>The initial vertical profile
5873of s can be set via parameters <a href="#s_surface">s_surface</a>,
5874      <a href="#s_vertical_gradient">s_vertical_gradient</a>
5875and&nbsp; <a href="#s_vertical_gradient_level">s_vertical_gradient_level</a>.
5876Boundary conditions can be set via <a href="#s_surface_initial_change">s_surface_initial_change</a>
5877and <a href="#surface_scalarflux">surface_scalarflux</a>.&nbsp;
5878      </p>
5879
5880
5881
5882 
5883     
5884     
5885     
5886      <p><b>Note:</b> <br>
5887
5888
5889
5890
5891With <span style="font-weight: bold;">passive_scalar</span>
5892switched
5893on, the simultaneous use of humidity (see&nbsp;<a href="#humidity">humidity</a>)
5894is impossible.</p>
5895
5896
5897
5898 </td>
5899
5900
5901
5902 </tr>
5903
5904
5905
5906 <tr>
5907
5908
5909
5910 <td style="vertical-align: top;"> 
5911     
5912     
5913     
5914      <p><a name="phi"></a><b>phi</b></p>
5915
5916
5917
5918
5919      </td>
5920
5921
5922
5923 <td style="vertical-align: top;">R</td>
5924
5925
5926
5927
5928      <td style="vertical-align: top;"><i>55.0</i></td>
5929
5930
5931
5932
5933      <td style="vertical-align: top;"> 
5934     
5935     
5936     
5937      <p>Geographical
5938latitude (in degrees).&nbsp; </p>
5939
5940
5941
5942 
5943     
5944     
5945     
5946      <p>The value of
5947this parameter determines the value of the
5948Coriolis parameters f and f*, provided that the angular velocity (see <a href="#omega">omega</a>)
5949is non-zero.</p>
5950
5951
5952
5953 </td>
5954
5955
5956
5957 </tr>
5958
5959
5960
5961 <tr>
5962
5963
5964
5965 <td style="vertical-align: top;"> 
5966     
5967     
5968     
5969      <p><a name="prandtl_layer"></a><b>prandtl_layer</b></p>
5970
5971
5972
5973
5974      </td>
5975
5976
5977
5978 <td style="vertical-align: top;">L</td>
5979
5980
5981
5982
5983      <td style="vertical-align: top;"><i>.T.</i></td>
5984
5985
5986
5987
5988      <td style="vertical-align: top;"> 
5989     
5990     
5991     
5992      <p>Parameter to
5993switch on a Prandtl layer.&nbsp; </p>
5994
5995
5996
5997 
5998     
5999     
6000     
6001      <p>By default,
6002a Prandtl layer is switched on at the bottom
6003boundary between z = 0 and z = 0.5 * <a href="#dz">dz</a>
6004(the first computational grid point above ground for u, v and the
6005scalar quantities).
6006In this case, at the bottom boundary, free-slip conditions for u and v
6007(see <a href="#bc_uv_b">bc_uv_b</a>)
6008are not allowed. Likewise, laminar
6009simulations with constant eddy diffusivities (<a href="#km_constant">km_constant</a>)
6010are forbidden.&nbsp; </p>
6011
6012
6013
6014 
6015     
6016     
6017     
6018      <p>With Prandtl-layer
6019switched off, the TKE boundary condition <a href="#bc_e_b">bc_e_b</a>
6020= '<i>(u*)**2+neumann'</i> must not be used and is
6021automatically
6022changed to <i>'neumann'</i> if necessary.&nbsp; Also,
6023the pressure
6024boundary condition <a href="#bc_p_b">bc_p_b</a>
6025= <i>'neumann+inhomo'</i>&nbsp; is not allowed. </p>
6026
6027
6028
6029
6030     
6031     
6032     
6033      <p>The roughness length is declared via the parameter <a href="#roughness_length">roughness_length</a>.</p>
6034
6035
6036
6037
6038      </td>
6039
6040
6041
6042 </tr>
6043
6044
6045
6046 <tr>
6047
6048
6049
6050 <td style="vertical-align: top;"> 
6051     
6052     
6053     
6054      <p><a name="precipitation"></a><b>precipitation</b></p>
6055
6056
6057
6058
6059      </td>
6060
6061
6062
6063 <td style="vertical-align: top;">L</td>
6064
6065
6066
6067
6068      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
6069
6070
6071
6072 <td style="vertical-align: top;"> 
6073     
6074     
6075     
6076      <p>Parameter to switch
6077on the precipitation scheme.<br>
6078
6079
6080
6081 </p>
6082
6083
6084
6085 
6086     
6087     
6088     
6089      <p>For
6090precipitation processes PALM uses a simplified Kessler
6091scheme. This scheme only considers the
6092so-called autoconversion, that means the generation of rain water by
6093coagulation of cloud drops among themselves. Precipitation begins and
6094is immediately removed from the flow as soon as the liquid water
6095content exceeds the critical value of 0.5 g/kg.</p>
6096
6097
6098
6099     
6100     
6101     
6102      <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>
6103
6104
6105
6106 </td>
6107
6108
6109
6110 </tr>
6111
6112
6113
6114
6115    <tr>
6116
6117
6118
6119      <td style="vertical-align: top;"><a name="pt_reference"></a><span style="font-weight: bold;">pt_reference</span></td>
6120
6121
6122
6123      <td style="vertical-align: top;">R</td>
6124
6125
6126
6127      <td style="vertical-align: top;"><span style="font-style: italic;">use horizontal average as
6128refrence</span></td>
6129
6130
6131
6132      <td style="vertical-align: top;">Reference
6133temperature to be used in all buoyancy terms (in K).<br>
6134
6135
6136
6137      <br>
6138
6139
6140
6141By
6142default, the instantaneous horizontal average over the total model
6143domain is used.<br>
6144
6145
6146
6147      <br>
6148
6149
6150
6151      <span style="font-weight: bold;">Attention:</span><br>
6152
6153
6154
6155In 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>
6156
6157
6158
6159    </tr>
6160
6161
6162
6163    <tr>
6164
6165
6166
6167 <td style="vertical-align: top;"> 
6168     
6169     
6170     
6171      <p><a name="pt_surface"></a><b>pt_surface</b></p>
6172
6173
6174
6175
6176      </td>
6177
6178
6179
6180 <td style="vertical-align: top;">R</td>
6181
6182
6183
6184
6185      <td style="vertical-align: top;"><i>300.0</i></td>
6186
6187
6188
6189
6190      <td style="vertical-align: top;"> 
6191     
6192     
6193     
6194      <p>Surface
6195potential temperature (in K).&nbsp; </p>
6196
6197
6198
6199 
6200     
6201     
6202     
6203      <p>This
6204parameter assigns the value of the potential temperature
6205      <span style="font-weight: bold;">pt</span> at the surface (k=0)<b>.</b> Starting from this value,
6206the
6207initial vertical temperature profile is constructed with <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6208and <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level
6209      </a>.
6210This profile is also used for the 1d-model as a stationary profile.</p>
6211
6212
6213
6214     
6215     
6216     
6217      <p><span style="font-weight: bold;">Attention:</span><br>
6218
6219
6220
6221In case of ocean runs (see <a href="#ocean">ocean</a>),
6222this parameter gives the temperature value at the sea surface, which is
6223at k=nzt. The profile is then constructed from the surface down to the
6224bottom of the model.</p>
6225
6226
6227
6228
6229      </td>
6230
6231
6232
6233 </tr>
6234
6235
6236
6237 <tr>
6238
6239
6240
6241 <td style="vertical-align: top;"> 
6242     
6243     
6244     
6245      <p><a name="pt_surface_initial_change"></a><b>pt_surface_initial</b>
6246      <br>
6247
6248
6249
6250 <b>_change</b></p>
6251
6252
6253
6254 </td>
6255
6256
6257
6258 <td style="vertical-align: top;">R</td>
6259
6260
6261
6262 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
6263
6264
6265
6266 </td>
6267
6268
6269
6270
6271      <td style="vertical-align: top;"> 
6272     
6273     
6274     
6275      <p>Change in
6276surface temperature to be made at the beginning of
6277the 3d run
6278(in K).&nbsp; </p>
6279
6280
6281
6282 
6283     
6284     
6285     
6286      <p>If <b>pt_surface_initial_change</b>
6287is set to a non-zero
6288value, the near surface sensible heat flux is not allowed to be given
6289simultaneously (see <a href="#surface_heatflux">surface_heatflux</a>).</p>
6290
6291
6292
6293
6294      </td>
6295
6296
6297
6298 </tr>
6299
6300
6301
6302 <tr>
6303
6304
6305
6306 <td style="vertical-align: top;"> 
6307     
6308     
6309     
6310      <p><a name="pt_vertical_gradient"></a><b>pt_vertical_gradient</b></p>
6311
6312
6313
6314
6315      </td>
6316
6317
6318
6319 <td style="vertical-align: top;">R (10)</td>
6320
6321
6322
6323
6324      <td style="vertical-align: top;"><i>10 * 0.0</i></td>
6325
6326
6327
6328
6329      <td style="vertical-align: top;"> 
6330     
6331     
6332     
6333      <p>Temperature
6334gradient(s) of the initial temperature profile (in
6335K
6336/ 100 m).&nbsp; </p>
6337
6338
6339
6340 
6341     
6342     
6343     
6344      <p>This temperature gradient
6345holds starting from the height&nbsp;
6346level defined by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>
6347(precisely: for all uv levels k where zu(k) &gt;
6348pt_vertical_gradient_level,
6349pt_init(k) is set: pt_init(k) = pt_init(k-1) + dzu(k) * <b>pt_vertical_gradient</b>)
6350up to the top boundary or up to the next height level defined
6351by <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>.
6352A total of 10 different gradients for 11 height intervals (10 intervals
6353if <a href="#pt_vertical_gradient_level">pt_vertical_gradient_level</a>(1)
6354= <i>0.0</i>) can be assigned. The surface temperature is
6355assigned via <a href="#pt_surface">pt_surface</a>.&nbsp;
6356      </p>
6357
6358
6359
6360 
6361     
6362     
6363     
6364      <p>Example:&nbsp; </p>
6365
6366
6367
6368 
6369     
6370     
6371     
6372      <ul>
6373
6374
6375
6376 
6377       
6378       
6379       
6380        <p><b>pt_vertical_gradient</b>
6381= <i>1.0</i>, <i>0.5</i>,&nbsp; <br>
6382
6383
6384
6385
6386        <b>pt_vertical_gradient_level</b> = <i>500.0</i>,
6387        <i>1000.0</i>,</p>
6388
6389
6390
6391 
6392     
6393     
6394     
6395      </ul>
6396
6397
6398
6399 
6400     
6401     
6402     
6403      <p>That
6404defines the temperature profile to be neutrally
6405stratified
6406up to z = 500.0 m with a temperature given by <a href="#pt_surface">pt_surface</a>.
6407For 500.0 m &lt; z &lt;= 1000.0 m the temperature gradient is
64081.0 K /
6409100 m and for z &gt; 1000.0 m up to the top boundary it is
64100.5 K / 100 m (it is assumed that the assigned height levels correspond
6411with uv levels).</p>
6412
6413
6414
6415     
6416     
6417     
6418      <p><span style="font-weight: bold;">Attention:</span><br>
6419
6420
6421
6422In case of ocean runs (see <a href="chapter_4.1.html#ocean">ocean</a>),
6423the profile is constructed like described above, but starting from the
6424sea surface (k=nzt) down to the bottom boundary of the model. Height
6425levels 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>
6426
6427
6428
6429 </td>
6430
6431
6432
6433 </tr>
6434
6435
6436
6437 <tr>
6438
6439
6440
6441 <td style="vertical-align: top;"> 
6442     
6443     
6444     
6445      <p><a name="pt_vertical_gradient_level"></a><b>pt_vertical_gradient</b>
6446      <br>
6447
6448
6449
6450 <b>_level</b></p>
6451
6452
6453
6454 </td>
6455
6456
6457
6458 <td style="vertical-align: top;">R (10)</td>
6459
6460
6461
6462 <td style="vertical-align: top;"> 
6463     
6464     
6465     
6466      <p><i>10 *</i>&nbsp;
6467      <span style="font-style: italic;">0.0</span><br>
6468
6469
6470
6471
6472      </p>
6473
6474
6475
6476 </td>
6477
6478
6479
6480 <td style="vertical-align: top;">
6481     
6482     
6483     
6484      <p>Height level from which on the temperature gradient defined by
6485      <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6486is effective (in m).&nbsp; </p>
6487
6488
6489
6490 
6491     
6492     
6493     
6494      <p>The height levels have to be assigned in ascending order. The
6495default values result in a neutral stratification regardless of the
6496values of <a href="#pt_vertical_gradient">pt_vertical_gradient</a>
6497(unless the top boundary of the model is higher than 100000.0 m).
6498For the piecewise construction of temperature profiles see <a href="#pt_vertical_gradient">pt_vertical_gradient</a>.</p>
6499
6500
6501
6502      <span style="font-weight: bold;">Attention:</span><br>
6503
6504
6505
6506In 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.
6507      </td>
6508
6509
6510
6511 </tr>
6512
6513
6514
6515 <tr>
6516
6517
6518
6519 <td style="vertical-align: top;"> 
6520     
6521     
6522     
6523      <p><a name="q_surface"></a><b>q_surface</b></p>
6524
6525
6526
6527
6528      </td>
6529
6530
6531
6532 <td style="vertical-align: top;">R</td>
6533
6534
6535
6536
6537      <td style="vertical-align: top;"><i>0.0</i></td>
6538
6539
6540
6541
6542      <td style="vertical-align: top;"> 
6543     
6544     
6545     
6546      <p>Surface
6547specific humidity / total water content (kg/kg).&nbsp; </p>
6548
6549
6550
6551 
6552     
6553     
6554     
6555      <p>This
6556parameter assigns the value of the specific humidity q at
6557the surface (k=0).&nbsp; Starting from this value, the initial
6558humidity
6559profile is constructed with&nbsp; <a href="#q_vertical_gradient">q_vertical_gradient</a>
6560and <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>.
6561This profile is also used for the 1d-model as a stationary profile.</p>
6562
6563
6564
6565
6566      </td>
6567
6568
6569
6570 </tr>
6571
6572
6573
6574 <tr>
6575
6576
6577
6578 <td style="vertical-align: top;"> 
6579     
6580     
6581     
6582      <p><a name="q_surface_initial_change"></a><b>q_surface_initial</b>
6583      <br>
6584
6585
6586
6587 <b>_change</b></p>
6588
6589
6590
6591 </td>
6592
6593
6594
6595 <td style="vertical-align: top;">R<br>
6596
6597
6598
6599 </td>
6600
6601
6602
6603 <td style="vertical-align: top;"><i>0.0</i></td>
6604
6605
6606
6607
6608      <td style="vertical-align: top;"> 
6609     
6610     
6611     
6612      <p>Change in
6613surface specific humidity / total water content to
6614be made at the beginning
6615of the 3d run (kg/kg).&nbsp; </p>
6616
6617
6618
6619 
6620     
6621     
6622     
6623      <p>If <b>q_surface_initial_change</b><i>
6624      </i>is set to a
6625non-zero value the
6626near surface latent heat flux (water flux) is not allowed to be given
6627simultaneously (see <a href="#surface_waterflux">surface_waterflux</a>).</p>
6628
6629
6630
6631
6632      </td>
6633
6634
6635
6636 </tr>
6637
6638
6639
6640 <tr>
6641
6642
6643
6644 <td style="vertical-align: top;"> 
6645     
6646     
6647     
6648      <p><a name="q_vertical_gradient"></a><b>q_vertical_gradient</b></p>
6649
6650
6651
6652
6653      </td>
6654
6655
6656
6657 <td style="vertical-align: top;">R (10)</td>
6658
6659
6660
6661
6662      <td style="vertical-align: top;"><i>10 * 0.0</i></td>
6663
6664
6665
6666
6667      <td style="vertical-align: top;"> 
6668     
6669     
6670     
6671      <p>Humidity
6672gradient(s) of the initial humidity profile
6673(in 1/100 m).&nbsp; </p>
6674
6675
6676
6677 
6678     
6679     
6680     
6681      <p>This humidity gradient
6682holds starting from the height
6683level&nbsp; defined by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>
6684(precisely: for all uv levels k, where zu(k) &gt;
6685q_vertical_gradient_level,
6686q_init(k) is set: q_init(k) = q_init(k-1) + dzu(k) * <b>q_vertical_gradient</b>)
6687up to the top boundary or up to the next height level defined
6688by <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>.
6689A total of 10 different gradients for 11 height intervals (10 intervals
6690if <a href="#q_vertical_gradient_level">q_vertical_gradient_level</a>(1)
6691= <i>0.0</i>) can be asigned. The surface humidity is
6692assigned
6693via <a href="#q_surface">q_surface</a>. </p>
6694
6695
6696
6697
6698     
6699     
6700     
6701      <p>Example:&nbsp; </p>
6702
6703
6704
6705 
6706     
6707     
6708     
6709      <ul>
6710
6711
6712
6713 
6714       
6715       
6716       
6717        <p><b>q_vertical_gradient</b>
6718= <i>0.001</i>, <i>0.0005</i>,&nbsp; <br>
6719
6720
6721
6722
6723        <b>q_vertical_gradient_level</b> = <i>500.0</i>,
6724        <i>1000.0</i>,</p>
6725
6726
6727
6728 
6729     
6730     
6731     
6732      </ul>
6733
6734
6735
6736
6737That defines the humidity to be constant with height up to z =
6738500.0
6739m with a
6740value given by <a href="#q_surface">q_surface</a>.
6741For 500.0 m &lt; z &lt;= 1000.0 m the humidity gradient is
67420.001 / 100
6743m and for z &gt; 1000.0 m up to the top boundary it is
67440.0005 / 100 m (it is assumed that the assigned height levels
6745correspond with uv
6746levels). </td>
6747
6748
6749
6750 </tr>
6751
6752
6753
6754 <tr>
6755
6756
6757
6758 <td style="vertical-align: top;"> 
6759     
6760     
6761     
6762      <p><a name="q_vertical_gradient_level"></a><b>q_vertical_gradient</b>
6763      <br>
6764
6765
6766
6767 <b>_level</b></p>
6768
6769
6770
6771 </td>
6772
6773
6774
6775 <td style="vertical-align: top;">R (10)</td>
6776
6777
6778
6779 <td style="vertical-align: top;"> 
6780     
6781     
6782     
6783      <p><i>10 *</i>&nbsp;
6784      <i>0.0</i></p>
6785
6786
6787
6788 </td>
6789
6790
6791
6792 <td style="vertical-align: top;"> 
6793     
6794     
6795     
6796      <p>Height level from
6797which on the humidity gradient defined by <a href="#q_vertical_gradient">q_vertical_gradient</a>
6798is effective (in m).&nbsp; </p>
6799
6800
6801
6802 
6803     
6804     
6805     
6806      <p>The height levels
6807are to be assigned in ascending order. The
6808default values result in a humidity constant with height regardless of
6809the values of <a href="#q_vertical_gradient">q_vertical_gradient</a>
6810(unless the top boundary of the model is higher than 100000.0 m). For
6811the piecewise construction of humidity profiles see <a href="#q_vertical_gradient">q_vertical_gradient</a>.</p>
6812
6813
6814
6815
6816      </td>
6817
6818
6819
6820 </tr>
6821
6822
6823
6824 <tr>
6825
6826
6827
6828 <td style="vertical-align: top;"> 
6829     
6830     
6831     
6832      <p><a name="radiation"></a><b>radiation</b></p>
6833
6834
6835
6836
6837      </td>
6838
6839
6840
6841 <td style="vertical-align: top;">L</td>
6842
6843
6844
6845
6846      <td style="vertical-align: top;"><i>.F.</i></td>
6847
6848
6849
6850
6851      <td style="vertical-align: top;"> 
6852     
6853     
6854     
6855      <p>Parameter to
6856switch on longwave radiation cooling at
6857cloud-tops.&nbsp; </p>
6858
6859
6860
6861 
6862     
6863     
6864     
6865      <p>Long-wave radiation
6866processes are parameterized by the
6867effective emissivity, which considers only the absorption and emission
6868of long-wave radiation at cloud droplets. The radiation scheme can be
6869used only with <a href="#cloud_physics">cloud_physics</a>
6870= .TRUE. .</p>
6871
6872
6873
6874 </td>
6875
6876
6877
6878 </tr>
6879
6880
6881
6882 <tr>
6883
6884
6885
6886 <td style="vertical-align: top;"> 
6887     
6888     
6889     
6890      <p><a name="random_generator"></a><b>random_generator</b></p>
6891
6892
6893
6894
6895      </td>
6896
6897
6898
6899 <td style="vertical-align: top;">C * 20</td>
6900
6901
6902
6903
6904      <td style="vertical-align: top;"> 
6905     
6906     
6907     
6908      <p><i>'numerical</i><br>
6909
6910
6911
6912
6913      <i>recipes'</i></p>
6914
6915
6916
6917 </td>
6918
6919
6920
6921 <td style="vertical-align: top;"> 
6922     
6923     
6924     
6925      <p>Random number
6926generator to be used for creating uniformly
6927distributed random numbers. <br>
6928
6929
6930
6931 </p>
6932
6933
6934
6935 
6936     
6937     
6938     
6939      <p>It is
6940used if random perturbations are to be imposed on the
6941velocity field or on the surface heat flux field (see <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>
6942and <a href="chapter_4.2.html#random_heatflux">random_heatflux</a>).
6943By default, the "Numerical Recipes" random number generator is used.
6944This one provides exactly the same order of random numbers on all
6945different machines and should be used in particular for comparison runs.<br>
6946
6947
6948
6949
6950      <br>
6951
6952
6953
6954
6955Besides, a system-specific generator is available ( <b>random_generator</b>
6956= <i>'system-specific')</i> which should particularly be
6957used for runs
6958on vector parallel computers (NEC), because the default generator
6959cannot be vectorized and therefore significantly drops down the code
6960performance on these machines.<br>
6961
6962
6963
6964 </p>
6965
6966
6967
6968 <span style="font-weight: bold;">Note:</span><br>
6969
6970
6971
6972
6973Results from two otherwise identical model runs will not be comparable
6974one-to-one if they used different random number generators.</td>
6975
6976
6977
6978 </tr>
6979
6980
6981
6982
6983    <tr>
6984
6985
6986
6987 <td style="vertical-align: top;"> 
6988     
6989     
6990     
6991      <p><a name="random_heatflux"></a><b>random_heatflux</b></p>
6992
6993
6994
6995
6996      </td>
6997
6998
6999
7000 <td style="vertical-align: top;">L</td>
7001
7002
7003
7004
7005      <td style="vertical-align: top;"><i>.F.</i></td>
7006
7007
7008
7009
7010      <td style="vertical-align: top;"> 
7011     
7012     
7013     
7014      <p>Parameter to
7015impose random perturbations on the internal two-dimensional near
7016surface heat flux field <span style="font-style: italic;">shf</span>.
7017      <br>
7018
7019
7020
7021 </p>
7022
7023
7024
7025If a near surface heat flux is used as bottom
7026boundary
7027condition (see <a href="#surface_heatflux">surface_heatflux</a>),
7028it is by default assumed to be horizontally homogeneous. Random
7029perturbations can be imposed on the internal
7030two-dimensional&nbsp;heat flux field <span style="font-style: italic;">shf</span> by assigning <b>random_heatflux</b>
7031= <i>.T.</i>. The disturbed heat flux field is calculated
7032by
7033multiplying the
7034values at each mesh point with a normally distributed random number
7035with a mean value and standard deviation of 1. This is repeated after
7036every timestep.<br>
7037
7038
7039
7040 <br>
7041
7042
7043
7044
7045In case of a non-flat <a href="#topography">topography</a>,&nbsp;assigning
7046      <b>random_heatflux</b>
7047= <i>.T.</i> imposes random perturbations on the
7048combined&nbsp;heat
7049flux field <span style="font-style: italic;">shf</span>
7050composed of <a href="#surface_heatflux">surface_heatflux</a>
7051at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a>
7052at the topography top face.</td>
7053
7054
7055
7056 </tr>
7057
7058
7059
7060 <tr>
7061
7062
7063
7064 <td style="vertical-align: top;"> 
7065     
7066     
7067     
7068      <p><a name="rif_max"></a><b>rif_max</b></p>
7069
7070
7071
7072
7073      </td>
7074
7075
7076
7077 <td style="vertical-align: top;">R</td>
7078
7079
7080
7081
7082      <td style="vertical-align: top;"><i>1.0</i></td>
7083
7084
7085
7086
7087      <td style="vertical-align: top;"> 
7088     
7089     
7090     
7091      <p>Upper limit of
7092the flux-Richardson number.&nbsp; </p>
7093
7094
7095
7096 
7097     
7098     
7099     
7100      <p>With the
7101Prandtl layer switched on (see <a href="#prandtl_layer">prandtl_layer</a>),
7102flux-Richardson numbers (rif) are calculated for z=z<sub>p</sub>
7103(k=1)
7104in the 3d-model (in the 1d model for all heights). Their values in
7105particular determine the
7106values of the friction velocity (1d- and 3d-model) and the values of
7107the eddy diffusivity (1d-model). With small wind velocities at the
7108Prandtl layer top or small vertical wind shears in the 1d-model, rif
7109can take up unrealistic large values. They are limited by an upper (<span style="font-weight: bold;">rif_max</span>) and lower
7110limit (see <a href="#rif_min">rif_min</a>)
7111for the flux-Richardson number. The condition <b>rif_max</b>
7112&gt; <b>rif_min</b>
7113must be met.</p>
7114
7115
7116
7117 </td>
7118
7119
7120
7121 </tr>
7122
7123
7124
7125 <tr>
7126
7127
7128
7129 <td style="vertical-align: top;"> 
7130     
7131     
7132     
7133      <p><a name="rif_min"></a><b>rif_min</b></p>
7134
7135
7136
7137
7138      </td>
7139
7140
7141
7142 <td style="vertical-align: top;">R</td>
7143
7144
7145
7146
7147      <td style="vertical-align: top;"><i>- 5.0</i></td>
7148
7149
7150
7151
7152      <td style="vertical-align: top;"> 
7153     
7154     
7155     
7156      <p>Lower limit of
7157the flux-Richardson number.&nbsp; </p>
7158
7159
7160
7161 
7162     
7163     
7164     
7165      <p>For further
7166explanations see <a href="#rif_max">rif_max</a>.
7167The condition <b>rif_max</b> &gt; <b>rif_min </b>must
7168be met.</p>
7169
7170
7171
7172 </td>
7173
7174
7175
7176 </tr>
7177
7178
7179
7180 <tr>
7181
7182
7183
7184 <td style="vertical-align: top;"> 
7185     
7186     
7187     
7188      <p><a name="roughness_length"></a><b>roughness_length</b></p>
7189
7190
7191
7192
7193      </td>
7194
7195
7196
7197 <td style="vertical-align: top;">R</td>
7198
7199
7200
7201
7202      <td style="vertical-align: top;"><i>0.1</i></td>
7203
7204
7205
7206
7207      <td style="vertical-align: top;"> 
7208     
7209     
7210     
7211      <p>Roughness
7212length (in m).&nbsp; </p>
7213
7214
7215
7216 
7217     
7218     
7219     
7220      <p>This parameter is
7221effective only in case that a Prandtl layer
7222is switched
7223on (see <a href="#prandtl_layer">prandtl_layer</a>).</p>
7224
7225
7226
7227
7228      </td>
7229
7230
7231
7232 </tr>
7233
7234
7235
7236 <tr>
7237
7238
7239
7240      <td style="vertical-align: top;"><a name="sa_surface"></a><span style="font-weight: bold;">sa_surface</span></td>
7241
7242
7243
7244      <td style="vertical-align: top;">R</td>
7245
7246
7247
7248      <td style="vertical-align: top;"><span style="font-style: italic;">35.0</span></td>
7249
7250
7251
7252      <td style="vertical-align: top;"> 
7253     
7254     
7255     
7256      <p>Surface salinity (in psu).&nbsp;</p>
7257
7258
7259
7260This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).
7261     
7262     
7263     
7264      <p>This
7265parameter 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,
7266the
7267initial 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>
7268and&nbsp;<a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level
7269      </a>.</p>
7270
7271
7272
7273      </td>
7274
7275
7276
7277    </tr>
7278
7279
7280
7281    <tr>
7282
7283
7284
7285      <td style="vertical-align: top;"><a name="sa_vertical_gradient"></a><span style="font-weight: bold;">sa_vertical_gradient</span></td>
7286
7287
7288
7289      <td style="vertical-align: top;">R(10)</td>
7290
7291
7292
7293      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
7294
7295
7296
7297      <td style="vertical-align: top;">
7298     
7299     
7300     
7301      <p>Salinity gradient(s) of the initial salinity profile (in psu
7302/ 100 m).&nbsp; </p>
7303
7304
7305
7306 
7307     
7308     
7309     
7310      <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p>
7311
7312
7313
7314     
7315     
7316     
7317      <p>This salinity gradient
7318holds starting from the height&nbsp;
7319level defined by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>
7320(precisely: for all uv levels k where zu(k) &lt;
7321sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) =
7322sa_init(k+1) - dzu(k+1) * <b>sa_vertical_gradient</b>) down to the bottom boundary or down to the next height level defined
7323by <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>.
7324A total of 10 different gradients for 11 height intervals (10 intervals
7325if <a href="chapter_4.1.html#sa_vertical_gradient_level">sa_vertical_gradient_level</a>(1)
7326= <i>0.0</i>) can be assigned. The surface salinity at k=nzt is
7327assigned via <a href="chapter_4.1.html#sa_surface">sa_surface</a>.&nbsp;
7328      </p>
7329
7330
7331
7332 
7333     
7334     
7335     
7336      <p>Example:&nbsp; </p>
7337
7338
7339
7340 
7341     
7342     
7343     
7344      <ul>
7345
7346
7347
7348       
7349       
7350       
7351        <p><b>sa_vertical_gradient</b>
7352= <i>1.0</i>, <i>0.5</i>,&nbsp; <br>
7353
7354
7355
7356
7357        <b>sa_vertical_gradient_level</b> = <i>-500.0</i>,
7358-<i>1000.0</i>,</p>
7359
7360
7361
7362     
7363     
7364     
7365      </ul>
7366
7367
7368
7369 
7370     
7371     
7372     
7373      <p>That
7374defines 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>.
7375For -500.0 m &lt; z &lt;= -1000.0 m the salinity gradient is
73761.0 psu /
7377100 m and for z &lt; -1000.0 m down to the bottom boundary it is
73780.5 psu / 100 m (it is assumed that the assigned height levels correspond
7379with uv levels).</p>
7380
7381
7382
7383      </td>
7384
7385
7386
7387    </tr>
7388
7389
7390
7391    <tr>
7392
7393
7394
7395      <td style="vertical-align: top;"><a name="sa_vertical_gradient_level"></a><span style="font-weight: bold;">sa_vertical_gradient_level</span></td>
7396
7397
7398
7399      <td style="vertical-align: top;">R(10)</td>
7400
7401
7402
7403      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
7404
7405
7406
7407      <td style="vertical-align: top;">
7408     
7409     
7410     
7411      <p>Height level from which on the salinity gradient defined by <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>
7412is effective (in m).&nbsp; </p>
7413
7414
7415
7416 
7417     
7418     
7419     
7420      <p>This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).</p>
7421
7422
7423
7424     
7425     
7426     
7427      <p>The height levels have to be assigned in descending order. The
7428default values result in a constant salinity profile regardless of the
7429values of <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>
7430(unless the bottom boundary of the model is lower than -100000.0 m).
7431For the piecewise construction of salinity profiles see <a href="chapter_4.1.html#sa_vertical_gradient">sa_vertical_gradient</a>.</p>
7432
7433
7434
7435      </td>
7436
7437
7438
7439    </tr>
7440
7441
7442
7443    <tr>
7444
7445
7446
7447 <td style="vertical-align: top;"> 
7448     
7449     
7450     
7451      <p><a name="scalar_advec"></a><b>scalar_advec</b></p>
7452
7453
7454
7455
7456      </td>
7457
7458
7459
7460 <td style="vertical-align: top;">C * 10</td>
7461
7462
7463
7464
7465      <td style="vertical-align: top;"><i>'pw-scheme'</i></td>
7466
7467
7468
7469
7470      <td style="vertical-align: top;"> 
7471     
7472     
7473     
7474      <p>Advection
7475scheme to be used for the scalar quantities.&nbsp; </p>
7476
7477
7478
7479 
7480     
7481     
7482     
7483      <p>The
7484user can choose between the following schemes:<br>
7485
7486
7487
7488 </p>
7489
7490
7491
7492 
7493     
7494     
7495     
7496      <p><span style="font-style: italic;">'pw-scheme'</span><br>
7497
7498
7499
7500
7501      </p>
7502
7503
7504
7505 
7506     
7507     
7508     
7509      <div style="margin-left: 40px;">The scheme of
7510Piascek and
7511Williams (1970, J. Comp. Phys., 6,
7512392-405) with central differences in the form C3 is used.<br>
7513
7514
7515
7516
7517If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a>
7518= <span style="font-style: italic;">'leapfrog+euler'</span>
7519the
7520advection scheme is - for the Euler-timestep - automatically switched
7521to an upstream-scheme. <br>
7522
7523
7524
7525 </div>
7526
7527
7528
7529 <br>
7530
7531
7532
7533 
7534     
7535     
7536     
7537      <p><span style="font-style: italic;">'bc-scheme'</span><br>
7538
7539
7540
7541
7542      </p>
7543
7544
7545
7546 
7547     
7548     
7549     
7550      <div style="margin-left: 40px;">The Bott
7551scheme modified by
7552Chlond (1994, Mon.
7553Wea. Rev., 122, 111-125). This is a conservative monotonous scheme with
7554very small numerical diffusion and therefore very good conservation of
7555scalar flow features. The scheme however, is computationally very
7556expensive both because it is expensive itself and because it does (so
7557far) not allow specific code optimizations (e.g. cache optimization).
7558Choice of this
7559scheme forces the Euler timestep scheme to be used for the scalar
7560quantities. For output of horizontally averaged
7561profiles of the resolved / total heat flux, <a href="chapter_4.2.html#data_output_pr">data_output_pr</a>
7562= <i>'w*pt*BC'</i> / <i>'wptBC' </i>should
7563be used, instead of the
7564standard profiles (<span style="font-style: italic;">'w*pt*'</span>
7565and <span style="font-style: italic;">'wpt'</span>)
7566because these are
7567too inaccurate with this scheme. However, for subdomain analysis (see <a href="#statistic_regions">statistic_regions</a>)
7568exactly the reverse holds: here <i>'w*pt*BC'</i> and <i>'wptBC'</i>
7569show very large errors and should not be used.<br>
7570
7571
7572
7573 <br>
7574
7575
7576
7577
7578This scheme is not allowed for non-cyclic lateral boundary conditions
7579(see <a href="#bc_lr">bc_lr</a>
7580and <a href="#bc_ns">bc_ns</a>).<br>
7581
7582
7583
7584 <br>
7585
7586
7587
7588
7589      </div>
7590
7591
7592
7593 <span style="font-style: italic;">'ups-scheme'</span><br>
7594
7595
7596
7597
7598     
7599     
7600     
7601      <p style="margin-left: 40px;">The upstream-spline-scheme
7602is used
7603(see Mahrer and Pielke,
76041978: Mon. Wea. Rev., 106, 818-830). In opposite to the Piascek
7605Williams scheme, this is characterized by much better numerical
7606features (less numerical diffusion, better preservation of flux
7607structures, e.g. vortices), but computationally it is much more
7608expensive. In
7609addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a>
7610= <span style="font-style: italic;">'</span><i>euler'</i>),
7611i.e. the
7612timestep accuracy is only first order. For this reason the advection of
7613momentum (see <a href="#momentum_advec">momentum_advec</a>)
7614should then also be carried out with the upstream-spline scheme,
7615because otherwise the momentum would
7616be subject to large numerical diffusion due to the upstream
7617scheme.&nbsp; </p>
7618
7619
7620
7621 
7622     
7623     
7624     
7625      <p style="margin-left: 40px;">Since
7626the cubic splines used tend
7627to overshoot under
7628certain circumstances, this effect must be adjusted by suitable
7629filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>,
7630      <a href="#long_filter_factor">long_filter_factor</a>,
7631      <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>).
7632This is always neccesssary for runs with stable stratification,
7633even if this stratification appears only in parts of the model
7634domain.&nbsp; </p>
7635
7636
7637
7638 
7639     
7640     
7641     
7642      <p style="margin-left: 40px;">With
7643stable stratification the
7644upstream-upline scheme also produces gravity waves with large
7645amplitude, which must be
7646suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br>
7647
7648
7649
7650
7651      </p>
7652
7653
7654
7655 
7656     
7657     
7658     
7659      <p style="margin-left: 40px;"><span style="font-weight: bold;">Important: </span>The&nbsp;
7660upstream-spline scheme is not implemented for humidity and passive
7661scalars (see&nbsp;<a href="#humidity">humidity</a>
7662and <a href="#passive_scalar">passive_scalar</a>)
7663and requires the use of a 2d-domain-decomposition. The last conditions
7664severely restricts code optimization on several machines leading to
7665very long execution times! This scheme is also not allowed for
7666non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
7667and <a href="#bc_ns">bc_ns</a>).</p>
7668
7669
7670
7671      <br>
7672
7673
7674
7675A
7676differing advection scheme can be choosed for the subgrid-scale TKE
7677using parameter <a href="chapter_4.1.html#use_upstream_for_tke">use_upstream_for_tke</a>.</td>
7678
7679
7680
7681
7682    </tr>
7683
7684
7685
7686 <tr>
7687
7688
7689
7690 <td style="vertical-align: top;">
7691     
7692     
7693     
7694      <p><a name="statistic_regions"></a><b>statistic_regions</b></p>
7695
7696
7697
7698
7699      </td>
7700
7701
7702
7703 <td style="vertical-align: top;">I</td>
7704
7705
7706
7707
7708      <td style="vertical-align: top;"><i>0</i></td>
7709
7710
7711
7712
7713      <td style="vertical-align: top;"> 
7714     
7715     
7716     
7717      <p>Number of
7718additional user-defined subdomains for which
7719statistical analysis
7720and corresponding output (profiles, time series) shall be
7721made.&nbsp; </p>
7722
7723
7724
7725 
7726     
7727     
7728     
7729      <p>By default, vertical profiles and
7730other statistical quantities
7731are calculated as horizontal and/or volume average of the total model
7732domain. Beyond that, these calculations can also be carried out for
7733subdomains which can be defined using the field <a href="chapter_3.5.3.html">rmask </a>within the
7734user-defined software
7735(see <a href="chapter_3.5.3.html">chapter
77363.5.3</a>). The number of these subdomains is determined with the
7737parameter <b>statistic_regions</b>. Maximum 9 additional
7738subdomains
7739are allowed. The parameter <a href="chapter_4.3.html#region">region</a>
7740can be used to assigned names (identifier) to these subdomains which
7741are then used in the headers
7742of the output files and plots.</p>
7743
7744
7745
7746     
7747     
7748     
7749      <p>If the default NetCDF
7750output format is selected (see parameter <a href="chapter_4.2.html#data_output_format">data_output_format</a>),
7751data for the total domain and all defined subdomains are output to the
7752same file(s) (<a href="chapter_3.4.html#DATA_1D_PR_NETCDF">DATA_1D_PR_NETCDF</a>,
7753      <a href="chapter_3.4.html#DATA_1D_TS_NETCDF">DATA_1D_TS_NETCDF</a>).
7754In case of <span style="font-weight: bold;">statistic_regions</span>
7755&gt; <span style="font-style: italic;">0</span>,
7756data on the file for the different domains can be distinguished by a
7757suffix which is appended to the quantity names. Suffix 0 means data for
7758the total domain, suffix 1 means data for subdomain 1, etc.</p>
7759
7760
7761
7762     
7763     
7764     
7765      <p>In
7766case of <span style="font-weight: bold;">data_output_format</span>
7767= <span style="font-style: italic;">'profil'</span>,
7768individual local files for profiles (<a href="chapter_3.4.html#PLOT1D_DATA">PLOT1D_DATA</a>)&nbsp;are
7769created for each subdomain. The individual subdomain files differ by
7770their name (the
7771number of the respective subdomain is attached, e.g.
7772PLOT1D_DATA_1). In this case the name of the file with the data of
7773the total domain is PLOT1D_DATA_0. If no subdomains
7774are declared (<b>statistic_regions</b> = <i>0</i>),
7775the name
7776PLOT1D_DATA is used (this must be considered in the
7777respective file connection statements of the <span style="font-weight: bold;">mrun</span> configuration
7778file).</p>
7779
7780
7781
7782 </td>
7783
7784
7785
7786 </tr>
7787
7788
7789
7790 <tr>
7791
7792
7793
7794 <td style="vertical-align: top;"> 
7795     
7796     
7797     
7798      <p><a name="surface_heatflux"></a><b>surface_heatflux</b></p>
7799
7800
7801
7802
7803      </td>
7804
7805
7806
7807 <td style="vertical-align: top;">R</td>
7808
7809
7810
7811
7812      <td style="vertical-align: top;"><span style="font-style: italic;">no prescribed<br>
7813
7814
7815
7816
7817heatflux<br>
7818
7819
7820
7821 </span></td>
7822
7823
7824
7825 <td style="vertical-align: top;"> 
7826     
7827     
7828     
7829      <p>Kinematic sensible
7830heat flux at the bottom surface (in K m/s).&nbsp; </p>
7831
7832
7833
7834 
7835     
7836     
7837     
7838      <p>If
7839a value is assigned to this parameter, the internal two-dimensional
7840surface heat flux field <span style="font-style: italic;">shf</span>
7841is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span>&nbsp;as
7842bottom (horizontally homogeneous) boundary condition for the
7843temperature equation. This additionally requires that a Neumann
7844condition must be used for the potential temperature (see <a href="#bc_pt_b">bc_pt_b</a>),
7845because otherwise the resolved scale may contribute to
7846the surface flux so that a constant value cannot be guaranteed. Also,
7847changes of the
7848surface temperature (see <a href="#pt_surface_initial_change">pt_surface_initial_change</a>)
7849are not allowed. The parameter <a href="#random_heatflux">random_heatflux</a>
7850can be used to impose random perturbations on the (homogeneous) surface
7851heat
7852flux field <span style="font-style: italic;">shf</span>.&nbsp;</p>
7853
7854
7855
7856
7857     
7858     
7859     
7860      <p>
7861In case of a non-flat <a href="#topography">topography</a>,&nbsp;the
7862internal two-dimensional&nbsp;surface heat
7863flux field <span style="font-style: italic;">shf</span>
7864is initialized with the value of <span style="font-weight: bold;">surface_heatflux</span>
7865at the bottom surface and <a href="#wall_heatflux">wall_heatflux(0)</a>
7866at the topography top face.&nbsp;The parameter<a href="#random_heatflux"> random_heatflux</a>
7867can be used to impose random perturbations on this combined surface
7868heat
7869flux field <span style="font-style: italic;">shf</span>.&nbsp;
7870      </p>
7871
7872
7873
7874 
7875     
7876     
7877     
7878      <p>If no surface heat flux is assigned, <span style="font-style: italic;">shf</span> is calculated
7879at each timestep by u<sub>*</sub> * theta<sub>*</sub>
7880(of course only with <a href="#prandtl_layer">prandtl_layer</a>
7881switched on). Here, u<sub>*</sub>
7882and theta<sub>*</sub> are calculated from the Prandtl law
7883assuming
7884logarithmic wind and temperature
7885profiles between k=0 and k=1. In this case a Dirichlet condition (see <a href="#bc_pt_b">bc_pt_b</a>)
7886must be used as bottom boundary condition for the potential temperature.</p>
7887
7888
7889
7890     
7891     
7892     
7893      <p>See
7894also <a href="#top_heatflux">top_heatflux</a>.</p>
7895
7896
7897
7898
7899      </td>
7900
7901
7902
7903 </tr>
7904
7905
7906
7907 <tr>
7908
7909
7910
7911 <td style="vertical-align: top;"> 
7912     
7913     
7914     
7915      <p><a name="surface_pressure"></a><b>surface_pressure</b></p>
7916
7917
7918
7919
7920      </td>
7921
7922
7923
7924 <td style="vertical-align: top;">R</td>
7925
7926
7927
7928
7929      <td style="vertical-align: top;"><i>1013.25</i></td>
7930
7931
7932
7933
7934      <td style="vertical-align: top;"> 
7935     
7936     
7937     
7938      <p>Atmospheric
7939pressure at the surface (in hPa).&nbsp; </p>
7940
7941
7942
7943
7944Starting from this surface value, the vertical pressure
7945profile is calculated once at the beginning of the run assuming a
7946neutrally stratified
7947atmosphere. This is needed for
7948converting between the liquid water potential temperature and the
7949potential temperature (see <a href="#cloud_physics">cloud_physics</a><span style="text-decoration: underline;"></span>).</td>
7950
7951
7952
7953
7954    </tr>
7955
7956
7957
7958 <tr>
7959
7960
7961
7962 <td style="vertical-align: top;">
7963     
7964     
7965     
7966      <p><a name="surface_scalarflux"></a><b>surface_scalarflux</b></p>
7967
7968
7969
7970
7971      </td>
7972
7973
7974
7975 <td style="vertical-align: top;">R</td>
7976
7977
7978
7979
7980      <td style="vertical-align: top;"><i>0.0</i></td>
7981
7982
7983
7984
7985      <td style="vertical-align: top;"> 
7986     
7987     
7988     
7989      <p>Scalar flux at
7990the surface (in kg/(m<sup>2</sup> s)).&nbsp; </p>
7991
7992
7993
7994
7995     
7996     
7997     
7998