source: palm/trunk/DOC/app/chapter_4.1.html @ 241

Last change on this file since 241 was 241, checked in by letzel, 13 years ago
  • Option to predefine a target bulk velocity for conserve_volume_flow
  • Property svn:keywords set to Id
File size: 223.4 KB
Line 
1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
2<html><head>
3
4
5
6
7
8
9
10 
11 
12 
13 
14 
15 
16  <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
17
18
19
20
21
22
23 
24 
25 
26 
27 
28 
29  <title>PALM chapter 4.1</title></head>
30<body>
31
32
33
34
35
36
37<h3><a name="chapter4.1"></a>4.1
38Initialization parameters</h3>
39
40
41
42
43
44
45
46<br>
47
48
49
50
51
52
53<table style="text-align: left; width: 100%;" border="1" cellpadding="2" cellspacing="2">
54
55
56
57
58
59
60 <tbody>
61
62
63
64
65
66
67
68    <tr>
69
70
71
72
73
74
75 <td style="vertical-align: top;"><font size="4"><b>Parameter name</b></font></td>
76
77
78
79
80
81
82
83      <td style="vertical-align: top;"><font size="4"><b>Type</b></font></td>
84
85
86
87
88
89
90
91      <td style="vertical-align: top;"> 
92     
93     
94     
95     
96     
97     
98      <p><b><font size="4">Default</font></b> <br>
99
100
101
102
103
104
105 <b><font size="4">value</font></b></p>
106
107
108
109
110
111
112 </td>
113
114
115
116
117
118
119
120      <td style="vertical-align: top;"><font size="4"><b>Explanation</b></font></td>
121
122
123
124
125
126
127
128    </tr>
129
130
131
132
133
134
135 <tr>
136
137
138
139
140
141
142 <td style="vertical-align: top;">
143     
144     
145     
146     
147     
148     
149      <p><a name="adjust_mixing_length"></a><b>adjust_mixing_length</b></p>
150
151
152
153
154
155
156
157      </td>
158
159
160
161
162
163
164 <td style="vertical-align: top;">L</td>
165
166
167
168
169
170
171
172      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
173
174
175
176
177
178
179 <td style="vertical-align: top;"> 
180     
181     
182     
183     
184     
185     
186      <p style="font-style: normal;">Near-surface adjustment of the
187mixing length to the Prandtl-layer law.&nbsp; </p>
188
189
190
191
192
193
194 
195     
196     
197     
198     
199     
200     
201      <p>Usually
202the mixing length in LES models l<sub>LES</sub>
203depends (as in PALM) on the grid size and is possibly restricted
204further in case of stable stratification and near the lower wall (see
205parameter <a href="#wall_adjustment">wall_adjustment</a>).
206With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span>
207the Prandtl' mixing length l<sub>PR</sub> = kappa * z/phi
208is calculated
209and the mixing length actually used in the model is set l = MIN (l<sub>LES</sub>,
210l<sub>PR</sub>). This usually gives a decrease of the
211mixing length at
212the bottom boundary and considers the fact that eddy sizes
213decrease in the vicinity of the wall.&nbsp; </p>
214
215
216
217
218
219
220 
221     
222     
223     
224     
225     
226     
227      <p style="font-style: normal;"><b>Warning:</b> So
228far, there is
229no good experience with <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> !&nbsp; </p>
230
231
232
233
234
235
236
237     
238     
239     
240     
241     
242     
243      <p>With <b>adjust_mixing_length</b> = <span style="font-style: italic;">.T.</span> and the
244Prandtl-layer being
245switched on (see <a href="#prandtl_layer">prandtl_layer</a>)
246      <span style="font-style: italic;">'(u*)** 2+neumann'</span>
247should always be set as the lower boundary condition for the TKE (see <a href="#bc_e_b">bc_e_b</a>),
248otherwise the near-surface value of the TKE is not in agreement with
249the Prandtl-layer law (Prandtl-layer law and Prandtl-Kolmogorov-Ansatz
250should provide the same value for K<sub>m</sub>). A warning
251is given,
252if this is not the case.</p>
253
254
255
256
257
258
259 </td>
260
261
262
263
264
265
266 </tr>
267
268
269
270
271
272
273 <tr>
274
275
276
277
278
279
280
281      <td style="vertical-align: top;"> 
282     
283     
284     
285     
286     
287     
288      <p><a name="alpha_surface"></a><b>alpha_surface</b></p>
289
290
291
292
293
294
295
296      </td>
297
298
299
300
301
302
303 <td style="vertical-align: top;">R<br>
304
305
306
307
308
309
310 </td>
311
312
313
314
315
316
317
318      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span><br>
319
320
321
322
323
324
325 </td>
326
327
328
329
330
331
332
333      <td style="vertical-align: top;"> 
334     
335     
336     
337     
338     
339     
340      <p style="font-style: normal;">Inclination of the model domain
341with respect to the horizontal (in degrees).&nbsp; </p>
342
343
344
345
346
347
348 
349     
350     
351     
352     
353     
354     
355      <p style="font-style: normal;">By means of <b>alpha_surface</b>
356the model domain can be inclined in x-direction with respect to the
357horizontal. In this way flows over inclined surfaces (e.g. drainage
358flows, gravity flows) can be simulated. In case of <b>alpha_surface
359      </b>/= <span style="font-style: italic;">0</span>
360the buoyancy term
361appears both in
362the equation of motion of the u-component and of the w-component.<br>
363
364
365
366
367
368
369
370      </p>
371
372
373
374
375
376
377 
378     
379     
380     
381     
382     
383     
384      <p style="font-style: normal;">An inclination
385is only possible in
386case of cyclic horizontal boundary conditions along x AND y (see <a href="#bc_lr">bc_lr</a>
387and <a href="#bc_ns">bc_ns</a>) and <a href="#topography">topography</a> = <span style="font-style: italic;">'flat'</span>. </p>
388
389
390
391
392
393
394
395     
396     
397     
398     
399     
400     
401      <p>Runs with inclined surface still require additional
402user-defined code as well as modifications to the default code. Please
403ask the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/PALM_group.html#0">PALM
404developer&nbsp; group</a>.</p>
405
406
407
408
409
410
411 </td>
412
413
414
415
416
417
418 </tr>
419
420
421
422
423
424
425
426    <tr>
427
428
429
430
431
432
433 <td style="vertical-align: top;"> 
434     
435     
436     
437     
438     
439     
440      <p><a name="bc_e_b"></a><b>bc_e_b</b></p>
441
442
443
444
445
446
447 </td>
448
449
450
451
452
453
454
455      <td style="vertical-align: top;">C * 20</td>
456
457
458
459
460
461
462 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
463
464
465
466
467
468
469
470      <td style="vertical-align: top;"> 
471     
472     
473     
474     
475     
476     
477      <p style="font-style: normal;">Bottom boundary condition of the
478TKE.&nbsp; </p>
479
480
481
482
483
484
485 
486     
487     
488     
489     
490     
491     
492      <p><b>bc_e_b</b> may be
493set to&nbsp;<span style="font-style: italic;">'neumann'</span>
494or <span style="font-style: italic;">'(u*) ** 2+neumann'</span>.
495      <b>bc_e_b</b>
496= <span style="font-style: italic;">'neumann'</span>
497yields to
498e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is calculated
499via the prognostic TKE equation. Choice of <span style="font-style: italic;">'(u*)**2+neumann'</span>
500also yields to
501e(k=0)=e(k=1), but the TKE at the Prandtl-layer top (k=1) is calculated
502diagnostically by e(k=1)=(us/0.1)**2. However, this is only allowed if
503a Prandtl-layer is used (<a href="#prandtl_layer">prandtl_layer</a>).
504If this is not the case, a warning is given and <b>bc_e_b</b>
505is reset
506to <span style="font-style: italic;">'neumann'</span>.&nbsp;
507      </p>
508
509
510
511
512
513
514 
515     
516     
517     
518     
519     
520     
521      <p style="font-style: normal;">At the top
522boundary a Neumann
523boundary condition is generally used: (e(nz+1) = e(nz)).</p>
524
525
526
527
528
529
530 </td>
531
532
533
534
535
536
537
538    </tr>
539
540
541
542
543
544
545 <tr>
546
547
548
549
550
551
552 <td style="vertical-align: top;">
553     
554     
555     
556     
557     
558     
559      <p><a name="bc_lr"></a><b>bc_lr</b></p>
560
561
562
563
564
565
566
567      </td>
568
569
570
571
572
573
574 <td style="vertical-align: top;">C * 20</td>
575
576
577
578
579
580
581
582      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
583
584
585
586
587
588
589
590      <td style="vertical-align: top;">Boundary
591condition along x (for all quantities).<br>
592
593
594
595
596
597
598 <br>
599
600
601
602
603
604
605
606By default, a cyclic boundary condition is used along x.<br>
607
608
609
610
611
612
613 <br>
614
615
616
617
618
619
620
621      <span style="font-weight: bold;">bc_lr</span> may
622also be
623assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
624(inflow from left, outflow to the right) or <span style="font-style: italic;">'radiation/dirichlet'</span>
625(inflow from
626right, outflow to the left). This requires the multi-grid method to be
627used 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>)
628and it also requires cyclic boundary conditions along y (see&nbsp;<a href="#bc_ns">bc_ns</a>).<br>
629
630
631
632
633
634
635 <br>
636
637
638
639
640
641
642
643In case of these non-cyclic lateral boundaries, a Dirichlet condition
644is used at the inflow for all quantities (initial vertical profiles -
645see <a href="#initializing_actions">initializing_actions</a>
646- are fixed during the run) except u, to which a Neumann (zero
647gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
648gradient) condition is used for the scalars. For perturbation
649pressure Neumann (zero gradient) conditions are assumed both at the
650inflow and at the outflow.<br>
651
652
653
654
655
656
657 <br>
658
659
660
661
662
663
664
665When using non-cyclic lateral boundaries, a filter is applied to the
666velocity field in the vicinity of the outflow in order to suppress any
667reflections of outgoing disturbances (see <a href="#km_damp_max">km_damp_max</a>
668and <a href="#outflow_damping_width">outflow_damping_width</a>).<br>
669
670
671
672
673
674
675
676      <br>
677
678
679
680
681
682
683
684In order to maintain a turbulent state of the flow, it may be
685neccessary to continuously impose perturbations on the horizontal
686velocity field in the vicinity of the inflow throughout the whole run.
687This 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>.
688The horizontal range to which these perturbations are applied is
689controlled by the parameters <a href="#inflow_disturbance_begin">inflow_disturbance_begin</a>
690and <a href="#inflow_disturbance_end">inflow_disturbance_end</a>.
691The vertical range and the perturbation amplitude are given by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_b</a>,
692      <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_level_t</a>,
693and <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#psolver">disturbance_amplitude</a>.
694The time interval at which perturbations are to be imposed is set by <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM_group/doc/app/chapter_4.2.html#dt_disturb">dt_disturb</a>.<br>
695
696
697
698
699
700
701
702      <br>
703
704
705
706
707
708
709
710In 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
711at_all_substeps</a> = .T. should be used.<br>
712
713
714
715
716
717
718 <br>
719
720
721
722
723
724
725 <span style="font-weight: bold;">Note:</span><br>
726
727
728
729
730
731
732
733Using non-cyclic lateral boundaries requires very sensitive adjustments
734of the inflow (vertical profiles) and the bottom boundary conditions,
735e.g. a surface heating should not be applied near the inflow boundary
736because this may significantly disturb the inflow. Please check the
737model results very carefully.</td>
738
739
740
741
742
743
744 </tr>
745
746
747
748
749
750
751 <tr>
752
753
754
755
756
757
758 <td style="vertical-align: top;"> 
759     
760     
761     
762     
763     
764     
765      <p><a name="bc_ns"></a><b>bc_ns</b></p>
766
767
768
769
770
771
772
773      </td>
774
775
776
777
778
779
780 <td style="vertical-align: top;">C * 20</td>
781
782
783
784
785
786
787
788      <td style="vertical-align: top;"><span style="font-style: italic;">'cyclic'</span></td>
789
790
791
792
793
794
795
796      <td style="vertical-align: top;">Boundary
797condition along y (for all quantities).<br>
798
799
800
801
802
803
804 <br>
805
806
807
808
809
810
811
812By default, a cyclic boundary condition is used along y.<br>
813
814
815
816
817
818
819 <br>
820
821
822
823
824
825
826
827      <span style="font-weight: bold;">bc_ns</span> may
828also be
829assigned the values <span style="font-style: italic;">'dirichlet/radiation'</span>
830(inflow from rear ("north"), outflow to the front ("south")) or <span style="font-style: italic;">'radiation/dirichlet'</span>
831(inflow from front ("south"), outflow to the rear ("north")). This
832requires the multi-grid
833method to be used for solving the Poisson equation for perturbation
834pressure (see <a href="chapter_4.2.html#psolver">psolver</a>)
835and it also requires cyclic boundary conditions along x (see<br>
836
837
838
839
840
841
842 <a href="#bc_lr">bc_lr</a>).<br>
843
844
845
846
847
848
849 <br>
850
851
852
853
854
855
856
857In case of these non-cyclic lateral boundaries, a Dirichlet condition
858is used at the inflow for all quantities (initial vertical profiles -
859see <a href="chapter_4.1.html#initializing_actions">initializing_actions</a>
860- are fixed during the run) except u, to which a Neumann (zero
861gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero
862gradient) condition is used for the scalars. For perturbation
863pressure Neumann (zero gradient) conditions are assumed both at the
864inflow and at the outflow.<br>
865
866
867
868
869
870
871 <br>
872
873
874
875
876
877
878
879For further details regarding non-cyclic lateral boundary conditions
880see <a href="#bc_lr">bc_lr</a>.</td>
881
882
883
884
885
886
887 </tr>
888
889
890
891
892
893
894
895    <tr>
896
897
898
899
900
901
902 <td style="vertical-align: top;"> 
903     
904     
905     
906     
907     
908     
909      <p><a name="bc_p_b"></a><b>bc_p_b</b></p>
910
911
912
913
914
915
916 </td>
917
918
919
920
921
922
923
924      <td style="vertical-align: top;">C * 20</td>
925
926
927
928
929
930
931 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
932
933
934
935
936
937
938
939      <td style="vertical-align: top;"> 
940     
941     
942     
943     
944     
945     
946      <p style="font-style: normal;">Bottom boundary condition of the
947perturbation pressure.&nbsp; </p>
948
949
950
951
952
953
954 
955     
956     
957     
958     
959     
960     
961      <p>Allowed values
962are <span style="font-style: italic;">'dirichlet'</span>,
963      <span style="font-style: italic;">'neumann'</span>
964and <span style="font-style: italic;">'neumann+inhomo'</span>.&nbsp;
965      <span style="font-style: italic;">'dirichlet'</span>
966sets
967p(k=0)=0.0,&nbsp; <span style="font-style: italic;">'neumann'</span>
968sets p(k=0)=p(k=1). <span style="font-style: italic;">'neumann+inhomo'</span>
969corresponds to an extended Neumann boundary condition where heat flux
970or temperature inhomogeneities near the
971surface (pt(k=1))&nbsp; are additionally regarded (see Shen and
972LeClerc
973(1995, Q.J.R. Meteorol. Soc.,
9741209)). This condition is only permitted with the Prandtl-layer
975switched on (<a href="#prandtl_layer">prandtl_layer</a>),
976otherwise the run is terminated.&nbsp; </p>
977
978
979
980
981
982
983 
984     
985     
986     
987     
988     
989     
990      <p>Since
991at the bottom boundary of the model the vertical
992velocity
993disappears (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>)
994dp/dz = 0 should
995be used, which leaves the vertical component w unchanged when the
996pressure solver is applied. Simultaneous use of the Neumann boundary
997conditions both at the bottom and at the top boundary (<a href="#bc_p_t">bc_p_t</a>)
998usually yields no consistent solution for the perturbation pressure and
999should be avoided.</p>
1000
1001
1002
1003
1004
1005
1006 </td>
1007
1008
1009
1010
1011
1012
1013 </tr>
1014
1015
1016
1017
1018
1019
1020 <tr>
1021
1022
1023
1024
1025
1026
1027 <td style="vertical-align: top;"> 
1028     
1029     
1030     
1031     
1032     
1033     
1034      <p><a name="bc_p_t"></a><b>bc_p_t</b></p>
1035
1036
1037
1038
1039
1040
1041
1042      </td>
1043
1044
1045
1046
1047
1048
1049 <td style="vertical-align: top;">C * 20</td>
1050
1051
1052
1053
1054
1055
1056
1057      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1058
1059
1060
1061
1062
1063
1064
1065      <td style="vertical-align: top;"> 
1066     
1067     
1068     
1069     
1070     
1071     
1072      <p style="font-style: normal;">Top boundary condition of the
1073perturbation pressure.&nbsp; </p>
1074
1075
1076
1077
1078
1079
1080 
1081     
1082     
1083     
1084     
1085     
1086     
1087      <p style="font-style: normal;">Allowed values are <span style="font-style: italic;">'dirichlet'</span>
1088(p(k=nz+1)= 0.0) or <span style="font-style: italic;">'neumann'</span>
1089(p(k=nz+1)=p(k=nz)).&nbsp; </p>
1090
1091
1092
1093
1094
1095
1096 
1097     
1098     
1099     
1100     
1101     
1102     
1103      <p>Simultaneous use
1104of Neumann boundary conditions both at the
1105top and bottom boundary (<a href="#bc_p_b">bc_p_b</a>)
1106usually yields no consistent solution for the perturbation pressure and
1107should be avoided. Since at the bottom boundary the Neumann
1108condition&nbsp; is a good choice (see <a href="#bc_p_b">bc_p_b</a>),
1109a Dirichlet condition should be set at the top boundary.</p>
1110
1111
1112
1113
1114
1115
1116 </td>
1117
1118
1119
1120
1121
1122
1123
1124    </tr>
1125
1126
1127
1128
1129
1130
1131 <tr>
1132
1133
1134
1135
1136
1137
1138 <td style="vertical-align: top;">
1139     
1140     
1141     
1142     
1143     
1144     
1145      <p><a name="bc_pt_b"></a><b>bc_pt_b</b></p>
1146
1147
1148
1149
1150
1151
1152
1153      </td>
1154
1155
1156
1157
1158
1159
1160 <td style="vertical-align: top;">C*20</td>
1161
1162
1163
1164
1165
1166
1167
1168      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1169
1170
1171
1172
1173
1174
1175
1176      <td style="vertical-align: top;"> 
1177     
1178     
1179     
1180     
1181     
1182     
1183      <p style="font-style: normal;">Bottom boundary condition of the
1184potential temperature.&nbsp; </p>
1185
1186
1187
1188
1189
1190
1191 
1192     
1193     
1194     
1195     
1196     
1197     
1198      <p>Allowed values
1199are <span style="font-style: italic;">'dirichlet'</span>
1200(pt(k=0) = const. = <a href="#pt_surface">pt_surface</a>
1201+ <a href="#pt_surface_initial_change">pt_surface_initial_change</a>;
1202the user may change this value during the run using user-defined code)
1203and <span style="font-style: italic;">'neumann'</span>
1204(pt(k=0)=pt(k=1)).&nbsp; <br>
1205
1206
1207
1208
1209
1210
1211
1212When a constant surface sensible heat flux is used (<a href="#surface_heatflux">surface_heatflux</a>), <b>bc_pt_b</b>
1213= <span style="font-style: italic;">'neumann'</span>
1214must be used, because otherwise the resolved scale may contribute to
1215the surface flux so that a constant value cannot be guaranteed.</p>
1216
1217
1218
1219
1220
1221
1222     
1223     
1224     
1225     
1226     
1227     
1228      <p>In the <a href="chapter_3.8.html">coupled</a> atmosphere executable,&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>
1229
1230
1231
1232
1233
1234
1235
1236      </td>
1237
1238
1239
1240
1241
1242
1243 </tr>
1244
1245
1246
1247
1248
1249
1250 <tr>
1251
1252
1253
1254
1255
1256
1257 <td style="vertical-align: top;"> 
1258     
1259     
1260     
1261     
1262     
1263     
1264      <p><a name="pc_pt_t"></a><b>bc_pt_t</b></p>
1265
1266
1267
1268
1269
1270
1271
1272      </td>
1273
1274
1275
1276
1277
1278
1279 <td style="vertical-align: top;">C * 20</td>
1280
1281
1282
1283
1284
1285
1286
1287      <td style="vertical-align: top;"><span style="font-style: italic;">'initial_ gradient'</span></td>
1288
1289
1290
1291
1292
1293
1294
1295      <td style="vertical-align: top;"> 
1296     
1297     
1298     
1299     
1300     
1301     
1302      <p style="font-style: normal;">Top boundary condition of the
1303potential temperature.&nbsp; </p>
1304
1305
1306
1307
1308
1309
1310 
1311     
1312     
1313     
1314     
1315     
1316     
1317      <p>Allowed are the
1318values <span style="font-style: italic;">'dirichlet' </span>(pt(k=nz+1)
1319does not change during the run), <span style="font-style: italic;">'neumann'</span>
1320(pt(k=nz+1)=pt(k=nz)), and <span style="font-style: italic;">'initial_gradient'</span>.
1321With the 'initial_gradient'-condition the value of the temperature
1322gradient at the top is
1323calculated from the initial
1324temperature profile (see <a href="#pt_surface">pt_surface</a>,
1325      <a href="#pt_vertical_gradient">pt_vertical_gradient</a>)
1326by bc_pt_t_val = (pt_init(k=nz+1) -
1327pt_init(k=nz)) / dzu(nz+1).<br>
1328
1329
1330
1331
1332
1333
1334
1335Using this value (assumed constant during the
1336run) the temperature boundary values are calculated as&nbsp; </p>
1337
1338
1339
1340
1341
1342
1343
1344     
1345     
1346     
1347     
1348     
1349     
1350      <ul>
1351
1352
1353
1354
1355
1356
1357 
1358       
1359       
1360       
1361       
1362       
1363       
1364        <p style="font-style: normal;">pt(k=nz+1) =
1365pt(k=nz) +
1366bc_pt_t_val * dzu(nz+1)</p>
1367
1368
1369
1370
1371
1372
1373 
1374     
1375     
1376     
1377     
1378     
1379     
1380      </ul>
1381
1382
1383
1384
1385
1386
1387 
1388     
1389     
1390     
1391     
1392     
1393     
1394      <p style="font-style: normal;">(up to k=nz the prognostic
1395equation for the temperature is solved).<br>
1396
1397
1398
1399
1400
1401
1402
1403When a constant sensible heat flux is used at the top boundary (<a href="chapter_4.1.html#top_heatflux">top_heatflux</a>),
1404      <b>bc_pt_t</b> = <span style="font-style: italic;">'neumann'</span>
1405must be used, because otherwise the resolved scale may contribute to
1406the top flux so that a constant value cannot be guaranteed.</p>
1407
1408
1409
1410
1411
1412
1413 </td>
1414
1415
1416
1417
1418
1419
1420
1421    </tr>
1422
1423
1424
1425
1426
1427
1428 <tr>
1429
1430
1431
1432
1433
1434
1435 <td style="vertical-align: top;">
1436     
1437     
1438     
1439     
1440     
1441     
1442      <p><a name="bc_q_b"></a><b>bc_q_b</b></p>
1443
1444
1445
1446
1447
1448
1449
1450      </td>
1451
1452
1453
1454
1455
1456
1457 <td style="vertical-align: top;">C * 20</td>
1458
1459
1460
1461
1462
1463
1464
1465      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1466
1467
1468
1469
1470
1471
1472
1473      <td style="vertical-align: top;"> 
1474     
1475     
1476     
1477     
1478     
1479     
1480      <p style="font-style: normal;">Bottom boundary condition of the
1481specific humidity / total water content.&nbsp; </p>
1482
1483
1484
1485
1486
1487
1488 
1489     
1490     
1491     
1492     
1493     
1494     
1495      <p>Allowed
1496values are <span style="font-style: italic;">'dirichlet'</span>
1497(q(k=0) = const. = <a href="#q_surface">q_surface</a>
1498+ <a href="#q_surface_initial_change">q_surface_initial_change</a>;
1499the user may change this value during the run using user-defined code)
1500and <span style="font-style: italic;">'neumann'</span>
1501(q(k=0)=q(k=1)).&nbsp; <br>
1502
1503
1504
1505
1506
1507
1508
1509When a constant surface latent heat flux is used (<a href="#surface_waterflux">surface_waterflux</a>), <b>bc_q_b</b>
1510= <span style="font-style: italic;">'neumann'</span>
1511must be used, because otherwise the resolved scale may contribute to
1512the surface flux so that a constant value cannot be guaranteed.</p>
1513
1514
1515
1516
1517
1518
1519
1520      </td>
1521
1522
1523
1524
1525
1526
1527 </tr>
1528
1529
1530
1531
1532
1533
1534 <tr>
1535
1536
1537
1538
1539
1540
1541 <td style="vertical-align: top;"> 
1542     
1543     
1544     
1545     
1546     
1547     
1548      <p><a name="bc_q_t"></a><b>bc_q_t</b></p>
1549
1550
1551
1552
1553
1554
1555
1556      </td>
1557
1558
1559
1560
1561
1562
1563 <td style="vertical-align: top;"><span style="font-style: italic;">C
1564* 20</span></td>
1565
1566
1567
1568
1569
1570
1571 <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1572
1573
1574
1575
1576
1577
1578
1579      <td style="vertical-align: top;"> 
1580     
1581     
1582     
1583     
1584     
1585     
1586      <p style="font-style: normal;">Top boundary condition of the
1587specific humidity / total water content.&nbsp; </p>
1588
1589
1590
1591
1592
1593
1594 
1595     
1596     
1597     
1598     
1599     
1600     
1601      <p>Allowed
1602are the values <span style="font-style: italic;">'dirichlet'</span>
1603(q(k=nz) and q(k=nz+1) do
1604not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1605With the Neumann boundary
1606condition the value of the humidity gradient at the top is calculated
1607from the
1608initial humidity profile (see <a href="#q_surface">q_surface</a>,
1609      <a href="#q_vertical_gradient">q_vertical_gradient</a>)
1610by: bc_q_t_val = ( q_init(k=nz) - q_init(k=nz-1)) / dzu(nz).<br>
1611
1612
1613
1614
1615
1616
1617
1618Using this value (assumed constant during the run) the humidity
1619boundary values
1620are calculated as&nbsp; </p>
1621
1622
1623
1624
1625
1626
1627 
1628     
1629     
1630     
1631     
1632     
1633     
1634      <ul>
1635
1636
1637
1638
1639
1640
1641 
1642       
1643       
1644       
1645       
1646       
1647       
1648        <p style="font-style: normal;">q(k=nz+1) =q(k=nz) +
1649bc_q_t_val * dzu(nz+1)</p>
1650
1651
1652
1653
1654
1655
1656 
1657     
1658     
1659     
1660     
1661     
1662     
1663      </ul>
1664
1665
1666
1667
1668
1669
1670 
1671     
1672     
1673     
1674     
1675     
1676     
1677      <p style="font-style: normal;">(up tp k=nz the prognostic
1678equation for q is solved). </p>
1679
1680
1681
1682
1683
1684
1685 </td>
1686
1687
1688
1689
1690
1691
1692 </tr>
1693
1694
1695
1696
1697
1698
1699 <tr>
1700
1701
1702
1703
1704
1705
1706
1707      <td style="vertical-align: top;"> 
1708     
1709     
1710     
1711     
1712     
1713     
1714      <p><a name="bc_s_b"></a><b>bc_s_b</b></p>
1715
1716
1717
1718
1719
1720
1721 </td>
1722
1723
1724
1725
1726
1727
1728
1729      <td style="vertical-align: top;">C * 20</td>
1730
1731
1732
1733
1734
1735
1736 <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
1737
1738
1739
1740
1741
1742
1743
1744      <td style="vertical-align: top;"> 
1745     
1746     
1747     
1748     
1749     
1750     
1751      <p style="font-style: normal;">Bottom boundary condition of the
1752scalar concentration.&nbsp; </p>
1753
1754
1755
1756
1757
1758
1759 
1760     
1761     
1762     
1763     
1764     
1765     
1766      <p>Allowed values
1767are <span style="font-style: italic;">'dirichlet'</span>
1768(s(k=0) = const. = <a href="#s_surface">s_surface</a>
1769+ <a href="#s_surface_initial_change">s_surface_initial_change</a>;
1770the user may change this value during the run using user-defined code)
1771and <span style="font-style: italic;">'neumann'</span>
1772(s(k=0) =
1773s(k=1)).&nbsp; <br>
1774
1775
1776
1777
1778
1779
1780
1781When a constant surface concentration flux is used (<a href="#surface_scalarflux">surface_scalarflux</a>), <b>bc_s_b</b>
1782= <span style="font-style: italic;">'neumann'</span>
1783must be used, because otherwise the resolved scale may contribute to
1784the surface flux so that a constant value cannot be guaranteed.</p>
1785
1786
1787
1788
1789
1790
1791
1792      </td>
1793
1794
1795
1796
1797
1798
1799 </tr>
1800
1801
1802
1803
1804
1805
1806 <tr>
1807
1808
1809
1810
1811
1812
1813 <td style="vertical-align: top;"> 
1814     
1815     
1816     
1817     
1818     
1819     
1820      <p><a name="bc_s_t"></a><b>bc_s_t</b></p>
1821
1822
1823
1824
1825
1826
1827
1828      </td>
1829
1830
1831
1832
1833
1834
1835 <td style="vertical-align: top;">C * 20</td>
1836
1837
1838
1839
1840
1841
1842
1843      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1844
1845
1846
1847
1848
1849
1850
1851      <td style="vertical-align: top;"> 
1852     
1853     
1854     
1855     
1856     
1857     
1858      <p style="font-style: normal;">Top boundary condition of the
1859scalar concentration.&nbsp; </p>
1860
1861
1862
1863
1864
1865
1866 
1867     
1868     
1869     
1870     
1871     
1872     
1873      <p>Allowed are the
1874values <span style="font-style: italic;">'dirichlet'</span>
1875(s(k=nz) and s(k=nz+1) do
1876not change during the run) and <span style="font-style: italic;">'neumann'</span>.
1877With the Neumann boundary
1878condition the value of the scalar concentration gradient at the top is
1879calculated
1880from the initial scalar concentration profile (see <a href="#s_surface">s_surface</a>, <a href="#s_vertical_gradient">s_vertical_gradient</a>)
1881by: bc_s_t_val = (s_init(k=nz) - s_init(k=nz-1)) / dzu(nz).<br>
1882
1883
1884
1885
1886
1887
1888
1889Using this value (assumed constant during the run) the concentration
1890boundary values
1891are calculated as </p>
1892
1893
1894
1895
1896
1897
1898 
1899     
1900     
1901     
1902     
1903     
1904     
1905      <ul>
1906
1907
1908
1909
1910
1911
1912 
1913       
1914       
1915       
1916       
1917       
1918       
1919        <p style="font-style: normal;">s(k=nz+1) = s(k=nz) +
1920bc_s_t_val * dzu(nz+1)</p>
1921
1922
1923
1924
1925
1926
1927 
1928     
1929     
1930     
1931     
1932     
1933     
1934      </ul>
1935
1936
1937
1938
1939
1940
1941 
1942     
1943     
1944     
1945     
1946     
1947     
1948      <p style="font-style: normal;">(up to k=nz the prognostic
1949equation for the scalar concentration is
1950solved).</p>
1951
1952
1953
1954
1955
1956
1957 </td>
1958
1959
1960
1961
1962
1963
1964 </tr>
1965
1966
1967
1968
1969
1970
1971 <tr>
1972
1973
1974
1975
1976
1977
1978      <td style="vertical-align: top;"><a name="bc_sa_t"></a><span style="font-weight: bold;">bc_sa_t</span></td>
1979
1980
1981
1982
1983
1984
1985      <td style="vertical-align: top;">C * 20</td>
1986
1987
1988
1989
1990
1991
1992      <td style="vertical-align: top;"><span style="font-style: italic;">'neumann'</span></td>
1993
1994
1995
1996
1997
1998
1999      <td style="vertical-align: top;">
2000     
2001     
2002     
2003     
2004     
2005     
2006      <p style="font-style: normal;">Top boundary condition of the salinity.&nbsp; </p>
2007
2008
2009
2010
2011
2012
2013 
2014     
2015     
2016     
2017     
2018     
2019     
2020      <p>This parameter only comes into effect for ocean runs (see parameter <a href="#ocean">ocean</a>).</p>
2021
2022
2023
2024
2025
2026
2027     
2028     
2029     
2030     
2031     
2032     
2033      <p style="font-style: normal;">Allowed are the
2034values <span style="font-style: italic;">'dirichlet' </span>(sa(k=nz+1)
2035does not change during the run) and <span style="font-style: italic;">'neumann'</span>
2036(sa(k=nz+1)=sa(k=nz))<span style="font-style: italic;"></span>.&nbsp;<br>
2037
2038
2039
2040
2041
2042
2043      <br>
2044
2045
2046
2047
2048
2049
2050
2051When a constant salinity flux is used at the top boundary (<a href="chapter_4.1.html#top_salinityflux">top_salinityflux</a>),
2052      <b>bc_sa_t</b> = <span style="font-style: italic;">'neumann'</span>
2053must be used, because otherwise the resolved scale may contribute to
2054the top flux so that a constant value cannot be guaranteed.</p>
2055
2056
2057
2058
2059
2060
2061      </td>
2062
2063
2064
2065
2066
2067
2068    </tr>
2069
2070
2071
2072
2073
2074
2075    <tr>
2076
2077
2078
2079
2080
2081
2082 <td style="vertical-align: top;"> 
2083     
2084     
2085     
2086     
2087     
2088     
2089      <p><a name="bc_uv_b"></a><b>bc_uv_b</b></p>
2090
2091
2092
2093
2094
2095
2096
2097      </td>
2098
2099
2100
2101
2102
2103
2104 <td style="vertical-align: top;">C * 20</td>
2105
2106
2107
2108
2109
2110
2111
2112      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
2113
2114
2115
2116
2117
2118
2119
2120      <td style="vertical-align: top;"> 
2121     
2122     
2123     
2124     
2125     
2126     
2127      <p style="font-style: normal;">Bottom boundary condition of the
2128horizontal velocity components u and v.&nbsp; </p>
2129
2130
2131
2132
2133
2134
2135 
2136     
2137     
2138     
2139     
2140     
2141     
2142      <p>Allowed
2143values are <span style="font-style: italic;">'dirichlet' </span>and
2144      <span style="font-style: italic;">'neumann'</span>. <b>bc_uv_b</b>
2145= <span style="font-style: italic;">'dirichlet'</span>
2146yields the
2147no-slip condition with u=v=0 at the bottom. Due to the staggered grid
2148u(k=0) and v(k=0) are located at z = - 0,5 * <a href="#dz">dz</a>
2149(below the bottom), while u(k=1) and v(k=1) are located at z = +0,5 *
2150dz. u=v=0 at the bottom is guaranteed using mirror boundary
2151condition:&nbsp; </p>
2152
2153
2154
2155
2156
2157
2158 
2159     
2160     
2161     
2162     
2163     
2164     
2165      <ul>
2166
2167
2168
2169
2170
2171
2172 
2173       
2174       
2175       
2176       
2177       
2178       
2179        <p style="font-style: normal;">u(k=0) = - u(k=1) and v(k=0) = -
2180v(k=1)</p>
2181
2182
2183
2184
2185
2186
2187 
2188     
2189     
2190     
2191     
2192     
2193     
2194      </ul>
2195
2196
2197
2198
2199
2200
2201 
2202     
2203     
2204     
2205     
2206     
2207     
2208      <p style="font-style: normal;">The
2209Neumann boundary condition
2210yields the free-slip condition with u(k=0) = u(k=1) and v(k=0) =
2211v(k=1).
2212With Prandtl - layer switched on, the free-slip condition is not
2213allowed (otherwise the run will be terminated)<font color="#000000">.</font></p>
2214
2215
2216
2217
2218
2219
2220
2221      </td>
2222
2223
2224
2225
2226
2227
2228 </tr>
2229
2230
2231
2232
2233
2234
2235 <tr>
2236
2237
2238
2239
2240
2241
2242 <td style="vertical-align: top;"> 
2243     
2244     
2245     
2246     
2247     
2248     
2249      <p><a name="bc_uv_t"></a><b>bc_uv_t</b></p>
2250
2251
2252
2253
2254
2255
2256
2257      </td>
2258
2259
2260
2261
2262
2263
2264 <td style="vertical-align: top;">C * 20</td>
2265
2266
2267
2268
2269
2270
2271
2272      <td style="vertical-align: top;"><span style="font-style: italic;">'dirichlet'</span></td>
2273
2274
2275
2276
2277
2278
2279
2280      <td style="vertical-align: top;"> 
2281     
2282     
2283     
2284     
2285     
2286     
2287      <p style="font-style: normal;">Top boundary condition of the
2288horizontal velocity components u and v.&nbsp; </p>
2289
2290
2291
2292
2293
2294
2295 
2296     
2297     
2298     
2299     
2300     
2301     
2302      <p>Allowed
2303values are <span style="font-style: italic;">'dirichlet'</span>, <span style="font-style: italic;">'dirichlet_0'</span>
2304and <span style="font-style: italic;">'neumann'</span>.
2305The
2306Dirichlet condition yields u(k=nz+1) = ug(nz+1) and v(k=nz+1) =
2307vg(nz+1),
2308Neumann condition yields the free-slip condition with u(k=nz+1) =
2309u(k=nz) and v(k=nz+1) = v(k=nz) (up to k=nz the prognostic equations
2310for the velocities are solved). The special condition&nbsp;<span style="font-style: italic;">'dirichlet_0'</span> can be used for channel flow, it yields the no-slip condition u(k=nz+1) = ug(nz+1) = 0 and v(k=nz+1) =
2311vg(nz+1) = 0.</p>
2312
2313
2314
2315
2316
2317
2318     
2319     
2320     
2321     
2322     
2323     
2324      <p>In the <a href="chapter_3.8.html">coupled</a> ocean executable, <a href="chapter_4.2.html#bc_uv_t">bc_uv_t</a>&nbsp;is internally set ('neumann') and does not need to be prescribed.</p>
2325
2326
2327
2328
2329
2330
2331 </td>
2332
2333
2334
2335
2336
2337
2338 </tr>
2339
2340
2341
2342
2343
2344
2345 <tr>
2346
2347
2348
2349
2350
2351
2352      <td style="vertical-align: top;"><a name="bottom_salinityflux"></a><span style="font-weight: bold;">bottom_salinityflux</span></td>
2353
2354
2355
2356
2357
2358
2359      <td style="vertical-align: top;">R</td>
2360
2361
2362
2363
2364
2365
2366      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
2367
2368
2369
2370
2371
2372
2373      <td style="vertical-align: top;">
2374     
2375     
2376     
2377     
2378     
2379     
2380      <p>Kinematic salinity flux near the surface (in psu m/s).&nbsp;</p>
2381
2382
2383
2384
2385
2386
2387This parameter only comes into effect for ocean runs (see parameter <a href="chapter_4.1.html#ocean">ocean</a>).
2388     
2389     
2390     
2391     
2392     
2393     
2394      <p>The
2395respective salinity flux value is used
2396as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann
2397condition must be used for the salinity, which is currently the only available condition.<br>
2398
2399
2400
2401
2402
2403
2404 </p>
2405
2406
2407
2408
2409
2410
2411 </td>
2412
2413
2414
2415
2416
2417
2418    </tr>
2419
2420
2421
2422
2423
2424
2425    <tr>
2426
2427
2428
2429
2430
2431
2432
2433      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_height"></a>building_height</span></td>
2434
2435
2436
2437
2438
2439
2440
2441      <td style="vertical-align: top;">R</td>
2442
2443
2444
2445
2446
2447
2448 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
2449
2450
2451
2452
2453
2454
2455 <td>Height
2456of a single building in m.<br>
2457
2458
2459
2460
2461
2462
2463 <br>
2464
2465
2466
2467
2468
2469
2470 <span style="font-weight: bold;">building_height</span> must
2471be less than the height of the model domain. This parameter requires
2472the use of&nbsp;<a href="#topography">topography</a>
2473= <span style="font-style: italic;">'single_building'</span>.</td>
2474
2475
2476
2477
2478
2479
2480
2481    </tr>
2482
2483
2484
2485
2486
2487
2488 <tr>
2489
2490
2491
2492
2493
2494
2495 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_x"></a>building_length_x</span></td>
2496
2497
2498
2499
2500
2501
2502
2503      <td style="vertical-align: top;">R</td>
2504
2505
2506
2507
2508
2509
2510 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
2511
2512
2513
2514
2515
2516
2517 <td><span style="font-style: italic;"></span>Width of a single
2518building in m.<br>
2519
2520
2521
2522
2523
2524
2525 <br>
2526
2527
2528
2529
2530
2531
2532
2533Currently, <span style="font-weight: bold;">building_length_x</span>
2534must be at least <span style="font-style: italic;">3
2535*&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>
2536      </span><span style="font-style: italic;">- <a href="#building_wall_left">building_wall_left</a></span>.
2537This parameter requires the use of&nbsp;<a href="#topography">topography</a>
2538= <span style="font-style: italic;">'single_building'</span>.</td>
2539
2540
2541
2542
2543
2544
2545
2546    </tr>
2547
2548
2549
2550
2551
2552
2553 <tr>
2554
2555
2556
2557
2558
2559
2560 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_length_y"></a>building_length_y</span></td>
2561
2562
2563
2564
2565
2566
2567
2568      <td style="vertical-align: top;">R</td>
2569
2570
2571
2572
2573
2574
2575 <td style="vertical-align: top;"><span style="font-style: italic;">50.0</span></td>
2576
2577
2578
2579
2580
2581
2582 <td>Depth
2583of a single building in m.<br>
2584
2585
2586
2587
2588
2589
2590 <br>
2591
2592
2593
2594
2595
2596
2597
2598Currently, <span style="font-weight: bold;">building_length_y</span>
2599must be at least <span style="font-style: italic;">3
2600*&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
2601the use of&nbsp;<a href="#topography">topography</a>
2602= <span style="font-style: italic;">'single_building'</span>.</td>
2603
2604
2605
2606
2607
2608
2609
2610    </tr>
2611
2612
2613
2614
2615
2616
2617 <tr>
2618
2619
2620
2621
2622
2623
2624 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_left"></a>building_wall_left</span></td>
2625
2626
2627
2628
2629
2630
2631
2632      <td style="vertical-align: top;">R</td>
2633
2634
2635
2636
2637
2638
2639 <td style="vertical-align: top;"><span style="font-style: italic;">building centered in x-direction</span></td>
2640
2641
2642
2643
2644
2645
2646
2647      <td>x-coordinate of the left building wall (distance between the
2648left building wall and the left border of the model domain) in m.<br>
2649
2650
2651
2652
2653
2654
2655
2656      <br>
2657
2658
2659
2660
2661
2662
2663
2664Currently, <span style="font-weight: bold;">building_wall_left</span>
2665must be at least <span style="font-style: italic;">1
2666*&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;
2667- 1 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a></span>.
2668This parameter requires the use of&nbsp;<a href="#topography">topography</a>
2669= <span style="font-style: italic;">'single_building'</span>.<br>
2670
2671
2672
2673
2674
2675
2676
2677      <br>
2678
2679
2680
2681
2682
2683
2684
2685The default value&nbsp;<span style="font-weight: bold;">building_wall_left</span>
2686= <span style="font-style: italic;">( ( <a href="#nx">nx</a>&nbsp;+
26871 ) * <a href="#dx">dx</a> -&nbsp; <a href="#building_length_x">building_length_x</a> ) / 2</span>
2688centers the building in x-direction.&nbsp;<font color="#000000">Due to the staggered grid the building will be displaced by -0.5 <a href="chapter_4.1.html#dx">dx</a> in x-direction and -0.5 <a href="chapter_4.1.html#dy">dy</a> in y-direction.</font> </td>
2689
2690
2691
2692
2693
2694
2695 </tr>
2696
2697
2698
2699
2700
2701
2702 <tr>
2703
2704
2705
2706
2707
2708
2709
2710      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="building_wall_south"></a>building_wall_south</span></td>
2711
2712
2713
2714
2715
2716
2717
2718      <td style="vertical-align: top;">R</td>
2719
2720
2721
2722
2723
2724
2725 <td style="vertical-align: top;"><span style="font-style: italic;"></span><span style="font-style: italic;">building centered in y-direction</span></td>
2726
2727
2728
2729
2730
2731
2732
2733      <td>y-coordinate of the South building wall (distance between the
2734South building wall and the South border of the model domain) in m.<br>
2735
2736
2737
2738
2739
2740
2741
2742      <br>
2743
2744
2745
2746
2747
2748
2749
2750Currently, <span style="font-weight: bold;">building_wall_south</span>
2751must be at least <span style="font-style: italic;">1
2752*&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;
2753- 1 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a></span>.
2754This parameter requires the use of&nbsp;<a href="#topography">topography</a>
2755= <span style="font-style: italic;">'single_building'</span>.<br>
2756
2757
2758
2759
2760
2761
2762
2763      <br>
2764
2765
2766
2767
2768
2769
2770
2771The default value&nbsp;<span style="font-weight: bold;">building_wall_south</span>
2772= <span style="font-style: italic;">( ( <a href="#ny">ny</a>&nbsp;+
27731 ) * <a href="#dy">dy</a> -&nbsp; <a href="#building_length_y">building_length_y</a> ) / 2</span>
2774centers the building in y-direction.&nbsp;<font color="#000000">Due to the staggered grid the building will be displaced by -0.5 <a href="chapter_4.1.html#dx">dx</a> in x-direction and -0.5 <a href="chapter_4.1.html#dy">dy</a> in y-direction.</font> </td>
2775
2776
2777
2778
2779
2780
2781 </tr>
2782
2783
2784
2785
2786
2787
2788 <tr>
2789
2790      <td style="vertical-align: top;"><a name="canopy_mode"></a><span style="font-weight: bold;">canopy_mode</span></td>
2791
2792      <td style="vertical-align: top;">C * 20</td>
2793
2794      <td style="vertical-align: top;"><span style="font-style: italic;">'block'</span></td>
2795
2796      <td style="vertical-align: top;">Canopy mode.<br>
2797
2798      <br>
2799
2800      <font color="#000000">
2801Besides using the default value, that will create a horizontally
2802homogeneous plant canopy that extends over the total horizontal
2803extension of the model domain, the user may add code to the user
2804interface subroutine <a href="chapter_3.5.1.html#user_init_plant_canopy">user_init_plant_canopy</a>
2805to allow further canopy&nbsp;modes. <br>
2806
2807      <br>
2808
2809The setting of <a href="#canopy_mode">canopy_mode</a> becomes only active, if&nbsp;<a href="#plant_canopy">plant_canopy</a> has been set <span style="font-style: italic;">.T.</span> and a non-zero <a href="#drag_coefficient">drag_coefficient</a> has been defined.</font></td>
2810
2811    </tr>
2812
2813    <tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_height"></a>canyon_height</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">50.0</td><td>Street canyon height
2814in m.<br>
2815
2816
2817
2818
2819
2820
2821 <br>
2822
2823
2824
2825
2826
2827
2828 <span style="font-weight: bold;">canyon_height</span> must
2829be less than the height of the model domain. This parameter requires&nbsp;<a href="chapter_4.1.html#topography">topography</a>
2830= <span style="font-style: italic;">'single_street_canyon'</span>.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_width_x"></a>canyon_width_x</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">9999999.9</td><td>Street canyon width in x-direction in m.<br>
2831
2832
2833
2834
2835
2836
2837 <br>
2838
2839
2840
2841
2842
2843
2844
2845Currently, <span style="font-weight: bold;">canyon_width_x</span>
2846must be at least <span style="font-style: italic;">3
2847*&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#dx">dx</a> and no more than <span style="font-style: italic;">(&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#nx">nx</a><span style="font-style: italic;"> - 1 ) </span><span style="font-style: italic;"> * <a href="chapter_4.1.html#dx">dx</a>
2848      </span><span style="font-style: italic;">- <a href="chapter_4.1.html#canyon_wall_left">canyon_wall_left</a></span>.
2849This parameter requires&nbsp;<a href="chapter_4.1.html#topography">topography</a>
2850= <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>. A non-default value implies a canyon orientation in y-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_width_y"></a>canyon_width_y</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;">9999999.9</td><td>Street canyon width in y-direction in m.<br>
2851
2852
2853
2854
2855
2856
2857 <br>
2858
2859
2860
2861
2862
2863
2864
2865Currently, <span style="font-weight: bold;">canyon_width_y</span>
2866must be at least <span style="font-style: italic;">3
2867*&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#dy">dy</a> and no more than <span style="font-style: italic;">(&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#ny">ny</a><span style="font-style: italic;"> - 1 )&nbsp;</span><span style="font-style: italic;"> * <a href="chapter_4.1.html#dy">dy</a></span><span style="font-style: italic;"> - <a href="chapter_4.1.html#canyon_wall_south">canyon_wall_south</a></span>. This parameter requires&nbsp;<a href="chapter_4.1.html#topography">topography</a>
2868= <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span>.&nbsp;A non-default value implies a canyon orientation in x-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_wall_left"></a>canyon_wall_left</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;"><span style="font-style: italic;">canyon centered in x-direction</span></td><td>x-coordinate of the left canyon wall (distance between the
2869left canyon wall and the left border of the model domain) in m.<br>
2870
2871
2872
2873
2874
2875
2876
2877      <br>
2878
2879
2880
2881
2882
2883
2884
2885Currently, <span style="font-weight: bold;">canyon_wall_left</span>
2886must be at least <span style="font-style: italic;">1
2887*&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#dx">dx</a> and less than <span style="font-style: italic;">( <a href="chapter_4.1.html#nx">nx</a>&nbsp;
2888- 1 ) * <a href="chapter_4.1.html#dx">dx</a> -&nbsp; <a href="chapter_4.1.html#canyon_width_x">canyon_width_x</a></span>.
2889This parameter requires&nbsp;<a href="chapter_4.1.html#topography">topography</a>
2890= <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>.<br>
2891
2892
2893
2894
2895
2896
2897
2898      <br>
2899
2900
2901
2902
2903
2904
2905
2906The default value <span style="font-weight: bold;">canyon_wall_left</span>
2907= <span style="font-style: italic;">( ( <a href="chapter_4.1.html#nx">nx</a>&nbsp;+
29081 ) * <a href="chapter_4.1.html#dx">dx</a> -&nbsp; <a href="chapter_4.1.html#canyon_width_x">canyon_width_x</a> ) / 2</span>
2909centers the canyon in x-direction.</td></tr><tr><td style="font-weight: bold; vertical-align: top;"><a name="canyon_wall_south"></a>canyon_wall_south</td><td style="vertical-align: top;">R</td><td style="font-style: italic; vertical-align: top;"><span style="font-style: italic;">canyon centered in y-direction</span></td><td>y-coordinate of the South canyon wall (distance between the
2910South canyon wall and the South border of the model domain) in m.<br>
2911
2912
2913
2914
2915
2916
2917
2918      <br>
2919
2920
2921
2922
2923
2924
2925
2926Currently, <span style="font-weight: bold;">canyon_wall_south</span>
2927must be at least <span style="font-style: italic;">1
2928*&nbsp;</span><a style="font-style: italic;" href="chapter_4.1.html#dy">dy</a> and less than <span style="font-style: italic;">( <a href="chapter_4.1.html#ny">ny</a>&nbsp;
2929- 1 ) * <a href="chapter_4.1.html#dy">dy</a> -&nbsp; <a href="chapter_4.1.html#canyon_width_y">canyon_width_y</a></span>.
2930This parameter requires&nbsp;<a href="chapter_4.1.html#topography">topography</a>
2931= <span style="font-style: italic;">'</span><span style="font-style: italic;">single_street_canyon</span><span style="font-style: italic;">'</span>.<br>
2932
2933
2934
2935
2936
2937
2938
2939      <br>
2940
2941
2942
2943
2944
2945
2946
2947The default value <span style="font-weight: bold;">canyon_wall_south</span>
2948= <span style="font-style: italic;">( ( <a href="chapter_4.1.html#ny">ny</a>&nbsp;+
29491 ) * <a href="chapter_4.1.html#dy">dy</a> -&nbsp;&nbsp;</span><a href="chapter_4.1.html#building_length_y"><span style="font-style: italic;"></span></a><a style="font-style: italic;" href="chapter_4.1.html#canyon_width_y">canyon_wid</a><span style="font-style: italic;"><a style="font-style: italic;" href="chapter_4.1.html#canyon_width_y">th_y</a> ) / 2</span>
2950centers the canyon in y-direction.</td></tr><tr>
2951
2952
2953
2954
2955
2956
2957
2958      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="cloud_droplets"></a>cloud_droplets</span><br>
2959
2960
2961
2962
2963
2964
2965
2966      </td>
2967
2968
2969
2970
2971
2972
2973 <td style="vertical-align: top;">L<br>
2974
2975
2976
2977
2978
2979
2980 </td>
2981
2982
2983
2984
2985
2986
2987
2988      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span><br>
2989
2990
2991
2992
2993
2994
2995 </td>
2996
2997
2998
2999
3000
3001
3002
3003      <td style="vertical-align: top;">Parameter to switch on
3004usage of cloud droplets.<br>
3005
3006
3007
3008
3009
3010
3011 <br>
3012
3013
3014
3015
3016
3017
3018
3019      <span style="font-weight: bold;"></span><span style="font-family: monospace;"></span>
3020
3021
3022
3023
3024Cloud droplets require to use&nbsp;particles (i.e. the NAMELIST group <span style="font-family: Courier New,Courier,monospace;">particles_par</span> has to be included in the parameter file<span style="font-family: monospace;"></span>). Then each particle is a representative for a certain number of droplets. The droplet
3025features (number of droplets, initial radius, etc.) can be steered with
3026the&nbsp; respective particle parameters (see e.g. <a href="#chapter_4.2.html#radius">radius</a>).
3027The real number of initial droplets in a grid cell is equal to the
3028initial number of droplets (defined by the particle source parameters <span lang="en-GB"><font face="Thorndale, serif"> </font></span><a href="chapter_4.2.html#pst"><span lang="en-GB"><font face="Thorndale, serif">pst</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psl"><span lang="en-GB"><font face="Thorndale, serif">psl</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psr"><span lang="en-GB"><font face="Thorndale, serif">psr</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pss"><span lang="en-GB"><font face="Thorndale, serif">pss</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psn"><span lang="en-GB"><font face="Thorndale, serif">psn</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#psb"><span lang="en-GB"><font face="Thorndale, serif">psb</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdx"><span lang="en-GB"><font face="Thorndale, serif">pdx</font></span></a><span lang="en-GB"><font face="Thorndale, serif">, </font></span><a href="chapter_4.2.html#pdy"><span lang="en-GB"><font face="Thorndale, serif">pdy</font></span></a>
3029      <span lang="en-GB"><font face="Thorndale, serif">and
3030      </font></span><a href="chapter_4.2.html#pdz"><span lang="en-GB"><font face="Thorndale, serif">pdz</font></span></a><span lang="en-GB"></span><span lang="en-GB"></span>)
3031times the <a href="#initial_weighting_factor">initial_weighting_factor</a>.<br>
3032
3033
3034
3035
3036
3037
3038
3039      <br>
3040
3041
3042
3043
3044
3045
3046
3047In case of using cloud droplets, the default condensation scheme in
3048PALM cannot be used, i.e. <a href="#cloud_physics">cloud_physics</a>
3049must be set <span style="font-style: italic;">.F.</span>.<br>
3050
3051
3052
3053
3054
3055
3056
3057      </td>
3058
3059
3060
3061
3062
3063
3064 </tr>
3065
3066
3067
3068
3069
3070
3071 <tr>
3072
3073
3074
3075
3076
3077
3078 <td style="vertical-align: top;"> 
3079     
3080     
3081     
3082     
3083     
3084     
3085      <p><a name="cloud_physics"></a><b>cloud_physics</b></p>
3086
3087
3088
3089
3090
3091
3092
3093      </td>
3094
3095
3096
3097
3098
3099
3100 <td style="vertical-align: top;">L<br>
3101
3102
3103
3104
3105
3106
3107 </td>
3108
3109
3110
3111
3112
3113
3114
3115      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
3116
3117
3118
3119
3120
3121
3122 <td style="vertical-align: top;"> 
3123     
3124     
3125     
3126     
3127     
3128     
3129      <p>Parameter to switch
3130on the condensation scheme.&nbsp; </p>
3131
3132
3133
3134
3135
3136
3137
3138For <b>cloud_physics =</b> <span style="font-style: italic;">.TRUE.</span>, equations
3139for the
3140liquid water&nbsp;
3141content and the liquid water potential temperature are solved instead
3142of those for specific humidity and potential temperature. Note
3143that a grid volume is assumed to be either completely saturated or
3144completely
3145unsaturated (0%-or-100%-scheme). A simple precipitation scheme can
3146additionally be switched on with parameter <a href="#precipitation">precipitation</a>.
3147Also cloud-top cooling by longwave radiation can be utilized (see <a href="#radiation">radiation</a>)<br>
3148
3149
3150
3151
3152
3153
3154 <b><br>
3155
3156
3157
3158
3159
3160
3161
3162cloud_physics =</b> <span style="font-style: italic;">.TRUE.
3163      </span>requires&nbsp;<a href="#humidity">humidity</a>
3164=<span style="font-style: italic;"> .TRUE.</span> .<br>
3165
3166
3167
3168
3169
3170
3171
3172Detailed information about the condensation scheme is given in the
3173description of the <a href="http://www.muk.uni-hannover.de/%7Eraasch/PALM-1/Dokumentationen/Cloud_physics/wolken.pdf">cloud
3174physics module</a> (pdf-file, only in German).<br>
3175
3176
3177
3178
3179
3180
3181 <br>
3182
3183
3184
3185
3186
3187
3188
3189This condensation scheme is not allowed if cloud droplets are simulated
3190explicitly (see <a href="#cloud_droplets">cloud_droplets</a>).<br>
3191
3192
3193
3194
3195
3196
3197
3198      </td>
3199
3200
3201
3202
3203
3204
3205 </tr>
3206
3207
3208
3209
3210
3211
3212 <tr>
3213
3214
3215
3216
3217
3218
3219 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow"></a>conserve_volume_flow</span></td>
3220
3221
3222
3223
3224
3225
3226
3227      <td style="vertical-align: top;">L</td>
3228
3229
3230
3231
3232
3233
3234 <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
3235
3236
3237
3238
3239
3240
3241 <td>Conservation
3242of volume flow in x- and y-direction.<br>
3243
3244
3245
3246
3247
3248
3249 <br>
3250
3251
3252
3253
3254
3255
3256 <span style="font-weight: bold;">conserve_volume_flow</span>
3257= <span style="font-style: italic;">.T.</span>
3258guarantees that the volume flow through the xz- and yz-cross-sections of
3259the total model domain remains constant throughout the run depending on the chosen <a href="#conserve_volume_flow_mode">conserve_volume_flow_mode</a>.<br><br>Note that&nbsp;<span style="font-weight: bold;">conserve_volume_flow</span>
3260= <span style="font-style: italic;">.T.</span> requires <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.F.</span> .<br>
3261
3262
3263
3264
3265
3266
3267
3268      </td>
3269
3270
3271
3272
3273
3274
3275 </tr>
3276
3277
3278
3279
3280
3281
3282 <tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="conserve_volume_flow_mode"></a>conserve_volume_flow_mode</span></td><td style="vertical-align: top;">C * 16</td><td style="vertical-align: top;"><span style="font-style: italic;">'default'</span></td><td>Modus of volume flow conservation.<br><br>The following values are allowed:<br><p style="font-style: normal;"><span style="font-style: italic;">'default'</span>
3283      </p>
3284
3285
3286
3287
3288
3289
3290 
3291     
3292     
3293     
3294     
3295     
3296     
3297      <ul><p>Per default, PALM uses&nbsp;<span style="font-style: italic;">'initial_profiles'</span> for cyclic lateral boundary conditions (<a href="#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>) and&nbsp;<span style="font-style: italic;">'inflow_profile'</span> for non-cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> /= <span style="font-style: italic;">'cyclic'</span> or <a href="chapter_4.1.html#bc_ns">bc_ns</a> /= <span style="font-style: italic;">'cyclic'</span>).</p></ul>
3298
3299
3300
3301
3302
3303
3304 
3305     
3306     
3307     
3308     
3309     
3310     
3311      <p style="font-style: italic;">'initial_profiles' </p>
3312
3313
3314
3315
3316
3317
3318
3319     
3320     
3321     
3322     
3323     
3324     
3325      <ul><p>The target volume flow&nbsp;is calculated at t=0 from the initial profiles of u and v.&nbsp;This setting is only allowed for&nbsp;cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="chapter_4.1.html#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>).</p></ul>
3326
3327
3328
3329
3330
3331
3332 
3333     
3334     
3335     
3336     
3337     
3338     
3339      <p style="font-style: normal;"><span style="font-style: italic;">'inflow_profile'</span>
3340      </p>
3341
3342
3343
3344
3345
3346
3347 
3348     
3349     
3350     
3351     
3352     
3353     
3354      <ul><p>The target volume flow&nbsp;is&nbsp;calculated at every timestep from the inflow profile of&nbsp;u or v, respectively. This setting&nbsp;is only allowed for&nbsp;non-cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> /= <span style="font-style: italic;">'cyclic'</span> or <a href="chapter_4.1.html#bc_ns">bc_ns</a> /= <span style="font-style: italic;">'cyclic'</span>).</p></ul>
3355
3356
3357
3358
3359
3360
3361 
3362     
3363     
3364     
3365     
3366     
3367     
3368      <p style="font-style: italic;">'bulk_velocity' </p>
3369
3370
3371
3372
3373
3374
3375
3376     
3377     
3378     
3379     
3380     
3381     
3382      <ul><p>The target volume flow is calculated from a predefined bulk velocity (see <a href="#u_bulk">u_bulk</a> and <a href="#v_bulk">v_bulk</a>). This setting is only allowed for&nbsp;cyclic lateral boundary conditions (<a href="chapter_4.1.html#bc_lr">bc_lr</a> = <span style="font-style: italic;">'cyclic'</span> and <a href="chapter_4.1.html#bc_ns">bc_ns</a> = <span style="font-style: italic;">'cyclic'</span>).</p></ul>
3383
3384
3385
3386
3387
3388
3389 
3390     
3391     
3392     
3393     
3394     
3395     
3396      <span style="font-style: italic;"></span>Note that&nbsp;<span style="font-weight: bold;">conserve_volume_flow_mode</span>
3397only comes into effect if <a href="#conserve_volume_flow">conserve_volume_flow</a> = <span style="font-style: italic;">.T. .</span> </td></tr><tr>
3398
3399      <td style="vertical-align: top;"><a name="cthf"></a><span style="font-weight: bold;">cthf</span></td>
3400
3401      <td style="vertical-align: top;">R</td>
3402
3403      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
3404
3405      <td style="vertical-align: top;">Average heat flux that is prescribed at the top of the plant canopy.<br>
3406
3407
3408      <br>
3409
3410
3411If <a href="#plant_canopy">plant_canopy</a> is set <span style="font-style: italic;">.T.</span>, the user can prescribe a heat flux at the top of the plant canopy.<br>
3412
3413
3414It is assumed that solar radiation penetrates the canopy and warms the
3415foliage which, in turn, warms the air in contact with it. <br>
3416
3417
3418Note: Instead of using the value prescribed by <a href="#surface_heatflux">surface_heatflux</a>,
3419the near surface heat flux is determined from an exponential function
3420that is dependent on the cumulative leaf_area_index (Shaw and Schumann
3421(1992, Boundary Layer Meteorol., 61, 47-64)).</td>
3422
3423    </tr>
3424
3425    <tr>
3426
3427
3428
3429
3430
3431
3432 <td style="vertical-align: top;"> 
3433     
3434     
3435     
3436     
3437     
3438     
3439      <p><a name="cut_spline_overshoot"></a><b>cut_spline_overshoot</b></p>
3440
3441
3442
3443
3444
3445
3446
3447      </td>
3448
3449
3450
3451
3452
3453
3454 <td style="vertical-align: top;">L</td>
3455
3456
3457
3458
3459
3460
3461
3462      <td style="vertical-align: top;"><span style="font-style: italic;">.T.</span></td>
3463
3464
3465
3466
3467
3468
3469 <td style="vertical-align: top;"> 
3470     
3471     
3472     
3473     
3474     
3475     
3476      <p>Cuts off of
3477so-called overshoots, which can occur with the
3478upstream-spline scheme.&nbsp; </p>
3479
3480
3481
3482
3483
3484
3485 
3486     
3487     
3488     
3489     
3490     
3491     
3492      <p><font color="#000000">The cubic splines tend to overshoot in
3493case of discontinuous changes of variables between neighbouring grid
3494points.</font><font color="#ff0000"> </font><font color="#000000">This
3495may lead to errors in calculating the advection tendency.</font>
3496Choice
3497of <b>cut_spline_overshoot</b> = <i>.TRUE.</i>
3498(switched on by
3499default)
3500allows variable values not to exceed an interval defined by the
3501respective adjacent grid points. This interval can be adjusted
3502seperately for every prognostic variable (see initialization parameters
3503      <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>,
3504etc.). This might be necessary in case that the
3505default interval has a non-tolerable effect on the model
3506results.&nbsp; </p>
3507
3508
3509
3510
3511
3512
3513 
3514     
3515     
3516     
3517     
3518     
3519     
3520      <p>Overshoots may also be removed
3521using the parameters <a href="#ups_limit_e">ups_limit_e</a>,
3522      <a href="#ups_limit_pt">ups_limit_pt</a>,
3523etc. as well as by applying a long-filter (see <a href="#long_filter_factor">long_filter_factor</a>).</p>
3524
3525
3526
3527
3528
3529
3530
3531      </td>
3532
3533
3534
3535
3536
3537
3538 </tr>
3539
3540
3541
3542
3543
3544
3545 <tr>
3546
3547
3548
3549
3550
3551
3552 <td style="vertical-align: top;"> 
3553     
3554     
3555     
3556     
3557     
3558     
3559      <p><a name="damp_level_1d"></a><b>damp_level_1d</b></p>
3560
3561
3562
3563
3564
3565
3566
3567      </td>
3568
3569
3570
3571
3572
3573
3574 <td style="vertical-align: top;">R</td>
3575
3576
3577
3578
3579
3580
3581
3582      <td style="vertical-align: top;"><span style="font-style: italic;">zu(nz+1)</span></td>
3583
3584
3585
3586
3587
3588
3589
3590      <td style="vertical-align: top;"> 
3591     
3592     
3593     
3594     
3595     
3596     
3597      <p>Height where
3598the damping layer begins in the 1d-model
3599(in m).&nbsp; </p>
3600
3601
3602
3603
3604
3605
3606 
3607     
3608     
3609     
3610     
3611     
3612     
3613      <p>This parameter is used to
3614switch on a damping layer for the
36151d-model, which is generally needed for the damping of inertia
3616oscillations. Damping is done by gradually increasing the value
3617of the eddy diffusivities about 10% per vertical grid level
3618(starting with the value at the height given by <b>damp_level_1d</b>,
3619or possibly from the next grid pint above), i.e. K<sub>m</sub>(k+1)
3620=
36211.1 * K<sub>m</sub>(k).
3622The values of K<sub>m</sub> are limited to 10 m**2/s at
3623maximum.&nbsp; <br>
3624
3625
3626
3627
3628
3629
3630
3631This parameter only comes into effect if the 1d-model is switched on
3632for
3633the initialization of the 3d-model using <a href="#initializing_actions">initializing_actions</a>
3634= <span style="font-style: italic;">'set_1d-model_profiles'</span>.
3635      <br>
3636
3637
3638
3639
3640
3641
3642 </p>
3643
3644
3645
3646
3647
3648
3649 </td>
3650
3651
3652
3653
3654
3655
3656 </tr>
3657
3658
3659
3660
3661
3662
3663 <tr>
3664
3665
3666
3667
3668
3669
3670 <td style="vertical-align: top;"><a name="dissipation_1d"></a><span style="font-weight: bold;">dissipation_1d</span><br>
3671
3672
3673
3674
3675
3676
3677
3678      </td>
3679
3680
3681
3682
3683
3684
3685 <td style="vertical-align: top;">C*20<br>
3686
3687
3688
3689
3690
3691
3692
3693      </td>
3694
3695
3696
3697
3698
3699
3700 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
3701
3702
3703
3704
3705
3706
3707 <span style="font-style: italic;">model'</span><br>
3708
3709
3710
3711
3712
3713
3714 </td>
3715
3716
3717
3718
3719
3720
3721
3722      <td style="vertical-align: top;">Calculation method for
3723the energy dissipation term in the TKE equation of the 1d-model.<br>
3724
3725
3726
3727
3728
3729
3730
3731      <br>
3732
3733
3734
3735
3736
3737
3738
3739By default the dissipation is calculated as in the 3d-model using diss
3740= (0.19 + 0.74 * l / l_grid) * e**1.5 / l.<br>
3741
3742
3743
3744
3745
3746
3747 <br>
3748
3749
3750
3751
3752
3753
3754
3755Setting <span style="font-weight: bold;">dissipation_1d</span>
3756= <span style="font-style: italic;">'detering'</span>
3757forces the dissipation to be calculated as diss = 0.064 * e**1.5 / l.<br>
3758
3759
3760
3761
3762
3763
3764
3765      </td>
3766
3767
3768
3769
3770
3771
3772 </tr>
3773    <tr><td style="vertical-align: top;"><p><a name="dp_external"></a><b>dp_external</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top; font-style: italic;">.F.</td><td>External pressure gradient switch.<br><br>This
3774parameter is used to switch on/off an external pressure gradient as
3775driving force. The external pressure gradient is controlled by the
3776parameters <a href="#dp_smooth">dp_smooth</a>, <a href="#dp_level_b">dp_level_b</a> and <a href="#dpdxy">dpdxy</a>.<br><br>Note that&nbsp;<span style="font-weight: bold;">dp_external</span> = <span style="font-style: italic;">.T.</span> requires <a href="#conserve_volume_flow">conserve_volume_flow</a> =<span style="font-style: italic;"> .F. </span>It is normally recommended to disable the Coriolis force by setting <a href="l#omega">omega</a> = 0.0.</td></tr><tr><td style="vertical-align: top;"><p><a name="dp_smooth"></a><b>dp_smooth</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top; font-style: italic;">.F.</td><td>Vertically smooth the external pressure gradient using a sinusoidal smoothing function.<br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span>. It is useful in combination with&nbsp;<a href="#dp_level_b">dp_level_b</a> &gt;&gt; 0 to generate a non-accelerated boundary layer well below&nbsp;<a href="#dp_level_b">dp_level_b</a>.</td></tr><tr><td style="vertical-align: top;"><p><a name="dp_level_b"></a><b>dp_level_b</b></p></td><td style="vertical-align: top;">R</td><td style="vertical-align: top; font-style: italic;">0.0</td><td><font size="3">Lower
3777limit of the vertical range for which the external pressure gradient is applied (</font>in <font size="3">m).</font><br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span><span lang="en-GB">It
3778must hold the condition zu(0) &lt;= <b>dp_level_b</b>
3779&lt;= zu(</span><a href="#nz"><span lang="en-GB">nz</span></a><span lang="en-GB">)</span><span lang="en-GB">.&nbsp;</span>It can be used in combination with&nbsp;<a href="#dp_smooth">dp_smooth</a> = <span style="font-style: italic;">.T.</span> to generate a non-accelerated boundary layer well below&nbsp;<span style="font-weight: bold;">dp_level_b</span> if&nbsp;<span style="font-weight: bold;">dp_level_b</span> &gt;&gt; 0.<br><br>Note
3780that there is no upper limit of the vertical range because the external
3781pressure gradient is always applied up to the top of the model domain.</td></tr><tr><td style="vertical-align: top;"><p><a name="dpdxy"></a><b>dpdxy</b></p></td><td style="vertical-align: top;">R(2)</td><td style="font-style: italic; vertical-align: top;">2 * 0.0</td><td>Values of the external pressure gradient applied in x- and y-direction, respectively (in Pa/m).<br><br>This parameter only applies if <a href="#dp_external">dp_external</a> = <span style="font-style: italic;">.T. </span>It sets the pressure gradient values. Negative values mean an acceleration, positive values mean deceleration. For example, <span style="font-weight: bold;">dpdxy</span> = -0.0002, 0.0, drives the flow in positive x-direction, <span lang="en-GB"></span></td></tr>
3782
3783
3784
3785
3786
3787
3788    <tr>
3789
3790      <td style="vertical-align: top;"><a name="drag_coefficient"></a><span style="font-weight: bold;">drag_coefficient</span></td>
3791
3792      <td style="vertical-align: top;">R</td>
3793
3794      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
3795
3796      <td style="vertical-align: top;">Drag coefficient used in the plant canopy model.<br>
3797
3798      <br>
3799
3800This parameter has to be non-zero, if the parameter <a href="#plant_canopy">plant_canopy</a> is set <span style="font-style: italic;">.T.</span>.</td>
3801
3802    </tr>
3803
3804    <tr>
3805
3806
3807
3808
3809
3810
3811 <td style="vertical-align: top;"> 
3812     
3813     
3814     
3815     
3816     
3817     
3818      <p><a name="dt"></a><b>dt</b></p>
3819
3820
3821
3822
3823
3824
3825 </td>
3826
3827
3828
3829
3830
3831
3832
3833      <td style="vertical-align: top;">R</td>
3834
3835
3836
3837
3838
3839
3840 <td style="vertical-align: top;"><span style="font-style: italic;">variable</span></td>
3841
3842
3843
3844
3845
3846
3847
3848      <td style="vertical-align: top;"> 
3849     
3850     
3851     
3852     
3853     
3854     
3855      <p>Time step for
3856the 3d-model (in s).&nbsp; </p>
3857
3858
3859
3860
3861
3862
3863 
3864     
3865     
3866     
3867     
3868     
3869     
3870      <p>By default, (i.e.
3871if a Runge-Kutta scheme is used, see <a href="#timestep_scheme">timestep_scheme</a>)
3872the value of the time step is calculating after each time step
3873(following the time step criteria) and
3874used for the next step.</p>
3875
3876
3877
3878
3879
3880
3881 
3882     
3883     
3884     
3885     
3886     
3887     
3888      <p>If the user assigns <b>dt</b>
3889a value, then the time step is
3890fixed to this value throughout the whole run (whether it fulfills the
3891time step
3892criteria or not). However, changes are allowed for restart runs,
3893because <b>dt</b> can also be used as a <a href="chapter_4.2.html#dt_laufparameter">run
3894parameter</a>.&nbsp; </p>
3895
3896
3897
3898
3899
3900
3901 
3902     
3903     
3904     
3905     
3906     
3907     
3908      <p>In case that the
3909calculated time step meets the condition<br>
3910
3911
3912
3913
3914
3915
3916 </p>
3917
3918
3919
3920
3921
3922
3923 
3924     
3925     
3926     
3927     
3928     
3929     
3930      <ul>
3931
3932
3933
3934
3935
3936
3937
3938       
3939       
3940       
3941       
3942       
3943       
3944        <p><b>dt</b> &lt; 0.00001 * <a href="chapter_4.2.html#dt_max">dt_max</a> (with dt_max
3945= 20.0)</p>
3946
3947
3948
3949
3950
3951
3952 
3953     
3954     
3955     
3956     
3957     
3958     
3959      </ul>
3960
3961
3962
3963
3964
3965
3966 
3967     
3968     
3969     
3970     
3971     
3972     
3973      <p>the simulation will be
3974aborted. Such situations usually arise
3975in case of any numerical problem / instability which causes a
3976non-realistic increase of the wind speed.&nbsp; </p>
3977
3978
3979
3980
3981
3982
3983 
3984     
3985     
3986     
3987     
3988     
3989     
3990      <p>A
3991small time step due to a large mean horizontal windspeed
3992speed may be enlarged by using a coordinate transformation (see <a href="#galilei_transformation">galilei_transformation</a>),
3993in order to spare CPU time.<br>
3994
3995
3996
3997
3998
3999
4000 </p>
4001
4002
4003
4004
4005
4006
4007 
4008     
4009     
4010     
4011     
4012     
4013     
4014      <p>If the
4015leapfrog timestep scheme is used (see <a href="#timestep_scheme">timestep_scheme</a>)
4016a temporary time step value dt_new is calculated first, with dt_new = <a href="chapter_4.2.html#fcl_factor">cfl_factor</a>
4017* dt_crit where dt_crit is the maximum timestep allowed by the CFL and
4018diffusion condition. Next it is examined whether dt_new exceeds or
4019falls below the
4020value of the previous timestep by at
4021least +5 % / -2%. If it is smaller, <span style="font-weight: bold;">dt</span>
4022= dt_new is immediately used for the next timestep. If it is larger,
4023then <span style="font-weight: bold;">dt </span>=
40241.02 * dt_prev
4025(previous timestep) is used as the new timestep, however the time
4026step is only increased if the last change of the time step is dated
4027back at
4028least 30 iterations. If dt_new is located in the interval mentioned
4029above, then dt
4030does not change at all. By doing so, permanent time step changes as
4031well as large
4032sudden changes (increases) in the time step are avoided.</p>
4033
4034
4035
4036
4037
4038
4039 </td>
4040
4041
4042
4043
4044
4045
4046
4047    </tr>
4048
4049
4050
4051
4052
4053
4054 <tr>
4055
4056
4057
4058
4059
4060
4061 <td style="vertical-align: top;">
4062     
4063     
4064     
4065     
4066     
4067     
4068      <p><a name="dt_pr_1d"></a><b>dt_pr_1d</b></p>
4069
4070
4071
4072
4073
4074
4075
4076      </td>
4077
4078
4079
4080
4081
4082
4083 <td style="vertical-align: top;">R</td>
4084
4085
4086
4087
4088
4089
4090
4091      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
4092
4093
4094
4095
4096
4097
4098
4099      <td style="vertical-align: top;"> 
4100     
4101     
4102     
4103     
4104     
4105     
4106      <p>Temporal
4107interval of vertical profile output of the 1D-model
4108(in s).&nbsp; </p>
4109
4110
4111
4112
4113
4114
4115 
4116     
4117     
4118     
4119     
4120     
4121     
4122      <p>Data are written in ASCII
4123format to file <a href="chapter_3.4.html#LIST_PROFIL_1D">LIST_PROFIL_1D</a>.
4124This parameter is only in effect if the 1d-model has been switched on
4125for the
4126initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
4127= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
4128
4129
4130
4131
4132
4133
4134
4135      </td>
4136
4137
4138
4139
4140
4141
4142 </tr>
4143
4144
4145
4146
4147
4148
4149 <tr>
4150
4151
4152
4153
4154
4155
4156 <td style="vertical-align: top;"> 
4157     
4158     
4159     
4160     
4161     
4162     
4163      <p><a name="dt_run_control_1d"></a><b>dt_run_control_1d</b></p>
4164
4165
4166
4167
4168
4169
4170
4171      </td>
4172
4173
4174
4175
4176
4177
4178 <td style="vertical-align: top;">R</td>
4179
4180
4181
4182
4183
4184
4185
4186      <td style="vertical-align: top;"><span style="font-style: italic;">60.0</span></td>
4187
4188
4189
4190
4191
4192
4193 <td style="vertical-align: top;"> 
4194     
4195     
4196     
4197     
4198     
4199     
4200      <p>Temporal interval of
4201runtime control output of the 1d-model
4202(in s).&nbsp; </p>
4203
4204
4205
4206
4207
4208
4209 
4210     
4211     
4212     
4213     
4214     
4215     
4216      <p>Data are written in ASCII
4217format to file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.
4218This parameter is only in effect if the 1d-model is switched on for the
4219initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
4220= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
4221
4222
4223
4224
4225
4226
4227
4228      </td>
4229
4230
4231
4232
4233
4234
4235 </tr>
4236
4237
4238
4239
4240
4241
4242 <tr>
4243
4244
4245
4246
4247
4248
4249 <td style="vertical-align: top;"> 
4250     
4251     
4252     
4253     
4254     
4255     
4256      <p><a name="dx"></a><b>dx</b></p>
4257
4258
4259
4260
4261
4262
4263
4264      </td>
4265
4266
4267
4268
4269
4270
4271 <td style="vertical-align: top;">R</td>
4272
4273
4274
4275
4276
4277
4278
4279      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
4280
4281
4282
4283
4284
4285
4286 <td style="vertical-align: top;"> 
4287     
4288     
4289     
4290     
4291     
4292     
4293      <p>Horizontal grid
4294spacing along the x-direction (in m).&nbsp; </p>
4295
4296
4297
4298
4299
4300
4301 
4302     
4303     
4304     
4305     
4306     
4307     
4308      <p>Along
4309x-direction only a constant grid spacing is allowed.</p>
4310
4311
4312
4313
4314
4315
4316     
4317     
4318     
4319     
4320     
4321     
4322      <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>
4323and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
4324
4325
4326
4327
4328
4329
4330 </td>
4331
4332
4333
4334
4335
4336
4337
4338    </tr>
4339
4340
4341
4342
4343
4344
4345 <tr>
4346
4347
4348
4349
4350
4351
4352 <td style="vertical-align: top;">
4353     
4354     
4355     
4356     
4357     
4358     
4359      <p><a name="dy"></a><b>dy</b></p>
4360
4361
4362
4363
4364
4365
4366
4367      </td>
4368
4369
4370
4371
4372
4373
4374 <td style="vertical-align: top;">R</td>
4375
4376
4377
4378
4379
4380
4381
4382      <td style="vertical-align: top;"><span style="font-style: italic;">1.0</span></td>
4383
4384
4385
4386
4387
4388
4389 <td style="vertical-align: top;"> 
4390     
4391     
4392     
4393     
4394     
4395     
4396      <p>Horizontal grid
4397spacing along the y-direction (in m).&nbsp; </p>
4398
4399
4400
4401
4402
4403
4404 
4405     
4406     
4407     
4408     
4409     
4410     
4411      <p>Along y-direction only a constant grid spacing is allowed.</p>
4412
4413
4414
4415
4416
4417
4418     
4419     
4420     
4421     
4422     
4423     
4424      <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>
4425and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
4426
4427
4428
4429
4430
4431
4432 </td>
4433
4434
4435
4436
4437
4438
4439
4440    </tr>
4441
4442
4443
4444
4445
4446
4447 <tr>
4448
4449
4450
4451
4452
4453
4454 <td style="vertical-align: top;">
4455     
4456     
4457     
4458     
4459     
4460     
4461      <p><a name="dz"></a><b>dz</b></p>
4462
4463
4464
4465
4466
4467
4468
4469      </td>
4470
4471
4472
4473
4474
4475
4476 <td style="vertical-align: top;">R</td>
4477
4478
4479
4480
4481
4482
4483
4484      <td style="vertical-align: top;"><br>
4485
4486
4487
4488
4489
4490
4491 </td>
4492
4493
4494
4495
4496
4497
4498 <td style="vertical-align: top;"> 
4499     
4500     
4501     
4502     
4503     
4504     
4505      <p>Vertical grid
4506spacing (in m).&nbsp; </p>
4507
4508
4509
4510
4511
4512
4513 
4514     
4515     
4516     
4517     
4518     
4519     
4520      <p>This parameter must be
4521assigned by the user, because no
4522default value is given.<br>
4523
4524
4525
4526
4527
4528
4529 </p>
4530
4531
4532
4533
4534
4535
4536 
4537     
4538     
4539     
4540     
4541     
4542     
4543      <p>By default, the
4544model uses constant grid spacing along z-direction, but it can be
4545stretched using the parameters <a href="#dz_stretch_level">dz_stretch_level</a>
4546and <a href="#dz_stretch_factor">dz_stretch_factor</a>.
4547In case of stretching, a maximum allowed grid spacing can be given by <a href="#dz_max">dz_max</a>.<br>
4548
4549
4550
4551
4552
4553
4554 </p>
4555
4556
4557
4558
4559
4560
4561 
4562     
4563     
4564     
4565     
4566     
4567     
4568      <p>Assuming
4569a constant <span style="font-weight: bold;">dz</span>,
4570the scalar levels (zu) are calculated directly by:&nbsp; </p>
4571
4572
4573
4574
4575
4576
4577
4578     
4579     
4580     
4581     
4582     
4583     
4584      <ul>
4585
4586
4587
4588
4589
4590
4591 
4592       
4593       
4594       
4595       
4596       
4597       
4598        <p>zu(0) = - dz * 0.5&nbsp; <br>
4599
4600
4601
4602
4603
4604
4605
4606zu(1) = dz * 0.5</p>
4607
4608
4609
4610
4611
4612
4613 
4614     
4615     
4616     
4617     
4618     
4619     
4620      </ul>
4621
4622
4623
4624
4625
4626
4627 
4628     
4629     
4630     
4631     
4632     
4633     
4634      <p>The w-levels lie
4635half between them:&nbsp; </p>
4636
4637
4638
4639
4640
4641
4642 
4643     
4644     
4645     
4646     
4647     
4648     
4649      <ul>
4650
4651
4652
4653
4654
4655
4656 
4657       
4658       
4659       
4660       
4661       
4662       
4663        <p>zw(k) =
4664( zu(k) + zu(k+1) ) * 0.5</p>
4665
4666
4667
4668
4669
4670
4671 
4672     
4673     
4674     
4675     
4676     
4677     
4678      </ul>
4679
4680
4681
4682
4683
4684
4685 </td>
4686
4687
4688
4689
4690
4691
4692 </tr>
4693
4694
4695
4696
4697
4698
4699
4700    <tr>
4701
4702
4703
4704
4705
4706
4707      <td style="vertical-align: top;"><a name="dz_max"></a><span style="font-weight: bold;">dz_max</span></td>
4708
4709
4710
4711
4712
4713
4714      <td style="vertical-align: top;">R</td>
4715
4716
4717
4718
4719
4720
4721      <td style="vertical-align: top;"><span style="font-style: italic;">9999999.9</span></td>
4722
4723
4724
4725
4726
4727
4728      <td style="vertical-align: top;">Allowed maximum vertical grid
4729spacing (in m).<br>
4730
4731
4732
4733
4734
4735
4736      <br>
4737
4738
4739
4740
4741
4742
4743If the vertical grid is stretched
4744(see <a href="#dz_stretch_factor">dz_stretch_factor</a>
4745and <a href="#dz_stretch_level">dz_stretch_level</a>),
4746      <span style="font-weight: bold;">dz_max</span> can
4747be used to limit the vertical grid spacing.</td>
4748
4749
4750
4751
4752
4753
4754    </tr>
4755
4756
4757
4758
4759
4760
4761    <tr>
4762
4763
4764
4765
4766
4767
4768
4769      <td style="vertical-align: top;"> 
4770     
4771     
4772     
4773     
4774     
4775     
4776      <p><a name="dz_stretch_factor"></a><b>dz_stretch_factor</b></p>
4777
4778
4779
4780
4781
4782
4783
4784      </td>
4785
4786
4787
4788
4789
4790
4791 <td style="vertical-align: top;">R</td>
4792
4793
4794
4795
4796
4797
4798
4799      <td style="vertical-align: top;"><span style="font-style: italic;">1.08</span></td>
4800
4801
4802
4803
4804
4805
4806 <td style="vertical-align: top;"> 
4807     
4808     
4809     
4810     
4811     
4812     
4813      <p>Stretch factor for a
4814vertically stretched grid (see <a href="#dz_stretch_level">dz_stretch_level</a>).&nbsp;
4815      </p>
4816
4817
4818
4819
4820
4821
4822 
4823     
4824     
4825     
4826     
4827     
4828     
4829      <p>The stretch factor should not exceed a value of
4830approx. 1.10 -
48311.12, otherwise the discretization errors due to the stretched grid not
4832negligible any more. (refer Kalnay de Rivas)</p>
4833
4834
4835
4836
4837
4838
4839 </td>
4840
4841
4842
4843
4844
4845
4846 </tr>
4847
4848
4849
4850
4851
4852
4853
4854    <tr>
4855
4856
4857
4858
4859
4860
4861 <td style="vertical-align: top;"> 
4862     
4863     
4864     
4865     
4866     
4867     
4868      <p><a name="dz_stretch_level"></a><b>dz_stretch_level</b></p>
4869
4870
4871
4872
4873
4874
4875
4876      </td>
4877
4878
4879
4880
4881
4882
4883 <td style="vertical-align: top;">R</td>
4884
4885
4886
4887
4888
4889
4890
4891      <td style="vertical-align: top;"><span style="font-style: italic;">100000.0</span><br>
4892
4893
4894
4895
4896
4897
4898 </td>
4899
4900
4901
4902
4903
4904
4905
4906      <td style="vertical-align: top;"> 
4907     
4908     
4909     
4910     
4911     
4912     
4913      <p>Height level
4914above/below which the grid is to be stretched
4915vertically (in m).&nbsp; </p>
4916
4917
4918
4919
4920
4921
4922 
4923     
4924     
4925     
4926     
4927     
4928     
4929      <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
4930vertically. The vertical grid
4931spacings <a href="#dz">dz</a>
4932above this level are calculated as&nbsp; </p>
4933
4934
4935
4936
4937
4938
4939 
4940     
4941     
4942     
4943     
4944     
4945     
4946      <ul>
4947
4948
4949
4950
4951
4952
4953 
4954       
4955       
4956       
4957       
4958       
4959       
4960        <p><b>dz</b>(k+1)
4961= <b>dz</b>(k) * <a href="#dz_stretch_factor">dz_stretch_factor</a></p>
4962
4963
4964
4965
4966
4967
4968
4969     
4970     
4971     
4972     
4973     
4974     
4975      </ul>
4976
4977
4978
4979
4980
4981
4982 
4983     
4984     
4985     
4986     
4987     
4988     
4989      <p>and used as spacings for the scalar levels (zu).
4990The
4991w-levels are then defined as:&nbsp; </p>
4992
4993
4994
4995
4996
4997
4998 
4999     
5000     
5001     
5002     
5003     
5004     
5005      <ul>
5006
5007
5008
5009
5010
5011
5012 
5013       
5014       
5015       
5016       
5017       
5018       
5019        <p>zw(k)
5020= ( zu(k) + zu(k+1) ) * 0.5.
5021
5022 
5023     
5024      </p>
5025
5026
5027
5028
5029     
5030     
5031     
5032     
5033      </ul>
5034
5035
5036
5037
5038     
5039     
5040     
5041     
5042      <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
5043vertically. The vertical grid
5044spacings <a href="chapter_4.1.html#dz">dz</a> below this level are calculated correspondingly as
5045
5046 
5047     
5048      </p>
5049
5050
5051
5052
5053     
5054     
5055     
5056     
5057      <ul>
5058
5059
5060
5061
5062       
5063       
5064       
5065       
5066        <p><b>dz</b>(k-1)
5067= <b>dz</b>(k) * <a href="chapter_4.1.html#dz_stretch_factor">dz_stretch_factor</a>.</p>
5068
5069
5070
5071
5072     
5073     
5074     
5075     
5076      </ul>
5077
5078
5079
5080
5081
5082
5083 </td>
5084
5085
5086
5087
5088
5089
5090 </tr>
5091
5092
5093
5094
5095
5096
5097
5098    <tr>
5099
5100
5101
5102
5103
5104      <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_init"></a>e_init</span></td>
5105
5106
5107
5108
5109
5110      <td style="vertical-align: top;">R</td>
5111
5112
5113
5114
5115
5116      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
5117
5118
5119
5120
5121
5122      <td>Initial subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
5123
5124
5125
5126
5127
5128
5129
5130      <br>
5131
5132
5133
5134
5135
5136
5137This
5138option 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>
5139
5140
5141
5142
5143
5144    </tr>
5145
5146
5147
5148
5149
5150    <tr>
5151
5152
5153
5154
5155
5156
5157 <td style="vertical-align: top;"><span style="font-weight: bold;"><a name="e_min"></a>e_min</span></td>
5158
5159
5160
5161
5162
5163
5164
5165      <td style="vertical-align: top;">R</td>
5166
5167
5168
5169
5170
5171
5172 <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
5173
5174
5175
5176
5177
5178
5179 <td>Minimum
5180subgrid-scale TKE in m<sup>2</sup>s<sup>-2</sup>.<br>
5181
5182
5183
5184
5185
5186
5187
5188      <br>
5189
5190
5191
5192
5193
5194
5195This
5196option&nbsp;adds artificial viscosity to the flow by ensuring that
5197the
5198subgrid-scale TKE does not fall below the minimum threshold <span style="font-weight: bold;">e_min</span>.</td>
5199
5200
5201
5202
5203
5204
5205 </tr>
5206
5207
5208
5209
5210
5211
5212
5213    <tr>
5214
5215
5216
5217
5218
5219
5220 <td style="vertical-align: top;"> 
5221     
5222     
5223     
5224     
5225     
5226     
5227      <p><a name="end_time_1d"></a><b>end_time_1d</b></p>
5228
5229
5230
5231
5232
5233
5234
5235      </td>
5236
5237
5238
5239
5240
5241
5242 <td style="vertical-align: top;">R</td>
5243
5244
5245
5246
5247
5248
5249
5250      <td style="vertical-align: top;"><span style="font-style: italic;">864000.0</span><br>
5251
5252
5253
5254
5255
5256
5257 </td>
5258
5259
5260
5261
5262
5263
5264
5265      <td style="vertical-align: top;"> 
5266     
5267     
5268     
5269     
5270     
5271     
5272      <p>Time to be
5273simulated for the 1d-model (in s).&nbsp; </p>
5274
5275
5276
5277
5278
5279
5280 
5281     
5282     
5283     
5284     
5285     
5286     
5287      <p>The
5288default value corresponds to a simulated time of 10 days.
5289Usually, after such a period the inertia oscillations have completely
5290decayed and the solution of the 1d-model can be regarded as stationary
5291(see <a href="#damp_level_1d">damp_level_1d</a>).
5292This parameter is only in effect if the 1d-model is switched on for the
5293initialization of the 3d-model with <a href="#initializing_actions">initializing_actions</a>
5294= <span style="font-style: italic;">'set_1d-model_profiles'</span>.</p>
5295
5296
5297
5298
5299
5300
5301
5302      </td>
5303
5304
5305
5306
5307
5308
5309 </tr>
5310
5311
5312
5313
5314
5315
5316 <tr>
5317
5318
5319
5320
5321
5322
5323 <td style="vertical-align: top;"> 
5324     
5325     
5326     
5327     
5328     
5329     
5330      <p><a name="fft_method"></a><b>fft_method</b></p>
5331
5332
5333
5334
5335
5336
5337
5338      </td>
5339
5340
5341
5342
5343
5344
5345 <td style="vertical-align: top;">C * 20</td>
5346
5347
5348
5349
5350
5351
5352
5353      <td style="vertical-align: top;"><span style="font-style: italic;">'system-</span><br style="font-style: italic;">
5354
5355
5356
5357
5358
5359
5360 <span style="font-style: italic;">specific'</span></td>
5361
5362
5363
5364
5365
5366
5367
5368      <td style="vertical-align: top;"> 
5369     
5370     
5371     
5372     
5373     
5374     
5375      <p>FFT-method to
5376be used.<br>
5377
5378
5379
5380
5381
5382
5383 </p>
5384
5385
5386
5387
5388
5389
5390 
5391     
5392     
5393     
5394     
5395     
5396     
5397      <p><br>
5398
5399
5400
5401
5402
5403
5404
5405The fast fourier transformation (FFT) is used for solving the
5406perturbation pressure equation with a direct method (see <a href="chapter_4.2.html#psolver">psolver</a>)
5407and for calculating power spectra (see optional software packages,
5408section <a href="chapter_4.2.html#spectra_package">4.2</a>).</p>
5409
5410
5411
5412
5413
5414
5415
5416     
5417     
5418     
5419     
5420     
5421     
5422      <p><br>
5423
5424
5425
5426
5427
5428
5429
5430By default, system-specific, optimized routines from external
5431vendor libraries are used. However, these are available only on certain
5432computers and there are more or less severe restrictions concerning the
5433number of gridpoints to be used with them.<br>
5434
5435
5436
5437
5438
5439
5440 </p>
5441
5442
5443
5444
5445
5446
5447 
5448     
5449     
5450     
5451     
5452     
5453     
5454      <p>There
5455are two other PALM internal methods available on every
5456machine (their respective source code is part of the PALM source code):</p>
5457
5458
5459
5460
5461
5462
5463
5464     
5465     
5466     
5467     
5468     
5469     
5470      <p>1.: The <span style="font-weight: bold;">Temperton</span>-method
5471from Clive Temperton (ECWMF) which is computationally very fast and
5472switched on with <b>fft_method</b> = <span style="font-style: italic;">'temperton-algorithm'</span>.
5473The number of horizontal gridpoints (nx+1, ny+1) to be used with this
5474method must be composed of prime factors 2, 3 and 5.<br>
5475
5476
5477
5478
5479
5480
5481 </p>
5482
5483
5484
5485
5486
5487
5488
54892.: The <span style="font-weight: bold;">Singleton</span>-method
5490which is very slow but has no restrictions concerning the number of
5491gridpoints to be used with, switched on with <b>fft_method</b>
5492= <span style="font-style: italic;">'singleton-algorithm'</span>.
5493      </td>
5494
5495
5496
5497
5498
5499
5500 </tr>
5501
5502
5503
5504
5505
5506
5507 <tr>
5508
5509
5510
5511
5512
5513
5514 <td style="vertical-align: top;"> 
5515     
5516     
5517     
5518     
5519     
5520     
5521      <p><a name="galilei_transformation"></a><b>galilei_transformation</b></p>
5522
5523
5524
5525
5526
5527
5528
5529      </td>
5530
5531
5532
5533
5534
5535
5536 <td style="vertical-align: top;">L</td>
5537
5538
5539
5540
5541
5542
5543
5544      <td style="vertical-align: top;"><i>.F.</i></td>
5545
5546
5547
5548
5549
5550
5551
5552      <td style="vertical-align: top;">Application of a
5553Galilei-transformation to the
5554coordinate
5555system of the model.<br>
5556
5557
5558
5559
5560
5561
5562     
5563     
5564     
5565     
5566     
5567     
5568      <p>With <b>galilei_transformation</b>
5569= <i>.T.,</i> a so-called
5570Galilei-transformation is switched on which ensures that the coordinate
5571system of the model is moved along with the geostrophical wind.
5572Alternatively, the model domain can be moved along with the averaged
5573horizontal wind (see <a href="#use_ug_for_galilei_tr">use_ug_for_galilei_tr</a>,
5574this can and will naturally change in time). With this method,
5575numerical inaccuracies of the Piascek - Williams - scheme (concerns in
5576particular the momentum advection) are minimized. Beyond that, in the
5577majority of cases the lower relative velocities in the moved system
5578permit a larger time step (<a href="#dt">dt</a>).
5579Switching the transformation on is only worthwhile if the geostrophical
5580wind (ug, vg)
5581and the averaged horizontal wind clearly deviate from the value 0. In
5582each case, the distance the coordinate system has been moved is written
5583to the file <a href="chapter_3.4.html#RUN_CONTROL">RUN_CONTROL</a>.&nbsp;
5584      </p>
5585
5586
5587
5588
5589
5590
5591 
5592     
5593     
5594     
5595     
5596     
5597     
5598      <p>Non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
5599and <a href="#bc_ns">bc_ns</a>), the specification
5600of a gestrophic
5601wind that is not constant with height
5602as well as e.g. stationary inhomogeneities at the bottom boundary do
5603not allow the use of this transformation.</p>
5604
5605
5606
5607
5608
5609
5610 </td>
5611
5612
5613
5614
5615
5616
5617 </tr>
5618
5619
5620
5621
5622
5623
5624
5625    <tr>
5626
5627
5628
5629
5630
5631
5632 <td style="vertical-align: top;"> 
5633     
5634     
5635     
5636     
5637     
5638     
5639      <p><a name="grid_matching"></a><b>grid_matching</b></p>
5640
5641
5642
5643
5644
5645
5646
5647      </td>
5648
5649
5650
5651
5652
5653
5654 <td style="vertical-align: top;">C * 6</td>
5655
5656
5657
5658
5659
5660
5661
5662      <td style="vertical-align: top;"><span style="font-style: italic;">'match'</span></td>
5663
5664
5665
5666
5667
5668
5669 <td style="vertical-align: top;">Variable to adjust the
5670subdomain
5671sizes in parallel runs.<br>
5672
5673
5674
5675
5676
5677
5678 <br>
5679
5680
5681
5682
5683
5684
5685
5686For <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>,
5687the subdomains are forced to have an identical
5688size on all processors. In this case the processor numbers in the
5689respective directions of the virtual processor net must fulfill certain
5690divisor conditions concerning the grid point numbers in the three
5691directions (see <a href="#nx">nx</a>, <a href="#ny">ny</a>
5692and <a href="#nz">nz</a>).
5693Advantage of this method is that all PEs bear the same computational
5694load.<br>
5695
5696
5697
5698
5699
5700
5701 <br>
5702
5703
5704
5705
5706
5707
5708
5709There is no such restriction by default, because then smaller
5710subdomains are allowed on those processors which
5711form the right and/or north boundary of the virtual processor grid. On
5712all other processors the subdomains are of same size. Whether smaller
5713subdomains are actually used, depends on the number of processors and
5714the grid point numbers used. Information about the respective settings
5715are 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>
5716
5717
5718
5719
5720
5721
5722
5723      <br>
5724
5725
5726
5727
5728
5729
5730
5731When 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>)
5732only <b>grid_matching</b> = <span style="font-style: italic;">'strict'</span>
5733is allowed.<br>
5734
5735
5736
5737
5738
5739
5740 <br>
5741
5742
5743
5744
5745
5746
5747 <b>Note:</b><br>
5748
5749
5750
5751
5752
5753
5754
5755In some cases for small processor numbers there may be a very bad load
5756balancing among the
5757processors which may reduce the performance of the code.</td>
5758
5759
5760
5761
5762
5763
5764 </tr>
5765
5766
5767
5768
5769
5770
5771
5772    <tr><td style="vertical-align: top;"><p><a name="humidity"></a><b>humidity</b></p></td><td style="vertical-align: top;">L</td><td style="vertical-align: top;"><i>.F.</i></td><td style="vertical-align: top;"><p>Parameter to
5773switch on the prognostic equation for specific
5774humidity q.<br>
5775
5776
5777
5778
5779
5780
5781 </p>
5782
5783
5784
5785
5786
5787
5788 
5789     
5790     
5791     
5792     
5793     
5794     
5795      <p>The initial vertical
5796profile 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>
5797and <a href="chapter_4.1.html#q_vertical_gradient_level">q_vertical_gradient_level</a>.&nbsp;
5798Boundary conditions can be set via <a href="chapter_4.1.html#q_surface_initial_change">q_surface_initial_change</a>
5799and <a href="chapter_4.1.html#surface_waterflux">surface_waterflux</a>.<br>
5800
5801
5802
5803
5804
5805
5806
5807      </p>
5808
5809
5810
5811
5812
5813
5814
5815If the condensation scheme is switched on (<a href="chapter_4.1.html#cloud_physics">cloud_physics</a>
5816= .TRUE.), q becomes the total liquid water content (sum of specific
5817humidity and liquid water content).</td></tr><tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="inflow_damping_height"></a>inflow_damping_height</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">from precursor run</span></td><td style="vertical-align: top;">Height below which the turbulence signal is used for turbulence recycling (in m).<br><br>In case of a turbulent inflow (see <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a>),
5818this parameter defines the vertical thickness of the turbulent layer up
5819to which the turbulence extracted at the recycling plane (see <a href="chapter_4.1.html#recycling_width">recycling_width</a>)
5820shall be imposed to the inflow. Above this level the turbulence signal
5821is linearly damped to zero. The transition range within which the
5822signal falls to zero is given by the parameter <a href="chapter_4.1.html#inflow_damping_width">inflow_damping_width</a>.<br><br>By default, this height is set as the height of the convective boundary layer as calculated from a precursor run. See <a href="chapter_3.9.html">chapter 3.9</a> about proper settings for getting this CBL height from a precursor run. </td></tr><tr><td style="vertical-align: top;"><span style="font-weight: bold;"><a name="inflow_damping_width"></a>inflow_damping_width</span></td><td style="vertical-align: top;">R</td><td style="vertical-align: top;"><span style="font-style: italic;">0.1 * <a href="chapter_4.1.html#inflow_damping_height">inflow_damping</a></span><a href="chapter_4.1.html#inflow_damping_height"><br style="font-style: italic;"><span style="font-style: italic;">_height</span></a></td><td style="vertical-align: top;">Transition range within which the turbulance signal is damped to zero (in m).<br><br>See <a href="chapter_4.1.html#inflow_damping_height">inflow_damping_height</a> for explanation.</td></tr><tr>
5823
5824
5825
5826
5827
5828
5829 <td style="vertical-align: top;"><a name="inflow_disturbance_begin"></a><b>inflow_disturbance_<br>
5830
5831
5832
5833
5834
5835
5836
5837begin</b></td>
5838
5839
5840
5841
5842
5843
5844 <td style="vertical-align: top;">I</td>
5845
5846
5847
5848
5849
5850
5851
5852      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(10,</span><br style="font-style: italic;">
5853
5854
5855
5856
5857
5858
5859 <span style="font-style: italic;">nx/2 or ny/2)</span></td>
5860
5861
5862
5863
5864
5865
5866
5867      <td style="vertical-align: top;">Lower
5868limit of the horizontal range for which random perturbations are to be
5869imposed on the horizontal velocity field (gridpoints).<br>
5870
5871
5872
5873
5874
5875
5876 <br>
5877
5878
5879
5880
5881
5882
5883
5884If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
5885or <a href="#bc_ns">bc_ns</a>),
5886this parameter gives the gridpoint number (counted horizontally from
5887the inflow)&nbsp; from which on perturbations are imposed on the
5888horizontal velocity field. Perturbations must be switched on with
5889parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
5890
5891
5892
5893
5894
5895
5896
5897    </tr>
5898
5899
5900
5901
5902
5903
5904 <tr>
5905
5906
5907
5908
5909
5910
5911 <td style="vertical-align: top;"><a name="inflow_disturbance_end"></a><b>inflow_disturbance_<br>
5912
5913
5914
5915
5916
5917
5918
5919end</b></td>
5920
5921
5922
5923
5924
5925
5926 <td style="vertical-align: top;">I</td>
5927
5928
5929
5930
5931
5932
5933
5934      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(100,</span><br style="font-style: italic;">
5935
5936
5937
5938
5939
5940
5941 <span style="font-style: italic;">3/4*nx or</span><br style="font-style: italic;">
5942
5943
5944
5945
5946
5947
5948 <span style="font-style: italic;">3/4*ny)</span></td>
5949
5950
5951
5952
5953
5954
5955 <td style="vertical-align: top;">Upper
5956limit of the horizontal range for which random perturbations are
5957to be imposed on the horizontal velocity field (gridpoints).<br>
5958
5959
5960
5961
5962
5963
5964 <br>
5965
5966
5967
5968
5969
5970
5971
5972If non-cyclic lateral boundary conditions are used (see <a href="#bc_lr">bc_lr</a>
5973or <a href="#bc_ns">bc_ns</a>),
5974this parameter gives the gridpoint number (counted horizontally from
5975the inflow)&nbsp; unto which perturbations are imposed on the
5976horizontal
5977velocity field. Perturbations must be switched on with parameter <a href="chapter_4.2.html#create_disturbances">create_disturbances</a>.</td>
5978
5979
5980
5981
5982
5983
5984
5985    </tr>
5986
5987
5988
5989
5990
5991
5992 <tr>
5993
5994
5995
5996
5997
5998
5999 <td style="vertical-align: top;">
6000     
6001     
6002     
6003     
6004     
6005     
6006      <p><a name="initializing_actions"></a><b>initializing_actions</b></p>
6007
6008
6009
6010
6011
6012
6013
6014      </td>
6015
6016
6017
6018
6019
6020
6021 <td style="vertical-align: top;">C * 100</td>
6022
6023
6024
6025
6026
6027
6028
6029      <td style="vertical-align: top;"><br>
6030
6031
6032
6033
6034
6035
6036 </td>
6037
6038
6039
6040
6041
6042
6043 <td style="vertical-align: top;"> 
6044     
6045     
6046     
6047     
6048     
6049     
6050      <p style="font-style: normal;">Initialization actions
6051to be carried out.&nbsp; </p>
6052
6053
6054
6055
6056
6057
6058 
6059     
6060     
6061     
6062     
6063     
6064     
6065      <p style="font-style: normal;">This parameter does not have a
6066default value and therefore must be assigned with each model run. For
6067restart runs <b>initializing_actions</b> = <span style="font-style: italic;">'read_restart_data'</span>
6068must be set. For the initial run of a job chain the following values
6069are allowed:&nbsp; </p>
6070
6071
6072
6073
6074
6075
6076 
6077     
6078     
6079     
6080     
6081     
6082     
6083      <p style="font-style: normal;"><span style="font-style: italic;">'set_constant_profiles'</span>
6084      </p>
6085
6086
6087
6088
6089
6090
6091 
6092     
6093     
6094     
6095     
6096     
6097     
6098      <ul>
6099
6100
6101
6102
6103
6104
6105 
6106       
6107       
6108       
6109       
6110       
6111       
6112        <p>A horizontal wind profile consisting
6113of linear sections (see <a href="#ug_surface">ug_surface</a>,
6114        <a href="#ug_vertical_gradient">ug_vertical_gradient</a>,
6115        <a href="#ug_vertical_gradient_level">ug_vertical_gradient_level</a>
6116and <a href="#vg_surface">vg_surface</a>, <a href="#vg_vertical_gradient">vg_vertical_gradient</a>,
6117        <a href="#vg_vertical_gradient_level">vg_vertical_gradient_level</a>,
6118respectively) as well as a vertical temperature (humidity) profile
6119consisting of
6120linear sections (see <a href="#pt_surface">pt_surface</a>,
6121        <a href="#pt_vertical_gradient">pt_vertical_gradient</a>,
6122        <a href="#q_surface">q_surface</a>
6123and <a href="#q_vertical_gradient">q_vertical_gradient</a>)
6124are assumed as initial profiles. The subgrid-scale TKE is set to 0 but K<sub>m</sub>
6125and K<sub>h</sub> are set to very small values because
6126otherwise no TKE
6127would be generated.</p>
6128
6129
6130
6131
6132
6133
6134 
6135     
6136     
6137     
6138     
6139     
6140     
6141      </ul>
6142
6143
6144
6145
6146
6147
6148 
6149     
6150     
6151     
6152     
6153     
6154     
6155      <p style="font-style: italic;">'set_1d-model_profiles' </p>
6156
6157
6158
6159
6160
6161
6162
6163     
6164     
6165     
6166     
6167     
6168     
6169      <ul>
6170
6171
6172
6173
6174
6175
6176 
6177       
6178       
6179       
6180       
6181       
6182       
6183        <p>The arrays of the 3d-model are initialized with
6184the
6185(stationary) solution of the 1d-model. These are the variables e, kh,
6186km, u, v and with Prandtl layer switched on rif, us, usws, vsws. The
6187temperature (humidity) profile consisting of linear sections is set as
6188for 'set_constant_profiles' and assumed as constant in time within the
61891d-model. For steering of the 1d-model a set of parameters with suffix
6190"_1d" (e.g. <a href="#end_time_1d">end_time_1d</a>,
6191        <a href="#damp_level_1d">damp_level_1d</a>)
6192is available.</p>
6193
6194
6195
6196
6197
6198
6199 
6200     
6201     
6202     
6203     
6204     
6205     
6206      </ul>
6207
6208
6209
6210
6211
6212
6213 
6214     
6215     
6216     
6217     
6218     
6219     
6220      <p><span style="font-style: italic;">'by_user'</span></p>
6221
6222
6223
6224
6225
6226
6227     
6228     
6229     
6230     
6231     
6232     
6233      <p style="margin-left: 40px;">The initialization of the arrays
6234of the 3d-model is under complete control of the user and has to be
6235done in routine <a href="chapter_3.5.1.html#user_init_3d_model">user_init_3d_model</a>
6236of the user-interface.<span style="font-style: italic;"></span></p>
6237
6238
6239
6240
6241
6242
6243     
6244     
6245     
6246     
6247     
6248     
6249      <p><span style="font-style: italic;">'initialize_vortex'</span>
6250      </p>
6251
6252
6253
6254
6255
6256
6257 
6258     
6259     
6260     
6261     
6262     
6263     
6264      <div style="margin-left: 40px;">The initial
6265velocity field of the
62663d-model corresponds to a
6267Rankine-vortex with vertical axis. This setting may be used to test
6268advection 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>)
6269are necessary. In order not to distort the vortex, an initial
6270horizontal wind profile constant
6271with height is necessary (to be set by <b>initializing_actions</b>
6272= <span style="font-style: italic;">'set_constant_profiles'</span>)
6273and some other conditions have to be met (neutral stratification,
6274diffusion must be
6275switched off, see <a href="#km_constant">km_constant</a>).
6276The center of the vortex is located at jc = (nx+1)/2. It
6277extends from k = 0 to k = nz+1. Its radius is 8 * <a href="#dx">dx</a>
6278and the exponentially decaying part ranges to 32 * <a href="#dx">dx</a>
6279(see init_rankine.f90). </div>
6280
6281
6282
6283
6284
6285
6286 
6287     
6288     
6289     
6290     
6291     
6292     
6293      <p><span style="font-style: italic;">'initialize_ptanom'</span>
6294      </p>
6295
6296
6297
6298
6299
6300
6301 
6302     
6303     
6304     
6305     
6306     
6307     
6308      <ul>
6309
6310
6311
6312
6313
6314
6315 
6316       
6317       
6318       
6319       
6320       
6321       
6322        <p>A 2d-Gauss-like shape disturbance
6323(x,y) is added to the
6324initial temperature field with radius 10.0 * <a href="#dx">dx</a>
6325and center at jc = (nx+1)/2. This may be used for tests of scalar
6326advection schemes
6327(see <a href="#scalar_advec">scalar_advec</a>).
6328Such tests require a horizontal wind profile constant with hight and
6329diffusion
6330switched off (see <span style="font-style: italic;">'initialize_vortex'</span>).
6331Additionally, the buoyancy term
6332must be switched of in the equation of motion&nbsp; for w (this
6333requires the user to comment out the call of <span style="font-family: monospace;">buoyancy</span> in the
6334source code of <span style="font-family: monospace;">prognostic_equations.f90</span>).</p></ul>
6335
6336
6337
6338
6339
6340
6341 
6342     
6343     
6344     
6345     
6346     
6347     
6348      <p style="font-style: italic;">'read_data_for_recycling'</p><p style="font-style: normal; margin-left: 40px;">Here,
63493d-data from a precursor run are read by the initial (main) run. The
6350precursor run is allowed to have a smaller domain along x and y
6351compared with the main run. Also, different numbers of processors can
6352be used for these two runs. Limitations are that the precursor run must
6353use cyclic horizontal boundary conditions and that the subdomains of
6354the main run must not be larger than the subdomains of the precursor
6355run. If the total domain of the main run is larger than that of the precursor
6356run, the domain is filled by cyclic repetition&nbsp;of the (cyclic)
6357precursor data. This initialization method is recommended if a
6358turbulent inflow is used (see <a href="chapter_4.1.html#turbulent_inflow">turbulent_inflow</a>). 3d-data must be made available to the run by activating an appropriate file connection statement for local file BININ. See <a href="chapter_3.9.html">chapter 3.9</a> for more details, where usage of a turbulent inflow is explained. </p><p style="font-style: normal;">Values may be
6359combined, e.g. <b>initializing_actions</b> = <span style="font-style: italic;">'set_constant_profiles
6360initialize_vortex'</span>, but the values of <span style="font-style: italic;">'set_constant_profiles'</span>,
6361      <span style="font-style: italic;">'set_1d-model_profiles'</span>
6362, and <span style="font-style: italic;">'by_user'</span>
6363must not be given at the same time.</p>
6364
6365
6366
6367
6368
6369
6370 
6371     
6372     
6373     
6374     
6375     
6376     
6377     
6378
6379
6380
6381
6382
6383
6384 </td>
6385
6386
6387
6388
6389
6390
6391 </tr>
6392
6393
6394
6395
6396
6397
6398
6399    <tr>
6400
6401
6402
6403
6404
6405
6406 <td style="vertical-align: top;"> 
6407     
6408     
6409     
6410     
6411     
6412     
6413      <p><a name="km_constant"></a><b>km_constant</b></p>
6414
6415
6416
6417
6418
6419
6420
6421      </td>
6422
6423
6424
6425
6426
6427
6428 <td style="vertical-align: top;">R</td>
6429
6430
6431
6432
6433
6434
6435
6436      <td style="vertical-align: top;"><i>variable<br>
6437
6438
6439
6440
6441
6442
6443
6444(computed from TKE)</i></td>
6445
6446
6447
6448
6449
6450
6451 <td style="vertical-align: top;"> 
6452     
6453     
6454     
6455     
6456     
6457     
6458      <p>Constant eddy
6459diffusivities are used (laminar
6460simulations).&nbsp; </p>
6461
6462
6463
6464
6465
6466
6467 
6468     
6469     
6470     
6471     
6472     
6473     
6474      <p>If this parameter is
6475specified, both in the 1d and in the
64763d-model constant values for the eddy diffusivities are used in
6477space and time with K<sub>m</sub> = <b>km_constant</b>
6478and K<sub>h</sub> = K<sub>m</sub> / <a href="chapter_4.2.html#prandtl_number">prandtl_number</a>.
6479The prognostic equation for the subgrid-scale TKE is switched off.
6480Constant eddy diffusivities are only allowed with the Prandtl layer (<a href="#prandtl_layer">prandtl_layer</a>)
6481switched off.</p>
6482
6483
6484
6485
6486
6487
6488 </td>
6489
6490
6491
6492
6493
6494
6495 </tr>
6496
6497
6498
6499
6500
6501
6502 <tr>
6503
6504
6505
6506
6507
6508
6509 <td style="vertical-align: top;"> 
6510     
6511     
6512     
6513     
6514     
6515     
6516      <p><a name="km_damp_max"></a><b>km_damp_max</b></p>
6517
6518
6519
6520
6521
6522
6523
6524      </td>
6525
6526
6527
6528
6529
6530
6531 <td style="vertical-align: top;">R</td>
6532
6533
6534
6535
6536
6537
6538
6539      <td style="vertical-align: top;"><span style="font-style: italic;">0.5*(dx
6540or dy)</span></td>
6541
6542
6543
6544
6545
6546
6547 <td style="vertical-align: top;">Maximum
6548diffusivity used for filtering the velocity field in the vicinity of
6549the outflow (in m<sup>2</sup>/s).<br>
6550
6551
6552
6553
6554
6555
6556 <br>
6557
6558
6559
6560
6561
6562
6563
6564When using non-cyclic lateral boundaries (see <a href="#bc_lr">bc_lr</a>
6565or <a href="#bc_ns">bc_ns</a>),
6566a smoothing has to be applied to the
6567velocity field in the vicinity of the outflow in order to suppress any
6568reflections of outgoing disturbances. Smoothing is done by increasing
6569the eddy diffusivity along the horizontal direction which is
6570perpendicular to the outflow boundary. Only velocity components
6571parallel to the outflow boundary are filtered (e.g. v and w, if the
6572outflow is along x). Damping is applied from the bottom to the top of
6573the domain.<br>
6574
6575
6576
6577
6578
6579
6580 <br>
6581
6582
6583
6584
6585
6586
6587
6588The horizontal range of the smoothing is controlled by <a href="#outflow_damping_width">outflow_damping_width</a>
6589which defines the number of gridpoints (counted from the outflow
6590boundary) from where on the smoothing is applied. Starting from that
6591point, the eddy diffusivity is linearly increased (from zero to its
6592maximum value given by <span style="font-weight: bold;">km_damp_max</span>)
6593until half of the damping range width, from where it remains constant
6594up to the outflow boundary. If at a certain grid point the eddy
6595diffusivity calculated from the flow field is larger than as described
6596above, it is used instead.<br>
6597
6598
6599
6600
6601
6602
6603 <br>
6604
6605
6606
6607
6608
6609
6610
6611The default value of <span style="font-weight: bold;">km_damp_max</span>
6612has been empirically proven to be sufficient.</td>
6613
6614
6615
6616
6617
6618
6619 </tr>
6620
6621
6622
6623
6624
6625
6626 <tr>
6627
6628      <td style="vertical-align: top;"><a name="lad_surface"></a><span style="font-weight: bold;">lad_surface</span></td>
6629
6630      <td style="vertical-align: top;">R</td>
6631
6632      <td style="vertical-align: top;"><span style="font-style: italic;">0.0</span></td>
6633
6634      <td style="vertical-align: top;">Surface value of the leaf area density (in m<sup>2</sup>/m<sup>3</sup>).<br>
6635
6636      <br>
6637
6638This
6639parameter assigns the value of the leaf area density <span style="font-weight: bold;">lad</span> at the surface (k=0)<b>.</b> Starting from this value,
6640the leaf area density profile is constructed with <a href="#lad_vertical_gradient">lad_vertical_gradient</a>
6641and <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level
6642      </a>.</td>
6643
6644    </tr>
6645
6646    <tr>
6647
6648      <td style="vertical-align: top;"><a name="lad_vertical_gradient"></a><span style="font-weight: bold;">lad_vertical_gradient</span></td>
6649
6650      <td style="vertical-align: top;">R (10)</td>
6651
6652      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
6653
6654      <td style="vertical-align: top;">Gradient(s) of the leaf area density (in&nbsp;m<sup>2</sup>/m<sup>4</sup>).<br>
6655
6656      <br>
6657
6658     
6659      <p>This leaf area density gradient
6660holds starting from the height&nbsp;
6661level defined by <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>
6662(precisely: for all uv levels k where zu(k) &gt; lad_vertical_gradient_level, lad(k) is set: lad(k) = lad(k-1) + dzu(k) * <b>lad_vertical_gradient</b>)
6663up to the level defined by <a href="#pch_index">pch_index</a>. Above that level lad(k) will automatically set to 0.0. A total of 10 different gradients for 11 height intervals (10 intervals
6664if <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>(1)
6665= <i>0.0</i>) can be assigned. The leaf area density at the surface is
6666assigned via <a href="#lad_surface">lad_surface</a>.&nbsp;
6667      </p>
6668
6669      </td>
6670
6671    </tr>
6672
6673    <tr>
6674
6675      <td style="vertical-align: top;"><a name="lad_vertical_gradient_level"></a><span style="font-weight: bold;">lad_vertical_gradient_level</span></td>
6676
6677      <td style="vertical-align: top;">R (10)</td>
6678
6679      <td style="vertical-align: top;"><span style="font-style: italic;">10 * 0.0</span></td>
6680
6681      <td style="vertical-align: top;">Height level from which on the&nbsp;gradient
6682of the leaf area density defined by <a href="#lad_vertical_gradient_level">lad_vertical_gradient_level</a>
6683is effective (in m).<br>
6684
6685      <br>
6686
6687The height levels have to be assigned in ascending order. The
6688default values result in a leaf area density that is constant with height uup to the top of the plant canopy layer defined by <a href="#pch_index">pch_index</a>. For the piecewise construction of temperature profiles see <a href="#lad_vertical_gradient">lad_vertical_gradient</a>.</td>
6689
6690    </tr>
6691
6692    <tr>
6693
6694      <td style="vertical-align: top;"><a name="leaf_surface_concentration"></a><b>leaf_surface_concentration</b></td>
6695
6696      <td style="vertical-align: top;">R</td>
6697
6698      <td style="vertical-align: top;"><i>0.0</i></td>
6699
6700      <td style="vertical-align: top;">Concentration of a passive scalar at the surface of a leaf (in K m/s).<br>
6701
6702
6703      <br>
6704
6705
6706This parameter is only of importance in cases in that both, <a href="#plant_canopy">plant_canopy</a> and <a href="#passive_scalar">passive_scalar</a>, are set <span style="font-style: italic;">.T.</span>.
6707The value of the concentration of a passive scalar at the surface of a
6708leaf is required for the parametrisation of the sources and sinks of
6709scalar concentration due to the canopy.</td>
6710
6711    </tr>
6712
6713    <tr>
6714
6715
6716
6717
6718
6719
6720
6721      <td style="vertical-align: top;"> 
6722     
6723     
6724     
6725     
6726     
6727     
6728      <p><a name="long_filter_factor"></a><b>long_filter_factor</b></p>
6729
6730
6731
6732
6733
6734
6735
6736      </td>
6737
6738
6739
6740
6741
6742
6743 <td style="vertical-align: top;">R</td>
6744
6745
6746
6747
6748
6749
6750
6751      <td style="vertical-align: top;"><i>0.0</i></td>
6752
6753
6754
6755
6756
6757
6758
6759      <td style="vertical-align: top;"> 
6760     
6761     
6762     
6763     
6764     
6765     
6766      <p>Filter factor
6767for the so-called Long-filter.<br>
6768
6769
6770
6771
6772
6773
6774 </p>
6775
6776
6777
6778
6779
6780
6781 
6782     
6783     
6784     
6785     
6786     
6787     
6788      <p><br>
6789
6790
6791
6792
6793
6794
6795
6796This filter very efficiently
6797eliminates 2-delta-waves sometimes cauesed by the upstream-spline
6798scheme (see Mahrer and
6799Pielke, 1978: Mon. Wea. Rev., 106, 818-830). It works in all three
6800directions in space. A value of <b>long_filter_factor</b>
6801= <i>0.01</i>
6802sufficiently removes the small-scale waves without affecting the
6803longer waves.<br>
6804
6805
6806
6807
6808
6809
6810 </p>
6811
6812
6813
6814
6815
6816
6817 
6818     
6819     
6820     
6821     
6822     
6823     
6824      <p>By default, the filter is
6825switched off (= <i>0.0</i>).
6826It is exclusively applied to the tendencies calculated by the
6827upstream-spline scheme (see <a href="#momentum_advec">momentum_advec</a>
6828and <a href="#scalar_advec">scalar_advec</a>),
6829not to the prognostic variables themselves. At the bottom and top
6830boundary of the model domain the filter effect for vertical
68312-delta-waves is reduced. There, the amplitude of these waves is only
6832reduced by approx. 50%, otherwise by nearly 100%.&nbsp; <br>
6833
6834
6835
6836
6837
6838
6839
6840Filter factors with values &gt; <i>0.01</i> also
6841reduce the amplitudes
6842of waves with wavelengths longer than 2-delta (see the paper by Mahrer
6843and
6844Pielke, quoted above). </p>
6845
6846
6847
6848
6849
6850
6851 </td>
6852
6853
6854
6855
6856
6857
6858 </tr>
6859
6860
6861
6862
6863
6864
6865 <tr>
6866
6867
6868
6869
6870
6871
6872      <td style="vertical-align: top;"><a name="loop_optimization"></a><span style="font-weight: bold;">loop_optimization</span></td>
6873
6874
6875
6876
6877
6878
6879      <td style="vertical-align: top;">C*16</td>
6880
6881
6882
6883
6884
6885
6886      <td style="vertical-align: top;"><span style="font-style: italic;">see right</span></td>
6887
6888
6889
6890
6891
6892
6893      <td>Method used to optimize loops for solving the prognostic equations .<br>
6894
6895
6896
6897
6898
6899
6900      <br>
6901
6902
6903
6904
6905
6906
6907By
6908default, the optimization method depends on the host on which PALM is
6909running. On machines with vector-type CPUs, single 3d-loops are used to
6910calculate each tendency term of each prognostic equation, while on all
6911other machines, all prognostic equations are solved within one big loop
6912over 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>
6913
6914
6915
6916
6917
6918
6919      <br>
6920
6921
6922
6923
6924
6925
6926The 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>
6927
6928
6929
6930
6931
6932
6933    </tr>
6934
6935
6936
6937
6938
6939
6940    <tr>
6941
6942
6943
6944
6945
6946
6947
6948      <td style="vertical-align: top;"><a name="mixing_length_1d"></a><span style="font-weight: bold;">mixing_length_1d</span><br>
6949
6950
6951
6952
6953
6954
6955
6956      </td>
6957
6958
6959
6960
6961
6962
6963 <td style="vertical-align: top;">C*20<br>
6964
6965
6966
6967
6968
6969
6970
6971      </td>
6972
6973
6974
6975
6976
6977
6978 <td style="vertical-align: top;"><span style="font-style: italic;">'as_in_3d_</span><br style="font-style: italic;">
6979
6980
6981
6982
6983
6984
6985 <span style="font-style: italic;">model'</span><br>
6986
6987
6988
6989
6990
6991
6992 </td>
6993
6994
6995
6996
6997
6998
6999
7000      <td style="vertical-align: top;">Mixing length used in the
70011d-model.<br>
7002
7003
7004
7005
7006
7007
7008 <br>
7009
7010
7011
7012
7013
7014
7015
7016By default the mixing length is calculated as in the 3d-model (i.e. it
7017depends on the grid spacing).<br>
7018
7019
7020
7021
7022
7023
7024 <br>
7025
7026
7027
7028
7029
7030
7031
7032By setting <span style="font-weight: bold;">mixing_length_1d</span>
7033= <span style="font-style: italic;">'blackadar'</span>,
7034the so-called Blackadar mixing length is used (l = kappa * z / ( 1 +
7035kappa * z / lambda ) with the limiting value lambda = 2.7E-4 * u_g / f).<br>
7036
7037
7038
7039
7040
7041
7042
7043      </td>
7044
7045
7046
7047
7048
7049
7050 </tr>
7051
7052
7053
7054
7055
7056
7057 
7058
7059
7060
7061
7062
7063
7064
7065    <tr>
7066
7067
7068
7069
7070
7071
7072 <td style="vertical-align: top;"> 
7073     
7074     
7075     
7076     
7077     
7078     
7079      <p><a name="momentum_advec"></a><b>momentum_advec</b></p>
7080
7081
7082
7083
7084
7085
7086
7087      </td>
7088
7089
7090
7091
7092
7093
7094 <td style="vertical-align: top;">C * 10</td>
7095
7096
7097
7098
7099
7100
7101
7102      <td style="vertical-align: top;"><i>'pw-scheme'</i></td>
7103
7104
7105
7106
7107
7108
7109
7110      <td style="vertical-align: top;"> 
7111     
7112     
7113     
7114     
7115     
7116     
7117      <p>Advection
7118scheme to be used for the momentum equations.<br>
7119
7120
7121
7122
7123
7124
7125 <br>
7126
7127
7128
7129
7130
7131
7132
7133The user can choose between the following schemes:<br>
7134
7135
7136
7137
7138
7139
7140
7141&nbsp;<br>
7142
7143
7144
7145
7146
7147
7148 <br>
7149
7150
7151
7152
7153
7154
7155 <span style="font-style: italic;">'pw-scheme'</span><br>
7156
7157
7158
7159
7160
7161
7162
7163      </p>
7164
7165
7166
7167
7168
7169
7170 
7171     
7172     
7173     
7174     
7175     
7176     
7177      <div style="margin-left: 40px;">The scheme of
7178Piascek and
7179Williams (1970, J. Comp. Phys., 6,
7180392-405) with central differences in the form C3 is used.<br>
7181
7182
7183
7184
7185
7186
7187
7188If intermediate Euler-timesteps are carried out in case of <a href="#timestep_scheme">timestep_scheme</a>
7189= <span style="font-style: italic;">'leapfrog+euler'</span>
7190the
7191advection scheme is - for the Euler-timestep - automatically switched
7192to an upstream-scheme.<br>
7193
7194
7195
7196
7197
7198
7199 </div>
7200
7201
7202
7203
7204
7205
7206 
7207     
7208     
7209     
7210     
7211     
7212     
7213      <p> </p>
7214
7215
7216
7217
7218
7219
7220 
7221     
7222     
7223     
7224     
7225     
7226     
7227      <p><span style="font-style: italic;">'ups-scheme'</span><br>
7228
7229
7230
7231
7232
7233
7234
7235      </p>
7236
7237
7238
7239
7240
7241
7242 
7243     
7244     
7245     
7246     
7247     
7248     
7249      <div style="margin-left: 40px;">The
7250upstream-spline scheme is
7251used
7252(see Mahrer and Pielke,
72531978: Mon. Wea. Rev., 106, 818-830). In opposite to the
7254Piascek-Williams scheme, this is characterized by much better numerical
7255features (less numerical diffusion, better preservation of flow
7256structures, e.g. vortices), but computationally it is much more
7257expensive. In
7258addition, the use of the Euler-timestep scheme is mandatory (<a href="#timestep_scheme">timestep_scheme</a>
7259= <span style="font-style: italic;">'</span><i>euler'</i>),
7260i.e. the
7261timestep accuracy is only of first order.
7262For this reason the advection of scalar variables (see <a href="#scalar_advec">scalar_advec</a>)
7263should then also be carried out with the upstream-spline scheme,
7264because otherwise the scalar variables would
7265be subject to large numerical diffusion due to the upstream
7266scheme.&nbsp; </div>
7267
7268
7269
7270
7271
7272
7273 
7274     
7275     
7276     
7277     
7278     
7279     
7280      <p style="margin-left: 40px;">Since
7281the cubic splines used tend
7282to overshoot under
7283certain circumstances, this effect must be adjusted by suitable
7284filtering and smoothing (see <a href="#cut_spline_overshoot">cut_spline_overshoot</a>,
7285      <a href="#long_filter_factor">long_filter_factor</a>,
7286      <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>).
7287This is always neccessary for runs with stable stratification,
7288even if this stratification appears only in parts of the model domain.<br>
7289
7290
7291
7292
7293
7294
7295
7296      </p>
7297
7298
7299
7300
7301
7302
7303 
7304     
7305     
7306     
7307     
7308     
7309     
7310      <div style="margin-left: 40px;">With stable
7311stratification the
7312upstream-spline scheme also
7313produces gravity waves with large amplitude, which must be
7314suitably damped (see <a href="chapter_4.2.html#rayleigh_damping_factor">rayleigh_damping_factor</a>).<br>
7315
7316
7317
7318
7319
7320
7321
7322      <br>
7323
7324
7325
7326
7327
7328
7329 <span style="font-weight: bold;">Important: </span>The&nbsp;
7330upstream-spline scheme is not implemented for humidity and passive
7331scalars (see&nbsp;<a href="#humidity">humidity</a>
7332and <a href="#passive_scalar">passive_scalar</a>)
7333and requires the use of a 2d-domain-decomposition. The last conditions
7334severely restricts code optimization on several machines leading to
7335very long execution times! The scheme is also not allowed for
7336non-cyclic lateral boundary conditions (see <a href="#bc_lr">bc_lr</a>
7337and <a href="#bc_ns">bc_ns</a>).</div>
7338
7339
7340
7341
7342
7343
7344 </td>
7345
7346
7347
7348
7349
7350
7351
7352    </tr>
7353
7354
7355
7356
7357
7358
7359 <tr>
7360
7361
7362
7363
7364
7365
7366 <td style="vertical-align: top;"><a name="netcdf_precision"></a><span style="font-weight: bold;">netcdf_precision</span><br>
7367
7368
7369
7370
7371
7372
7373
7374      </td>
7375
7376
7377
7378
7379
7380
7381 <td style="vertical-align: top;">C*20<br>
7382
7383
7384
7385
7386
7387
7388
7389(10)<br>
7390
7391
7392
7393
7394
7395
7396 </td>
7397
7398
7399
7400
7401
7402
7403 <td style="vertical-align: top;"><span style="font-style: italic;">single preci-</span><br style="font-style: italic;">
7404
7405
7406
7407
7408
7409
7410 <span style="font-style: italic;">sion for all</span><br style="font-style: italic;">
7411
7412
7413
7414
7415
7416
7417 <span style="font-style: italic;">output quan-</span><br style="font-style: italic;">
7418
7419
7420
7421
7422
7423
7424 <span style="font-style: italic;">tities</span><br>
7425
7426
7427
7428
7429
7430
7431 </td>
7432
7433
7434
7435
7436
7437
7438
7439      <td style="vertical-align: top;">Defines the accuracy of
7440the NetCDF output.<br>
7441
7442
7443
7444
7445
7446
7447 <br>
7448
7449
7450
7451
7452
7453
7454
7455By default, all NetCDF output data (see <a href="chapter_4.2.html#data_output_format">data_output_format</a>)
7456have single precision&nbsp; (4 byte) accuracy. Double precision (8
7457byte) can be choosen alternatively.<br>
7458
7459
7460
7461
7462
7463
7464
7465Accuracy for the different output data (cross sections, 3d-volume data,
7466spectra, etc.) can be set independently.<br>
7467
7468
7469
7470
7471
7472
7473 <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL4'</span>
7474(single precision) or <span style="font-style: italic;">'&lt;out&gt;_NF90_REAL8'</span>
7475(double precision) are the two principally allowed values for <span style="font-weight: bold;">netcdf_precision</span>,
7476where the string <span style="font-style: italic;">'&lt;out&gt;'
7477      </span>can be chosen out of the following list:<br>
7478
7479
7480
7481
7482
7483
7484 <br>
7485
7486
7487
7488
7489
7490
7491
7492     
7493     
7494     
7495     
7496     
7497     
7498      <table style="text-align: left; width: 284px; height: 234px;" border="1" cellpadding="2" cellspacing="2">
7499
7500
7501
7502
7503
7504
7505 <tbody>
7506
7507
7508
7509
7510
7511
7512
7513          <tr>
7514
7515
7516
7517
7518
7519
7520 <td style="vertical-align: top;"><span style="font-style: italic;">'xy'</span><br>
7521
7522
7523
7524
7525
7526
7527 </td>
7528
7529
7530
7531
7532
7533
7534
7535            <td style="vertical-align: top;">horizontal cross section<br>
7536
7537
7538
7539
7540
7541
7542
7543            </td>
7544
7545
7546
7547
7548
7549
7550 </tr>
7551
7552
7553
7554
7555
7556
7557 <tr>
7558
7559
7560
7561
7562
7563
7564 <td style="vertical-align: top;"><span style="font-style: italic;">'xz'</span><br>
7565
7566
7567
7568
7569
7570
7571 </td>
7572
7573
7574
7575
7576
7577
7578
7579            <td style="vertical-align: top;">vertical (xz) cross
7580section<br>
7581
7582
7583
7584
7585
7586
7587 </td>
7588
7589
7590
7591
7592
7593
7594 </tr>
7595
7596
7597
7598
7599
7600
7601 <tr>
7602
7603
7604
7605
7606
7607
7608 <td style="vertical-align: top;"><span style="font-style: italic;">'yz'</span><br>
7609
7610
7611
7612
7613
7614
7615 </td>
7616
7617
7618
7619
7620
7621
7622
7623            <td style="vertical-align: top;">vertical (yz) cross
7624section<br>
7625
7626
7627
7628
7629
7630
7631 </td>
7632
7633
7634
7635
7636
7637
7638 </tr>
7639
7640
7641
7642
7643
7644
7645 <tr>
7646
7647
7648
7649
7650
7651
7652 <td style="vertical-align: top;"><span style="font-style: italic;">'2d'</span><br>
7653
7654
7655
7656
7657
7658
7659 </td>
7660
7661
7662
7663
7664
7665
7666
7667            <td style="vertical-align: top;">all cross sections<br>
7668
7669
7670
7671
7672
7673
7674
7675            </td>
7676
7677
7678
7679
7680
7681
7682 </tr>
7683
7684
7685
7686
7687
7688
7689 <tr>
7690
7691
7692
7693
7694
7695
7696 <td style="vertical-align: top;"><span style="font-style: italic;">'3d'</span><br>
7697
7698
7699
7700
7701
7702
7703 </td>
7704
7705
7706
7707
7708
7709
7710
7711            <td style="vertical-align: top;">volume data<br>
7712
7713
7714
7715
7716
7717
7718 </td>
7719
7720
7721
7722
7723
7724
7725
7726          </tr>
7727
7728
7729
7730
7731
7732
7733 <tr>
7734
7735
7736
7737
7738
7739
7740 <td style="vertical-align: top;"><span style="font-style: italic;">'pr'</span><br>
7741
7742
7743
7744
7745
7746
7747 </td>
7748
7749
7750
7751
7752
7753
7754
7755            <td style="vertical-align: top;">vertical profiles<br>
7756
7757
7758
7759
7760
7761
7762
7763            </td>
7764
7765
7766
7767
7768
7769
7770 </tr>
7771
7772
7773
7774
7775
7776
7777 <tr>
7778
7779
7780
7781
7782
7783
7784 <td style="vertical-align: top;"><span style="font-style: italic;">'ts'</span><br>
7785
7786
7787
7788
7789
7790
7791 </td>
7792
7793
7794
7795
7796
7797
7798
7799            <td style="vertical-align: top;">time series, particle
7800time series<br>
7801
7802
7803
7804
7805
7806
7807 </td>
7808
7809
7810
7811
7812
7813
7814 </tr>
7815
7816
7817
7818
7819
7820
7821 <tr>
7822
7823
7824
7825
7826
7827
7828 <td style="vertical-align: top;"><span style="font-style: italic;">'sp'</span><br>
7829
7830
7831
7832
7833
7834
7835 </td>
7836
7837
7838
7839
7840
7841
7842
7843            <td style="vertical-align: top;">spectra<br>
7844
7845
7846
7847
7848
7849
7850 </td>
7851
7852
7853
7854
7855
7856
7857
7858          </tr>
7859
7860
7861
7862
7863
7864
7865 <tr>
7866
7867
7868
7869
7870
7871
7872 <td style="vertical-align: top;"><span style="font-style: italic;">'prt'</span><br>
7873
7874
7875
7876
7877
7878
7879 </td>
7880
7881
7882
7883
7884
7885
7886
7887            <td style="vertical-align: top;">particles<br>
7888
7889
7890
7891
7892
7893
7894 </td>
7895
7896
7897
7898
7899
7900
7901
7902          </tr>
7903
7904
7905
7906
7907
7908
7909 <tr>
7910
7911
7912
7913
7914
7915
7916 <td style="vertical-align: top;"><span style="font-style: italic;">'all'</span><br>
7917
7918
7919
7920
7921
7922
7923 </td>
7924
7925
7926
7927
7928
7929
7930
7931            <td style="vertical-align: top;">all output quantities<br>
7932
7933
7934
7935
7936
7937
7938
7939            </td>
7940
7941
7942
7943
7944
7945
7946 </tr>
7947
7948
7949
7950
7951
7952
7953 
7954       
7955       
7956       
7957       
7958       
7959       
7960        </tbody> 
7961     
7962     
7963     
7964     
7965     
7966     
7967      </table>
7968
7969
7970
7971
7972
7973
7974 <br>
7975
7976
7977
7978
7979
7980
7981 <span style="font-weight: bold;">Example:</span><br>
7982
7983
7984
7985
7986
7987
7988
7989If all cross section data and the particle data shall be output in
7990double 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>
7991has to be assigned.<br>
7992
7993
7994
7995
7996
7997
7998 </td>
7999
8000
8001
8002
8003
8004
8005 </tr>
8006
8007
8008
8009
8010
8011
8012
8013   
8014
8015
8016
8017
8018
8019
8020 
8021
8022
8023
8024
8025
8026
8027
8028    <tr>
8029
8030
8031
8032
8033
8034
8035 <td style="vertical-align: top;"> 
8036     
8037     
8038     
8039     
8040     
8041     
8042      <p><a name="nsor_ini"></a><b>nsor_ini</b></p>
8043
8044
8045
8046
8047
8048
8049
8050      </td>
8051
8052
8053
8054
8055
8056
8057 <td style="vertical-align: top;">I</td>
8058
8059
8060
8061
8062
8063
8064
8065      <td style="vertical-align: top;"><i>100</i></td>
8066
8067
8068
8069
8070
8071
8072
8073      <td style="vertical-align: top;"> 
8074     
8075     
8076     
8077     
8078     
8079     
8080      <p>Initial number
8081of iterations with the SOR algorithm.&nbsp; </p>
8082
8083
8084
8085
8086
8087
8088 
8089     
8090     
8091     
8092     
8093     
8094     
8095      <p>This
8096parameter is only effective if the SOR algorithm was
8097selected as the pressure solver scheme (<a href="chapter_4.2.html#psolver">psolver</a>
8098= <span style="font-style: italic;">'sor'</span>)
8099and specifies the
8100number of initial iterations of the SOR
8101scheme (at t = 0). The number of subsequent iterations at the following
8102timesteps is determined
8103with the parameter <a href="#nsor">nsor</a>.
8104Usually <b>nsor</b> &lt; <b>nsor_ini</b>,
8105since in each case
8106subsequent calls to <a href="chapter_4.2.html#psolver">psolver</a>
8107use the solution of the previous call as initial value. Suitable
8108test runs should determine whether sufficient convergence of the
8109solution is obtained with the default value and if necessary the value
8110of <b>nsor_ini</b> should be changed.</p>
8111
8112
8113
8114
8115
8116
8117 </td>
8118
8119
8120
8121
8122
8123
8124
8125    </tr>
8126
8127
8128
8129
8130
8131
8132 <tr>
8133
8134
8135
8136
8137
8138
8139 <td style="vertical-align: top;">
8140     
8141     
8142     
8143     
8144     
8145     
8146      <p><a name="nx"></a><b>nx</b></p>
8147
8148
8149
8150
8151
8152
8153
8154      </td>
8155
8156
8157
8158
8159
8160
8161 <td style="vertical-align: top;">I</td>
8162
8163
8164
8165
8166
8167
8168
8169      <td style="vertical-align: top;"><br>
8170
8171
8172
8173
8174
8175
8176 </td>
8177
8178
8179
8180
8181
8182
8183 <td style="vertical-align: top;"> 
8184     
8185     
8186     
8187     
8188     
8189     
8190      <p>Number of grid
8191points in x-direction.&nbsp; </p>
8192
8193
8194
8195
8196
8197
8198 
8199     
8200     
8201     
8202     
8203     
8204     
8205      <p>A value for this
8206parameter must be assigned. Since the lower
8207array bound in PALM
8208starts with i = 0, the actual number of grid points is equal to <b>nx+1</b>.
8209In case of cyclic boundary conditions along x, the domain size is (<b>nx+1</b>)*
8210      <a href="#dx">dx</a>.</p>
8211
8212
8213
8214
8215
8216
8217 
8218     
8219     
8220     
8221     
8222     
8223     
8224      <p>For
8225parallel runs, in case of <a href="#grid_matching">grid_matching</a>
8226= <span style="font-style: italic;">'strict'</span>,
8227      <b>nx+1</b> must
8228be an integral multiple
8229of the processor numbers (see <a href="#npex">npex</a>
8230and <a href="#npey">npey</a>)
8231along x- as well as along y-direction (due to data
8232transposition restrictions).</p>
8233
8234
8235
8236
8237
8238
8239     
8240     
8241     
8242     
8243     
8244     
8245      <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>
8246and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
8247
8248
8249
8250
8251
8252
8253 </td>
8254
8255
8256
8257
8258
8259
8260 </tr>
8261
8262
8263
8264
8265
8266
8267 <tr>
8268
8269
8270
8271
8272
8273
8274
8275      <td style="vertical-align: top;"> 
8276     
8277     
8278     
8279     
8280     
8281     
8282      <p><a name="ny"></a><b>ny</b></p>
8283
8284
8285
8286
8287
8288
8289
8290      </td>
8291
8292
8293
8294
8295
8296
8297 <td style="vertical-align: top;">I</td>
8298
8299
8300
8301
8302
8303
8304
8305      <td style="vertical-align: top;"><br>
8306
8307
8308
8309
8310
8311
8312 </td>
8313
8314
8315
8316
8317
8318
8319 <td style="vertical-align: top;"> 
8320     
8321     
8322     
8323     
8324     
8325     
8326      <p>Number of grid
8327points in y-direction.&nbsp; </p>
8328
8329
8330
8331
8332
8333
8334 
8335     
8336     
8337     
8338     
8339     
8340     
8341      <p>A value for this
8342parameter must be assigned. Since the lower
8343array bound in PALM starts with j = 0, the actual number of grid points
8344is equal to <b>ny+1</b>. In case of cyclic boundary
8345conditions along
8346y, the domain size is (<b>ny+1</b>) * <a href="#dy">dy</a>.</p>
8347
8348
8349
8350
8351
8352
8353
8354     
8355     
8356     
8357     
8358     
8359     
8360      <p>For parallel runs, in case of <a href="#grid_matching">grid_matching</a>
8361= <span style="font-style: italic;">'strict'</span>,
8362      <b>ny+1</b> must
8363be an integral multiple
8364of the processor numbers (see <a href="#npex">npex</a>
8365and <a href="#npey">npey</a>)&nbsp;
8366along y- as well as along x-direction (due to data
8367transposition restrictions).</p>
8368
8369
8370
8371
8372
8373
8374     
8375     
8376     
8377     
8378     
8379     
8380      <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>
8381and&nbsp;<a href="chapter_3.4.html#PARIN"><font style="font-size: 10pt;" size="2">PARIN_O</font></a>.</p>
8382
8383
8384
8385
8386
8387
8388 </td>
8389
8390
8391
8392
8393
8394
8395 </tr>
8396
8397
8398
8399
8400
8401
8402 <tr>
8403
8404
8405
8406
8407
8408
8409
8410      <td style="vertical-align: top;"> 
8411     
8412     
8413     
8414     
8415     
8416     
8417      <p><a name="nz"></a><b>nz</b></p>
8418
8419
8420
8421
8422
8423
8424
8425      </td>
8426
8427
8428
8429
8430
8431
8432 <td style="vertical-align: top;">I</td>
8433
8434
8435
8436
8437
8438
8439
8440      <td style="vertical-align: top;"><br>
8441
8442
8443
8444
8445
8446
8447 </td>
8448
8449
8450
8451
8452
8453
8454 <td style="vertical-align: top;"> 
8455     
8456     
8457     
8458     
8459     
8460     
8461      <p>Number of grid
8462points in z-direction.&nbsp; </p>
8463
8464
8465
8466
8467
8468
8469 
8470     
8471     
8472     
8473     
8474     
8475     
8476      <p>A value for this
8477parameter must be assigned. Since the lower
8478array bound in PALM
8479starts with k = 0 and since one additional grid point is added at the
8480top boundary (k = <b>nz+1</b>), the actual number of grid
8481points is <b>nz+2</b>.
8482However, the prognostic equations are only solved up to <b>nz</b>
8483(u,
8484v)
8485or up to <b>nz-1</b> (w, scalar quantities). The top
8486boundary for u
8487and v is at k = <b>nz+1</b> (u, v) while at k = <b>nz</b>
8488for all
8489other quantities.&nbsp; </p>
8490
8491
8492
8493
8494
8495
8496 
8497     
8498     
8499     
8500     
8501     
8502     
8503      <p>For parallel
8504runs,&nbsp; in case of <a href="#grid_matching">grid_matching</a>
8505= <span style="font-style: italic;">'strict'</span>,
8506      <b>nz</b> must
8507be an integral multiple of
8508the number of processors in x-direction (due to data transposition
8509restrictions).</p>
8510
8511
8512
8513
8514
8515
8516 </td>
8517
8518
8519
8520
8521
8522
8523 </tr>
8524
8525
8526
8527
8528
8529
8530 <tr>
8531
8532
8533
8534
8535
8536
8537      <td style="vertical-align: top;"><a name="ocean"></a><span style="font-weight: bold;">ocean</span></td>
8538
8539
8540
8541
8542
8543
8544      <td style="vertical-align: top;">L</td>
8545
8546
8547
8548
8549
8550
8551      <td style="vertical-align: top;"><span style="font-style: italic;">.F.</span></td>
8552
8553
8554
8555
8556
8557
8558      <td style="vertical-align: top;">Parameter to switch on&nbsp;ocean runs.<br>
8559
8560
8561
8562
8563
8564
8565      <br>
8566
8567
8568
8569
8570
8571
8572By 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>
8573
8574
8575
8576
8577
8578
8579      <br>
8580
8581
8582
8583
8584
8585
8586     
8587     
8588     
8589     
8590     
8591     
8592      <ul>
8593
8594
8595
8596
8597
8598
8599        <li>An additional prognostic equation for salinity is solved.</li>
8600
8601
8602
8603
8604
8605
8606        <li>Potential temperature in buoyancy and stability-related terms is replaced by potential density.</li>
8607
8608
8609
8610
8611
8612
8613        <li>Potential
8614density is calculated from the equation of state for seawater after
8615each timestep, using the algorithm proposed by Jackett et al. (2006, J.
8616Atmos. Oceanic Technol., <span style="font-weight: bold;">23</span>, 1709-1728).<br>
8617
8618
8619
8620
8621
8622
8623So far, only the initial hydrostatic pressure is entered into this equation.</li>
8624
8625
8626
8627
8628
8629
8630        <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>
8631
8632
8633
8634
8635
8636
8637        <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>
8638
8639
8640
8641
8642
8643
8644        <li>Zero salinity flux is used as default boundary condition at the bottom of the sea.</li>
8645
8646
8647
8648
8649
8650
8651        <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>
8652
8653
8654
8655
8656
8657
8658     
8659     
8660     
8661     
8662     
8663     
8664      </ul>
8665
8666
8667
8668
8669
8670
8671      <br>
8672
8673
8674
8675
8676
8677
8678Relevant 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>
8679
8680
8681
8682
8683
8684
8685      <br>
8686
8687
8688
8689
8690
8691
8692Section <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>
8693
8694
8695
8696
8697
8698
8699      <br>
8700
8701
8702
8703
8704
8705
8706      <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>
8707
8708
8709
8710      </td>
8711
8712
8713
8714
8715
8716
8717    </tr>
8718
8719
8720
8721
8722
8723
8724    <tr>
8725
8726
8727
8728
8729
8730
8731 <td style="vertical-align: top;"> 
8732     
8733     
8734     
8735     
8736     
8737     
8738      <p><a name="omega"></a><b>omega</b></p>
8739
8740
8741
8742
8743
8744
8745
8746      </td>
8747
8748
8749
8750
8751
8752
8753 <td style="vertical-align: top;">R</td>
8754
8755
8756
8757
8758
8759
8760
8761      <td style="vertical-align: top;"><i>7.29212E-5</i></td>
8762
8763
8764
8765
8766
8767
8768
8769      <td style="vertical-align: top;"> 
8770     
8771     
8772     
8773     
8774     
8775     
8776      <p>Angular
8777velocity of the rotating system (in rad s<sup>-1</sup>).&nbsp;
8778      </p>
8779
8780
8781
8782
8783
8784
8785 
8786     
8787     
8788     
8789     
8790     
8791     
8792      <p>The angular velocity of the earth is set by
8793default. The
8794values
8795of the Coriolis parameters are calculated as:&nbsp; </p>
8796
8797
8798
8799
8800
8801
8802 
8803     
8804     
8805     
8806     
8807     
8808     
8809      <ul>
8810
8811
8812
8813
8814
8815
8816
8817       
8818       
8819       
8820       
8821       
8822       
8823        <p>f = 2.0 * <b>omega</b> * sin(<a href="#phi">phi</a>)&nbsp;
8824        <br>
8825
8826
8827
8828
8829
8830
8831f* = 2.0 * <b>omega</b> * cos(<a href="#phi">phi</a>)</p>
8832
8833
8834
8835
8836
8837
8838
8839     
8840     
8841     
8842     
8843     
8844     
8845      </ul>
8846
8847
8848
8849
8850
8851
8852 </td>
8853
8854
8855
8856
8857
8858
8859 </tr>
8860
8861
8862
8863
8864
8865
8866 <tr>
8867
8868
8869
8870
8871
8872
8873 <td style="vertical-align: top;"> 
8874     
8875     
8876     
8877     
8878     
8879     
8880      <p><a name="outflow_damping_width"></a><b>outflow_damping_width</b></p>
8881
8882
8883
8884
8885
8886
8887
8888      </td>
8889
8890
8891
8892
8893
8894
8895 <td style="vertical-align: top;">I</td>
8896
8897
8898
8899
8900
8901
8902
8903      <td style="vertical-align: top;"><span style="font-style: italic;">MIN(20,
8904nx/2</span> or <span style="font-style: italic;">ny/2)</span></td>
8905
8906
8907
8908
8909
8910
8911
8912      <td style="vertical-align: top;">Width of
8913the damping range in the vicinity of the outflow (gridpoints).<br>
8914
8915
8916
8917
8918
8919
8920
8921      <br>
8922
8923
8924
8925
8926
8927
8928
8929When using non-cyclic lateral boundaries (see <a href="chapter_4.1.html#bc_lr">bc_lr</a>
8930or <a href="chapter_4.1.html#bc_ns">bc_ns</a>),
8931a smoothing has to be applied to the
8932velocity field in the vicinity of the outflow in order to suppress any
8933reflections of outgoing disturbances. This parameter controlls the
8934horizontal range to which the smoothing is applied. The range is given
8935in gridpoints counted from the respective outflow boundary. For further
8936details about the smoothing see parameter <a href="chapter_4.1.html#km_damp_max">km_damp_max</a>,
8937which defines the magnitude of the damping.</td>
8938
8939
8940
8941
8942
8943
8944 </tr>
8945
8946
8947
8948
8949
8950
8951
8952    <tr>
8953
8954
8955
8956
8957
8958
8959 <td style="vertical-align: top;"> 
8960     
8961     
8962     
8963     
8964     
8965     
8966      <p><a name="overshoot_limit_e"></a><b>overshoot_limit_e</b></p>
8967
8968
8969
8970
8971
8972
8973
8974      </td>
8975
8976
8977
8978
8979
8980
8981 <td style="vertical-align: top;">R</td>
8982
8983
8984
8985
8986
8987
8988
8989      <td style="vertical-align: top;"><i>0.0</i></td>
8990
8991
8992
8993
8994
8995
8996
8997      <td style="vertical-align: top;"> 
8998     
8999     
9000     
9001     
9002     
9003     
9004      <p>Allowed limit
9005for the overshooting of subgrid-scale TKE in
9006case that the upstream-spline scheme is switched on (in m<sup>2</sup>/s<sup>2</sup>).&nbsp;
9007      </p>
9008
9009
9010
9011
9012
9013
9014 
9015     
9016     
9017     
9018     
9019     
9020     
9021      <p<