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init_grid.f90 @ 4529

Last change on this file since 4529 was 4507, checked in by gronemeier, 5 years ago

netcdf_data_input_mod:

bugfix: check terrain height for fill values directly after reading (PA0550)
changes:
- remove check for negative zt (PA0551)
- add reference height from input file to PALM reference height (origin_z)

init_grid:

update origin_z with shifting height of orography (oro_min)
remove message PA0505

Property svn:keywords set to Id

File size: 118.3 KB

Line
1	!> @file init_grid.f90
2	!------------------------------------------------------------------------------!
3	! This file is part of the PALM model system.
4	!
5	! PALM is free software: you can redistribute it and/or modify it under the
6	! terms of the GNU General Public License as published by the Free Software
7	! Foundation, either version 3 of the License, or (at your option) any later
8	! version.
9	!
10	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
11	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
13	!
14	! You should have received a copy of the GNU General Public License along with
15	! PALM. If not, see <http://www.gnu.org/licenses/>.
16	!
17	! Copyright 1997-2020 Leibniz Universitaet Hannover
18	!------------------------------------------------------------------------------!
19	!
20	! Current revisions:
21	! -----------------
22	!
23	!
24	! Former revisions:
25	! -----------------
26	! $Id: init_grid.f90 4507 2020-04-22 18:21:45Z moh.hefny $
27	! update origin_z with shifting height of orography (oro_min)
28	!
29	! 4457 2020-03-11 14:20:43Z raasch
30	! use statement for exchange horiz added,
31	! bugfix for call of exchange horiz 2d
32	!
33	! 4444 2020-03-05 15:59:50Z raasch
34	! bugfix: cpp-directives for serial mode added
35	!
36	! 4414 2020-02-19 20:16:04Z suehring
37	! - Remove deprecated topography arrays nzb_s_inner, nzb_u_inner, etc.
38	! - Move initialization of boundary conditions and multigrid into an extra
39	! module interface.
40	!
41	! 4386 2020-01-27 15:07:30Z Giersch
42	! Allocation statements, comments, naming of variables revised and _wp added to
43	! real type values
44	!
45	! 4360 2020-01-07 11:25:50Z suehring
46	! Revise error messages for generic tunnel setup.
47	!
48	! 4346 2019-12-18 11:55:56Z motisi
49	! Introduction of wall_flags_total_0, which currently sets bits based on static
50	! topography information used in wall_flags_static_0
51	!
52	! 4340 2019-12-16 08:17:03Z Giersch
53	! Topography closed channel flow with symmetric boundaries implemented
54	!
55	! 4329 2019-12-10 15:46:36Z motisi
56	! Renamed wall_flags_0 to wall_flags_static_0
57	!
58	! 4328 2019-12-09 18:53:04Z suehring
59	! Minor change in nzb_max computation. Commentation added.
60	!
61	! 4314 2019-11-29 10:29:20Z suehring
62	! Set additional topography flag 4 to mark topography grid points emerged
63	! from the filtering process.
64	!
65	! 4294 2019-11-13 18:34:16Z suehring
66	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
67	! building surfaces in all cases, in order to enable terrain-following output
68	! also when no land- or urban-surface model is applied.
69	!
70	! 4265 2019-10-15 16:16:24Z suehring
71	! Bugfix for last commit, exchange oro_max variable only when it is allocated
72	! (not necessarily the case when topography is input from ASCII file).
73	!
74	! 4245 2019-09-30 08:40:37Z pavelkrc
75	! Store oro_max (building z-offset) in 2D for building surfaces
76	!
77	! 4189 2019-08-26 16:19:38Z suehring
78	! - Add check for proper setting of namelist parameter topography
79	! - Set flag to indicate land surfaces in case no topography is provided
80	!
81	! 4182 2019-08-22 15:20:23Z scharf
82	! Corrected "Former revisions" section
83	!
84	! 4168 2019-08-16 13:50:17Z suehring
85	! Pre-calculate topography top index and store it on an array (replaces former
86	! functions get_topography_top_index)
87	!
88	! 4159 2019-08-15 13:31:35Z suehring
89	! Revision of topography processing. This was not consistent between 2D and 3D
90	! buildings.
91	!
92	! 4144 2019-08-06 09:11:47Z raasch
93	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
94	!
95	! 4115 2019-07-24 12:50:49Z suehring
96	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
97	!
98	! 4110 2019-07-22 17:05:21Z suehring
99	! - Separate initialization of advection flags for momentum and scalars.
100	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
101	!
102	! 4109 2019-07-22 17:00:34Z suehring
103	! Fix bad commit
104	!
105	! 3926 2019-04-23 12:56:42Z suehring
106	! Minor bugfix in building mapping when all building IDs in the model domain
107	! are missing
108	!
109	! 3857 2019-04-03 13:00:16Z knoop
110	! In projection of non-building 3D objects onto numerical grid remove
111	! dependency on building_type
112	!
113	! 3763 2019-02-25 17:33:49Z suehring
114	! Replace work-around for ghost point exchange of 1-byte arrays with specific
115	! routine as already done in other routines
116	!
117	! 3761 2019-02-25 15:31:42Z raasch
118	! unused variables removed
119	!
120	! 3661 2019-01-08 18:22:50Z suehring
121	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
122	! order degradation of advection scheme is handeled directly in advec_ws
123	!
124	! 3655 2019-01-07 16:51:22Z knoop
125	! Comment added
126	!
127	! Revision 1.1 1997/08/11 06:17:45 raasch
128	! Initial revision (Testversion)
129	!
130	!
131	! Description:
132	! -----------------------------------------------------------------------------!
133	!> Creating grid depending constants
134	!> @todo: Rearrange topo flag list
135	!> @todo: reference 3D buildings on top of orography is not tested and may need
136	!> further improvement for steep slopes
137	!> @todo: Use more advanced setting of building type at filled holes
138	!------------------------------------------------------------------------------!
139	SUBROUTINE init_grid
140
141	USE arrays_3d, &
142	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
143
144	USE control_parameters, &
145	ONLY: constant_flux_layer, dz, dz_max, dz_stretch_factor, &
146	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
147	dz_stretch_level_end_index, dz_stretch_level_start_index, &
148	dz_stretch_level_start, ibc_uv_b, message_string, &
149	number_stretch_level_end, &
150	number_stretch_level_start, &
151	ocean_mode, &
152	psolver, &
153	symmetry_flag, &
154	topography, &
155	use_surface_fluxes
156
157	USE grid_variables, &
158	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
159
160	USE indices, &
161	ONLY: nbgp, &
162	nx, &
163	nxl, &
164	nxlg, &
165	nxr, &
166	nxrg, &
167	ny, &
168	nyn, &
169	nyng, &
170	nys, &
171	nysg, &
172	nz, &
173	nzb, &
174	nzb_diff, &
175	nzb_max, &
176	nzt, &
177	topo_top_ind, &
178	topo_min_level
179
180	USE kinds
181
182	USE pegrid
183
184	#if defined( __parallel )
185	USE vertical_nesting_mod, &
186	ONLY: vnested, vnest_init_grid
187	#endif
188
189	IMPLICIT NONE
190
191	INTEGER(iwp) :: i !< index variable along x
192	INTEGER(iwp) :: j !< index variable along y
193	INTEGER(iwp) :: k !< index variable along z
194	INTEGER(iwp) :: k_top !< topography top index on local PE
195	INTEGER(iwp) :: n !< loop variable for stretching
196	INTEGER(iwp) :: number_dz !< number of user-specified dz values
197	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
198	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
199
200	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
201
202	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
203	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
204
205	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
206
207
208	!
209	!-- Calculation of horizontal array bounds including ghost layers
210	nxlg = nxl - nbgp
211	nxrg = nxr + nbgp
212	nysg = nys - nbgp
213	nyng = nyn + nbgp
214
215	!
216	!-- Allocate grid arrays
217	ALLOCATE( x(0:nx) )
218	ALLOCATE( xu(0:nx) )
219
220	DO i = 0, nx
221	xu(i) = i * dx
222	x(i) = i * dx + 0.5_wp * dx
223	ENDDO
224
225	ALLOCATE( y(0:ny) )
226	ALLOCATE( yv(0:ny) )
227
228	DO j = 0, ny
229	yv(j) = j * dy
230	y(j) = j * dy + 0.5_wp * dy
231	ENDDO
232
233	ALLOCATE( ddzu(1:nzt+1) )
234	ALLOCATE( ddzw(1:nzt+1) )
235	ALLOCATE( dd2zu(1:nzt) )
236	ALLOCATE( dzu(1:nzt+1) )
237	ALLOCATE( dzw(1:nzt+1) )
238	ALLOCATE( zu(nzb:nzt+1) )
239	ALLOCATE( zw(nzb:nzt+1) )
240
241	!
242	!-- For constructing an appropriate grid, the vertical grid spacing dz has to
243	!-- be specified with a non-negative value in the parameter file
244	IF ( dz(1) == -1.0_wp ) THEN
245	message_string = 'missing dz'
246	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
247	ELSEIF ( dz(1) <= 0.0_wp ) THEN
248	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
249	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
250	ENDIF
251
252	!
253	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
254	!-- if it was set by the user
255	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
256	dz_stretch_level_start(1) = dz_stretch_level
257	ENDIF
258
259	!
260	!-- Determine number of dz values and stretching levels specified by the
261	!-- user to allow right controlling of the stretching mechanism and to
262	!-- perform error checks. The additional requirement that dz /= dz_max
263	!-- for counting number of user-specified dz values is necessary. Otherwise
264	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
265	!-- is used (Attention: The user is not allowed to specify a dz value equal
266	!-- to the default of dz_max = 999.0).
267	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
268	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
269	-9999999.9_wp )
270	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
271	9999999.9_wp )
272
273	!
274	!-- The number of specified end levels +1 has to be the same as the number
275	!-- of specified dz values
276	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
277	WRITE( message_string, * ) 'The number of values for dz = ', &
278	number_dz, 'has to be the same as& ', &
279	'the number of values for ', &
280	'dz_stretch_level_end + 1 = ', &
281	number_stretch_level_end+1
282	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
283	ENDIF
284
285	!
286	!-- The number of specified start levels has to be the same or one less than
287	!-- the number of specified dz values
288	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
289	number_dz /= number_stretch_level_start ) THEN
290	WRITE( message_string, * ) 'The number of values for dz = ', &
291	number_dz, 'has to be the same as or one ', &
292	'more than& the number of values for ', &
293	'dz_stretch_level_start = ', &
294	number_stretch_level_start
295	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
296	ENDIF
297
298	!-- The number of specified start levels has to be the same or one more than
299	!-- the number of specified end levels
300	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
301	number_stretch_level_start /= number_stretch_level_end ) THEN
302	WRITE( message_string, * ) 'The number of values for ', &
303	'dz_stretch_level_start = ', &
304	dz_stretch_level_start, 'has to be the ', &
305	'same or one more than& the number of ', &
306	'values for dz_stretch_level_end = ', &
307	number_stretch_level_end
308	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
309	ENDIF
310
311	!
312	!-- Initialize dz for the free atmosphere with the value of dz_max
313	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
314	number_stretch_level_start /= 0 ) THEN
315	dz(number_stretch_level_start+1) = dz_max
316	ENDIF
317
318	!
319	!-- Initialize the stretching factor if (infinitely) stretching in the free
320	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
321	!-- free atmosphere)
322	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
323	dz_stretch_factor_array(number_stretch_level_start) = &
324	dz_stretch_factor
325	ENDIF
326
327	!
328	!-- Allocation of arrays for stretching
329	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
330
331	!
332	!-- Define the vertical grid levels. Start with atmosphere branch
333	IF ( .NOT. ocean_mode ) THEN
334
335	!
336	!-- The stretching region has to be large enough to allow for a smooth
337	!-- transition between two different grid spacings. The number 4 is an
338	!-- empirical value
339	DO n = 1, number_stretch_level_start
340	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
341	4 * MAX( dz(n),dz(n+1) )
342	ENDDO
343
344	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
345	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
346	message_string= 'Each dz_stretch_level_end has to be larger ' // &
347	'than its corresponding value for &' // &
348	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
349	'to allow for smooth grid stretching'
350	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
351	ENDIF
352
353	!
354	!-- Stretching must not be applied within the surface layer
355	!-- (first two grid points). For the default case dz_stretch_level_start
356	!-- is negative. Therefore the absolut value is checked here.
357	IF ( ANY( ABS( dz_stretch_level_start ) <= dz(1) * 1.5_wp ) ) THEN
358	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
359	'larger than ', dz(1) * 1.5
360	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
361	ENDIF
362
363	!
364	!-- The stretching has to start and end on a grid level. Therefore
365	!-- user-specified values are mapped to the next lowest level. The
366	!-- calculation of the first level is realized differently just because of
367	!-- historical reasons (the advanced/new stretching mechanism was realized
368	!-- in a way that results don't change if the old parameters
369	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
370	IF ( number_stretch_level_start /= 0 ) THEN
371	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
372	dz(1)/2.0) / dz(1) ) &
373	* dz(1) + dz(1)/2.0
374	ENDIF
375
376	IF ( number_stretch_level_start > 1 ) THEN
377	DO n = 2, number_stretch_level_start
378	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
379	dz(n) ) * dz(n)
380	ENDDO
381	ENDIF
382
383	IF ( number_stretch_level_end /= 0 ) THEN
384	DO n = 1, number_stretch_level_end
385	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
386	dz(n+1) ) * dz(n+1)
387	ENDDO
388	ENDIF
389
390	!
391	!-- Determine stretching factor if necessary
392	IF ( number_stretch_level_end >= 1 ) THEN
393	CALL calculate_stretching_factor( number_stretch_level_end )
394	ENDIF
395
396	!
397	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
398	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
399	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
400	!-- The second u-level (k=1) corresponds to the top of the
401	!-- surface layer. In case of symmetric boundaries (closed channel flow),
402	!-- the first grid point is always at z=0.
403	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. &
404	topography == 'closed_channel' ) THEN
405	zu(0) = 0.0_wp
406	ELSE
407	zu(0) = - dz(1) * 0.5_wp
408	ENDIF
409
410	zu(1) = dz(1) * 0.5_wp
411
412	!
413	!-- Determine u and v height levels considering the possibility of grid
414	!-- stretching in several heights.
415	n = 1
416	dz_stretch_level_start_index = nzt+1
417	dz_stretch_level_end_index = nzt+1
418	dz_stretched = dz(1)
419
420	!-- The default value of dz_stretch_level_start is negative, thus the first
421	!-- condition is true even if no stretching shall be applied. Hence, the
422	!-- second condition is also necessary.
423	DO k = 2, nzt+1-symmetry_flag
424	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
425	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
426	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
427
428	IF ( dz(n) > dz(n+1) ) THEN
429	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
430	ELSE
431	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
432	ENDIF
433
434	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
435	dz_stretch_level_start_index(n) = k-1
436
437	ENDIF
438
439	zu(k) = zu(k-1) + dz_stretched
440
441	!
442	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
443	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
444
445	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
446	zu(k) = dz_stretch_level_end(n)
447	dz_stretched = dz(n+1)
448	dz_stretch_level_end_index(n) = k
449	n = n + 1
450	ENDIF
451	ENDDO
452
453	!
454	!-- If a closed channel flow is simulated, make sure that grid structure is
455	!-- the same for both bottom and top boundary. (Hint: Using a different dz
456	!-- at the bottom and at the top makes no sense due to symmetric boundaries
457	!-- where dz should be equal. Therefore, different dz at the bottom and top
458	!-- causes an abort (see check_parameters).)
459	IF ( topography == 'closed_channel' ) THEN
460	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
461	ENDIF
462
463	!
464	!-- Compute the w-levels. They are always staggered half-way between the
465	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
466	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
467	!-- Per default, the top w-level is extrapolated linearly. In case of
468	!-- a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
469	!-- (Hint: Using a different dz at the bottom and at the top makes no sense
470	!-- due to symmetric boundaries where dz should be equal. Therefore,
471	!-- different dz at the bottom and top causes an abort (see
472	!-- check_parameters).)
473	zw(0) = 0.0_wp
474	DO k = 1, nzt-symmetry_flag
475	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
476	ENDDO
477	IF ( topography == 'closed_channel' ) THEN
478	zw(nzt) = zw(nzt-1) + dz(1)
479	zw(nzt+1) = zw(nzt) + dz(1)
480	ELSE
481	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
482	ENDIF
483
484	ELSE !ocean branch
485
486	!
487	!-- The stretching region has to be large enough to allow for a smooth
488	!-- transition between two different grid spacings. The number 4 is an
489	!-- empirical value
490	DO n = 1, number_stretch_level_start
491	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
492	4 * MAX( dz(n),dz(n+1) )
493	ENDDO
494
495	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
496	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
497	message_string= 'Each dz_stretch_level_end has to be less ' // &
498	'than its corresponding value for &' // &
499	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
500	'to allow for smooth grid stretching'
501	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
502	ENDIF
503
504	!
505	!-- Stretching must not be applied close to the surface (last two grid
506	!-- points). For the default case dz_stretch_level_start is negative.
507	IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) ) THEN
508	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
509	'less than ', -dz(1) * 1.5
510	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
511	ENDIF
512
513	!
514	!-- The stretching has to start and end on a grid level. Therefore
515	!-- user-specified values are mapped to the next highest level. The
516	!-- calculation of the first level is realized differently just because of
517	!-- historical reasons (the advanced/new stretching mechanism was realized
518	!-- in a way that results don't change if the old parameters
519	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
520	IF ( number_stretch_level_start /= 0 ) THEN
521	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
522	dz(1)/2.0) / dz(1) ) &
523	* dz(1) - dz(1)/2.0
524	ENDIF
525
526	IF ( number_stretch_level_start > 1 ) THEN
527	DO n = 2, number_stretch_level_start
528	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
529	dz(n) ) * dz(n)
530	ENDDO
531	ENDIF
532
533	IF ( number_stretch_level_end /= 0 ) THEN
534	DO n = 1, number_stretch_level_end
535	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
536	dz(n+1) ) * dz(n+1)
537	ENDDO
538	ENDIF
539
540	!
541	!-- Determine stretching factor if necessary
542	IF ( number_stretch_level_end >= 1 ) THEN
543	CALL calculate_stretching_factor( number_stretch_level_end )
544	ENDIF
545
546	!
547	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
548	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
549	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
550	!-- w-level are defined at same height, but staggered from the second level.
551	!-- The second u-level (k=1) corresponds to the top of the surface layer.
552	!-- z values are negative starting from z=0 (surface)
553	zu(nzt+1) = dz(1) * 0.5_wp
554	zu(nzt) = - dz(1) * 0.5_wp
555
556	!
557	!-- Determine u and v height levels considering the possibility of grid
558	!-- stretching in several heights.
559	n = 1
560	dz_stretch_level_start_index = 0
561	dz_stretch_level_end_index = 0
562	dz_stretched = dz(1)
563
564	DO k = nzt-1, 0, -1
565
566	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
567	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
568
569	IF ( dz(n) > dz(n+1) ) THEN
570	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
571	ELSE
572	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
573	ENDIF
574
575	IF ( dz_stretch_level_start_index(n) == 0 ) &
576	dz_stretch_level_start_index(n) = k+1
577
578	ENDIF
579
580	zu(k) = zu(k+1) - dz_stretched
581
582	!
583	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
584	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
585
586	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
587	zu(k) = dz_stretch_level_end(n)
588	dz_stretched = dz(n+1)
589	dz_stretch_level_end_index(n) = k
590	n = n + 1
591	ENDIF
592	ENDDO
593
594	!
595	!-- Compute the w-levels. They are always staggered half-way between the
596	!-- corresponding u-levels, except in case of dirichlet bc for u and v
597	!-- at the ground. In this case the first u- and w-level are defined at
598	!-- same height. The top w-level (nzt+1) is not used but set for
599	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
600	zw(nzt+1) = dz(1)
601	zw(nzt) = 0.0_wp
602	DO k = 0, nzt
603	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
604	ENDDO
605
606	!
607	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
608	!-- at same height.
609	IF ( ibc_uv_b == 0 ) THEN
610	zu(0) = zw(0)
611	ENDIF
612
613	ENDIF !End of defining the vertical grid levels
614
615	!
616	!-- Compute grid lengths.
617	DO k = 1, nzt+1
618	dzu(k) = zu(k) - zu(k-1)
619	ddzu(k) = 1.0_wp / dzu(k)
620	dzw(k) = zw(k) - zw(k-1)
621	ddzw(k) = 1.0_wp / dzw(k)
622	ENDDO
623
624	DO k = 1, nzt
625	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
626	ENDDO
627
628	!
629	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
630	!-- everywhere. For the actual grid, the grid spacing at the lowest level
631	!-- is only dz/2, but should be dz. Therefore, an additional array
632	!-- containing with appropriate grid information is created for these
633	!-- solvers.
634	IF ( psolver(1:9) /= 'multigrid' ) THEN
635	ALLOCATE( ddzu_pres(1:nzt+1) )
636	ddzu_pres = ddzu
637	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
638	ENDIF
639
640	!
641	!-- Compute the reciprocal values of the horizontal grid lengths.
642	ddx = 1.0_wp / dx
643	ddy = 1.0_wp / dy
644	dx2 = dx * dx
645	dy2 = dy * dy
646	ddx2 = 1.0_wp / dx2
647	ddy2 = 1.0_wp / dy2
648
649	!
650	!-- Allocate 3D array to set topography
651	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
652	topo = 0
653	!
654	!-- Initialize topography by generic topography or read topography from file.
655	CALL init_topo( topo )
656	!
657	!-- Set flags to mask topography on the grid.
658	CALL set_topo_flags( topo )
659
660	!
661	!-- Determine the maximum level of topography. It is used for
662	!-- steering the degradation of order of the applied advection scheme,
663	!-- as well in the lpm.
664	k_top = 0
665	DO i = nxl, nxr
666	DO j = nys, nyn
667	DO k = nzb, nzt + 1
668	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
669	ENDDO
670	ENDDO
671	ENDDO
672	#if defined( __parallel )
673	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, &
674	MPI_MAX, comm2d, ierr )
675	#else
676	nzb_max = k_top
677	#endif
678	!
679	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
680	!-- Further, in case topography extents up to the model top, limit to nzt.
681	nzb_max = MIN( nzb_max+1, nzt )
682	!
683	!-- Determine minimum index of topography. Usually, this will be nzb. In case
684	!-- there is elevated topography, however, the lowest topography will be higher.
685	!-- This index is e.g. used to calculate mean first-grid point atmosphere
686	!-- temperature, surface pressure and density, etc. .
687	topo_min_level = 0
688	#if defined( __parallel )
689	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
690	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
691	#else
692	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
693	#endif
694
695	!
696	!-- Check topography for consistency with model domain. Therefore, use
697	!-- maximum and minium topography-top indices. Note, minimum topography top
698	!-- index is already calculated.
699	IF ( TRIM( topography ) /= 'flat' ) THEN
700	#if defined( __parallel )
701	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
702	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
703	#else
704	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
705	#endif
706	nzb_local_min = topo_min_level
707	!
708	!-- Consistency checks
709	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
710	WRITE( message_string, * ) 'nzb_local values are outside the', &
711	' model domain', &
712	'&MINVAL( nzb_local ) = ', nzb_local_min, &
713	'&MAXVAL( nzb_local ) = ', nzb_local_max
714	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
715	ENDIF
716	ENDIF
717	!
718	!-- Define vertical gridpoint from (or to) which on the usual finite difference
719	!-- form (which does not use surface fluxes) is applied
720	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
721	nzb_diff = nzb + 2
722	ELSE
723	nzb_diff = nzb + 1
724	ENDIF
725
726	IF ( TRIM( topography ) /= 'flat' ) THEN
727	!
728	!-- Allocate and set the arrays containing the topography height (for output
729	!-- reasons only).
730	IF ( nxr == nx .AND. nyn /= ny ) THEN
731	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
732	zw_w_inner(nxl:nxr+1,nys:nyn) )
733	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
734	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
735	zw_w_inner(nxl:nxr,nys:nyn+1) )
736	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
737	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
738	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
739	ELSE
740	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
741	zw_w_inner(nxl:nxr,nys:nyn) )
742	ENDIF
743
744	zu_s_inner = 0.0_wp
745	zw_w_inner = 0.0_wp
746	!
747	!-- Determine local topography height on scalar and w-grid. Note, setting
748	!-- lateral boundary values is not necessary, realized via wall_flags_static_0
749	!-- array. Further, please note that loop bounds are different from
750	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
751	!-- use intrinsic lbound and ubound functions to infer array bounds.
752	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
753	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
754	!
755	!-- Topography height on scalar grid. Therefore, determine index of
756	!-- upward-facing surface element on scalar grid.
757	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
758	!
759	!-- Topography height on w grid. Therefore, determine index of
760	!-- upward-facing surface element on w grid.
761	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
762	ENDDO
763	ENDDO
764	ENDIF
765
766	#if defined( __parallel )
767	!
768	!-- Vertical nesting: communicate vertical grid level arrays between fine and
769	!-- coarse grid
770	IF ( vnested ) CALL vnest_init_grid
771	#endif
772
773	END SUBROUTINE init_grid
774
775
776	! Description:
777	! -----------------------------------------------------------------------------!
778	!> Calculation of the stretching factor through an iterative method. Ideas were
779	!> taken from the paper "Regional stretched grid generation and its application
780	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
781	!> system of equations has two variables (r,l) but four requirements
782	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
783	!> results into an overdetermined system.
784	!------------------------------------------------------------------------------!
785	SUBROUTINE calculate_stretching_factor( number_end )
786
787	USE control_parameters, &
788	ONLY: dz, dz_stretch_factor_array, &
789	dz_stretch_level_end, dz_stretch_level_start, message_string
790
791	USE kinds
792
793	IMPLICIT NONE
794
795	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
796	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
797	INTEGER(iwp) :: n !< loop variable for stretching
798
799	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
800
801	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
802	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
803	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
804	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
805	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
806	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
807	REAL(wp) :: numerator !< numerator of the quotient
808	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
809	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
810
811	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
812
813	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06_wp !< interval for sampling possible stretching factors
814	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88_wp !< lowest possible stretching factor
815	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12_wp !< highest possible stretching factor
816
817
818	l = 0
819	DO n = 1, number_end
820
821	iterations = 1
822	stretch_factor_1 = 1.0_wp
823	stretch_factor_2 = 1.0_wp
824	delta_total_old = 1.0_wp
825
826	!
827	!-- First branch for stretching from rough to fine
828	IF ( dz(n) > dz(n+1) ) THEN
829	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
830
831	stretch_factor_1 = 1.0_wp - iterations * stretch_factor_interval
832	distance = ABS( dz_stretch_level_end(n) - &
833	dz_stretch_level_start(n) )
834	numerator = distance*stretch_factor_1/dz(n) + &
835	stretch_factor_1 - distance/dz(n)
836
837	IF ( numerator > 0.0_wp ) THEN
838	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
839	l_rounded = NINT( l )
840	delta_l = ABS( l_rounded - l ) / l
841	ENDIF
842
843	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
844
845	delta_stretch_factor = ABS( stretch_factor_1 - &
846	stretch_factor_2 ) / &
847	stretch_factor_2
848
849	delta_total_new = delta_l + delta_stretch_factor
850
851	!
852	!-- stretch_factor_1 is taken to guarantee that the stretching
853	!-- procedure ends as close as possible to dz_stretch_level_end.
854	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
855	!-- equal to dz(n+1) after l_rounded grid levels.
856	IF (delta_total_new < delta_total_old) THEN
857	dz_stretch_factor_array(n) = stretch_factor_1
858	dz_stretch_factor_array_2(n) = stretch_factor_2
859	delta_total_old = delta_total_new
860	ENDIF
861
862	iterations = iterations + 1
863
864	ENDDO
865
866	!
867	!-- Second branch for stretching from fine to rough
868	ELSEIF ( dz(n) < dz(n+1) ) THEN
869	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
870
871	stretch_factor_1 = 1.0_wp + iterations * stretch_factor_interval
872	distance = ABS( dz_stretch_level_end(n) - &
873	dz_stretch_level_start(n) )
874	numerator = distance*stretch_factor_1/dz(n) + &
875	stretch_factor_1 - distance/dz(n)
876
877	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
878	l_rounded = NINT( l )
879	delta_l = ABS( l_rounded - l ) / l
880
881	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
882
883	delta_stretch_factor = ABS( stretch_factor_1 - &
884	stretch_factor_2 ) / &
885	stretch_factor_2
886
887	delta_total_new = delta_l + delta_stretch_factor
888
889	!
890	!-- stretch_factor_1 is taken to guarantee that the stretching
891	!-- procedure ends as close as possible to dz_stretch_level_end.
892	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
893	!-- equal to dz(n+1) after l_rounded grid levels.
894	IF (delta_total_new < delta_total_old) THEN
895	dz_stretch_factor_array(n) = stretch_factor_1
896	dz_stretch_factor_array_2(n) = stretch_factor_2
897	delta_total_old = delta_total_new
898	ENDIF
899
900	iterations = iterations + 1
901	ENDDO
902
903	ELSE
904	message_string= 'Two adjacent values of dz must be different'
905	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
906
907	ENDIF
908
909	!
910	!-- Check if also the second stretching factor fits into the allowed
911	!-- interval. If not, print a warning for the user.
912	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
913	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
914	WRITE( message_string, * ) 'stretch_factor_2 = ', &
915	dz_stretch_factor_array_2(n), ' which is',&
916	' responsible for exactly reaching& dz =',&
917	dz(n+1), 'after a specific amount of', &
918	' grid levels& exceeds the upper', &
919	' limit =', stretch_factor_upper_limit, &
920	' &or lower limit = ', &
921	stretch_factor_lower_limit
922	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
923
924	ENDIF
925	ENDDO
926
927	END SUBROUTINE calculate_stretching_factor
928
929
930	! Description:
931	! -----------------------------------------------------------------------------!
932	!> Set temporary topography flags and reference buildings on top of underlying
933	!> orography.
934	!------------------------------------------------------------------------------!
935	SUBROUTINE process_topography( topo_3d )
936
937	USE arrays_3d, &
938	ONLY: zu, zw
939
940	USE control_parameters, &
941	ONLY: bc_lr_cyc, bc_ns_cyc, ocean_mode
942
943	USE exchange_horiz_mod, &
944	ONLY: exchange_horiz_int, exchange_horiz_2d
945
946	USE indices, &
947	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
948	nzt
949
950	USE netcdf_data_input_mod, &
951	ONLY: buildings_f, building_id_f, building_type_f, &
952	init_model, &
953	input_pids_static, &
954	terrain_height_f
955
956	USE kinds
957
958	USE pegrid
959
960	IMPLICIT NONE
961
962	INTEGER(iwp) :: i !< running index along x-direction
963	INTEGER(iwp) :: j !< running index along y-direction
964	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
965	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
966	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
967	INTEGER(iwp) :: num_build !< counter for number of buildings
968	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
969
970	#if defined( __parallel )
971	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
972	#endif
973	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
974	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
975	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
976	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
977	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
978
979	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
980	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
981
982	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
983
984	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
985	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
986	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
987	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
988
989	!
990	!-- Reference lowest terrain height to zero. This ensures that first,
991	!-- non-required gird levels (those which lie entirely below the minimum
992	!-- orography) are avoided, and second, that also negative orography can be used
993	!-- within the input file.
994	!-- Please note, in case of a nested run, the global minimum from all parent and
995	!-- childs need to be remove to avoid steep edges at the child-domain boundaries.
996	IF ( input_pids_static ) THEN
997
998	#if defined( __parallel )
999	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
1000	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
1001	#else
1002	oro_min = MINVAL( terrain_height_f%var )
1003	#endif
1004	terrain_height_f%var = terrain_height_f%var - oro_min
1005	!
1006	!-- Update reference height used within output files
1007	init_model%origin_z = init_model%origin_z + oro_min
1008
1009	ENDIF
1010
1011	!
1012	!-- In the following, buildings and orography are further preprocessed
1013	!-- before they are mapped on the LES grid.
1014	!-- Buildings are mapped on top of the orography by maintaining the roof
1015	!-- shape of the building. This can be achieved by referencing building on
1016	!-- top of the maximum terrain height within the area occupied by the
1017	!-- respective building. As buildings and terrain height are defined PE-wise,
1018	!-- parallelization of this referencing is required (a building can be
1019	!-- distributed between different PEs).
1020	!-- In a first step, determine the number of buildings with different
1021	!-- building id on each PE. In a next step, all building ids are gathered
1022	!-- into one array which is present to all PEs. For each building ID,
1023	!-- the maximum terrain height occupied by the respective building is
1024	!-- computed and distributed to each PE.
1025	!-- Finally, for each building id and its respective reference orography,
1026	!-- builidings are mapped on top.
1027	!--
1028	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
1029	!-- buildings
1030	!-- classify the respective surfaces.
1031	topo_3d = IBSET( topo_3d, 0 )
1032	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
1033	!
1034	!-- In order to map topography on PALM grid also in case of ocean simulations,
1035	!-- pre-calculate an offset value.
1036	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
1037	!
1038	!-- Reference buildings on top of orography. This is not necessary
1039	!-- if topography is read from ASCII file as no distinction between buildings
1040	!-- and terrain height can be made. Moreover, this is also not necessary if
1041	!-- urban-surface and land-surface model are used at the same time.
1042	IF ( input_pids_static ) THEN
1043
1044	IF ( buildings_f%from_file ) THEN
1045	num_buildings_l = 0
1046	num_buildings = 0
1047	!
1048	!-- Allocate at least one element for building ids and give it an inital
1049	!-- negative value that will be overwritten later. This, however, is
1050	!-- necessary in case there all IDs in the model domain are fill values.
1051	ALLOCATE( build_ids_l(1) )
1052	build_ids_l = -1
1053	DO i = nxl, nxr
1054	DO j = nys, nyn
1055	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1056	IF ( num_buildings_l(myid) > 0 ) THEN
1057	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
1058	THEN
1059	CYCLE
1060	ELSE
1061	num_buildings_l(myid) = num_buildings_l(myid) + 1
1062	!
1063	!-- Resize array with different local building ids
1064	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
1065	build_ids_l_tmp = build_ids_l
1066	DEALLOCATE( build_ids_l )
1067	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
1068	build_ids_l(1:num_buildings_l(myid)-1) = &
1069	build_ids_l_tmp(1:num_buildings_l(myid)-1)
1070	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
1071	DEALLOCATE( build_ids_l_tmp )
1072	ENDIF
1073	!
1074	!-- First occuring building id on PE
1075	ELSE
1076	num_buildings_l(myid) = num_buildings_l(myid) + 1
1077	build_ids_l(1) = building_id_f%var(j,i)
1078	ENDIF
1079	ENDIF
1080	ENDDO
1081	ENDDO
1082	!
1083	!-- Determine number of different building ids for the entire domain
1084	#if defined( __parallel )
1085	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
1086	MPI_INTEGER, MPI_SUM, comm2d, ierr )
1087	#else
1088	num_buildings = num_buildings_l
1089	#endif
1090	!
1091	!-- Gather all buildings ids on each PEs.
1092	!-- First, allocate array encompassing all building ids in model domain.
1093	ALLOCATE( build_ids(1:SUM(num_buildings)) )
1094	#if defined( __parallel )
1095	!
1096	!-- Allocate array for displacements.
1097	!-- As each PE may has a different number of buildings, so that
1098	!-- the block sizes send by each PE may not be equal. Hence,
1099	!-- information about the respective displacement is required, indicating
1100	!-- the respective adress where each MPI-task writes into the receive
1101	!-- buffer array
1102	ALLOCATE( displace_dum(0:numprocs-1) )
1103	displace_dum(0) = 0
1104	DO i = 1, numprocs-1
1105	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
1106	ENDDO
1107
1108	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
1109	num_buildings(myid), &
1110	MPI_INTEGER, &
1111	build_ids, &
1112	num_buildings, &
1113	displace_dum, &
1114	MPI_INTEGER, &
1115	comm2d, ierr )
1116
1117	DEALLOCATE( displace_dum )
1118
1119	#else
1120	build_ids = build_ids_l
1121	#endif
1122
1123	!
1124	!-- Note, in parallel mode building ids can occure mutliple times, as
1125	!-- each PE has send its own ids. Therefore, sort out building ids which
1126	!-- appear more than one time.
1127	num_build = 0
1128	DO nr = 1, SIZE(build_ids)
1129
1130	IF ( ALLOCATED(build_ids_final) ) THEN
1131	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
1132	CYCLE
1133	ELSE
1134	num_build = num_build + 1
1135	!
1136	!-- Resize
1137	ALLOCATE( build_ids_final_tmp(1:num_build) )
1138	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
1139	DEALLOCATE( build_ids_final )
1140	ALLOCATE( build_ids_final(1:num_build) )
1141	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
1142	build_ids_final(num_build) = build_ids(nr)
1143	DEALLOCATE( build_ids_final_tmp )
1144	ENDIF
1145	ELSE
1146	num_build = num_build + 1
1147	ALLOCATE( build_ids_final(1:num_build) )
1148	build_ids_final(num_build) = build_ids(nr)
1149	ENDIF
1150	ENDDO
1151
1152	!
1153	!-- Determine maximumum terrain height occupied by the respective
1154	!-- building and temporalily store on oro_max
1155	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
1156	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
1157	oro_max_l = 0.0_wp
1158
1159	DO nr = 1, SIZE(build_ids_final)
1160	oro_max_l(nr) = MAXVAL( &
1161	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
1162	0.0_wp, &
1163	building_id_f%var(nys:nyn,nxl:nxr) == &
1164	build_ids_final(nr) ) )
1165	ENDDO
1166
1167	#if defined( __parallel )
1168	IF ( SIZE(build_ids_final) >= 1 ) THEN
1169	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
1170	MPI_MAX, comm2d, ierr )
1171	ENDIF
1172	#else
1173	oro_max = oro_max_l
1174	#endif
1175	!
1176	!-- Finally, determine discrete grid height of maximum orography occupied
1177	!-- by a building. Use all-or-nothing approach, i.e. if terrain
1178	!-- exceeds the scalar level the grid box is fully terrain and the
1179	!-- maximum terrain is set to the zw level.
1180	!-- terrain or
1181	oro_max_l = 0.0
1182	DO nr = 1, SIZE(build_ids_final)
1183	DO k = nzb, nzt
1184	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
1185	oro_max_l(nr) = zw(k) - ocean_offset
1186	ENDDO
1187	oro_max(nr) = oro_max_l(nr)
1188	ENDDO
1189	ENDIF
1190	!
1191	!-- Allocate array for storing terrain height under buildings
1192	IF ( buildings_f%from_file ) THEN
1193	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
1194	buildings_f%oro_max = buildings_f%fill1
1195	END IF
1196	!
1197	!-- Map orography as well as buildings onto grid.
1198	DO i = nxl, nxr
1199	DO j = nys, nyn
1200	topo_top_index = 0
1201	!
1202	!-- Obtain index in global building_id array
1203	IF ( buildings_f%from_file ) THEN
1204	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1205	!
1206	!-- Determine index where maximum terrain height occupied by
1207	!-- the respective building height is stored.
1208	nr = MINLOC( ABS( build_ids_final - &
1209	building_id_f%var(j,i) ), DIM = 1 )
1210	!
1211	!-- Save grid-indexed oro_max
1212	buildings_f%oro_max(j,i) = oro_max(nr)
1213	ENDIF
1214	ENDIF
1215	DO k = nzb, nzt
1216	!
1217	!-- In a first step, if grid point is below or equal the given
1218	!-- terrain height, grid point is flagged to be of type natural.
1219	!-- Please note, in case there is also a building which is lower
1220	!-- than the vertical grid spacing, initialization of surface
1221	!-- attributes will not be correct as given surface information
1222	!-- will not be in accordance to the classified grid points.
1223	!-- Hence, in this case, also a building flag.
1224	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
1225	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1226	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1227	topo_top_index = k ! topo_top_index + 1
1228	ENDIF
1229	!
1230	!-- Set building grid points. Here, only consider 2D buildings.
1231	!-- 3D buildings require separate treatment.
1232	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
1233	!
1234	!-- Fill-up the terrain to the level of maximum orography
1235	!-- within the building-covered area.
1236	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1237	!
1238	!-- Note, oro_max is always on zw level
1239	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
1240	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1241	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1242	ELSEIF ( zu(k) - ocean_offset <= &
1243	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
1244	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1245	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1246	ENDIF
1247	ENDIF
1248	ENDIF
1249	ENDDO
1250	!
1251	!-- Special treatment for non grid-resolved buildings. This case,
1252	!-- the uppermost terrain grid point is flagged as building as well
1253	!-- well, even though no building exists at all. However, the
1254	!-- surface element will be identified as urban-surface and the
1255	!-- input data provided by the drivers is consistent to the surface
1256	!-- classification. Else, all non grid-resolved buildings would vanish
1257	!-- and identified as terrain grid points, which, however, won't be
1258	!-- consistent with the input data.
1259	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
1260	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1261	DO k = nzb, nzt
1262	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
1263	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
1264	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1265	ENDIF
1266	ENDIF
1267	ENDDO
1268	ENDIF
1269	ENDIF
1270	!
1271	!-- Map 3D buildings onto terrain height.
1272	!-- In case of any slopes, map building on top of maximum terrain
1273	!-- height covered by the building. In other words, extend
1274	!-- building down to the respective local terrain-surface height.
1275	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
1276	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1277	!
1278	!-- Extend building down to the terrain surface, i.e. fill-up
1279	!-- surface irregularities below a building. Note, oro_max
1280	!-- is already a discrete height according to the all-or-nothing
1281	!-- approach, i.e. grid box is either topography or atmosphere,
1282	!-- terrain top is defined at upper bound of the grid box.
1283	!-- Hence, check for zw in this case.
1284	!-- Note, do this only for buildings which are surface mounted,
1285	!-- i.e. building types 1-6. Below bridges, which are represented
1286	!-- exclusively by building type 7, terrain shape should be
1287	!-- maintained.
1288	IF ( building_type_f%from_file ) THEN
1289	IF ( building_type_f%var(j,i) /= 7 ) THEN
1290	DO k = topo_top_index + 1, nzt + 1
1291	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
1292	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1293	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1294	ENDIF
1295	ENDDO
1296	!
1297	!-- After surface irregularities are smoothen, determine
1298	!-- lower start index where building starts.
1299	DO k = nzb, nzt
1300	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
1301	topo_top_index = k
1302	ENDDO
1303	ENDIF
1304	ENDIF
1305	!
1306	!-- Finally, map building on top.
1307	k2 = 0
1308	DO k = topo_top_index, nzt + 1
1309	IF ( k2 <= buildings_f%nz-1 ) THEN
1310	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
1311	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1312	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1313	ENDIF
1314	ENDIF
1315	k2 = k2 + 1
1316	ENDDO
1317	ENDIF
1318	ENDIF
1319	ENDDO
1320	ENDDO
1321	!
1322	!-- Horizontal exchange the oro_max array, which is required to for
1323	!-- initialization of building-surface properties.
1324	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
1325	CALL exchange_horiz_2d( buildings_f%oro_max(:,:) )
1326	ENDIF
1327	!
1328	!-- Deallocate temporary arrays required for processing and reading data
1329	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
1330	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
1331	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
1332	!
1333	!-- Topography input via ASCII format.
1334	ELSE
1335	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
1336	!
1337	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
1338	!-- and clear all grid points at nzb, where alway a surface is defined.
1339	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
1340	!-- used for masked data output and further processing. Note, in the
1341	!-- ASCII case no distinction is made between buildings and terrain,
1342	!-- so that setting of bit 1 and 2 at the same time has no effect.
1343	topo_3d = IBSET( topo_3d, 0 )
1344	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
1345	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
1346	DO i = nxl, nxr
1347	DO j = nys, nyn
1348	DO k = nzb, nzt
1349	!
1350	!-- Flag topography for all grid points which are below
1351	!-- the local topography height.
1352	!-- Note, each topography is flagged as building.
1353	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
1354	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1355	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
1356	ENDIF
1357	ENDDO
1358	ENDDO
1359	ENDDO
1360	ENDIF
1361
1362	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1363
1364	IF ( .NOT. bc_ns_cyc ) THEN
1365	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
1366	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
1367	ENDIF
1368
1369	IF ( .NOT. bc_lr_cyc ) THEN
1370	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
1371	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
1372	ENDIF
1373
1374	END SUBROUTINE process_topography
1375
1376
1377	! Description:
1378	! -----------------------------------------------------------------------------!
1379	!> Filter topography, i.e. fill holes resolved by only one grid point.
1380	!> Such holes are suspected to lead to velocity blow-ups as continuity
1381	!> equation on discrete grid cannot be fulfilled in such case.
1382	!------------------------------------------------------------------------------!
1383	SUBROUTINE filter_topography( topo_3d )
1384
1385	USE control_parameters, &
1386	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
1387
1388	USE exchange_horiz_mod, &
1389	ONLY: exchange_horiz_int, exchange_horiz_2d_byte, exchange_horiz_2d_int
1390
1391	USE indices, &
1392	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
1393
1394	USE netcdf_data_input_mod, &
1395	ONLY: building_id_f, building_type_f
1396
1397	USE pegrid
1398
1399	IMPLICIT NONE
1400
1401	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
1402
1403	INTEGER(iwp) :: i !< running index along x-direction
1404	INTEGER(iwp) :: j !< running index along y-direction
1405	INTEGER(iwp) :: k !< running index along z-direction
1406	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
1407	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
1408	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
1409
1410	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
1411	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
1412	!
1413	!-- Before checking for holes, set lateral boundary conditions for
1414	!-- topography. After hole-filling, boundary conditions must be set again.
1415	!-- Several iterations are performed, in order to fill holes which might
1416	!-- emerge by the filling-algorithm itself.
1417	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
1418	topo_tmp = 0
1419
1420	num_hole = 99999
1421	DO WHILE ( num_hole > 0 )
1422
1423	num_hole = 0
1424	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1425	!
1426	!-- Exchange also building ID and type. Note, building_type is an one-byte
1427	!-- variable.
1428	IF ( building_id_f%from_file ) &
1429	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
1430	IF ( building_type_f%from_file ) &
1431	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
1432
1433	topo_tmp = topo_3d
1434	!
1435	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
1436	!-- a solid wall. Thus, intermediate spaces of one grid point between
1437	!-- boundary and some topographic structure will be filled.
1438	IF ( .NOT. bc_ns_cyc ) THEN
1439	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
1440	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
1441	ENDIF
1442
1443	IF ( .NOT. bc_lr_cyc ) THEN
1444	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
1445	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
1446	ENDIF
1447
1448	num_hole_l = 0
1449	DO i = nxl, nxr
1450	DO j = nys, nyn
1451	DO k = nzb+1, nzt
1452	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
1453	num_wall = 0
1454	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
1455	num_wall = num_wall + 1
1456	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
1457	num_wall = num_wall + 1
1458	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
1459	num_wall = num_wall + 1
1460	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
1461	num_wall = num_wall + 1
1462	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
1463	num_wall = num_wall + 1
1464	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
1465	num_wall = num_wall + 1
1466
1467	IF ( num_wall >= 4 ) THEN
1468	num_hole_l = num_hole_l + 1
1469	!
1470	!-- Clear flag 0 and set special flag ( bit 4) to indicate
1471	!-- that new topography point is a result of filtering process.
1472	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1473	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
1474	!
1475	!-- If filled grid point is occupied by a building, classify
1476	!-- it as building grid point.
1477	IF ( building_type_f%from_file ) THEN
1478	IF ( building_type_f%var(j,i) /= &
1479	building_type_f%fill .OR. &
1480	building_type_f%var(j+1,i) /= &
1481	building_type_f%fill .OR. &
1482	building_type_f%var(j-1,i) /= &
1483	building_type_f%fill .OR. &
1484	building_type_f%var(j,i+1) /= &
1485	building_type_f%fill .OR. &
1486	building_type_f%var(j,i-1) /= &
1487	building_type_f%fill ) THEN
1488	!
1489	!-- Set flag indicating building surfaces
1490	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1491	!
1492	!-- Set building_type and ID at this position if not
1493	!-- already set. This is required for proper
1494	!-- initialization of urban-surface energy balance
1495	!-- solver.
1496	IF ( building_type_f%var(j,i) == &
1497	building_type_f%fill ) THEN
1498
1499	IF ( building_type_f%var(j+1,i) /= &
1500	building_type_f%fill ) THEN
1501	building_type_f%var(j,i) = &
1502	building_type_f%var(j+1,i)
1503	building_id_f%var(j,i) = &
1504	building_id_f%var(j+1,i)
1505	ELSEIF ( building_type_f%var(j-1,i) /= &
1506	building_type_f%fill ) THEN
1507	building_type_f%var(j,i) = &
1508	building_type_f%var(j-1,i)
1509	building_id_f%var(j,i) = &
1510	building_id_f%var(j-1,i)
1511	ELSEIF ( building_type_f%var(j,i+1) /= &
1512	building_type_f%fill ) THEN
1513	building_type_f%var(j,i) = &
1514	building_type_f%var(j,i+1)
1515	building_id_f%var(j,i) = &
1516	building_id_f%var(j,i+1)
1517	ELSEIF ( building_type_f%var(j,i-1) /= &
1518	building_type_f%fill ) THEN
1519	building_type_f%var(j,i) = &
1520	building_type_f%var(j,i-1)
1521	building_id_f%var(j,i) = &
1522	building_id_f%var(j,i-1)
1523	ENDIF
1524	ENDIF
1525	ENDIF
1526	ENDIF
1527	!
1528	!-- If filled grid point is already classified as building
1529	!-- everything is fine, else classify this grid point as
1530	!-- natural type grid point. This case, values for the
1531	!-- surface type are already set.
1532	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
1533	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1534	ENDIF
1535	ENDIF
1536	ENDIF
1537	ENDDO
1538	ENDDO
1539	ENDDO
1540	!
1541	!-- Count the total number of holes, required for informative message.
1542	#if defined( __parallel )
1543	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
1544	comm2d, ierr )
1545	#else
1546	num_hole = num_hole_l
1547	#endif
1548	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
1549
1550	ENDDO
1551	!
1552	!-- Create an informative message if any holes were filled.
1553	IF ( filled ) THEN
1554	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
1555	'resolved by only one grid point ' // &
1556	'were filled during initialization.'
1557	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
1558	ENDIF
1559
1560	DEALLOCATE( topo_tmp )
1561	!
1562	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
1563	!-- condition in case of non-cyclic lateral boundaries.
1564	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1565
1566	IF ( .NOT. bc_ns_cyc ) THEN
1567	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
1568	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
1569	ENDIF
1570
1571	IF ( .NOT. bc_lr_cyc ) THEN
1572	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
1573	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
1574	ENDIF
1575	!
1576	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
1577	IF ( building_id_f%from_file ) &
1578	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
1579	IF ( building_type_f%from_file ) &
1580	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
1581
1582	END SUBROUTINE filter_topography
1583
1584
1585	! Description:
1586	! -----------------------------------------------------------------------------!
1587	!> Reads topography information from file or sets generic topography. Moreover,
1588	!> all topography-relevant topography arrays are initialized, and grid flags
1589	!> are set.
1590	!------------------------------------------------------------------------------!
1591	SUBROUTINE init_topo( topo )
1592
1593	USE arrays_3d, &
1594	ONLY: zw
1595
1596	USE control_parameters, &
1597	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
1598	building_length_y, building_wall_left, building_wall_south, &
1599	canyon_height, canyon_wall_left, canyon_wall_south, &
1600	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
1601	message_string, topography, topography_grid_convention, &
1602	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
1603	tunnel_wall_depth
1604
1605	USE exchange_horiz_mod, &
1606	ONLY: exchange_horiz_int
1607
1608	USE grid_variables, &
1609	ONLY: dx, dy
1610
1611	USE indices, &
1612	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
1613	nzb, nzt
1614
1615	USE kinds
1616
1617	USE netcdf_data_input_mod, &
1618	ONLY: buildings_f, terrain_height_f
1619
1620	USE pegrid
1621
1622	IMPLICIT NONE
1623
1624	INTEGER(iwp) :: bh !< temporary vertical index of building height
1625	INTEGER(iwp) :: ngp_bx !< grid point number of building size along x
1626	INTEGER(iwp) :: ngp_by !< grid point number of building size along y
1627	INTEGER(iwp) :: index_left_bwall !< index for left building wall
1628	INTEGER(iwp) :: index_right_bwall !< index for right building wall
1629	INTEGER(iwp) :: index_north_bwall !< index for north building wall
1630	INTEGER(iwp) :: index_south_bwall !< index for south building wall
1631	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
1632	INTEGER(iwp) :: ngp_cx !< grid point number of canyon size along x
1633	INTEGER(iwp) :: ngp_cy !< grid point number of canyon size along y
1634	INTEGER(iwp) :: index_left_cwall !< index for left canyon wall
1635	INTEGER(iwp) :: index_right_cwall !< index for right canyon wall
1636	INTEGER(iwp) :: index_north_cwall !< index for north canyon wall
1637	INTEGER(iwp) :: index_south_cwall !< index for south canyon wall
1638	INTEGER(iwp) :: i !< index variable along x
1639	INTEGER(iwp) :: j !< index variable along y
1640	INTEGER(iwp) :: k !< index variable along z
1641	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
1642	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
1643	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
1644	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
1645	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
1646	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
1647	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
1648	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
1649	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
1650	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
1651	INTEGER(iwp) :: td !< tunnel wall depth
1652	INTEGER(iwp) :: th !< height of outer tunnel wall
1653
1654	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
1655	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
1656	!
1657	!-- Check for correct setting of the namelist parameter topography. If
1658	!-- topography information is read from file but topography = 'flat',
1659	!-- initialization does not work properly.
1660	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
1661	TRIM( topography ) /= 'read_from_file' ) THEN
1662	message_string = 'If topography information is provided (via ' // &
1663	'Netcdf or ASCII input) topography = ' // &
1664	'"read_from_file" is required.'
1665	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
1666	ENDIF
1667	!
1668	!-- Set outer and inner index arrays for non-flat topography.
1669	!-- Here consistency checks concerning domain size and periodicity are
1670	!-- necessary.
1671	!-- Within this SELECT CASE structure only nzb_local is initialized
1672	!-- individually depending on the chosen topography type, all other index
1673	!-- arrays are initialized further below.
1674	SELECT CASE ( TRIM( topography ) )
1675
1676	CASE ( 'flat' )
1677	!
1678	!-- Initialilize 3D topography array, used later for initializing flags
1679	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
1680
1681	CASE ( 'closed_channel' )
1682	!
1683	!-- Initialilize 3D topography array, used later for initializing flags
1684	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
1685
1686	CASE ( 'single_building' )
1687	!
1688	!-- Single rectangular building, by default centered in the middle of the
1689	!-- total domain
1690	ngp_bx = NINT( building_length_x / dx )
1691	ngp_by = NINT( building_length_y / dy )
1692	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
1693	IF ( ABS( zw(bh) - building_height ) == &
1694	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
1695	IF ( building_wall_left == 9999999.9_wp ) THEN
1696	building_wall_left = ( nx + 1 - ngp_bx ) / 2 * dx
1697	ENDIF
1698	index_left_bwall = NINT( building_wall_left / dx )
1699	index_right_bwall = index_left_bwall + ngp_bx
1700
1701	IF ( building_wall_south == 9999999.9_wp ) THEN
1702	building_wall_south = ( ny + 1 - ngp_by ) / 2 * dy
1703	ENDIF
1704	index_south_bwall = NINT( building_wall_south / dy )
1705	index_north_bwall = index_south_bwall + ngp_by
1706
1707	!
1708	!-- Building size has to meet some requirements
1709	IF ( ( index_left_bwall < 1 ) .OR. ( index_right_bwall > nx-1 ) .OR. &
1710	( index_right_bwall < index_left_bwall+3 ) .OR. &
1711	( index_south_bwall < 1 ) .OR. ( index_north_bwall > ny-1 ) .OR.&
1712	( index_north_bwall < index_south_bwall+3 ) ) THEN
1713	WRITE( message_string, * ) 'inconsistent building parameters:', &
1714	'&index_left_bwall=', index_left_bwall, &
1715	'index_right_bwall=', index_right_bwall, &
1716	'index_south_bwall=', index_south_bwall, &
1717	'index_north_bwall=', index_north_bwall, &
1718	'nx=', nx, 'ny=', ny
1719	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
1720	ENDIF
1721
1722	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
1723	nzb_local = 0
1724	!
1725	!-- Define the building.
1726	IF ( index_left_bwall <= nxr .AND. index_right_bwall >= nxl .AND. &
1727	index_south_bwall <= nyn .AND. index_north_bwall >= nys ) &
1728	nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall), &
1729	MAX(nxl,index_left_bwall):MIN(nxr,index_right_bwall)) = bh
1730	!
1731	!-- Set bit array on basis of nzb_local
1732	DO i = nxl, nxr
1733	DO j = nys, nyn
1734	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
1735	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
1736	ENDDO
1737	ENDDO
1738
1739	DEALLOCATE( nzb_local )
1740
1741	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1742	!
1743	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
1744	!-- boundary conditions for topography.
1745	IF ( .NOT. bc_ns_cyc ) THEN
1746	IF ( nys == 0 ) THEN
1747	DO i = 1, nbgp
1748	topo(:,nys-i,:) = topo(:,nys,:)
1749	ENDDO
1750	ENDIF
1751	IF ( nyn == ny ) THEN
1752	DO i = 1, nbgp
1753	topo(:,nyn+i,:) = topo(:,nyn,:)
1754	ENDDO
1755	ENDIF
1756	ENDIF
1757	IF ( .NOT. bc_lr_cyc ) THEN
1758	IF ( nxl == 0 ) THEN
1759	DO i = 1, nbgp
1760	topo(:,:,nxl-i) = topo(:,:,nxl)
1761	ENDDO
1762	ENDIF
1763	IF ( nxr == nx ) THEN
1764	DO i = 1, nbgp
1765	topo(:,:,nxr+i) = topo(:,:,nxr)
1766	ENDDO
1767	ENDIF
1768	ENDIF
1769
1770	CASE ( 'single_street_canyon' )
1771	!
1772	!-- Single quasi-2D street canyon of infinite length in x or y direction.
1773	!-- The canyon is centered in the other direction by default.
1774	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1775	!
1776	!-- Street canyon in y direction
1777	ngp_cx = NINT( canyon_width_x / dx )
1778	IF ( canyon_wall_left == 9999999.9_wp ) THEN
1779	canyon_wall_left = ( nx + 1 - ngp_cx ) / 2 * dx
1780	ENDIF
1781	index_left_cwall= NINT( canyon_wall_left / dx )
1782	index_right_cwall= index_left_cwall+ ngp_cx
1783	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1784	!
1785	!-- Street canyon in x direction
1786	ngp_cy = NINT( canyon_width_y / dy )
1787	IF ( canyon_wall_south == 9999999.9_wp ) THEN
1788	canyon_wall_south = ( ny + 1 - ngp_cy ) / 2 * dy
1789	ENDIF
1790	index_south_cwall = NINT( canyon_wall_south / dy )
1791	index_north_cwall = index_south_cwall + ngp_cy
1792
1793	ELSE
1794
1795	message_string = 'no street canyon width given'
1796	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
1797
1798	ENDIF
1799
1800	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
1801	IF ( ABS( zw(ch) - canyon_height ) == &
1802	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
1803	dp_level_ind_b = ch
1804	!
1805	!-- Street canyon size has to meet some requirements
1806	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1807	IF ( ( index_left_cwall< 1 ) .OR. ( index_right_cwall> nx-1 ) .OR.&
1808	( ngp_cx < 3 ) .OR. ( ch < 3 ) ) THEN
1809	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
1810	'&index_left_cwall=', index_left_cwall, &
1811	' index_right_cwall=', index_right_cwall, &
1812	' ngp_cx=', ngp_cx, &
1813	' ch=', ch, ' nx=', nx, ' ny=', ny
1814	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
1815	ENDIF
1816	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1817	IF ( ( index_south_cwall < 1 ) .OR. &
1818	( index_north_cwall > ny-1 ) .OR. ( ngp_cy < 3 ) .OR. &
1819	( ch < 3 ) ) THEN
1820	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
1821	'&index_south_cwall=', index_south_cwall, &
1822	' index_north_cwall=', index_north_cwall, &
1823	' ngp_cy=', ngp_cy, &
1824	' ch=', ch, ' nx=', nx, ' ny=', ny
1825	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
1826	ENDIF
1827	ENDIF
1828	IF ( canyon_width_x /= 9999999.9_wp .AND. &
1829	canyon_width_y /= 9999999.9_wp ) THEN
1830	message_string = 'inconsistent canyon parameters:' // &
1831	'&street canyon can only be oriented' // &
1832	' either in x- or in y-direction'
1833	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
1834	ENDIF
1835
1836	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
1837	nzb_local = ch
1838	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1839	IF ( index_left_cwall<= nxr .AND. index_right_cwall>= nxl ) &
1840	nzb_local(:,MAX(nxl,index_left_cwall+1):MIN(nxr,index_right_cwall-1)) = 0
1841	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1842	IF ( index_south_cwall <= nyn .AND. index_north_cwall >= nys ) &
1843	nzb_local(MAX(nys,index_south_cwall+1):MIN(nyn,index_north_cwall-1),:) = 0
1844	ENDIF
1845	!
1846	!-- Set bit array on basis of nzb_local
1847	DO i = nxl, nxr
1848	DO j = nys, nyn
1849	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
1850	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
1851	ENDDO
1852	ENDDO
1853	DEALLOCATE( nzb_local )
1854
1855	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1856	!
1857	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
1858	!-- boundary conditions for topography.
1859	IF ( .NOT. bc_ns_cyc ) THEN
1860	IF ( nys == 0 ) THEN
1861	DO i = 1, nbgp
1862	topo(:,nys-i,:) = topo(:,nys,:)
1863	ENDDO
1864	ENDIF
1865	IF ( nyn == ny ) THEN
1866	DO i = 1, nbgp
1867	topo(:,nyn+i,:) = topo(:,nyn,:)
1868	ENDDO
1869	ENDIF
1870	ENDIF
1871	IF ( .NOT. bc_lr_cyc ) THEN
1872	IF ( nxl == 0 ) THEN
1873	DO i = 1, nbgp
1874	topo(:,:,nxl-i) = topo(:,:,nxl)
1875	ENDDO
1876	ENDIF
1877	IF ( nxr == nx ) THEN
1878	DO i = 1, nbgp
1879	topo(:,:,nxr+i) = topo(:,:,nxr)
1880	ENDDO
1881	ENDIF
1882	ENDIF
1883
1884	CASE ( 'tunnel' )
1885
1886	!
1887	!-- Tunnel height
1888	IF ( tunnel_height == 9999999.9_wp ) THEN
1889	th = zw( INT( 0.2 * nz) )
1890	ELSE
1891	th = tunnel_height
1892	ENDIF
1893	!
1894	!-- Tunnel-wall depth
1895	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
1896	td = MAX ( dx, dy, dz(1) )
1897	ELSE
1898	td = tunnel_wall_depth
1899	ENDIF
1900	!
1901	!-- Check for tunnel width
1902	IF ( tunnel_width_x == 9999999.9_wp .AND. &
1903	tunnel_width_y == 9999999.9_wp ) THEN
1904	message_string = 'No tunnel width is given. '
1905	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
1906	ENDIF
1907	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
1908	tunnel_width_y /= 9999999.9_wp ) THEN
1909	message_string = 'Inconsistent tunnel parameters:' // &
1910	'tunnel can only be oriented' // &
1911	'either in x- or in y-direction.'
1912	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
1913	ENDIF
1914	!
1915	!-- Check for too small tunnel width in x- and y-direction
1916	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
1917	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) THEN
1918	message_string = 'tunnel_width_x too small'
1919	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
1920	ENDIF
1921	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
1922	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) THEN
1923	message_string = 'tunnel_width_y too small'
1924	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
1925	ENDIF
1926	!
1927	!-- Check for too large tunnel width.
1928	!-- Tunnel axis along y.
1929	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
1930	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
1931	message_string = 'tunnel_width_x too large'
1932	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
1933	ENDIF
1934
1935	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
1936	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
1937	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
1938	( tunnel_width_x * 0.5_wp - td ) )
1939	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
1940	( tunnel_width_x * 0.5_wp - td ) )
1941
1942	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
1943	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
1944	tys_in = tys_out
1945	tye_in = tye_out
1946	ENDIF
1947	!
1948	!-- Tunnel axis along x.
1949	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
1950	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
1951	message_string = 'tunnel_width_y too large'
1952	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
1953	ENDIF
1954
1955	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
1956	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
1957	txs_in = txs_out
1958	txe_in = txe_out
1959
1960	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
1961	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
1962	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
1963	( tunnel_width_y * 0.5_wp - td ) )
1964	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
1965	( tunnel_width_y * 0.5_wp - td ) )
1966	ENDIF
1967
1968	topo = 0
1969	DO i = nxl, nxr
1970	DO j = nys, nyn
1971	!
1972	!-- Use heaviside function to model outer tunnel surface
1973	hv_out = th * 0.5_wp * &
1974	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
1975	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
1976
1977	hv_out = hv_out * 0.5_wp * &
1978	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
1979	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
1980	!
1981	!-- Use heaviside function to model inner tunnel surface
1982	hv_in = ( th - td ) * 0.5_wp * &
1983	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
1984	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
1985
1986	hv_in = hv_in * 0.5_wp * &
1987	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
1988	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
1989	!
1990	!-- Set flags at x-y-positions without any tunnel surface
1991	IF ( hv_out - hv_in == 0.0_wp ) THEN
1992	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
1993	!
1994	!-- Set flags at x-y-positions with tunnel surfaces
1995	ELSE
1996	DO k = nzb + 1, nzt + 1
1997	!
1998	!-- Inner tunnel
1999	IF ( hv_out - hv_in == th ) THEN
2000	IF ( zw(k) <= hv_out ) THEN
2001	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
2002	ELSE
2003	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2004	ENDIF
2005	ENDIF
2006	!
2007	!-- Lateral tunnel walls
2008	IF ( hv_out - hv_in == td ) THEN
2009	IF ( zw(k) <= hv_in ) THEN
2010	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2011	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
2012	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
2013	ELSEIF ( zw(k) > hv_out ) THEN
2014	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2015	ENDIF
2016	ENDIF
2017	ENDDO
2018	ENDIF
2019	ENDDO
2020	ENDDO
2021
2022	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2023	!
2024	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
2025	!-- boundary conditions for topography.
2026	IF ( .NOT. bc_ns_cyc ) THEN
2027	IF ( nys == 0 ) THEN
2028	DO i = 1, nbgp
2029	topo(:,nys-i,:) = topo(:,nys,:)
2030	ENDDO
2031	ENDIF
2032	IF ( nyn == ny ) THEN
2033	DO i = 1, nbgp
2034	topo(:,nyn+i,:) = topo(:,nyn,:)
2035	ENDDO
2036	ENDIF
2037	ENDIF
2038	IF ( .NOT. bc_lr_cyc ) THEN
2039	IF ( nxl == 0 ) THEN
2040	DO i = 1, nbgp
2041	topo(:,:,nxl-i) = topo(:,:,nxl)
2042	ENDDO
2043	ENDIF
2044	IF ( nxr == nx ) THEN
2045	DO i = 1, nbgp
2046	topo(:,:,nxr+i) = topo(:,:,nxr)
2047	ENDDO
2048	ENDIF
2049	ENDIF
2050
2051	CASE ( 'read_from_file' )
2052	!
2053	!-- Note, topography information have been already read.
2054	!-- If required, further process topography, i.e. reference buildings on
2055	!-- top of orography and set temporary 3D topography array, which is
2056	!-- used later to set grid flags. Calling of this rouinte is also
2057	!-- required in case of ASCII input, even though no distinction between
2058	!-- terrain- and building height is made in this case.
2059	CALL process_topography( topo )
2060	!
2061	!-- Filter holes resolved by only one grid-point
2062	CALL filter_topography( topo )
2063	!
2064	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
2065	!-- conditions.
2066	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2067	!
2068	!-- Set lateral boundary conditions for topography on all ghost layers
2069	IF ( .NOT. bc_ns_cyc ) THEN
2070	IF ( nys == 0 ) THEN
2071	DO i = 1, nbgp
2072	topo(:,nys-i,:) = topo(:,nys,:)
2073	ENDDO
2074	ENDIF
2075	IF ( nyn == ny ) THEN
2076	DO i = 1, nbgp
2077	topo(:,nyn+i,:) = topo(:,nyn,:)
2078	ENDDO
2079	ENDIF
2080	ENDIF
2081
2082	IF ( .NOT. bc_lr_cyc ) THEN
2083	IF ( nxl == 0 ) THEN
2084	DO i = 1, nbgp
2085	topo(:,:,nxl-i) = topo(:,:,nxl)
2086	ENDDO
2087	ENDIF
2088	IF ( nxr == nx ) THEN
2089	DO i = 1, nbgp
2090	topo(:,:,nxr+i) = topo(:,:,nxr)
2091	ENDDO
2092	ENDIF
2093	ENDIF
2094
2095
2096	CASE DEFAULT
2097	!
2098	!-- The DEFAULT case is reached either if the parameter topography
2099	!-- contains a wrong character string or if the user has defined a special
2100	!-- case in the user interface. There, the subroutine user_init_grid
2101	!-- checks which of these two conditions applies.
2102	CALL user_init_grid( topo )
2103	CALL filter_topography( topo )
2104
2105	END SELECT
2106	!
2107	!-- Consistency checks and index array initialization are only required for
2108	!-- non-flat topography.
2109	IF ( TRIM( topography ) /= 'flat' ) THEN
2110	!
2111	!-- In case of non-flat topography, check whether the convention how to
2112	!-- define the topography grid has been set correctly, or whether the default
2113	!-- is applicable. If this is not possible, abort.
2114	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
2115	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
2116	TRIM( topography ) /= 'single_building' .AND. &
2117	TRIM( topography ) /= 'single_street_canyon' .AND. &
2118	TRIM( topography ) /= 'tunnel' .AND. &
2119	TRIM( topography ) /= 'read_from_file') THEN
2120	!-- The default value is not applicable here, because it is only valid
2121	!-- for the four standard cases 'single_building',
2122	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
2123	!-- defined in init_grid.
2124	WRITE( message_string, * ) &
2125	'The value for "topography_grid_convention" ', &
2126	'is not set. Its default value is & only valid for ', &
2127	'"topography" = ''single_building'', ''tunnel'' ', &
2128	'''single_street_canyon'', ''closed_channel'' & or ', &
2129	'''read_from_file''.', &
2130	'& Choose ''cell_edge'' or ''cell_center''.'
2131	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
2132	ELSE
2133	!-- The default value is applicable here.
2134	!-- Set convention according to topography.
2135	IF ( TRIM( topography ) == 'single_building' .OR. &
2136	TRIM( topography ) == 'single_street_canyon' ) THEN
2137	topography_grid_convention = 'cell_edge'
2138	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
2139	TRIM( topography ) == 'tunnel') THEN
2140	topography_grid_convention = 'cell_center'
2141	ENDIF
2142	ENDIF
2143	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
2144	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
2145	WRITE( message_string, * ) &
2146	'The value for "topography_grid_convention" is ', &
2147	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
2148	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
2149	ENDIF
2150
2151
2152	IF ( topography_grid_convention == 'cell_edge' ) THEN
2153	!
2154	!-- The array nzb_local as defined using the 'cell_edge' convention
2155	!-- describes the actual total size of topography which is defined at the
2156	!-- cell edges where u=0 on the topography walls in x-direction and v=0
2157	!-- on the topography walls in y-direction. However, PALM uses individual
2158	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
2159	!-- Therefore, the extent of topography in nzb_local is now reduced by
2160	!-- 1dx at the E topography walls and by 1dy at the N topography walls
2161	!-- to form the basis for nzb_s_inner.
2162	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
2163	!-- required at this point.
2164	DO j = nys+1, nyn+1
2165	DO i = nxl-1, nxr
2166	DO k = nzb, nzt+1
2167	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
2168	BTEST( topo(k,j,i+1), 0 ) ) &
2169	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2170	ENDDO
2171	ENDDO
2172	ENDDO
2173	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2174
2175	DO i = nxl, nxr+1
2176	DO j = nys-1, nyn
2177	DO k = nzb, nzt+1
2178	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
2179	BTEST( topo(k,j+1,i), 0 ) ) &
2180	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2181	ENDDO
2182	ENDDO
2183	ENDDO
2184	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2185
2186	ENDIF
2187	ENDIF
2188
2189
2190	END SUBROUTINE init_topo
2191
2192	SUBROUTINE set_topo_flags(topo)
2193
2194	USE control_parameters, &
2195	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
2196	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
2197
2198	USE exchange_horiz_mod, &
2199	ONLY: exchange_horiz_int
2200
2201	USE indices, &
2202	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
2203	nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
2204
2205	USE kinds
2206
2207	IMPLICIT NONE
2208
2209	INTEGER(iwp) :: i !< index variable along x
2210	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
2211	INTEGER(iwp) :: j !< index variable along y
2212	INTEGER(iwp) :: k !< index variable along z
2213
2214	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
2215
2216	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
2217	wall_flags_static_0 = 0
2218	!
2219	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
2220	!-- Further special flags will be set in following loops.
2221	DO i = nxl, nxr
2222	DO j = nys, nyn
2223	DO k = nzb, nzt+1
2224	!
2225	!-- scalar grid
2226	IF ( BTEST( topo(k,j,i), 0 ) ) &
2227	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
2228	!
2229	!-- u grid
2230	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
2231	BTEST( topo(k,j,i-1), 0 ) ) &
2232	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
2233	!
2234	!-- v grid
2235	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
2236	BTEST( topo(k,j-1,i), 0 ) ) &
2237	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
2238
2239	ENDDO
2240
2241	DO k = nzb, nzt
2242	!
2243	!-- w grid
2244	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
2245	BTEST( topo(k+1,j,i), 0 ) ) &
2246	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
2247	ENDDO
2248
2249	IF ( topography /= 'closed_channel' ) THEN
2250	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
2251	ENDIF
2252
2253	ENDDO
2254	ENDDO
2255
2256	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
2257
2258	!
2259	!-- Set outer array for scalars to mask near-surface grid points. Note, on
2260	!-- basis of flag 24 futher flags will be derived which are used to control
2261	!-- production of subgrid TKE production near walls.
2262
2263	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
2264	wall_flags_total_0 = 0
2265
2266	DO i = nxl, nxr
2267	DO j = nys, nyn
2268	DO k = nzb, nzt+1
2269	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
2270	ENDDO
2271	ENDDO
2272	ENDDO
2273
2274	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
2275
2276	DO i = nxl, nxr
2277	DO j = nys, nyn
2278	DO k = nzb, nzt+1
2279	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
2280	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
2281	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
2282	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
2283	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
2284	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
2285	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
2286	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
2287	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
2288	ENDDO
2289	ENDDO
2290	ENDDO
2291	!
2292	!-- Set further special flags
2293	DO i = nxl, nxr
2294	DO j = nys, nyn
2295	DO k = nzb, nzt+1
2296	!
2297	!-- scalar grid, former nzb_diff_s_inner.
2298	!-- Note, use this flag also to mask topography in diffusion_u and
2299	!-- diffusion_v along the vertical direction. In case of
2300	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
2301	!-- gradient approach is applied. Please note, in case of u- and v-
2302	!-- diffuison, a small error is made at edges (on the east side for u,
2303	!-- at the north side for v), since topography on scalar grid point
2304	!-- is used instead of topography on u/v-grid. As number of topography grid
2305	!-- points on uv-grid is different than s-grid, different number of
2306	!-- surface elements would be required. In order to avoid this,
2307	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
2308	!-- points are not masked within diffusion_u. Tests had shown that the
2309	!-- effect on the flow is negligible.
2310	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2311	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2312	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
2313	ELSE
2314	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
2315	ENDIF
2316
2317	ENDDO
2318	!
2319	!-- Special flag to control vertical diffusion at model top - former
2320	!-- nzt_diff
2321	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
2322	IF ( use_top_fluxes ) &
2323	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
2324
2325
2326	DO k = nzb+1, nzt
2327	!
2328	!-- Special flag on u grid, former nzb_u_inner + 1, required
2329	!-- for disturb_field and initialization. Do not disturb directly at
2330	!-- topography, as well as initialize u with zero one grid point outside
2331	!-- of topography.
2332	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
2333	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
2334	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
2335	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
2336	!
2337	!-- Special flag on v grid, former nzb_v_inner + 1, required
2338	!-- for disturb_field and initialization. Do not disturb directly at
2339	!-- topography, as well as initialize v with zero one grid point outside
2340	!-- of topography.
2341	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
2342	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
2343	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
2344	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
2345	!
2346	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
2347	!-- lpm_sgs_tke
2348	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2349	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2350	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2351	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
2352	!
2353	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
2354	!-- in production_e
2355	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2356	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
2357	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
2358	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2359	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
2360	ELSE
2361	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2362	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
2363	ENDIF
2364	!
2365	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
2366	!-- in production_e
2367	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2368	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2369	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2370	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2371	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
2372	ELSE
2373	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2374	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
2375	ENDIF
2376	ENDDO
2377	!
2378	!-- Flags indicating downward facing walls
2379	DO k = nzb+1, nzt+1
2380	!
2381	!-- Scalar grid
2382	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2383	.NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2384	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
2385	!
2386	!-- Downward facing wall on u grid
2387	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
2388	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
2389	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
2390	!
2391	!-- Downward facing wall on v grid
2392	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
2393	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
2394	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
2395	!
2396	!-- Downward facing wall on w grid
2397	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
2398	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
2399	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
2400	ENDDO
2401	!
2402	!-- Flags indicating upward facing walls
2403	DO k = nzb, nzt
2404	!
2405	!-- Upward facing wall on scalar grid
2406	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2407	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2408	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
2409	!
2410	!-- Upward facing wall on u grid
2411	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
2412	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
2413	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
2414
2415	!
2416	!-- Upward facing wall on v grid
2417	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
2418	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
2419	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
2420
2421	!
2422	!-- Upward facing wall on w grid
2423	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
2424	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
2425	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
2426	!
2427	!-- Special flag on scalar grid, former nzb_s_inner
2428	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
2429	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
2430	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
2431	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
2432	!
2433	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
2434	!-- flow_statistics
2435	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2436	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2437	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2438	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
2439	ELSE
2440	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
2441	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
2442	ENDIF
2443
2444
2445	ENDDO
2446	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
2447	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
2448	!
2449	!-- Set flags indicating that topography is close by in horizontal
2450	!-- direction, i.e. flags that infold the topography. These will be used
2451	!-- to set advection flags for passive scalars, where due to large
2452	!-- gradients near buildings stationary numerical oscillations can produce
2453	!-- unrealistically high concentrations. This is only necessary if
2454	!-- WS-scheme is applied for scalar advection. Note, these flags will be
2455	!-- only used for passive scalars such as chemical species or aerosols.
2456	IF ( scalar_advec == 'ws-scheme' ) THEN
2457	DO k = nzb, nzt
2458	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
2459	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
2460	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
2461	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
2462	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
2463	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
2464	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
2465	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
2466	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
2467	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
2468	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
2469	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
2470	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
2471	) ) &
2472	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
2473
2474	ENDDO
2475	ENDIF
2476	ENDDO
2477	ENDDO
2478	!
2479	!-- Finally, set identification flags indicating natural terrain or buildings.
2480	!-- Natural terrain grid points. Information on the type of the surface is
2481	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
2482	!-- when topography is read from file. In order to run the land-surface model
2483	!-- also without topography information, set bit 1 explicitely in this case.
2484	!--
2485	!-- Natural terrain grid points
2486	!-- If no topography is initialized, the land-surface is at k = nzb.
2487	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
2488	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
2489	ELSE
2490	DO i = nxl, nxr
2491	DO j = nys, nyn
2492	DO k = nzb, nzt+1
2493	!
2494	!-- Natural terrain grid point
2495	IF ( BTEST( topo(k,j,i), 1 ) ) &
2496	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
2497	ENDDO
2498	ENDDO
2499	ENDDO
2500	ENDIF
2501	!
2502	!-- Building grid points.
2503	DO i = nxl, nxr
2504	DO j = nys, nyn
2505	DO k = nzb, nzt+1
2506	IF ( BTEST( topo(k,j,i), 2 ) ) &
2507	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
2508	ENDDO
2509	ENDDO
2510	ENDDO
2511	!
2512	!-- Set flag 4, indicating new topography grid points due to filtering.
2513	DO i = nxl, nxr
2514	DO j = nys, nyn
2515	DO k = nzb, nzt+1
2516	IF ( BTEST( topo(k,j,i), 4 ) ) &
2517	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
2518	ENDDO
2519	ENDDO
2520	ENDDO
2521
2522	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
2523
2524	DO i = nxl, nxr
2525	DO j = nys, nyn
2526	DO k = nzb, nzt+1
2527	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
2528	ENDDO
2529	ENDDO
2530	ENDDO
2531	!
2532	!-- Exchange ghost points for wall flags
2533	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
2534	!
2535	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
2536	!-- boundary conditions for topography.
2537	IF ( .NOT. bc_ns_cyc ) THEN
2538	IF ( nys == 0 ) THEN
2539	DO i = 1, nbgp
2540	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
2541	ENDDO
2542	ENDIF
2543	IF ( nyn == ny ) THEN
2544	DO i = 1, nbgp
2545	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
2546	ENDDO
2547	ENDIF
2548	ENDIF
2549	IF ( .NOT. bc_lr_cyc ) THEN
2550	IF ( nxl == 0 ) THEN
2551	DO i = 1, nbgp
2552	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
2553	ENDDO
2554	ENDIF
2555	IF ( nxr == nx ) THEN
2556	DO i = 1, nbgp
2557	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
2558	ENDDO
2559	ENDIF
2560	ENDIF
2561	!
2562	!-- Pre-calculate topography top indices (former get_topography_top_index
2563	!-- function)
2564	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
2565	!
2566	!-- Uppermost topography index on scalar grid
2567	ibit = 12
2568	topo_top_ind(:,:,0) = MAXLOC( &
2569	MERGE( 1, 0, &
2570	BTEST( wall_flags_total_0(:,:,:), ibit ) &
2571	), DIM = 1 &
2572	) - 1
2573	!
2574	!-- Uppermost topography index on u grid
2575	ibit = 14
2576	topo_top_ind(:,:,1) = MAXLOC( &
2577	MERGE( 1, 0, &
2578	BTEST( wall_flags_total_0(:,:,:), ibit ) &
2579	), DIM = 1 &
2580	) - 1
2581	!
2582	!-- Uppermost topography index on v grid
2583	ibit = 16
2584	topo_top_ind(:,:,2) = MAXLOC( &
2585	MERGE( 1, 0, &
2586	BTEST( wall_flags_total_0(:,:,:), ibit ) &
2587	), DIM = 1 &
2588	) - 1
2589	!
2590	!-- Uppermost topography index on w grid
2591	ibit = 18
2592	topo_top_ind(:,:,3) = MAXLOC( &
2593	MERGE( 1, 0, &
2594	BTEST( wall_flags_total_0(:,:,:), ibit ) &
2595	), DIM = 1 &
2596	) - 1
2597	!
2598	!-- Uppermost topography index on scalar outer grid
2599	ibit = 24
2600	topo_top_ind(:,:,4) = MAXLOC( &
2601	MERGE( 1, 0, &
2602	BTEST( wall_flags_total_0(:,:,:), ibit ) &
2603	), DIM = 1 &
2604	) - 1
2605
2606	END SUBROUTINE set_topo_flags

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source: palm/trunk/SOURCE/init_grid.f90 @ 4529

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