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source: palm/trunk/SOURCE/init_grid.f90 @ 4699

Last change on this file since 4699 was 4691, checked in by suehring, 4 years ago
Reference model topography to the lowest grid point also in ASCII input case
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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 terms of the GNU General
6	! Public License as published by the Free Software Foundation, either version 3 of the License, or
7	! (at your option) any later version.
8	!
9	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
10	! implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
11	! Public License for more details.
12	!
13	! You should have received a copy of the GNU General Public License along with PALM. If not, see
14	! <http://www.gnu.org/licenses/>.
15	!
16	! Copyright 1997-2020 Leibniz Universitaet Hannover
17	!--------------------------------------------------------------------------------------------------!
18	!
19	! Current revisions:
20	! -----------------
21	!
22	!
23	! Former revisions:
24	! -----------------
25	! $Id: init_grid.f90 4691 2020-09-22 14:38:38Z maronga $
26	! Reference model topography to the lowest grid point also in ASCII input case
27	!
28	! 4653 2020-08-27 08:54:43Z pavelkrc
29	! file re-formatted to follow the PALM coding standard
30	!
31	! 4630 2020-07-30 14:54:34Z suehring
32	! In case of ASCII topography input flag grid points as terrain and building.
33	!
34	! 4601 2020-07-14 12:06:09Z suehring
35	! Minor formatting adjustments
36	!
37	! 4564 2020-06-12 14:03:36Z raasch
38	! Vertical nesting method of Huq et al. (2019) removed
39	!
40	! 4543 2020-05-20 14:12:22Z gronemeier
41	! Remove non-required check for canyon height
42	!
43	! 4507 2020-04-22 18:21:45Z gronemeier
44	! update origin_z with shifting height of orography (oro_min)
45	!
46	! 4457 2020-03-11 14:20:43Z raasch
47	! use statement for exchange horiz added,
48	! bugfix for call of exchange horiz 2d
49	!
50	! 4444 2020-03-05 15:59:50Z raasch
51	! bugfix: cpp-directives for serial mode added
52	!
53	! 4414 2020-02-19 20:16:04Z suehring
54	! - Remove deprecated topography arrays nzb_s_inner, nzb_u_inner, etc.
55	! - Move initialization of boundary conditions and multigrid into an extra module interface.
56	!
57	! 4386 2020-01-27 15:07:30Z Giersch
58	! Allocation statements, comments, naming of variables revised and _wp added to real type values
59	!
60	! 4360 2020-01-07 11:25:50Z suehring
61	! Revise error messages for generic tunnel setup.
62	!
63	! 4346 2019-12-18 11:55:56Z motisi
64	! Introduction of wall_flags_total_0, which currently sets bits based on static topography
65	! information used in wall_flags_static_0
66	!
67	! 4340 2019-12-16 08:17:03Z Giersch
68	! Topography closed channel flow with symmetric boundaries implemented
69	!
70	! 4329 2019-12-10 15:46:36Z motisi
71	! Renamed wall_flags_0 to wall_flags_static_0
72	!
73	! 4328 2019-12-09 18:53:04Z suehring
74	! Minor change in nzb_max computation. Commentation added.
75	!
76	! 4314 2019-11-29 10:29:20Z suehring
77	! Set additional topography flag 4 to mark topography grid points emerged from the filtering process.
78	!
79	! 4294 2019-11-13 18:34:16Z suehring
80	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and building surfaces in all
81	! cases, in order to enable terrain-following output also when no land- or urban-surface model is
82	! applied.
83	!
84	! 4265 2019-10-15 16:16:24Z suehring
85	! Bugfix for last commit, exchange oro_max variable only when it is allocated (not necessarily the
86	! case when topography is input from ASCII file).
87	!
88	! 4245 2019-09-30 08:40:37Z pavelkrc
89	! Store oro_max (building z-offset) in 2D for building surfaces
90	!
91	! 4189 2019-08-26 16:19:38Z suehring
92	! - Add check for proper setting of namelist parameter topography
93	! - Set flag to indicate land surfaces in case no topography is provided
94	!
95	! 4182 2019-08-22 15:20:23Z scharf
96	! Corrected "Former revisions" section
97	!
98	! 4168 2019-08-16 13:50:17Z suehring
99	! Pre-calculate topography top index and store it on an array (replaces former functions
100	! get_topography_top_index)
101	!
102	! 4159 2019-08-15 13:31:35Z suehring
103	! Revision of topography processing. This was not consistent between 2D and 3D buildings.
104	!
105	! 4144 2019-08-06 09:11:47Z raasch
106	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
107	!
108	! 4115 2019-07-24 12:50:49Z suehring
109	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
110	!
111	! 4110 2019-07-22 17:05:21Z suehring
112	! - Separate initialization of advection flags for momentum and scalars.
113	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
114	!
115	! 4109 2019-07-22 17:00:34Z suehring
116	! Fix bad commit
117	!
118	! 3926 2019-04-23 12:56:42Z suehring
119	! Minor bugfix in building mapping when all building IDs in the model domain are missing
120	!
121	! 3857 2019-04-03 13:00:16Z knoop
122	! In projection of non-building 3D objects onto numerical grid remove dependency on building_type
123	!
124	! 3763 2019-02-25 17:33:49Z suehring
125	! Replace work-around for ghost point exchange of 1-byte arrays with specific routine as already
126	! done in other routines
127	!
128	! 3761 2019-02-25 15:31:42Z raasch
129	! unused variables removed
130	!
131	! 3661 2019-01-08 18:22:50Z suehring
132	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead, order degradation of
133	! advection scheme is handeled directly in advec_ws
134	!
135	! 3655 2019-01-07 16:51:22Z knoop
136	! Comment added
137	!
138	! Revision 1.1 1997/08/11 06:17:45 raasch
139	! Initial revision (Testversion)
140	!
141	!
142	! Description:
143	! -------------------------------------------------------------------------------------------------!
144	!> Creating grid depending constants
145	!> @todo: Rearrange topo flag list
146	!> @todo: reference 3D buildings on top of orography is not tested and may need further improvement
147	!> for steep slopes
148	!> @todo: Use more advanced setting of building type at filled holes
149	!--------------------------------------------------------------------------------------------------!
150	SUBROUTINE init_grid
151
152	USE arrays_3d, &
153	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
154
155	USE control_parameters, &
156	ONLY: constant_flux_layer, dz, dz_max, dz_stretch_factor, &
157	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end, &
158	dz_stretch_level_end_index, dz_stretch_level_start_index, &
159	dz_stretch_level_start, ibc_uv_b, message_string, &
160	number_stretch_level_end, &
161	number_stretch_level_start, &
162	ocean_mode, &
163	psolver, &
164	symmetry_flag, &
165	topography, &
166	use_surface_fluxes
167
168	USE grid_variables, &
169	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
170
171	USE indices, &
172	ONLY: nbgp, &
173	nx, &
174	nxl, &
175	nxlg, &
176	nxr, &
177	nxrg, &
178	ny, &
179	nyn, &
180	nyng, &
181	nys, &
182	nysg, &
183	nz, &
184	nzb, &
185	nzb_diff, &
186	nzb_max, &
187	nzt, &
188	topo_top_ind, &
189	topo_min_level
190
191	USE kinds
192
193	USE pegrid
194
195	IMPLICIT NONE
196
197	INTEGER(iwp) :: i !< index variable along x
198	INTEGER(iwp) :: j !< index variable along y
199	INTEGER(iwp) :: k !< index variable along z
200	INTEGER(iwp) :: k_top !< topography top index on local PE
201	INTEGER(iwp) :: n !< loop variable for stretching
202	INTEGER(iwp) :: number_dz !< number of user-specified dz values
203	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
204	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
205
206	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
207
208	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
209	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
210
211	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching
212	!< can end
213
214
215	!
216	!-- Calculation of horizontal array bounds including ghost layers
217	nxlg = nxl - nbgp
218	nxrg = nxr + nbgp
219	nysg = nys - nbgp
220	nyng = nyn + nbgp
221
222	!
223	!-- Allocate grid arrays
224	ALLOCATE( x(0:nx) )
225	ALLOCATE( xu(0:nx) )
226
227	DO i = 0, nx
228	xu(i) = i * dx
229	x(i) = i * dx + 0.5_wp * dx
230	ENDDO
231
232	ALLOCATE( y(0:ny) )
233	ALLOCATE( yv(0:ny) )
234
235	DO j = 0, ny
236	yv(j) = j * dy
237	y(j) = j * dy + 0.5_wp * dy
238	ENDDO
239
240	ALLOCATE( ddzu(1:nzt+1) )
241	ALLOCATE( ddzw(1:nzt+1) )
242	ALLOCATE( dd2zu(1:nzt) )
243	ALLOCATE( dzu(1:nzt+1) )
244	ALLOCATE( dzw(1:nzt+1) )
245	ALLOCATE( zu(nzb:nzt+1) )
246	ALLOCATE( zw(nzb:nzt+1) )
247
248	!
249	!-- For constructing an appropriate grid, the vertical grid spacing dz has to be specified with a
250	!-- non-negative value in the parameter file.
251	IF ( dz(1) == -1.0_wp ) THEN
252	message_string = 'missing dz'
253	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
254	ELSEIF ( dz(1) <= 0.0_wp ) THEN
255	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
256	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
257	ENDIF
258
259	!
260	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level if it was set by the user.
261	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
262	dz_stretch_level_start(1) = dz_stretch_level
263	ENDIF
264
265	!
266	!-- Determine number of dz values and stretching levels specified by the user to allow right
267	!-- controlling of the stretching mechanism and to perform error checks. The additional requirement
268	!-- that dz /= dz_max for counting number of user-specified dz values is necessary. Otherwise
269	!-- restarts would abort if the old stretching mechanism with dz_stretch_level is used (Attention:
270	!-- The user is not allowed to specify a dz value equal to the default of dz_max = 999.0).
271	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
272	number_stretch_level_start = COUNT( dz_stretch_level_start /= -9999999.9_wp )
273	number_stretch_level_end = COUNT( dz_stretch_level_end /= 9999999.9_wp )
274
275	!
276	!-- The number of specified end levels +1 has to be the same as the number
277	!-- of specified dz values
278	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
279	WRITE( message_string, * ) 'The number of values for dz = ', number_dz, &
280	'has to be the same as& ', 'the number of values for ', &
281	'dz_stretch_level_end + 1 = ', 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 the number of specified
287	!-- 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 = ', number_dz, &
291	'has to be the same as or one ', &
292	'more than& the number of values for ', &
293	'dz_stretch_level_start = ', number_stretch_level_start
294	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
295	ENDIF
296
297	!-- The number of specified start levels has to be the same or one more than the number of specified
298	!-- end levels
299	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
300	number_stretch_level_start /= number_stretch_level_end ) THEN
301	WRITE( message_string, * ) 'The number of values for ', &
302	'dz_stretch_level_start = ', dz_stretch_level_start, &
303	'has to be the ', 'same or one more than& the number of ', &
304	'values for dz_stretch_level_end = ', number_stretch_level_end
305	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
306	ENDIF
307
308	!
309	!-- Initialize dz for the free atmosphere with the value of dz_max
310	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. number_stretch_level_start /= 0 ) THEN
311	dz(number_stretch_level_start+1) = dz_max
312	ENDIF
313
314	!
315	!-- Initialize the stretching factor if (infinitely) stretching in the free atmosphere is desired
316	!-- (dz_stretch_level_end was not specified for the free atmosphere)
317	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
318	dz_stretch_factor_array(number_stretch_level_start) = dz_stretch_factor
319	ENDIF
320
321	!
322	!-- Allocation of arrays for stretching
323	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
324
325	!
326	!-- Define the vertical grid levels. Start with atmosphere branch
327	IF ( .NOT. ocean_mode ) THEN
328
329	!
330	!-- The stretching region has to be large enough to allow for a smooth transition between two
331	!-- different grid spacings. The number 4 is an empirical value.
332	DO n = 1, number_stretch_level_start
333	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + 4 * MAX( dz(n),dz(n+1) )
334	ENDDO
335
336	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
337	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
338	message_string= 'Each dz_stretch_level_end has to be larger ' // &
339	'than its corresponding value for &' // &
340	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '// &
341	'to allow for smooth grid stretching'
342	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
343	ENDIF
344
345	!
346	!-- Stretching must not be applied within the surface layer (first two grid points). For the
347	!-- default case dz_stretch_level_start is negative. Therefore the absolut value is checked here.
348	IF ( ANY( ABS( dz_stretch_level_start ) <= dz(1) * 1.5_wp ) ) THEN
349	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ', &
350	'larger than ', dz(1) * 1.5
351	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
352	ENDIF
353
354	!
355	!-- The stretching has to start and end on a grid level. Therefore user-specified values are
356	!-- mapped to the next lowest level. The calculation of the first level is realized differently
357	!-- just because of historical reasons (the advanced/new stretching mechanism was realized in a
358	!-- way that results don't change if the old parameters dz_stretch_level, dz_stretch_factor and
359	!-- dz_max are used).
360	IF ( number_stretch_level_start /= 0 ) THEN
361	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - dz(1)/2.0) / dz(1) ) &
362	* dz(1) + dz(1)/2.0
363	ENDIF
364
365	IF ( number_stretch_level_start > 1 ) THEN
366	DO n = 2, number_stretch_level_start
367	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / dz(n) ) * dz(n)
368	ENDDO
369	ENDIF
370
371	IF ( number_stretch_level_end /= 0 ) THEN
372	DO n = 1, number_stretch_level_end
373	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / dz(n+1) ) * dz(n+1)
374	ENDDO
375	ENDIF
376
377	!
378	!-- Determine stretching factor if necessary
379	IF ( number_stretch_level_end >= 1 ) THEN
380	CALL calculate_stretching_factor( number_stretch_level_end )
381	ENDIF
382
383	!
384	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
385	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v the first u/v- and
386	!-- w-level (k=0) are defined at same height (z=0).
387	!-- The second u-level (k=1) corresponds to the top of the surface layer. In case of symmetric
388	!-- boundaries (closed channel flow), the first grid point is always at z=0.
389	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. topography == 'closed_channel' ) THEN
390	zu(0) = 0.0_wp
391	ELSE
392	zu(0) = - dz(1) * 0.5_wp
393	ENDIF
394
395	zu(1) = dz(1) * 0.5_wp
396
397	!
398	!-- Determine u and v height levels considering the possibility of grid stretching in several
399	!-- heights.
400	n = 1
401	dz_stretch_level_start_index = nzt+1
402	dz_stretch_level_end_index = nzt+1
403	dz_stretched = dz(1)
404
405	!-- The default value of dz_stretch_level_start is negative, thus the first condition is true
406	!-- even if no stretching shall be applied. Hence, the second condition is also necessary.
407	DO k = 2, nzt+1-symmetry_flag
408	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
409	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
410	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
411
412	IF ( dz(n) > dz(n+1) ) THEN
413	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
414	ELSE
415	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
416	ENDIF
417
418	IF ( dz_stretch_level_start_index(n) == nzt+1 ) dz_stretch_level_start_index(n) = k-1
419
420	ENDIF
421
422	zu(k) = zu(k-1) + dz_stretched
423
424	!
425	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
426	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
427
428	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
429	zu(k) = dz_stretch_level_end(n)
430	dz_stretched = dz(n+1)
431	dz_stretch_level_end_index(n) = k
432	n = n + 1
433	ENDIF
434	ENDDO
435
436	!
437	!-- If a closed channel flow is simulated, make sure that grid structure is the same for both
438	!-- bottom and top boundary. (Hint: Using a different dz at the bottom and at the top makes no
439	!-- sense due to symmetric boundaries where dz should be equal. Therefore, different dz at the
440	!-- bottom and top causes an abort (see check_parameters).)
441	IF ( topography == 'closed_channel' ) THEN
442	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
443	ENDIF
444
445	!
446	!-- Compute the w-levels. They are always staggered half-way between the corresponding u-levels.
447	!-- In case of dirichlet bc for u and v at the ground the first u- and w-level (k=0) are defined
448	!-- at same height (z=0).
449	!-- Per default, the top w-level is extrapolated linearly. In case of a closed channel flow,
450	!-- zu(nzt+1) and zw(nzt) must be set explicitely.
451	!-- (Hint: Using a different dz at the bottom and at the top makes no sense due to symmetric
452	!-- boundaries where dz should be equal. Therefore, different dz at the bottom and top causes an
453	!-- abort (see check_parameters).)
454	zw(0) = 0.0_wp
455	DO k = 1, nzt-symmetry_flag
456	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
457	ENDDO
458	IF ( topography == 'closed_channel' ) THEN
459	zw(nzt) = zw(nzt-1) + dz(1)
460	zw(nzt+1) = zw(nzt) + dz(1)
461	ELSE
462	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
463	ENDIF
464
465	ELSE !ocean branch
466
467	!
468	!-- The stretching region has to be large enough to allow for a smooth transition between two
469	!-- different grid spacings. The number 4 is an empirical value
470	DO n = 1, number_stretch_level_start
471	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - 4 * MAX( dz(n),dz(n+1) )
472	ENDDO
473
474	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
475	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
476	message_string= 'Each dz_stretch_level_end has to be less ' // &
477	'than its corresponding value for &' // &
478	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '// &
479	'to allow for smooth grid stretching'
480	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
481	ENDIF
482
483	!
484	!-- Stretching must not be applied close to the surface (last two grid points). For the default
485	!-- case dz_stretch_level_start is negative.
486	IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) ) THEN
487	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ', &
488	'less than ', -dz(1) * 1.5
489	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
490	ENDIF
491
492	!
493	!-- The stretching has to start and end on a grid level. Therefore user-specified values are
494	!-- mapped to the next highest level. The calculation of the first level is realized differently
495	!-- just because of historical reasons (the advanced/new stretching mechanism was realized in a
496	!-- way that results don't change if the old parameters dz_stretch_level, dz_stretch_factor and
497	!-- dz_max are used)
498	IF ( number_stretch_level_start /= 0 ) THEN
499	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + dz(1)/2.0) / dz(1) ) &
500	* dz(1) - dz(1)/2.0
501	ENDIF
502
503	IF ( number_stretch_level_start > 1 ) THEN
504	DO n = 2, number_stretch_level_start
505	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / dz(n) ) * dz(n)
506	ENDDO
507	ENDIF
508
509	IF ( number_stretch_level_end /= 0 ) THEN
510	DO n = 1, number_stretch_level_end
511	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / dz(n+1) ) * dz(n+1)
512	ENDDO
513	ENDIF
514
515	!
516	!-- Determine stretching factor if necessary
517	IF ( number_stretch_level_end >= 1 ) THEN
518	CALL calculate_stretching_factor( number_stretch_level_end )
519	ENDIF
520
521	!
522	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
523	!-- In case of neumann bc at the ground the first first u-level (k=0) lies below the first
524	!-- w-level (k=0). In case of dirichlet bc the first u- and w-level are defined at same height,
525	!-- but staggered from the second level.
526	!-- The second u-level (k=1) corresponds to the top of the surface layer.
527	!-- z values are negative starting from z=0 (surface)
528	zu(nzt+1) = dz(1) * 0.5_wp
529	zu(nzt) = - dz(1) * 0.5_wp
530
531	!
532	!-- Determine u and v height levels considering the possibility of grid stretching in several
533	!-- heights.
534	n = 1
535	dz_stretch_level_start_index = 0
536	dz_stretch_level_end_index = 0
537	dz_stretched = dz(1)
538
539	DO k = nzt-1, 0, -1
540
541	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
542	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
543
544	IF ( dz(n) > dz(n+1) ) THEN
545	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
546	ELSE
547	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
548	ENDIF
549
550	IF ( dz_stretch_level_start_index(n) == 0 ) dz_stretch_level_start_index(n) = k+1
551
552	ENDIF
553
554	zu(k) = zu(k+1) - dz_stretched
555
556	!
557	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
558	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
559
560	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
561	zu(k) = dz_stretch_level_end(n)
562	dz_stretched = dz(n+1)
563	dz_stretch_level_end_index(n) = k
564	n = n + 1
565	ENDIF
566	ENDDO
567
568	!
569	!-- Compute the w-levels. They are always staggered half-way between the corresponding u-levels,
570	!-- except in case of dirichlet bc for u and v at the ground. In this case the first u- and
571	!-- w-level are defined at same height. The top w-level (nzt+1) is not used but set for
572	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
573	zw(nzt+1) = dz(1)
574	zw(nzt) = 0.0_wp
575	DO k = 0, nzt
576	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
577	ENDDO
578
579	!
580	!-- In case of dirichlet bc for u and v the first u- and w-level are defined at same height.
581	IF ( ibc_uv_b == 0 ) THEN
582	zu(0) = zw(0)
583	ENDIF
584
585	ENDIF !End of defining the vertical grid levels
586
587	!
588	!-- Compute grid lengths.
589	DO k = 1, nzt+1
590	dzu(k) = zu(k) - zu(k-1)
591	ddzu(k) = 1.0_wp / dzu(k)
592	dzw(k) = zw(k) - zw(k-1)
593	ddzw(k) = 1.0_wp / dzw(k)
594	ENDDO
595
596	DO k = 1, nzt
597	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
598	ENDDO
599
600	!
601	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid everywhere. For the
602	!-- actual grid, the grid spacing at the lowest level is only dz/2, but should be dz. Therefore, an
603	!-- additional array containing with appropriate grid information is created for these solvers.
604	IF ( psolver(1:9) /= 'multigrid' ) THEN
605	ALLOCATE( ddzu_pres(1:nzt+1) )
606	ddzu_pres = ddzu
607	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
608	ENDIF
609
610	!
611	!-- Compute the reciprocal values of the horizontal grid lengths.
612	ddx = 1.0_wp / dx
613	ddy = 1.0_wp / dy
614	dx2 = dx * dx
615	dy2 = dy * dy
616	ddx2 = 1.0_wp / dx2
617	ddy2 = 1.0_wp / dy2
618
619	!
620	!-- Allocate 3D array to set topography
621	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
622	topo = 0
623	!
624	!-- Initialize topography by generic topography or read topography from file.
625	CALL init_topo( topo )
626	!
627	!-- Set flags to mask topography on the grid.
628	CALL set_topo_flags( topo )
629
630	!
631	!-- Determine the maximum level of topography. It is used for steering the degradation of order of
632	!-- the applied advection scheme, as well in the lpm.
633	k_top = 0
634	DO i = nxl, nxr
635	DO j = nys, nyn
636	DO k = nzb, nzt + 1
637	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
638	ENDDO
639	ENDDO
640	ENDDO
641	#if defined( __parallel )
642	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
643	#else
644	nzb_max = k_top
645	#endif
646	!
647	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
648	!-- Further, in case topography extents up to the model top, limit to nzt.
649	nzb_max = MIN( nzb_max+1, nzt )
650	!
651	!-- Determine minimum index of topography. Usually, this will be nzb. In case there is elevated
652	!-- topography, however, the lowest topography will be higher.
653	!-- This index is e.g. used to calculate mean first-grid point atmosphere temperature, surface
654	!-- pressure and density, etc. .
655	topo_min_level = 0
656	#if defined( __parallel )
657	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), topo_min_level, 1, MPI_INTEGER, &
658	MPI_MIN, comm2d, ierr )
659	#else
660	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
661	#endif
662
663	!
664	!-- Check topography for consistency with model domain. Therefore, use maximum and minium
665	!-- topography-top indices. Note, minimum topography top index is already calculated.
666	IF ( TRIM( topography ) /= 'flat' ) THEN
667	#if defined( __parallel )
668	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), nzb_local_max, 1, &
669	MPI_INTEGER, MPI_MAX, comm2d, ierr )
670	#else
671	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
672	#endif
673	nzb_local_min = topo_min_level
674	!
675	!-- Consistency checks
676	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
677	WRITE( message_string, * ) 'nzb_local values are outside the model domain', &
678	'&MINVAL( nzb_local ) = ', nzb_local_min, &
679	'&MAXVAL( nzb_local ) = ', nzb_local_max
680	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
681	ENDIF
682	ENDIF
683	!
684	!-- Define vertical gridpoint from (or to) which on the usual finite difference form (which does not
685	!-- use surface fluxes) is applied.
686	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
687	nzb_diff = nzb + 2
688	ELSE
689	nzb_diff = nzb + 1
690	ENDIF
691
692	IF ( TRIM( topography ) /= 'flat' ) THEN
693	!
694	!-- Allocate and set the arrays containing the topography height (for output reasons only).
695	IF ( nxr == nx .AND. nyn /= ny ) THEN
696	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), zw_w_inner(nxl:nxr+1,nys:nyn) )
697	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
698	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), zw_w_inner(nxl:nxr,nys:nyn+1) )
699	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
700	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), zw_w_inner(nxl:nxr+1,nys:nyn+1) )
701	ELSE
702	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), zw_w_inner(nxl:nxr,nys:nyn) )
703	ENDIF
704
705	zu_s_inner = 0.0_wp
706	zw_w_inner = 0.0_wp
707	!
708	!-- Determine local topography height on scalar and w-grid. Note, setting lateral boundary values
709	!-- is not necessary, realized via wall_flags_static_0 array. Further, please note that loop
710	!-- bounds are different from nxl to nxr and nys to nyn on south and right model boundary, hence,
711	!-- use intrinsic lbound and ubound functions to infer array bounds.
712	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
713	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
714	!
715	!-- Topography height on scalar grid. Therefore, determine index of upward-facing surface
716	!-- element on scalar grid.
717	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
718	!
719	!-- Topography height on w grid. Therefore, determine index of upward-facing surface
720	!-- element on w grid.
721	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
722	ENDDO
723	ENDDO
724	ENDIF
725
726	END SUBROUTINE init_grid
727
728
729	! Description:
730	! -------------------------------------------------------------------------------------------------!
731	!> Calculation of the stretching factor through an iterative method. Ideas were taken from the paper
732	!> "Regional stretched grid generation and its application to the NCAR RegCM (1999)". Normally, no
733	!> analytic solution exists because the system of equations has two variables (r,l) but four
734	!> requirements (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which results into
735	!> an overdetermined system.
736	!--------------------------------------------------------------------------------------------------!
737	SUBROUTINE calculate_stretching_factor( number_end )
738
739	USE control_parameters, &
740	ONLY: dz, dz_stretch_factor_array, dz_stretch_level_end, dz_stretch_level_start, &
741	message_string
742
743	USE kinds
744
745	IMPLICIT NONE
746
747	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06_wp !< interval for sampling possible stretching factors
748	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88_wp !< lowest possible stretching factor
749	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12_wp !< highest possible stretching factor
750
751	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
752	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
753	INTEGER(iwp) :: n !< loop variable for stretching
754
755	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
756
757	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
758	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
759	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as
760	!< possible)
761	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
762	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
763	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1
764	!< exactly
765	REAL(wp) :: numerator !< numerator of the quotient
766	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
767	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
768
769	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to
770	!< stretch_factor_1
771
772
773	l = 0
774	DO n = 1, number_end
775
776	iterations = 1
777	stretch_factor_1 = 1.0_wp
778	stretch_factor_2 = 1.0_wp
779	delta_total_old = 1.0_wp
780
781	!
782	!-- First branch for stretching from rough to fine
783	IF ( dz(n) > dz(n+1) ) THEN
784	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
785
786	stretch_factor_1 = 1.0_wp - iterations * stretch_factor_interval
787	distance = ABS( dz_stretch_level_end(n) - dz_stretch_level_start(n) )
788	numerator = distance * stretch_factor_1 / dz(n) + stretch_factor_1 - distance / dz(n)
789
790	IF ( numerator > 0.0_wp ) THEN
791	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
792	l_rounded = NINT( l )
793	delta_l = ABS( l_rounded - l ) / l
794	ENDIF
795
796	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
797
798	delta_stretch_factor = ABS( stretch_factor_1 - stretch_factor_2 ) / stretch_factor_2
799
800	delta_total_new = delta_l + delta_stretch_factor
801
802	!
803	!-- stretch_factor_1 is taken to guarantee that the stretching procedure ends as close as
804	!-- possible to dz_stretch_level_end.
805	!-- stretch_factor_2 would guarantee that the stretched dz(n) is equal to dz(n+1) after
806	!-- l_rounded grid levels.
807	IF (delta_total_new < delta_total_old) THEN
808	dz_stretch_factor_array(n) = stretch_factor_1
809	dz_stretch_factor_array_2(n) = stretch_factor_2
810	delta_total_old = delta_total_new
811	ENDIF
812
813	iterations = iterations + 1
814
815	ENDDO
816
817	!
818	!-- Second branch for stretching from fine to rough
819	ELSEIF ( dz(n) < dz(n+1) ) THEN
820	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
821
822	stretch_factor_1 = 1.0_wp + iterations * stretch_factor_interval
823	distance = ABS( dz_stretch_level_end(n) - dz_stretch_level_start(n) )
824	numerator = distance * stretch_factor_1 / dz(n) + stretch_factor_1 - distance / dz(n)
825
826	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
827	l_rounded = NINT( l )
828	delta_l = ABS( l_rounded - l ) / l
829
830	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
831
832	delta_stretch_factor = ABS( stretch_factor_1 - stretch_factor_2 ) / stretch_factor_2
833
834	delta_total_new = delta_l + delta_stretch_factor
835
836	!
837	!-- stretch_factor_1 is taken to guarantee that the stretching procedure ends as close as
838	!-- possible to dz_stretch_level_end.
839	!-- stretch_factor_2 would guarantee that the stretched dz(n) is equal to dz(n+1) after
840	!-- l_rounded grid levels.
841	IF (delta_total_new < delta_total_old) THEN
842	dz_stretch_factor_array(n) = stretch_factor_1
843	dz_stretch_factor_array_2(n) = stretch_factor_2
844	delta_total_old = delta_total_new
845	ENDIF
846
847	iterations = iterations + 1
848	ENDDO
849
850	ELSE
851	message_string= 'Two adjacent values of dz must be different'
852	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
853
854	ENDIF
855
856	!
857	!-- Check if also the second stretching factor fits into the allowed interval. If not, print a
858	!-- warning for the user.
859	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
860	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
861	WRITE( message_string, * ) 'stretch_factor_2 = ', dz_stretch_factor_array_2(n), &
862	' which is', ' responsible for exactly reaching& dz =', &
863	dz(n+1), 'after a specific amount of', &
864	' grid levels& exceeds the upper', &
865	' limit =', stretch_factor_upper_limit, &
866	' &or lower limit = ', stretch_factor_lower_limit
867	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
868
869	ENDIF
870	ENDDO
871
872	END SUBROUTINE calculate_stretching_factor
873
874
875	! Description:
876	! -------------------------------------------------------------------------------------------------!
877	!> Set temporary topography flags and reference buildings on top of underlying orography.
878	!--------------------------------------------------------------------------------------------------!
879	SUBROUTINE process_topography( topo_3d )
880
881	USE arrays_3d, &
882	ONLY: zu, zw
883
884	USE control_parameters, &
885	ONLY: bc_lr_cyc, bc_ns_cyc, ocean_mode
886
887	USE exchange_horiz_mod, &
888	ONLY: exchange_horiz_2d, exchange_horiz_int
889
890	USE indices, &
891	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
892
893	USE netcdf_data_input_mod, &
894	ONLY: buildings_f, building_id_f, building_type_f, &
895	init_model, &
896	input_pids_static, &
897	terrain_height_f
898
899	USE kinds
900
901	USE pegrid
902
903	IMPLICIT NONE
904
905	INTEGER(iwp) :: i !< running index along x-direction
906	INTEGER(iwp) :: j !< running index along y-direction
907	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
908	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
909	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
910	INTEGER(iwp) :: num_build !< counter for number of buildings
911	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
912
913	#if defined( __parallel )
914	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
915	#endif
916	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
917	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are
918	!< sorted out
919	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
920	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
921	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
922
923	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
924	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
925
926	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting
927	!< "outer"-flags
928
929	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography
930	!< definition
931	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference
932	!< terrain to zero
933	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
934	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id,
935	!< on local subdomain
936
937	!
938	!-- Reference lowest terrain height to zero. This ensures that first, non-required gird levels
939	!-- (those which lie entirely below the minimum orography) are avoided, and second, that also
940	!-- negative orography can be used within the input file.
941	!-- Please note, in case of a nested run, the global minimum from all parent and childs needs to be
942	!-- removed to avoid steep edges at the child-domain boundaries.
943	IF ( input_pids_static ) THEN
944
945	#if defined( __parallel )
946	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, MPI_REAL, MPI_MIN, &
947	MPI_COMM_WORLD, ierr )
948	#else
949	oro_min = MINVAL( terrain_height_f%var )
950	#endif
951	terrain_height_f%var = terrain_height_f%var - oro_min
952	!
953	!-- Update reference height used within output files
954	init_model%origin_z = init_model%origin_z + oro_min
955	!
956	!-- ASCII topography branch. In this case, in contrast to the static driver input, topography is
957	!-- assumed to be building; thus the minimum building height is substracted from the building array.
958	ELSE
959	#if defined( __parallel )
960	CALL MPI_ALLREDUCE( MINVAL( buildings_f%var_2d ), oro_min, 1, MPI_REAL, MPI_MIN, &
961	MPI_COMM_WORLD, ierr )
962	#else
963	oro_min = MINVAL( buildings_f%var_2d )
964	#endif
965	buildings_f%var_2d = buildings_f%var_2d - oro_min
966	!
967	!-- Update reference height used within output files
968	init_model%origin_z = init_model%origin_z + oro_min
969	ENDIF
970
971	!
972	!-- In the following, buildings and orography are further preprocessed before they are mapped on the
973	!-- LES grid.
974	!-- Buildings are mapped on top of the orography by maintaining the roof shape of the building. This
975	!-- can be achieved by referencing building on top of the maximum terrain height within the area
976	!-- occupied by the respective building. As buildings and terrain height are defined PE-wise,
977	!-- parallelization of this referencing is required (a building can be distributed between different
978	!-- PEs).
979	!-- In a first step, determine the number of buildings with different building id on each PE. In a
980	!-- next step, all building ids are gathered into one array which is present to all PEs. For each
981	!-- building ID, the maximum terrain height occupied by the respective building is computed and
982	!-- distributed to each PE.
983	!-- Finally, for each building id and its respective reference orography, builidings are mapped on
984	!-- top.
985	!--
986	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2 buildings classify the
987	!-- respective surfaces.
988	topo_3d = IBSET( topo_3d, 0 )
989	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
990	!
991	!-- In order to map topography on PALM grid also in case of ocean simulations, pre-calculate an
992	!-- offset value.
993	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
994	!
995	!-- Reference buildings on top of orography. This is not necessary if topography is read from ASCII
996	!-- file as no distinction between buildings and terrain height can be made. Moreover, this is also
997	!-- not necessary if urban-surface and land-surface model are used at the same time.
998	IF ( input_pids_static ) THEN
999
1000	IF ( buildings_f%from_file ) THEN
1001	num_buildings_l = 0
1002	num_buildings = 0
1003	!
1004	!-- Allocate at least one element for building ids and give it an inital negative value that
1005	!-- will be overwritten later. This, however, is necessary in case there all IDs in the model
1006	!-- domain are fill values.
1007	ALLOCATE( build_ids_l(1) )
1008	build_ids_l = -1
1009	DO i = nxl, nxr
1010	DO j = nys, nyn
1011	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1012	IF ( num_buildings_l(myid) > 0 ) THEN
1013	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) THEN
1014	CYCLE
1015	ELSE
1016	num_buildings_l(myid) = num_buildings_l(myid) + 1
1017	!
1018	!-- Resize array with different local building ids
1019	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
1020	build_ids_l_tmp = build_ids_l
1021	DEALLOCATE( build_ids_l )
1022	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
1023	build_ids_l(1:num_buildings_l(myid)-1) = &
1024	build_ids_l_tmp(1:num_buildings_l(myid)-1)
1025	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
1026	DEALLOCATE( build_ids_l_tmp )
1027	ENDIF
1028	!
1029	!-- First occuring building id on PE
1030	ELSE
1031	num_buildings_l(myid) = num_buildings_l(myid) + 1
1032	build_ids_l(1) = building_id_f%var(j,i)
1033	ENDIF
1034	ENDIF
1035	ENDDO
1036	ENDDO
1037	!
1038	!-- Determine number of different building ids for the entire domain
1039	#if defined( __parallel )
1040	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, MPI_INTEGER, MPI_SUM, &
1041	comm2d, ierr )
1042	#else
1043	num_buildings = num_buildings_l
1044	#endif
1045	!
1046	!-- Gather all buildings ids on each PEs.
1047	!-- First, allocate array encompassing all building ids in model domain.
1048	ALLOCATE( build_ids(1:SUM(num_buildings)) )
1049	#if defined( __parallel )
1050	!
1051	!-- Allocate array for displacements.
1052	!-- As each PE may has a different number of buildings, so that the block sizes send by each
1053	!-- PE may not be equal. Hence, information about the respective displacement is required,
1054	!-- indicating the respective adress where each MPI-task writes into the receive buffer array.
1055	ALLOCATE( displace_dum(0:numprocs-1) )
1056	displace_dum(0) = 0
1057	DO i = 1, numprocs-1
1058	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
1059	ENDDO
1060
1061	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), num_buildings(myid), &
1062	MPI_INTEGER, build_ids, num_buildings, displace_dum, MPI_INTEGER, &
1063	comm2d, ierr )
1064
1065	DEALLOCATE( displace_dum )
1066
1067	#else
1068	build_ids = build_ids_l
1069	#endif
1070
1071	!
1072	!-- Note, in parallel mode building ids can occure mutliple times, as each PE has send its own
1073	!-- ids. Therefore, sort out building ids which appear more than one time.
1074	num_build = 0
1075	DO nr = 1, SIZE(build_ids)
1076
1077	IF ( ALLOCATED(build_ids_final) ) THEN
1078	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
1079	CYCLE
1080	ELSE
1081	num_build = num_build + 1
1082	!
1083	!-- Resize
1084	ALLOCATE( build_ids_final_tmp(1:num_build) )
1085	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
1086	DEALLOCATE( build_ids_final )
1087	ALLOCATE( build_ids_final(1:num_build) )
1088	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
1089	build_ids_final(num_build) = build_ids(nr)
1090	DEALLOCATE( build_ids_final_tmp )
1091	ENDIF
1092	ELSE
1093	num_build = num_build + 1
1094	ALLOCATE( build_ids_final(1:num_build) )
1095	build_ids_final(num_build) = build_ids(nr)
1096	ENDIF
1097	ENDDO
1098
1099	!
1100	!-- Determine maximumum terrain height occupied by the respective building and temporalily
1101	!-- store on oro_max.
1102	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
1103	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
1104	oro_max_l = 0.0_wp
1105
1106	DO nr = 1, SIZE(build_ids_final)
1107	oro_max_l(nr) = MAXVAL( MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
1108	0.0_wp, &
1109	building_id_f%var(nys:nyn,nxl:nxr) == &
1110	build_ids_final(nr) ) )
1111	ENDDO
1112
1113	#if defined( __parallel )
1114	IF ( SIZE(build_ids_final) >= 1 ) THEN
1115	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL, MPI_MAX, comm2d, &
1116	ierr )
1117	ENDIF
1118	#else
1119	oro_max = oro_max_l
1120	#endif
1121	!
1122	!-- Finally, determine discrete grid height of maximum orography occupied by a building. Use
1123	!-- all-or-nothing approach, i.e. if terrain exceeds the scalar level the grid box is fully
1124	!-- terrain and the maximum terrain is set to the zw level.
1125	!-- terrain or
1126	oro_max_l = 0.0
1127	DO nr = 1, SIZE(build_ids_final)
1128	DO k = nzb, nzt
1129	IF ( zu(k) - ocean_offset <= oro_max(nr) ) oro_max_l(nr) = zw(k) - ocean_offset
1130	ENDDO
1131	oro_max(nr) = oro_max_l(nr)
1132	ENDDO
1133	ENDIF
1134	!
1135	!-- Allocate array for storing terrain height under buildings
1136	IF ( buildings_f%from_file ) THEN
1137	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
1138	buildings_f%oro_max = buildings_f%fill1
1139	END IF
1140	!
1141	!-- Map orography as well as buildings onto grid.
1142	DO i = nxl, nxr
1143	DO j = nys, nyn
1144	topo_top_index = 0
1145	!
1146	!-- Obtain index in global building_id array
1147	IF ( buildings_f%from_file ) THEN
1148	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1149	!
1150	!-- Determine index where maximum terrain height occupied by the respective building
1151	!-- height is stored.
1152	nr = MINLOC( ABS( build_ids_final - building_id_f%var(j,i) ), DIM=1 )
1153	!
1154	!-- Save grid-indexed oro_max
1155	buildings_f%oro_max(j,i) = oro_max(nr)
1156	ENDIF
1157	ENDIF
1158	DO k = nzb, nzt
1159	!
1160	!-- In a first step, if grid point is below or equal the given terrain height, grid
1161	!-- point is flagged to be of type natural.
1162	!-- Please note, in case there is also a building which is lower than the vertical grid
1163	!-- spacing, initialization of surface attributes will not be correct as given surface
1164	!-- information will not be in accordance to the classified grid points.
1165	!-- Hence, in this case, also a building flag.
1166	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
1167	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1168	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1169	topo_top_index = k ! topo_top_index + 1
1170	ENDIF
1171	!
1172	!-- Set building grid points. Here, only consider 2D buildings.
1173	!-- 3D buildings require separate treatment.
1174	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
1175	!
1176	!-- Fill-up the terrain to the level of maximum orography within the building-covered
1177	!-- area.
1178	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1179	!
1180	!-- Note, oro_max is always on zw level
1181	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
1182	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1183	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1184	ELSEIF ( zu(k) - ocean_offset <= oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
1185	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1186	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1187	ENDIF
1188	ENDIF
1189	ENDIF
1190	ENDDO
1191	!
1192	!-- Special treatment for non grid-resolved buildings. This case, the uppermost terrain
1193	!-- grid point is flagged as building as well, even though no building exists at all.
1194	!-- However, the surface element will be identified as urban-surface and the input data
1195	!-- provided by the drivers is consistent to the surface classification. Else, all non
1196	!-- grid-resolved buildings would vanish and identified as terrain grid points, which,
1197	!-- however, won't be consistent with the input data.
1198	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
1199	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1200	DO k = nzb, nzt
1201	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
1202	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
1203	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1204	ENDIF
1205	ENDIF
1206	ENDDO
1207	ENDIF
1208	ENDIF
1209	!
1210	!-- Map 3D buildings onto terrain height.
1211	!-- In case of any slopes, map building on top of maximum terrain height covered by the
1212	!-- building. In other words, extend building down to the respective local terrain-surface
1213	!-- height.
1214	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
1215	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
1216	!
1217	!-- Extend building down to the terrain surface, i.e. fill-up surface irregularities
1218	!-- below a building. Note, oro_max is already a discrete height according to the
1219	!-- all-or-nothing approach, i.e. grid box is either topography or atmosphere,
1220	!-- terrain top is defined at upper bound of the grid box.
1221	!-- Hence, check for zw in this case.
1222	!-- Note, do this only for buildings which are surface mounted, i.e. building types
1223	!-- 1-6. Below bridges, which are represented exclusively by building type 7, terrain
1224	!-- shape should be maintained.
1225	IF ( building_type_f%from_file ) THEN
1226	IF ( building_type_f%var(j,i) /= 7 ) THEN
1227	DO k = topo_top_index + 1, nzt + 1
1228	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
1229	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1230	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1231	ENDIF
1232	ENDDO
1233	!
1234	!-- After surface irregularities are smoothen, determine lower start index
1235	!-- where building starts.
1236	DO k = nzb, nzt
1237	IF ( zu(k) - ocean_offset <= oro_max(nr) ) topo_top_index = k
1238	ENDDO
1239	ENDIF
1240	ENDIF
1241	!
1242	!-- Finally, map building on top.
1243	k2 = 0
1244	DO k = topo_top_index, nzt + 1
1245	IF ( k2 <= buildings_f%nz-1 ) THEN
1246	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
1247	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1248	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1249	ENDIF
1250	ENDIF
1251	k2 = k2 + 1
1252	ENDDO
1253	ENDIF
1254	ENDIF
1255	ENDDO
1256	ENDDO
1257	!
1258	!-- Horizontal exchange the oro_max array, which is required to for initialization of
1259	!-- building-surface properties.
1260	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
1261	CALL exchange_horiz_2d( buildings_f%oro_max(:,:) )
1262	ENDIF
1263	!
1264	!-- Deallocate temporary arrays required for processing and reading data
1265	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
1266	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
1267	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
1268	!
1269	!-- Topography input via ASCII format.
1270	ELSE
1271	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
1272	!
1273	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero and clear all grid points
1274	!-- at nzb, where alway a surface is defined.
1275	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further used for masked data
1276	!-- output and further processing. Note, in the ASCII case no distinction is made between
1277	!-- buildings and terrain, so that setting of bit 1 and 2 at the same time has no effect.
1278	topo_3d = IBSET( topo_3d, 0 )
1279	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
1280	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
1281	DO i = nxl, nxr
1282	DO j = nys, nyn
1283	DO k = nzb, nzt
1284	!
1285	!-- Flag topography for all grid points which are below the local topography height.
1286	!-- Note, each topography is flagged as building (bit 2) as well as terrain (bit 1) in
1287	!-- order to employ urban-surface as well as land-surface model.
1288	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
1289	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1290	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 1 )
1291	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1292	ENDIF
1293	ENDDO
1294	ENDDO
1295	ENDDO
1296	ENDIF
1297
1298	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1299
1300	IF ( .NOT. bc_ns_cyc ) THEN
1301	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
1302	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
1303	ENDIF
1304
1305	IF ( .NOT. bc_lr_cyc ) THEN
1306	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
1307	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
1308	ENDIF
1309
1310	END SUBROUTINE process_topography
1311
1312
1313	! Description:
1314	! -------------------------------------------------------------------------------------------------!
1315	!> Filter topography, i.e. fill holes resolved by only one grid point.
1316	!> Such holes are suspected to lead to velocity blow-ups as continuity equation on discrete grid
1317	!> cannot be fulfilled in such case.
1318	!--------------------------------------------------------------------------------------------------!
1319	SUBROUTINE filter_topography( topo_3d )
1320
1321	USE control_parameters, &
1322	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
1323
1324	USE exchange_horiz_mod, &
1325	ONLY: exchange_horiz_int, exchange_horiz_2d_byte, exchange_horiz_2d_int
1326
1327	USE indices, &
1328	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
1329
1330	USE netcdf_data_input_mod, &
1331	ONLY: building_id_f, building_type_f
1332
1333	USE pegrid
1334
1335	IMPLICIT NONE
1336
1337	INTEGER(iwp) :: i !< running index along x-direction
1338	INTEGER(iwp) :: j !< running index along y-direction
1339	INTEGER(iwp) :: k !< running index along z-direction
1340	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
1341	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
1342	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
1343
1344	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
1345	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and
1346	!< orography
1347
1348	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
1349
1350	!
1351	!-- Before checking for holes, set lateral boundary conditions for
1352	!-- topography. After hole-filling, boundary conditions must be set again.
1353	!-- Several iterations are performed, in order to fill holes which might
1354	!-- emerge by the filling-algorithm itself.
1355	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
1356	topo_tmp = 0
1357
1358	num_hole = 99999
1359	DO WHILE ( num_hole > 0 )
1360
1361	num_hole = 0
1362	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1363	!
1364	!-- Exchange also building ID and type. Note, building_type is an one-byte variable.
1365	IF ( building_id_f%from_file ) &
1366	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
1367	IF ( building_type_f%from_file ) &
1368	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
1369
1370	topo_tmp = topo_3d
1371	!
1372	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be a solid wall. Thus,
1373	!-- intermediate spaces of one grid point between boundary and some topographic structure will be
1374	!-- filled.
1375	IF ( .NOT. bc_ns_cyc ) THEN
1376	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
1377	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
1378	ENDIF
1379
1380	IF ( .NOT. bc_lr_cyc ) THEN
1381	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
1382	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
1383	ENDIF
1384
1385	num_hole_l = 0
1386	DO i = nxl, nxr
1387	DO j = nys, nyn
1388	DO k = nzb+1, nzt
1389	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
1390	num_wall = 0
1391	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) num_wall = num_wall + 1
1392	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) num_wall = num_wall + 1
1393	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) num_wall = num_wall + 1
1394	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) num_wall = num_wall + 1
1395	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) num_wall = num_wall + 1
1396	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) num_wall = num_wall + 1
1397
1398	IF ( num_wall >= 4 ) THEN
1399	num_hole_l = num_hole_l + 1
1400	!
1401	!-- Clear flag 0 and set special flag ( bit 4) to indicate that new topography
1402	!-- point is a result of filtering process.
1403	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
1404	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
1405	!
1406	!-- If filled grid point is occupied by a building, classify it as building grid
1407	!-- point.
1408	IF ( building_type_f%from_file ) THEN
1409	IF ( building_type_f%var(j,i) /= building_type_f%fill .OR. &
1410	building_type_f%var(j+1,i) /= building_type_f%fill .OR. &
1411	building_type_f%var(j-1,i) /= building_type_f%fill .OR. &
1412	building_type_f%var(j,i+1) /= building_type_f%fill .OR. &
1413	building_type_f%var(j,i-1) /= building_type_f%fill ) THEN
1414	!
1415	!-- Set flag indicating building surfaces
1416	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
1417	!
1418	!-- Set building_type and ID at this position if not already set. This is
1419	!-- required for proper initialization of urban-surface energy balance
1420	!-- solver.
1421	IF ( building_type_f%var(j,i) == building_type_f%fill ) THEN
1422
1423	IF ( building_type_f%var(j+1,i) /= building_type_f%fill ) THEN
1424	building_type_f%var(j,i) = building_type_f%var(j+1,i)
1425	building_id_f%var(j,i) = building_id_f%var(j+1,i)
1426	ELSEIF ( building_type_f%var(j-1,i) /= building_type_f%fill ) THEN
1427	building_type_f%var(j,i) = building_type_f%var(j-1,i)
1428	building_id_f%var(j,i) = building_id_f%var(j-1,i)
1429	ELSEIF ( building_type_f%var(j,i+1) /= building_type_f%fill ) THEN
1430	building_type_f%var(j,i) = building_type_f%var(j,i+1)
1431	building_id_f%var(j,i) = building_id_f%var(j,i+1)
1432	ELSEIF ( building_type_f%var(j,i-1) /= building_type_f%fill ) THEN
1433	building_type_f%var(j,i) = building_type_f%var(j,i-1)
1434	building_id_f%var(j,i) = building_id_f%var(j,i-1)
1435	ENDIF
1436	ENDIF
1437	ENDIF
1438	ENDIF
1439	!
1440	!-- If filled grid point is already classified as building everything is fine,
1441	!-- else classify this grid point as natural type grid point. This case, values
1442	!-- for the surface type are already set.
1443	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
1444	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
1445	ENDIF
1446	ENDIF
1447	ENDIF
1448	ENDDO
1449	ENDDO
1450	ENDDO
1451	!
1452	!-- Count the total number of holes, required for informative message.
1453	#if defined( __parallel )
1454	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, comm2d, ierr )
1455	#else
1456	num_hole = num_hole_l
1457	#endif
1458	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
1459
1460	ENDDO
1461	!
1462	!-- Create an informative message if any holes were filled.
1463	IF ( filled ) THEN
1464	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
1465	'resolved by only one grid point ' // &
1466	'were filled during initialization.'
1467	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
1468	ENDIF
1469
1470	DEALLOCATE( topo_tmp )
1471	!
1472	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary condition in case of
1473	!-- non-cyclic lateral boundaries.
1474	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
1475
1476	IF ( .NOT. bc_ns_cyc ) THEN
1477	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
1478	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
1479	ENDIF
1480
1481	IF ( .NOT. bc_lr_cyc ) THEN
1482	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
1483	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
1484	ENDIF
1485	!
1486	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
1487	IF ( building_id_f%from_file ) &
1488	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
1489	IF ( building_type_f%from_file ) &
1490	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
1491
1492	END SUBROUTINE filter_topography
1493
1494
1495	! Description:
1496	! -------------------------------------------------------------------------------------------------!
1497	!> Reads topography information from file or sets generic topography. Moreover, all
1498	!> topography-relevant topography arrays are initialized, and grid flags are set.
1499	!--------------------------------------------------------------------------------------------------!
1500	SUBROUTINE init_topo( topo )
1501
1502	USE arrays_3d, &
1503	ONLY: zw
1504
1505	USE control_parameters, &
1506	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, building_length_y, &
1507	building_wall_left, building_wall_south, canyon_height, canyon_wall_left, &
1508	canyon_wall_south, canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
1509	message_string, topography, topography_grid_convention, tunnel_height, &
1510	tunnel_length, tunnel_width_x, tunnel_width_y, tunnel_wall_depth
1511
1512	USE exchange_horiz_mod, &
1513	ONLY: exchange_horiz_int
1514
1515	USE grid_variables, &
1516	ONLY: dx, dy
1517
1518	USE indices, &
1519	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, nzb, nzt
1520
1521	USE kinds
1522
1523	USE netcdf_data_input_mod, &
1524	ONLY: buildings_f, terrain_height_f
1525
1526	USE pegrid
1527
1528	IMPLICIT NONE
1529
1530	INTEGER(iwp) :: bh !< temporary vertical index of building height
1531	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
1532	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
1533	INTEGER(iwp) :: i !< index variable along x
1534	INTEGER(iwp) :: index_left_bwall !< index for left building wall
1535	INTEGER(iwp) :: index_north_bwall !< index for north building wall
1536	INTEGER(iwp) :: index_right_bwall !< index for right building wall
1537	INTEGER(iwp) :: index_south_bwall !< index for south building wall
1538	INTEGER(iwp) :: index_left_cwall !< index for left canyon wall
1539	INTEGER(iwp) :: index_north_cwall !< index for north canyon wall
1540	INTEGER(iwp) :: index_right_cwall !< index for right canyon wall
1541	INTEGER(iwp) :: index_south_cwall !< index for south canyon wall
1542	INTEGER(iwp) :: j !< index variable along y
1543	INTEGER(iwp) :: k !< index variable along z
1544	INTEGER(iwp) :: ngp_bx !< grid point number of building size along x
1545	INTEGER(iwp) :: ngp_by !< grid point number of building size along y
1546	INTEGER(iwp) :: ngp_cx !< grid point number of canyon size along x
1547	INTEGER(iwp) :: ngp_cy !< grid point number of canyon size along y
1548	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
1549	INTEGER(iwp) :: td !< tunnel wall depth
1550	INTEGER(iwp) :: th !< height of outer tunnel wall
1551	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
1552	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
1553	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
1554	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
1555	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
1556	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
1557	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
1558	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
1559
1560	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
1561	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting
1562	!< "outer"-flags
1563	!
1564	!-- Check for correct setting of the namelist parameter topography. If topography information is
1565	!-- read from file but topography = 'flat', initialization does not work properly.
1566	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
1567	TRIM( topography ) /= 'read_from_file' ) THEN
1568	message_string = 'If topography information is provided (via ' // &
1569	'Netcdf or ASCII input) topography = ' // &
1570	'"read_from_file" is required.'
1571	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
1572	ENDIF
1573	!
1574	!-- Set outer and inner index arrays for non-flat topography.
1575	!-- Here consistency checks concerning domain size and periodicity are necessary.
1576	!-- Within this SELECT CASE structure only nzb_local is initialized individually depending on the
1577	!-- chosen topography type, all other index arrays are initialized further below.
1578	SELECT CASE ( TRIM( topography ) )
1579
1580	CASE ( 'flat' )
1581	!
1582	!-- Initialilize 3D topography array, used later for initializing flags
1583	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
1584
1585	CASE ( 'closed_channel' )
1586	!
1587	!-- Initialilize 3D topography array, used later for initializing flags
1588	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
1589
1590	CASE ( 'single_building' )
1591	!
1592	!-- Single rectangular building, by default centered in the middle of the
1593	!-- total domain
1594	ngp_bx = NINT( building_length_x / dx )
1595	ngp_by = NINT( building_length_y / dy )
1596	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
1597	IF ( ABS( zw(bh) - building_height ) == ABS( zw(bh+1) - building_height ) ) bh = bh + 1
1598	IF ( building_wall_left == 9999999.9_wp ) THEN
1599	building_wall_left = ( nx + 1 - ngp_bx ) / 2 * dx
1600	ENDIF
1601	index_left_bwall = NINT( building_wall_left / dx )
1602	index_right_bwall = index_left_bwall + ngp_bx
1603
1604	IF ( building_wall_south == 9999999.9_wp ) THEN
1605	building_wall_south = ( ny + 1 - ngp_by ) / 2 * dy
1606	ENDIF
1607	index_south_bwall = NINT( building_wall_south / dy )
1608	index_north_bwall = index_south_bwall + ngp_by
1609
1610	!
1611	!-- Building size has to meet some requirements
1612	IF ( ( index_left_bwall < 1 ) .OR. ( index_right_bwall > nx-1 ) .OR. &
1613	( index_right_bwall < index_left_bwall+3 ) .OR. &
1614	( index_south_bwall < 1 ) .OR. ( index_north_bwall > ny-1 ) .OR. &
1615	( index_north_bwall < index_south_bwall+3 ) ) THEN
1616	WRITE( message_string, * ) 'inconsistent building parameters:', &
1617	'&index_left_bwall=', index_left_bwall, &
1618	'index_right_bwall=', index_right_bwall, &
1619	'index_south_bwall=', index_south_bwall, &
1620	'index_north_bwall=', index_north_bwall, &
1621	'nx=', nx, 'ny=', ny
1622	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
1623	ENDIF
1624
1625	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
1626	nzb_local = 0
1627	!
1628	!-- Define the building.
1629	IF ( index_left_bwall <= nxr .AND. index_right_bwall >= nxl .AND. &
1630	index_south_bwall <= nyn .AND. index_north_bwall >= nys ) &
1631	nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall), &
1632	MAX(nxl,index_left_bwall):MIN(nxr,index_right_bwall)) = bh
1633	!
1634	!-- Set bit array on basis of nzb_local
1635	DO i = nxl, nxr
1636	DO j = nys, nyn
1637	topo(nzb_local(j,i)+1:nzt+1,j,i) = IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
1638	ENDDO
1639	ENDDO
1640
1641	DEALLOCATE( nzb_local )
1642
1643	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1644	!
1645	!-- Set boundary conditions also for flags. Can be interpreted as Neumannb oundary conditions
1646	!-- for topography.
1647	IF ( .NOT. bc_ns_cyc ) THEN
1648	IF ( nys == 0 ) THEN
1649	DO i = 1, nbgp
1650	topo(:,nys-i,:) = topo(:,nys,:)
1651	ENDDO
1652	ENDIF
1653	IF ( nyn == ny ) THEN
1654	DO i = 1, nbgp
1655	topo(:,nyn+i,:) = topo(:,nyn,:)
1656	ENDDO
1657	ENDIF
1658	ENDIF
1659	IF ( .NOT. bc_lr_cyc ) THEN
1660	IF ( nxl == 0 ) THEN
1661	DO i = 1, nbgp
1662	topo(:,:,nxl-i) = topo(:,:,nxl)
1663	ENDDO
1664	ENDIF
1665	IF ( nxr == nx ) THEN
1666	DO i = 1, nbgp
1667	topo(:,:,nxr+i) = topo(:,:,nxr)
1668	ENDDO
1669	ENDIF
1670	ENDIF
1671
1672	CASE ( 'single_street_canyon' )
1673	!
1674	!-- Single quasi-2D street canyon of infinite length in x or y direction.
1675	!-- The canyon is centered in the other direction by default.
1676	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1677	!
1678	!-- Street canyon in y direction
1679	ngp_cx = NINT( canyon_width_x / dx )
1680	IF ( canyon_wall_left == 9999999.9_wp ) THEN
1681	canyon_wall_left = ( nx + 1 - ngp_cx ) / 2 * dx
1682	ENDIF
1683	index_left_cwall= NINT( canyon_wall_left / dx )
1684	index_right_cwall= index_left_cwall+ ngp_cx
1685	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1686	!
1687	!-- Street canyon in x direction
1688	ngp_cy = NINT( canyon_width_y / dy )
1689	IF ( canyon_wall_south == 9999999.9_wp ) THEN
1690	canyon_wall_south = ( ny + 1 - ngp_cy ) / 2 * dy
1691	ENDIF
1692	index_south_cwall = NINT( canyon_wall_south / dy )
1693	index_north_cwall = index_south_cwall + ngp_cy
1694
1695	ELSE
1696
1697	message_string = 'no street canyon width given'
1698	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
1699
1700	ENDIF
1701
1702	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
1703	IF ( ABS( zw(ch) - canyon_height ) == ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
1704	dp_level_ind_b = ch
1705	!
1706	!-- Street canyon size has to meet some requirements
1707	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1708	IF ( ( index_left_cwall< 1 ) .OR. ( index_right_cwall> nx-1 ) .OR. &
1709	( ngp_cx < 3 ) ) THEN
1710	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
1711	'&index_left_cwall=', index_left_cwall, &
1712	' index_right_cwall=', index_right_cwall, &
1713	' ngp_cx=', ngp_cx, ' ch=', ch, ' nx=', nx, ' ny=', ny
1714	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
1715	ENDIF
1716	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1717	IF ( ( index_south_cwall < 1 ) .OR. &
1718	( index_north_cwall > ny-1 ) .OR. ( ngp_cy < 3 ) ) THEN
1719	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
1720	'&index_south_cwall=', index_south_cwall, &
1721	' index_north_cwall=', index_north_cwall, &
1722	' ngp_cy=', ngp_cy, ' ch=', ch, ' nx=', nx, ' ny=', ny
1723	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
1724	ENDIF
1725	ENDIF
1726	IF ( canyon_width_x /= 9999999.9_wp .AND. canyon_width_y /= 9999999.9_wp ) THEN
1727	message_string = 'inconsistent canyon parameters:' // &
1728	'&street canyon can only be oriented' // &
1729	' either in x- or in y-direction'
1730	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
1731	ENDIF
1732
1733	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
1734	nzb_local = ch
1735	IF ( canyon_width_x /= 9999999.9_wp ) THEN
1736	IF ( index_left_cwall<= nxr .AND. index_right_cwall>= nxl ) &
1737	nzb_local(:,MAX(nxl,index_left_cwall+1):MIN(nxr,index_right_cwall-1)) = 0
1738	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
1739	IF ( index_south_cwall <= nyn .AND. index_north_cwall >= nys ) &
1740	nzb_local(MAX(nys,index_south_cwall+1):MIN(nyn,index_north_cwall-1),:) = 0
1741	ENDIF
1742	!
1743	!-- Set bit array on basis of nzb_local
1744	DO i = nxl, nxr
1745	DO j = nys, nyn
1746	topo(nzb_local(j,i)+1:nzt+1,j,i) = IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
1747	ENDDO
1748	ENDDO
1749	DEALLOCATE( nzb_local )
1750
1751	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1752	!
1753	!-- Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions
1754	!-- for topography.
1755	IF ( .NOT. bc_ns_cyc ) THEN
1756	IF ( nys == 0 ) THEN
1757	DO i = 1, nbgp
1758	topo(:,nys-i,:) = topo(:,nys,:)
1759	ENDDO
1760	ENDIF
1761	IF ( nyn == ny ) THEN
1762	DO i = 1, nbgp
1763	topo(:,nyn+i,:) = topo(:,nyn,:)
1764	ENDDO
1765	ENDIF
1766	ENDIF
1767	IF ( .NOT. bc_lr_cyc ) THEN
1768	IF ( nxl == 0 ) THEN
1769	DO i = 1, nbgp
1770	topo(:,:,nxl-i) = topo(:,:,nxl)
1771	ENDDO
1772	ENDIF
1773	IF ( nxr == nx ) THEN
1774	DO i = 1, nbgp
1775	topo(:,:,nxr+i) = topo(:,:,nxr)
1776	ENDDO
1777	ENDIF
1778	ENDIF
1779
1780	CASE ( 'tunnel' )
1781
1782	!
1783	!-- Tunnel height
1784	IF ( tunnel_height == 9999999.9_wp ) THEN
1785	th = zw( INT( 0.2 * nz) )
1786	ELSE
1787	th = tunnel_height
1788	ENDIF
1789	!
1790	!-- Tunnel-wall depth
1791	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
1792	td = MAX ( dx, dy, dz(1) )
1793	ELSE
1794	td = tunnel_wall_depth
1795	ENDIF
1796	!
1797	!-- Check for tunnel width
1798	IF ( tunnel_width_x == 9999999.9_wp .AND. tunnel_width_y == 9999999.9_wp ) THEN
1799	message_string = 'No tunnel width is given. '
1800	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
1801	ENDIF
1802	IF ( tunnel_width_x /= 9999999.9_wp .AND. tunnel_width_y /= 9999999.9_wp ) THEN
1803	message_string = 'Inconsistent tunnel parameters:' // &
1804	'tunnel can only be oriented' // &
1805	'either in x- or in y-direction.'
1806	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
1807	ENDIF
1808	!
1809	!-- Check for too small tunnel width in x- and y-direction
1810	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
1811	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) THEN
1812	message_string = 'tunnel_width_x too small'
1813	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
1814	ENDIF
1815	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
1816	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) THEN
1817	message_string = 'tunnel_width_y too small'
1818	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
1819	ENDIF
1820	!
1821	!-- Check for too large tunnel width.
1822	!-- Tunnel axis along y.
1823	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
1824	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
1825	message_string = 'tunnel_width_x too large'
1826	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
1827	ENDIF
1828
1829	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
1830	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
1831	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - ( tunnel_width_x * 0.5_wp - td ) )
1832	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + ( tunnel_width_x * 0.5_wp - td ) )
1833
1834	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
1835	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
1836	tys_in = tys_out
1837	tye_in = tye_out
1838	ENDIF
1839	!
1840	!-- Tunnel axis along x.
1841	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
1842	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
1843	message_string = 'tunnel_width_y too large'
1844	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
1845	ENDIF
1846
1847	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
1848	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
1849	txs_in = txs_out
1850	txe_in = txe_out
1851
1852	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
1853	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
1854	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - ( tunnel_width_y * 0.5_wp - td ) )
1855	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + ( tunnel_width_y * 0.5_wp - td ) )
1856	ENDIF
1857
1858	topo = 0
1859	DO i = nxl, nxr
1860	DO j = nys, nyn
1861	!
1862	!-- Use heaviside function to model outer tunnel surface
1863	hv_out = th * 0.5_wp * ( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
1864	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
1865
1866	hv_out = hv_out * 0.5_wp * ( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
1867	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
1868	!
1869	!-- Use heaviside function to model inner tunnel surface
1870	hv_in = ( th - td ) * 0.5_wp * ( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
1871	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
1872
1873	hv_in = hv_in * 0.5_wp * ( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
1874	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
1875	!
1876	!-- Set flags at x-y-positions without any tunnel surface
1877	IF ( hv_out - hv_in == 0.0_wp ) THEN
1878	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
1879	!
1880	!-- Set flags at x-y-positions with tunnel surfaces
1881	ELSE
1882	DO k = nzb + 1, nzt + 1
1883	!
1884	!-- Inner tunnel
1885	IF ( hv_out - hv_in == th ) THEN
1886	IF ( zw(k) <= hv_out ) THEN
1887	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
1888	ELSE
1889	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
1890	ENDIF
1891	ENDIF
1892	!
1893	!-- Lateral tunnel walls
1894	IF ( hv_out - hv_in == td ) THEN
1895	IF ( zw(k) <= hv_in ) THEN
1896	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
1897	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
1898	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
1899	ELSEIF ( zw(k) > hv_out ) THEN
1900	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
1901	ENDIF
1902	ENDIF
1903	ENDDO
1904	ENDIF
1905	ENDDO
1906	ENDDO
1907
1908	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1909	!
1910	!-- Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions
1911	!-- for topography.
1912	IF ( .NOT. bc_ns_cyc ) THEN
1913	IF ( nys == 0 ) THEN
1914	DO i = 1, nbgp
1915	topo(:,nys-i,:) = topo(:,nys,:)
1916	ENDDO
1917	ENDIF
1918	IF ( nyn == ny ) THEN
1919	DO i = 1, nbgp
1920	topo(:,nyn+i,:) = topo(:,nyn,:)
1921	ENDDO
1922	ENDIF
1923	ENDIF
1924	IF ( .NOT. bc_lr_cyc ) THEN
1925	IF ( nxl == 0 ) THEN
1926	DO i = 1, nbgp
1927	topo(:,:,nxl-i) = topo(:,:,nxl)
1928	ENDDO
1929	ENDIF
1930	IF ( nxr == nx ) THEN
1931	DO i = 1, nbgp
1932	topo(:,:,nxr+i) = topo(:,:,nxr)
1933	ENDDO
1934	ENDIF
1935	ENDIF
1936
1937	CASE ( 'read_from_file' )
1938	!
1939	!-- Note, topography information have been already read.
1940	!-- If required, further process topography, i.e. reference buildings on top of orography and
1941	!-- set temporary 3D topography array, which is used later to set grid flags. Calling of this
1942	!-- rouinte is also required in case of ASCII input, even though no distinction between
1943	!-- terrain- and building height is made in this case.
1944	CALL process_topography( topo )
1945	!
1946	!-- Filter holes resolved by only one grid-point
1947	CALL filter_topography( topo )
1948	!
1949	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary conditions.
1950	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
1951	!
1952	!-- Set lateral boundary conditions for topography on all ghost layers
1953	IF ( .NOT. bc_ns_cyc ) THEN
1954	IF ( nys == 0 ) THEN
1955	DO i = 1, nbgp
1956	topo(:,nys-i,:) = topo(:,nys,:)
1957	ENDDO
1958	ENDIF
1959	IF ( nyn == ny ) THEN
1960	DO i = 1, nbgp
1961	topo(:,nyn+i,:) = topo(:,nyn,:)
1962	ENDDO
1963	ENDIF
1964	ENDIF
1965
1966	IF ( .NOT. bc_lr_cyc ) THEN
1967	IF ( nxl == 0 ) THEN
1968	DO i = 1, nbgp
1969	topo(:,:,nxl-i) = topo(:,:,nxl)
1970	ENDDO
1971	ENDIF
1972	IF ( nxr == nx ) THEN
1973	DO i = 1, nbgp
1974	topo(:,:,nxr+i) = topo(:,:,nxr)
1975	ENDDO
1976	ENDIF
1977	ENDIF
1978
1979
1980	CASE DEFAULT
1981	!
1982	!-- The DEFAULT case is reached either if the parameter topography contains a wrong character
1983	!-- string or if the user has defined a special case in the user interface. There, the
1984	!-- subroutine user_init_grid checks which of these two conditions applies.
1985	CALL user_init_grid( topo )
1986	CALL filter_topography( topo )
1987
1988	END SELECT
1989	!
1990	!-- Consistency checks and index array initialization are only required for non-flat topography.
1991	IF ( TRIM( topography ) /= 'flat' ) THEN
1992	!
1993	!-- In case of non-flat topography, check whether the convention how to define the topography
1994	!-- grid has been set correctly, or whether the default is applicable. If this is not possible,
1995	!-- abort.
1996	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
1997	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
1998	TRIM( topography ) /= 'single_building' .AND. &
1999	TRIM( topography ) /= 'single_street_canyon' .AND. &
2000	TRIM( topography ) /= 'tunnel' .AND. &
2001	TRIM( topography ) /= 'read_from_file') THEN
2002	!-- The default value is not applicable here, because it is only valid for the four
2003	!-- standard cases 'single_building', 'single_street_canyon', 'tunnel' and 'read_from_file'
2004	!-- defined in init_grid.
2005	WRITE( message_string, * ) 'The value for "topography_grid_convention" ', &
2006	'is not set. Its default value is & only valid for ', &
2007	'"topography" = ''single_building'', ''tunnel'' ', &
2008	'''single_street_canyon'', ''closed_channel'' & or ', &
2009	'''read_from_file''.', &
2010	'& Choose ''cell_edge'' or ''cell_center''.'
2011	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
2012	ELSE
2013	!-- The default value is applicable here.
2014	!-- Set convention according to topography.
2015	IF ( TRIM( topography ) == 'single_building' .OR. &
2016	TRIM( topography ) == 'single_street_canyon' ) THEN
2017	topography_grid_convention = 'cell_edge'
2018	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
2019	TRIM( topography ) == 'tunnel') THEN
2020	topography_grid_convention = 'cell_center'
2021	ENDIF
2022	ENDIF
2023	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
2024	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
2025	WRITE( message_string, * ) 'The value for "topography_grid_convention" is ', &
2026	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
2027	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
2028	ENDIF
2029
2030
2031	IF ( topography_grid_convention == 'cell_edge' ) THEN
2032	!
2033	!-- The array nzb_local as defined using the 'cell_edge' convention
2034	!-- describes the actual total size of topography which is defined at the
2035	!-- cell edges where u=0 on the topography walls in x-direction and v=0
2036	!-- on the topography walls in y-direction. However, PALM uses individual
2037	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
2038	!-- Therefore, the extent of topography in nzb_local is now reduced by
2039	!-- 1dx at the E topography walls and by 1dy at the N topography walls
2040	!-- to form the basis for nzb_s_inner.
2041	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
2042	!-- required at this point.
2043	DO j = nys+1, nyn+1
2044	DO i = nxl-1, nxr
2045	DO k = nzb, nzt+1
2046	IF ( BTEST( topo(k,j,i), 0 ) .OR. BTEST( topo(k,j,i+1), 0 ) ) &
2047	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2048	ENDDO
2049	ENDDO
2050	ENDDO
2051	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2052
2053	DO i = nxl, nxr+1
2054	DO j = nys-1, nyn
2055	DO k = nzb, nzt+1
2056	IF ( BTEST( topo(k,j,i), 0 ) .OR. BTEST( topo(k,j+1,i), 0 ) ) &
2057	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
2058	ENDDO
2059	ENDDO
2060	ENDDO
2061	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
2062
2063	ENDIF
2064	ENDIF
2065
2066
2067	END SUBROUTINE init_topo
2068
2069	SUBROUTINE set_topo_flags(topo)
2070
2071	USE control_parameters, &
2072	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, scalar_advec, topography, &
2073	use_surface_fluxes, use_top_fluxes
2074
2075	USE exchange_horiz_mod, &
2076	ONLY: exchange_horiz_int
2077
2078	USE indices, &
2079	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt, topo_top_ind, &
2080	wall_flags_static_0, wall_flags_total_0
2081
2082	USE kinds
2083
2084	IMPLICIT NONE
2085
2086	INTEGER(iwp) :: i !< index variable along x
2087	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
2088	INTEGER(iwp) :: j !< index variable along y
2089	INTEGER(iwp) :: k !< index variable along z
2090
2091	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting
2092	!< "outer"-flags
2093
2094	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
2095	wall_flags_static_0 = 0
2096	!
2097	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
2098	!-- Further special flags will be set in following loops.
2099	DO i = nxl, nxr
2100	DO j = nys, nyn
2101	DO k = nzb, nzt+1
2102	!
2103	!-- scalar grid
2104	IF ( BTEST( topo(k,j,i), 0 ) ) &
2105	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
2106	!
2107	!-- u grid
2108	IF ( BTEST( topo(k,j,i), 0 ) .AND. BTEST( topo(k,j,i-1), 0 ) ) &
2109	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
2110	!
2111	!-- v grid
2112	IF ( BTEST( topo(k,j,i), 0 ) .AND. BTEST( topo(k,j-1,i), 0 ) ) &
2113	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
2114
2115	ENDDO
2116
2117	DO k = nzb, nzt
2118	!
2119	!-- w grid
2120	IF ( BTEST( topo(k,j,i), 0 ) .AND. BTEST( topo(k+1,j,i), 0 ) ) &
2121	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
2122	ENDDO
2123
2124	IF ( topography /= 'closed_channel' ) THEN
2125	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
2126	ENDIF
2127
2128	ENDDO
2129	ENDDO
2130
2131	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
2132
2133	!
2134	!-- Set outer array for scalars to mask near-surface grid points. Note, on basis of flag 24 futher
2135	!-- flags will be derived which are used to control production of subgrid TKE production near walls.
2136
2137	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
2138	wall_flags_total_0 = 0
2139
2140	DO i = nxl, nxr
2141	DO j = nys, nyn
2142	DO k = nzb, nzt+1
2143	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
2144	ENDDO
2145	ENDDO
2146	ENDDO
2147
2148	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
2149
2150	DO i = nxl, nxr
2151	DO j = nys, nyn
2152	DO k = nzb, nzt+1
2153	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
2154	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
2155	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
2156	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
2157	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
2158	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
2159	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
2160	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
2161	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
2162	ENDDO
2163	ENDDO
2164	ENDDO
2165	!
2166	!-- Set further special flags
2167	DO i = nxl, nxr
2168	DO j = nys, nyn
2169	DO k = nzb, nzt+1
2170	!
2171	!-- scalar grid, former nzb_diff_s_inner.
2172	!-- Note, use this flag also to mask topography in diffusion_u and diffusion_v along the
2173	!-- vertical direction. In case of use_surface_fluxes, fluxes are calculated via MOST,
2174	!-- else, simple gradient approach is applied. Please note, in case of u- and v-diffuison,
2175	!-- a small error is made at edges (on the east side for u, at the north side for v), since
2176	!-- topography on scalar grid point is used instead of topography on u/v-grid. As number of
2177	!-- topography grid points on uv-grid is different than s-grid, different number of surface
2178	!-- elements would be required. In order to avoid this, treat edges (u(k,j,i+1)) simply by
2179	!-- a gradient approach, i.e. these points are not masked within diffusion_u. Tests had
2180	!-- shown that the effect on the flow is negligible.
2181	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2182	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2183	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
2184	ELSE
2185	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
2186	ENDIF
2187
2188	ENDDO
2189	!
2190	!-- Special flag to control vertical diffusion at model top - former nzt_diff
2191	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
2192	IF ( use_top_fluxes ) &
2193	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
2194
2195
2196	DO k = nzb+1, nzt
2197	!
2198	!-- Special flag on u grid, former nzb_u_inner + 1, required for disturb_field and
2199	!-- initialization. Do not disturb directly at topography, as well as initialize u with
2200	!-- zero one grid point outside of topography.
2201	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
2202	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
2203	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
2204	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
2205	!
2206	!-- Special flag on v grid, former nzb_v_inner + 1, required for disturb_field and
2207	!-- initialization. Do not disturb directly at topography, as well as initialize v with
2208	!-- zero one grid point outside of topography.
2209	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
2210	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
2211	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
2212	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
2213	!
2214	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for lpm_sgs_tke
2215	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2216	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2217	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2218	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
2219	!
2220	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in in production_e
2221	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2222	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
2223	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
2224	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2225	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
2226	ELSE
2227	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2228	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
2229	ENDIF
2230	!
2231	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
2232	!-- in production_e
2233	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2234	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2235	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2236	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2237	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
2238	ELSE
2239	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2240	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
2241	ENDIF
2242	ENDDO
2243	!
2244	!-- Flags indicating downward facing walls
2245	DO k = nzb+1, nzt+1
2246	!
2247	!-- Scalar grid
2248	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
2249	.NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
2250	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
2251	!
2252	!-- Downward facing wall on u grid
2253	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
2254	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
2255	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
2256	!
2257	!-- Downward facing wall on v grid
2258	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
2259	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
2260	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
2261	!
2262	!-- Downward facing wall on w grid
2263	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
2264	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
2265	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
2266	ENDDO
2267	!
2268	!-- Flags indicating upward facing walls
2269	DO k = nzb, nzt
2270	!
2271	!-- Upward facing wall on scalar grid
2272	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2273	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2274	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
2275	!
2276	!-- Upward facing wall on u grid
2277	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
2278	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
2279	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
2280
2281	!
2282	!-- Upward facing wall on v grid
2283	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
2284	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
2285	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
2286
2287	!
2288	!-- Upward facing wall on w grid
2289	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
2290	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
2291	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
2292	!
2293	!-- Special flag on scalar grid, former nzb_s_inner
2294	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
2295	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
2296	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
2297	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
2298	!
2299	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
2300	!-- flow_statistics
2301	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
2302	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
2303	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
2304	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
2305	ELSE
2306	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
2307	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
2308	ENDIF
2309
2310
2311	ENDDO
2312	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
2313	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
2314	!
2315	!-- Set flags indicating that topography is close by in horizontal direction, i.e. flags that
2316	!-- infold the topography. These will be used to set advection flags for passive scalars,
2317	!-- where due to large gradients near buildings stationary numerical oscillations can produce
2318	!-- unrealistically high concentrations. This is only necessary if WS-scheme is applied for
2319	!-- scalar advection. Note, these flags will be only used for passive scalars such as chemical
2320	!-- species or aerosols.
2321	IF ( scalar_advec == 'ws-scheme' ) THEN
2322	DO k = nzb, nzt
2323	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
2324	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR. &
2325	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR. &
2326	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR. &
2327	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR. &
2328	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR. &
2329	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR. &
2330	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR. &
2331	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR. &
2332	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR. &
2333	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR. &
2334	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR. &
2335	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
2336	) &
2337	) &
2338	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
2339	ENDDO
2340	ENDIF
2341	ENDDO
2342	ENDDO
2343	!
2344	!-- Finally, set identification flags indicating natural terrain or buildings.
2345	!-- Natural terrain grid points. Information on the type of the surface is stored in bit 1 of
2346	!-- 3D Integer array topo. However, this bit is only set when topography is read from file. In order
2347	!-- to run the land-surface model also without topography information, set bit 1 explicitely in this
2348	!-- case.
2349	!--
2350	!-- Natural terrain grid points
2351	!-- If no topography is initialized, the land-surface is at k = nzb.
2352	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
2353	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
2354	ELSE
2355	DO i = nxl, nxr
2356	DO j = nys, nyn
2357	DO k = nzb, nzt+1
2358	!
2359	!-- Natural terrain grid point
2360	IF ( BTEST( topo(k,j,i), 1 ) ) &
2361	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
2362	ENDDO
2363	ENDDO
2364	ENDDO
2365	ENDIF
2366	!
2367	!-- Building grid points.
2368	DO i = nxl, nxr
2369	DO j = nys, nyn
2370	DO k = nzb, nzt+1
2371	IF ( BTEST( topo(k,j,i), 2 ) ) &
2372	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
2373	ENDDO
2374	ENDDO
2375	ENDDO
2376	!
2377	!-- Set flag 4, indicating new topography grid points due to filtering.
2378	DO i = nxl, nxr
2379	DO j = nys, nyn
2380	DO k = nzb, nzt+1
2381	IF ( BTEST( topo(k,j,i), 4 ) ) &
2382	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
2383	ENDDO
2384	ENDDO
2385	ENDDO
2386
2387	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
2388
2389	DO i = nxl, nxr
2390	DO j = nys, nyn
2391	DO k = nzb, nzt+1
2392	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
2393	ENDDO
2394	ENDDO
2395	ENDDO
2396	!
2397	!-- Exchange ghost points for wall flags
2398	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
2399	!
2400	!-- Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions for
2401	!-- topography.
2402	IF ( .NOT. bc_ns_cyc ) THEN
2403	IF ( nys == 0 ) THEN
2404	DO i = 1, nbgp
2405	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
2406	ENDDO
2407	ENDIF
2408	IF ( nyn == ny ) THEN
2409	DO i = 1, nbgp
2410	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
2411	ENDDO
2412	ENDIF
2413	ENDIF
2414	IF ( .NOT. bc_lr_cyc ) THEN
2415	IF ( nxl == 0 ) THEN
2416	DO i = 1, nbgp
2417	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
2418	ENDDO
2419	ENDIF
2420	IF ( nxr == nx ) THEN
2421	DO i = 1, nbgp
2422	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
2423	ENDDO
2424	ENDIF
2425	ENDIF
2426	!
2427	!-- Pre-calculate topography top indices (former get_topography_top_index
2428	!-- function)
2429	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:5) )
2430	!
2431	!-- Uppermost topography index on scalar grid
2432	ibit = 12
2433	topo_top_ind(:,:,0) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
2434	- 1
2435	!
2436	!-- Uppermost topography index on u grid
2437	ibit = 14
2438	topo_top_ind(:,:,1) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
2439	- 1
2440	!
2441	!-- Uppermost topography index on v grid
2442	ibit = 16
2443	topo_top_ind(:,:,2) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
2444	- 1
2445	!
2446	!-- Uppermost topography index on w grid
2447	ibit = 18
2448	topo_top_ind(:,:,3) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
2449	- 1
2450	!
2451	!-- Uppermost topography index on scalar outer grid
2452	ibit = 24
2453	topo_top_ind(:,:,4) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
2454	- 1
2455	!
2456	!-- Uppermost topography index including full-3D geometry
2457	ibit = 12
2458	DO k = nzb, nzt+1
2459	WHERE( BTEST( wall_flags_total_0(k,:,:), ibit ) ) topo_top_ind(:,:,5) = k
2460	ENDDO
2461
2462	END SUBROUTINE set_topo_flags

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