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source: palm/trunk/SOURCE/init_grid.f90 @ 4444

Last change on this file since 4444 was 4444, checked in by raasch, 4 years ago
bugfix: cpp-directives for serial mode added
Property svn:keywords set to `Id`
File size: 117.8 KB

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[1682]	1	!> @file init_grid.f90
[2000]	2	!------------------------------------------------------------------------------!
[2696]	3	! This file is part of the PALM model system.
[1036]	4	!
[2000]	5	! PALM is free software: you can redistribute it and/or modify it under the
	6	! terms of the GNU General Public License as published by the Free Software
	7	! Foundation, either version 3 of the License, or (at your option) any later
	8	! version.
[1036]	9	!
	10	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
	11	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
	12	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
	13	!
	14	! You should have received a copy of the GNU General Public License along with
	15	! PALM. If not, see <http://www.gnu.org/licenses/>.
	16	!
[4360]	17	! Copyright 1997-2020 Leibniz Universitaet Hannover
[2000]	18	!------------------------------------------------------------------------------!
[1036]	19	!
[254]	20	! Current revisions:
[1]	21	! -----------------
[2233]	22	!
[4110]	23	!
[2233]	24	! Former revisions:
	25	! -----------------
	26	! $Id: init_grid.f90 4444 2020-03-05 15:59:50Z raasch $
[4444]	27	! bugfix: cpp-directives for serial mode added
	28	!
	29	! 4414 2020-02-19 20:16:04Z suehring
[4414]	30	! - Remove deprecated topography arrays nzb_s_inner, nzb_u_inner, etc.
	31	! - Move initialization of boundary conditions and multigrid into an extra
	32	! module interface.
	33	!
	34	! 4386 2020-01-27 15:07:30Z Giersch
[4386]	35	! Allocation statements, comments, naming of variables revised and _wp added to
	36	! real type values
	37	!
	38	! 4360 2020-01-07 11:25:50Z suehring
[4356]	39	! Revise error messages for generic tunnel setup.
	40	!
	41	! 4346 2019-12-18 11:55:56Z motisi
[4346]	42	! Introduction of wall_flags_total_0, which currently sets bits based on static
	43	! topography information used in wall_flags_static_0
	44	!
	45	! 4340 2019-12-16 08:17:03Z Giersch
[4340]	46	! Topography closed channel flow with symmetric boundaries implemented
	47	!
	48	! 4329 2019-12-10 15:46:36Z motisi
[4329]	49	! Renamed wall_flags_0 to wall_flags_static_0
	50	!
	51	! 4328 2019-12-09 18:53:04Z suehring
[4328]	52	! Minor change in nzb_max computation. Commentation added.
	53	!
	54	! 4314 2019-11-29 10:29:20Z suehring
[4314]	55	! Set additional topography flag 4 to mark topography grid points emerged
	56	! from the filtering process.
	57	!
	58	! 4294 2019-11-13 18:34:16Z suehring
[4294]	59	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
	60	! building surfaces in all cases, in order to enable terrain-following output
	61	! also when no land- or urban-surface model is applied.
	62	!
	63	! 4265 2019-10-15 16:16:24Z suehring
[4265]	64	! Bugfix for last commit, exchange oro_max variable only when it is allocated
	65	! (not necessarily the case when topography is input from ASCII file).
	66	!
	67	! 4245 2019-09-30 08:40:37Z pavelkrc
[4245]	68	! Store oro_max (building z-offset) in 2D for building surfaces
	69	!
	70	! 4189 2019-08-26 16:19:38Z suehring
[4189]	71	! - Add check for proper setting of namelist parameter topography
	72	! - Set flag to indicate land surfaces in case no topography is provided
	73	!
	74	! 4182 2019-08-22 15:20:23Z scharf
[4182]	75	! Corrected "Former revisions" section
	76	!
	77	! 4168 2019-08-16 13:50:17Z suehring
[4168]	78	! Pre-calculate topography top index and store it on an array (replaces former
	79	! functions get_topography_top_index)
	80	!
	81	! 4159 2019-08-15 13:31:35Z suehring
[4159]	82	! Revision of topography processing. This was not consistent between 2D and 3D
	83	! buildings.
	84	!
	85	! 4144 2019-08-06 09:11:47Z raasch
[4144]	86	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	87	!
	88	! 4115 2019-07-24 12:50:49Z suehring
[4115]	89	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	90	!
	91	! 4110 2019-07-22 17:05:21Z suehring
[4110]	92	! - Separate initialization of advection flags for momentum and scalars.
	93	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	94	!
	95	! 4109 2019-07-22 17:00:34Z suehring
[3927]	96	! Fix bad commit
	97	!
	98	! 3926 2019-04-23 12:56:42Z suehring
[3925]	99	! Minor bugfix in building mapping when all building IDs in the model domain
	100	! are missing
	101	!
	102	! 3857 2019-04-03 13:00:16Z knoop
[3855]	103	! In projection of non-building 3D objects onto numerical grid remove
	104	! dependency on building_type
	105	!
	106	! 3763 2019-02-25 17:33:49Z suehring
[3763]	107	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	108	! routine as already done in other routines
	109	!
	110	! 3761 2019-02-25 15:31:42Z raasch
[3761]	111	! unused variables removed
	112	!
	113	! 3661 2019-01-08 18:22:50Z suehring
[3661]	114	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	115	! order degradation of advection scheme is handeled directly in advec_ws
	116	!
	117	! 3655 2019-01-07 16:51:22Z knoop
[3538]	118	! Comment added
[2716]	119	!
[4182]	120	! Revision 1.1 1997/08/11 06:17:45 raasch
	121	! Initial revision (Testversion)
	122	!
	123	!
[1]	124	! Description:
[2696]	125	! -----------------------------------------------------------------------------!
[1682]	126	!> Creating grid depending constants
[2696]	127	!> @todo: Rearrange topo flag list
	128	!> @todo: reference 3D buildings on top of orography is not tested and may need
	129	!> further improvement for steep slopes
	130	!> @todo: Use more advanced setting of building type at filled holes
[1]	131	!------------------------------------------------------------------------------!
[1682]	132	SUBROUTINE init_grid
[1]	133
[1320]	134	USE arrays_3d, &
[3857]	135	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[4414]	136
[1353]	137	USE control_parameters, &
[4414]	138	ONLY: constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	139	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	140	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	141	dz_stretch_level_start, ibc_uv_b, message_string, &
[4414]	142	number_stretch_level_end, &
	143	number_stretch_level_start, &
	144	ocean_mode, &
	145	psolver, &
	146	symmetry_flag, &
	147	topography, &
	148	use_surface_fluxes
	149
[1320]	150	USE grid_variables, &
[2232]	151	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[4414]	152
[1320]	153	USE indices, &
[4414]	154	ONLY: nbgp, &
	155	nx, &
	156	nxl, &
	157	nxlg, &
	158	nxr, &
	159	nxrg, &
	160	ny, &
	161	nyn, &
	162	nyng, &
	163	nys, &
	164	nysg, &
	165	nz, &
	166	nzb, &
	167	nzb_diff, &
	168	nzb_max, &
	169	nzt, &
	170	topo_top_ind, &
	171	topo_min_level
	172
[1320]	173	USE kinds
[2696]	174
[1]	175	USE pegrid
	176
[4444]	177	#if defined( __parallel )
[2365]	178	USE vertical_nesting_mod, &
	179	ONLY: vnested, vnest_init_grid
[4444]	180	#endif
[2365]	181
[1]	182	IMPLICIT NONE
	183
[3182]	184	INTEGER(iwp) :: i !< index variable along x
	185	INTEGER(iwp) :: j !< index variable along y
	186	INTEGER(iwp) :: k !< index variable along z
	187	INTEGER(iwp) :: k_top !< topography top index on local PE
	188	INTEGER(iwp) :: n !< loop variable for stretching
	189	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	190	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	191	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[1]	192
[2696]	193	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	194
[3065]	195	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	196	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	197
	198	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	199
[1]	200
	201	!
[709]	202	!-- Calculation of horizontal array bounds including ghost layers
[667]	203	nxlg = nxl - nbgp
	204	nxrg = nxr + nbgp
	205	nysg = nys - nbgp
	206	nyng = nyn + nbgp
[709]	207
[667]	208	!
[1]	209	!-- Allocate grid arrays
[4386]	210	ALLOCATE( x(0:nx) )
	211	ALLOCATE( xu(0:nx) )
	212
[3857]	213	DO i = 0, nx
	214	xu(i) = i * dx
	215	x(i) = i * dx + 0.5_wp * dx
	216	ENDDO
	217
[4386]	218	ALLOCATE( y(0:ny) )
	219	ALLOCATE( yv(0:ny) )
	220
[3857]	221	DO j = 0, ny
	222	yv(j) = j * dy
	223	y(j) = j * dy + 0.5_wp * dy
	224	ENDDO
	225
[4386]	226	ALLOCATE( ddzu(1:nzt+1) )
	227	ALLOCATE( ddzw(1:nzt+1) )
	228	ALLOCATE( dd2zu(1:nzt) )
	229	ALLOCATE( dzu(1:nzt+1) )
	230	ALLOCATE( dzw(1:nzt+1) )
	231	ALLOCATE( zu(nzb:nzt+1) )
	232	ALLOCATE( zw(nzb:nzt+1) )
[1]	233
	234	!
[4386]	235	!-- For constructing an appropriate grid, the vertical grid spacing dz has to
	236	!-- be specified with a non-negative value in the parameter file
[3065]	237	IF ( dz(1) == -1.0_wp ) THEN
[254]	238	message_string = 'missing dz'
	239	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	240	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	241	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	242	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	243	ENDIF
[94]	244
[1]	245	!
[3065]	246	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	247	!-- if it was set by the user
	248	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	249	dz_stretch_level_start(1) = dz_stretch_level
	250	ENDIF
	251
	252	!
	253	!-- Determine number of dz values and stretching levels specified by the
	254	!-- user to allow right controlling of the stretching mechanism and to
[3139]	255	!-- perform error checks. The additional requirement that dz /= dz_max
	256	!-- for counting number of user-specified dz values is necessary. Otherwise
	257	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	258	!-- is used (Attention: The user is not allowed to specify a dz value equal
	259	!-- to the default of dz_max = 999.0).
	260	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	261	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	262	-9999999.9_wp )
	263	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	264	9999999.9_wp )
	265
	266	!
[4386]	267	!-- The number of specified end levels +1 has to be the same as the number
[3065]	268	!-- of specified dz values
	269	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
[4386]	270	WRITE( message_string, * ) 'The number of values for dz = ', &
	271	number_dz, 'has to be the same as& ', &
	272	'the number of values for ', &
	273	'dz_stretch_level_end + 1 = ', &
[3065]	274	number_stretch_level_end+1
	275	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	276	ENDIF
	277
	278	!
[4386]	279	!-- The number of specified start levels has to be the same or one less than
	280	!-- the number of specified dz values
	281	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
[3065]	282	number_dz /= number_stretch_level_start ) THEN
[4386]	283	WRITE( message_string, * ) 'The number of values for dz = ', &
	284	number_dz, 'has to be the same as or one ', &
	285	'more than& the number of values for ', &
	286	'dz_stretch_level_start = ', &
[3065]	287	number_stretch_level_start
	288	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	289	ENDIF
	290
[4386]	291	!-- The number of specified start levels has to be the same or one more than
	292	!-- the number of specified end levels
	293	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
[3065]	294	number_stretch_level_start /= number_stretch_level_end ) THEN
[4386]	295	WRITE( message_string, * ) 'The number of values for ', &
	296	'dz_stretch_level_start = ', &
	297	dz_stretch_level_start, 'has to be the ', &
	298	'same or one more than& the number of ', &
	299	'values for dz_stretch_level_end = ', &
[3065]	300	number_stretch_level_end
	301	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	302	ENDIF
	303
	304	!
	305	!-- Initialize dz for the free atmosphere with the value of dz_max
	306	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	307	number_stretch_level_start /= 0 ) THEN
	308	dz(number_stretch_level_start+1) = dz_max
	309	ENDIF
	310
	311	!
	312	!-- Initialize the stretching factor if (infinitely) stretching in the free
	313	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	314	!-- free atmosphere)
	315	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	316	dz_stretch_factor_array(number_stretch_level_start) = &
	317	dz_stretch_factor
	318	ENDIF
	319
	320	!
	321	!-- Allocation of arrays for stretching
	322	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	323
[3065]	324	!
[4386]	325	!-- Define the vertical grid levels. Start with atmosphere branch
[3294]	326	IF ( .NOT. ocean_mode ) THEN
[3065]	327
[94]	328	!
[3065]	329	!-- The stretching region has to be large enough to allow for a smooth
[4386]	330	!-- transition between two different grid spacings. The number 4 is an
	331	!-- empirical value
[3065]	332	DO n = 1, number_stretch_level_start
	333	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	334	4 * MAX( dz(n),dz(n+1) )
	335	ENDDO
	336
[3066]	337	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	338	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[4386]	339	message_string= 'Each dz_stretch_level_end has to be larger ' // &
[3065]	340	'than its corresponding value for &' // &
	341	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	342	'to allow for smooth grid stretching'
	343	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	344	ENDIF
	345
	346	!
[4386]	347	!-- Stretching must not be applied within the surface layer
[3065]	348	!-- (first two grid points). For the default case dz_stretch_level_start
	349	!-- is negative. Therefore the absolut value is checked here.
[4386]	350	IF ( ANY( ABS( dz_stretch_level_start ) <= dz(1) * 1.5_wp ) ) THEN
	351	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
[3065]	352	'larger than ', dz(1) * 1.5
	353	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	354	ENDIF
	355
	356	!
	357	!-- The stretching has to start and end on a grid level. Therefore
[4386]	358	!-- user-specified values are mapped to the next lowest level. The
	359	!-- calculation of the first level is realized differently just because of
	360	!-- historical reasons (the advanced/new stretching mechanism was realized
	361	!-- in a way that results don't change if the old parameters
	362	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
[3065]	363	IF ( number_stretch_level_start /= 0 ) THEN
	364	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	365	dz(1)/2.0) / dz(1) ) &
	366	* dz(1) + dz(1)/2.0
	367	ENDIF
	368
	369	IF ( number_stretch_level_start > 1 ) THEN
	370	DO n = 2, number_stretch_level_start
	371	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	372	dz(n) ) * dz(n)
	373	ENDDO
	374	ENDIF
	375
	376	IF ( number_stretch_level_end /= 0 ) THEN
	377	DO n = 1, number_stretch_level_end
	378	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	379	dz(n+1) ) * dz(n+1)
	380	ENDDO
	381	ENDIF
[4386]	382
[3065]	383	!
	384	!-- Determine stretching factor if necessary
	385	IF ( number_stretch_level_end >= 1 ) THEN
	386	CALL calculate_stretching_factor( number_stretch_level_end )
	387	ENDIF
	388
	389	!
[94]	390	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	391	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	392	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	393	!-- The second u-level (k=1) corresponds to the top of the
[4386]	394	!-- surface layer. In case of symmetric boundaries (closed channel flow),
[4340]	395	!-- the first grid point is always at z=0.
	396	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. &
	397	topography == 'closed_channel' ) THEN
[1353]	398	zu(0) = 0.0_wp
[667]	399	ELSE
[3065]	400	zu(0) = - dz(1) * 0.5_wp
[667]	401	ENDIF
[3065]	402
	403	zu(1) = dz(1) * 0.5_wp
	404
	405	!
	406	!-- Determine u and v height levels considering the possibility of grid
	407	!-- stretching in several heights.
	408	n = 1
	409	dz_stretch_level_start_index = nzt+1
	410	dz_stretch_level_end_index = nzt+1
	411	dz_stretched = dz(1)
[1]	412
[3065]	413	!-- The default value of dz_stretch_level_start is negative, thus the first
[4386]	414	!-- condition is true even if no stretching shall be applied. Hence, the
	415	!-- second condition is also necessary.
[4340]	416	DO k = 2, nzt+1-symmetry_flag
[3065]	417	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	418	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	419	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	420
	421	IF ( dz(n) > dz(n+1) ) THEN
	422	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	423	ELSE
	424	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	425	ENDIF
	426
	427	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	428	dz_stretch_level_start_index(n) = k-1
	429
[94]	430	ENDIF
[3065]	431
[94]	432	zu(k) = zu(k-1) + dz_stretched
[3065]	433
	434	!
	435	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	436	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	437
	438	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	439	zu(k) = dz_stretch_level_end(n)
	440	dz_stretched = dz(n+1)
	441	dz_stretch_level_end_index(n) = k
	442	n = n + 1
	443	ENDIF
[94]	444	ENDDO
[4340]	445
	446	!
	447	!-- If a closed channel flow is simulated, make sure that grid structure is
	448	!-- the same for both bottom and top boundary. (Hint: Using a different dz
	449	!-- at the bottom and at the top makes no sense due to symmetric boundaries
	450	!-- where dz should be equal. Therefore, different dz at the bottom and top
	451	!-- causes an abort (see check_parameters).)
	452	IF ( topography == 'closed_channel' ) THEN
	453	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
	454	ENDIF
[1]	455
	456	!
[94]	457	!-- Compute the w-levels. They are always staggered half-way between the
[843]	458	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	459	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
[4340]	460	!-- Per default, the top w-level is extrapolated linearly. In case of
	461	!-- a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
	462	!-- (Hint: Using a different dz at the bottom and at the top makes no sense
	463	!-- due to symmetric boundaries where dz should be equal. Therefore,
	464	!-- different dz at the bottom and top causes an abort (see
	465	!-- check_parameters).)
[1353]	466	zw(0) = 0.0_wp
[4340]	467	DO k = 1, nzt-symmetry_flag
[1353]	468	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	469	ENDDO
[4340]	470	IF ( topography == 'closed_channel' ) THEN
	471	zw(nzt) = zw(nzt-1) + dz(1)
	472	zw(nzt+1) = zw(nzt) + dz(1)
	473	ELSE
	474	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
	475	ENDIF
[1]	476
[4386]	477	ELSE !ocean branch
[3065]	478
[1]	479	!
[3065]	480	!-- The stretching region has to be large enough to allow for a smooth
[4386]	481	!-- transition between two different grid spacings. The number 4 is an
	482	!-- empirical value
[3065]	483	DO n = 1, number_stretch_level_start
	484	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	485	4 * MAX( dz(n),dz(n+1) )
	486	ENDDO
	487
[3066]	488	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	489	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[4386]	490	message_string= 'Each dz_stretch_level_end has to be less ' // &
[3065]	491	'than its corresponding value for &' // &
	492	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	493	'to allow for smooth grid stretching'
	494	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	495	ENDIF
	496
	497	!
[3068]	498	!-- Stretching must not be applied close to the surface (last two grid
	499	!-- points). For the default case dz_stretch_level_start is negative.
[4386]	500	IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) ) THEN
	501	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
	502	'less than ', -dz(1) * 1.5
[3065]	503	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	504	ENDIF
	505
	506	!
	507	!-- The stretching has to start and end on a grid level. Therefore
[4386]	508	!-- user-specified values are mapped to the next highest level. The
	509	!-- calculation of the first level is realized differently just because of
	510	!-- historical reasons (the advanced/new stretching mechanism was realized
	511	!-- in a way that results don't change if the old parameters
	512	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
[3065]	513	IF ( number_stretch_level_start /= 0 ) THEN
	514	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	515	dz(1)/2.0) / dz(1) ) &
	516	* dz(1) - dz(1)/2.0
	517	ENDIF
	518
	519	IF ( number_stretch_level_start > 1 ) THEN
	520	DO n = 2, number_stretch_level_start
	521	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	522	dz(n) ) * dz(n)
	523	ENDDO
	524	ENDIF
	525
	526	IF ( number_stretch_level_end /= 0 ) THEN
	527	DO n = 1, number_stretch_level_end
	528	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	529	dz(n+1) ) * dz(n+1)
	530	ENDDO
	531	ENDIF
	532
	533	!
	534	!-- Determine stretching factor if necessary
	535	IF ( number_stretch_level_end >= 1 ) THEN
	536	CALL calculate_stretching_factor( number_stretch_level_end )
	537	ENDIF
	538
	539	!
[843]	540	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	541	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	542	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	543	!-- w-level are defined at same height, but staggered from the second level.
[4386]	544	!-- The second u-level (k=1) corresponds to the top of the surface layer.
[3065]	545	!-- z values are negative starting from z=0 (surface)
	546	zu(nzt+1) = dz(1) * 0.5_wp
	547	zu(nzt) = - dz(1) * 0.5_wp
[94]	548
[3065]	549	!
	550	!-- Determine u and v height levels considering the possibility of grid
	551	!-- stretching in several heights.
	552	n = 1
	553	dz_stretch_level_start_index = 0
	554	dz_stretch_level_end_index = 0
	555	dz_stretched = dz(1)
	556
[94]	557	DO k = nzt-1, 0, -1
[3065]	558
	559	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	560	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	561
	562	IF ( dz(n) > dz(n+1) ) THEN
	563	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	564	ELSE
	565	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	566	ENDIF
	567
	568	IF ( dz_stretch_level_start_index(n) == 0 ) &
	569	dz_stretch_level_start_index(n) = k+1
	570
	571	ENDIF
	572
	573	zu(k) = zu(k+1) - dz_stretched
	574
[1418]	575	!
[3065]	576	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	577	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	578
	579	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	580	zu(k) = dz_stretch_level_end(n)
	581	dz_stretched = dz(n+1)
	582	dz_stretch_level_end_index(n) = k
	583	n = n + 1
[94]	584	ENDIF
	585	ENDDO
[3065]	586
[94]	587	!
	588	!-- Compute the w-levels. They are always staggered half-way between the
[843]	589	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	590	!-- at the ground. In this case the first u- and w-level are defined at
	591	!-- same height. The top w-level (nzt+1) is not used but set for
	592	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	593	zw(nzt+1) = dz(1)
[1353]	594	zw(nzt) = 0.0_wp
[94]	595	DO k = 0, nzt
[1353]	596	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	597	ENDDO
	598
[843]	599	!
	600	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	601	!-- at same height.
	602	IF ( ibc_uv_b == 0 ) THEN
	603	zu(0) = zw(0)
	604	ENDIF
	605
[4386]	606	ENDIF !End of defining the vertical grid levels
[94]	607
	608	!
[1]	609	!-- Compute grid lengths.
	610	DO k = 1, nzt+1
	611	dzu(k) = zu(k) - zu(k-1)
[1353]	612	ddzu(k) = 1.0_wp / dzu(k)
[1]	613	dzw(k) = zw(k) - zw(k-1)
[1353]	614	ddzw(k) = 1.0_wp / dzw(k)
[1]	615	ENDDO
	616
	617	DO k = 1, nzt
[1353]	618	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	619	ENDDO
[667]	620
	621	!
[709]	622	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	623	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	624	!-- is only dz/2, but should be dz. Therefore, an additional array
	625	!-- containing with appropriate grid information is created for these
	626	!-- solvers.
[1575]	627	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	628	ALLOCATE( ddzu_pres(1:nzt+1) )
	629	ddzu_pres = ddzu
[864]	630	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	631	ENDIF
	632
	633	!
	634	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	635	ddx = 1.0_wp / dx
	636	ddy = 1.0_wp / dy
[1]	637	dx2 = dx * dx
	638	dy2 = dy * dy
[1353]	639	ddx2 = 1.0_wp / dx2
	640	ddy2 = 1.0_wp / dy2
[1]	641
	642	!
[2696]	643	!-- Allocate 3D array to set topography
	644	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	645	topo = 0
	646	!
[4386]	647	!-- Initialize topography by generic topography or read topography from file.
[2696]	648	CALL init_topo( topo )
	649	!
	650	!-- Set flags to mask topography on the grid.
[4414]	651	CALL set_topo_flags( topo )
[2696]	652
	653	!
	654	!-- Determine the maximum level of topography. It is used for
	655	!-- steering the degradation of order of the applied advection scheme,
[4328]	656	!-- as well in the lpm.
[2696]	657	k_top = 0
	658	DO i = nxl, nxr
	659	DO j = nys, nyn
	660	DO k = nzb, nzt + 1
[4109]	661	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	662	ENDDO
	663	ENDDO
[1]	664	ENDDO
[2696]	665	#if defined( __parallel )
[4328]	666	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, &
[2696]	667	MPI_MAX, comm2d, ierr )
	668	#else
[4328]	669	nzb_max = k_top
[2696]	670	#endif
[1]	671	!
[4328]	672	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
	673	!-- Further, in case topography extents up to the model top, limit to nzt.
	674	nzb_max = MIN( nzb_max+1, nzt )
	675	!
[2968]	676	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	677	!-- there is elevated topography, however, the lowest topography will be higher.
	678	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	679	!-- temperature, surface pressure and density, etc. .
	680	topo_min_level = 0
	681	#if defined( __parallel )
[4168]	682	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	683	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	684	#else
[4168]	685	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	686	#endif
[3182]	687
[2696]	688	!
[2968]	689	!-- Check topography for consistency with model domain. Therefore, use
	690	!-- maximum and minium topography-top indices. Note, minimum topography top
	691	!-- index is already calculated.
[2696]	692	IF ( TRIM( topography ) /= 'flat' ) THEN
	693	#if defined( __parallel )
[4168]	694	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	695	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	696	#else
[4168]	697	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	698	#endif
[2968]	699	nzb_local_min = topo_min_level
[2696]	700	!
	701	!-- Consistency checks
	702	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	703	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	704	' model domain', &
[3046]	705	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	706	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	707	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	708	ENDIF
	709	ENDIF
[1]	710	!
[19]	711	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	712	!-- form (which does not use surface fluxes) is applied
[1691]	713	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	714	nzb_diff = nzb + 2
	715	ELSE
	716	nzb_diff = nzb + 1
	717	ENDIF
	718
[4414]	719	IF ( TRIM( topography ) /= 'flat' ) THEN
[2696]	720	!
[4414]	721	!-- Allocate and set the arrays containing the topography height (for output
	722	!-- reasons only).
	723	IF ( nxr == nx .AND. nyn /= ny ) THEN
	724	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	725	zw_w_inner(nxl:nxr+1,nys:nyn) )
	726	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	727	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	728	zw_w_inner(nxl:nxr,nys:nyn+1) )
	729	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	730	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	731	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	732	ELSE
	733	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	734	zw_w_inner(nxl:nxr,nys:nyn) )
[2696]	735	ENDIF
[1]	736
[4414]	737	zu_s_inner = 0.0_wp
	738	zw_w_inner = 0.0_wp
[1]	739	!
[4414]	740	!-- Determine local topography height on scalar and w-grid. Note, setting
	741	!-- lateral boundary values is not necessary, realized via wall_flags_static_0
	742	!-- array. Further, please note that loop bounds are different from
	743	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	744	!-- use intrinsic lbound and ubound functions to infer array bounds.
	745	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	746	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
[2696]	747	!
[4414]	748	!-- Topography height on scalar grid. Therefore, determine index of
	749	!-- upward-facing surface element on scalar grid.
	750	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	751	!
[4414]	752	!-- Topography height on w grid. Therefore, determine index of
	753	!-- upward-facing surface element on w grid.
	754	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
	755	ENDDO
[2696]	756	ENDDO
	757	ENDIF
[4444]	758
	759	#if defined( __parallel )
[2696]	760	!
	761	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	762	!-- coarse grid
	763	IF ( vnested ) CALL vnest_init_grid
[4444]	764	#endif
[2696]	765
	766	END SUBROUTINE init_grid
	767
[3065]	768
[2696]	769	! Description:
	770	! -----------------------------------------------------------------------------!
[3065]	771	!> Calculation of the stretching factor through an iterative method. Ideas were
	772	!> taken from the paper "Regional stretched grid generation and its application
	773	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	774	!> system of equations has two variables (r,l) but four requirements
	775	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	776	!> results into an overdetermined system.
	777	!------------------------------------------------------------------------------!
	778	SUBROUTINE calculate_stretching_factor( number_end )
	779
	780	USE control_parameters, &
[3241]	781	ONLY: dz, dz_stretch_factor_array, &
[3065]	782	dz_stretch_level_end, dz_stretch_level_start, message_string
	783
	784	USE kinds
	785
	786	IMPLICIT NONE
	787
	788	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	789	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	790	INTEGER(iwp) :: n !< loop variable for stretching
	791
	792	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	793
	794	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	795	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	796	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	797	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	798	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	799	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	800	REAL(wp) :: numerator !< numerator of the quotient
	801	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	802	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	803
[3068]	804	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	805
[4386]	806	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06_wp !< interval for sampling possible stretching factors
	807	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88_wp !< lowest possible stretching factor
	808	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12_wp !< highest possible stretching factor
[3065]	809
	810
[3068]	811	l = 0
	812	DO n = 1, number_end
	813
	814	iterations = 1
[4386]	815	stretch_factor_1 = 1.0_wp
	816	stretch_factor_2 = 1.0_wp
	817	delta_total_old = 1.0_wp
[3065]	818
[4386]	819	!
	820	!-- First branch for stretching from rough to fine
[3068]	821	IF ( dz(n) > dz(n+1) ) THEN
	822	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	823
[4386]	824	stretch_factor_1 = 1.0_wp - iterations * stretch_factor_interval
	825	distance = ABS( dz_stretch_level_end(n) - &
	826	dz_stretch_level_start(n) )
	827	numerator = distance*stretch_factor_1/dz(n) + &
[3068]	828	stretch_factor_1 - distance/dz(n)
	829
[4386]	830	IF ( numerator > 0.0_wp ) THEN
	831	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
[3068]	832	l_rounded = NINT( l )
	833	delta_l = ABS( l_rounded - l ) / l
	834	ENDIF
	835
	836	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	837
[4386]	838	delta_stretch_factor = ABS( stretch_factor_1 - &
	839	stretch_factor_2 ) / &
[3068]	840	stretch_factor_2
	841
	842	delta_total_new = delta_l + delta_stretch_factor
[3065]	843
	844	!
[4386]	845	!-- stretch_factor_1 is taken to guarantee that the stretching
	846	!-- procedure ends as close as possible to dz_stretch_level_end.
	847	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	848	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	849	IF (delta_total_new < delta_total_old) THEN
	850	dz_stretch_factor_array(n) = stretch_factor_1
	851	dz_stretch_factor_array_2(n) = stretch_factor_2
	852	delta_total_old = delta_total_new
	853	ENDIF
	854
	855	iterations = iterations + 1
	856
	857	ENDDO
[4386]	858
	859	!
	860	!-- Second branch for stretching from fine to rough
[3068]	861	ELSEIF ( dz(n) < dz(n+1) ) THEN
	862	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	863
[4386]	864	stretch_factor_1 = 1.0_wp + iterations * stretch_factor_interval
	865	distance = ABS( dz_stretch_level_end(n) - &
[3068]	866	dz_stretch_level_start(n) )
[4386]	867	numerator = distance*stretch_factor_1/dz(n) + &
[3068]	868	stretch_factor_1 - distance/dz(n)
	869
[4386]	870	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
[3068]	871	l_rounded = NINT( l )
	872	delta_l = ABS( l_rounded - l ) / l
	873
	874	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	875
[4386]	876	delta_stretch_factor = ABS( stretch_factor_1 - &
	877	stretch_factor_2 ) / &
[3068]	878	stretch_factor_2
	879
	880	delta_total_new = delta_l + delta_stretch_factor
	881
[3065]	882	!
[4386]	883	!-- stretch_factor_1 is taken to guarantee that the stretching
	884	!-- procedure ends as close as possible to dz_stretch_level_end.
	885	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	886	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	887	IF (delta_total_new < delta_total_old) THEN
	888	dz_stretch_factor_array(n) = stretch_factor_1
	889	dz_stretch_factor_array_2(n) = stretch_factor_2
	890	delta_total_old = delta_total_new
	891	ENDIF
[3065]	892
[3068]	893	iterations = iterations + 1
	894	ENDDO
	895
	896	ELSE
	897	message_string= 'Two adjacent values of dz must be different'
	898	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	899
	900	ENDIF
	901
	902	!
	903	!-- Check if also the second stretching factor fits into the allowed
	904	!-- interval. If not, print a warning for the user.
	905	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	906	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	907	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	908	dz_stretch_factor_array_2(n), ' which is',&
	909	' responsible for exactly reaching& dz =',&
	910	dz(n+1), 'after a specific amount of', &
	911	' grid levels& exceeds the upper', &
	912	' limit =', stretch_factor_upper_limit, &
	913	' &or lower limit = ', &
	914	stretch_factor_lower_limit
	915	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	916
	917	ENDIF
	918	ENDDO
[3065]	919
	920	END SUBROUTINE calculate_stretching_factor
	921
	922
	923	! Description:
	924	! -----------------------------------------------------------------------------!
[2696]	925	!> Set temporary topography flags and reference buildings on top of underlying
	926	!> orography.
	927	!------------------------------------------------------------------------------!
	928	SUBROUTINE process_topography( topo_3d )
	929
	930	USE arrays_3d, &
[2747]	931	ONLY: zu, zw
[2696]	932
	933	USE control_parameters, &
[3294]	934	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	935
	936	USE indices, &
	937	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	938	nzt
	939
	940	USE netcdf_data_input_mod, &
[3115]	941	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	942	terrain_height_f
	943
	944	USE kinds
	945
	946	USE pegrid
	947
	948	IMPLICIT NONE
	949
[2867]	950	INTEGER(iwp) :: i !< running index along x-direction
	951	INTEGER(iwp) :: j !< running index along y-direction
	952	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	953	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	954	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	955	INTEGER(iwp) :: num_build !< counter for number of buildings
	956	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	957
[4444]	958	#if defined( __parallel )
[2696]	959	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
[4444]	960	#endif
[2696]	961	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	962	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	963	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	964	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	965	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	966
	967	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	968	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	969
	970	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	971
	972	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	973	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	974	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	975	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	976
	977	!
[3103]	978	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	979	!-- is non-zero, all grid points of the lower vertical grid levels might be
	980	!-- entirely below the surface, meaning a waste of computational resources.
	981	!-- In order to avoid this, remove the lowest terrain height. Please note,
	982	!-- in case of a nested run, the global minimum from all parent and childs
	983	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	984	IF ( input_pids_static ) THEN
[4159]	985
[3200]	986	#if defined( __parallel )
[3103]	987	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	988	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	989	#else
	990	oro_min = MINVAL( terrain_height_f%var )
	991	#endif
[3103]	992	terrain_height_f%var = terrain_height_f%var - oro_min
	993	!
	994	!-- Give an informative message that terrain height is referenced to zero
	995	IF ( oro_min > 0.0_wp ) THEN
	996	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	997	'downwards by ', oro_min, 'meter(s) to save ' // &
	998	'computational resources.'
	999	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	1000	ENDIF
	1001	ENDIF
	1002
	1003	!
[2696]	1004	!-- In the following, buildings and orography are further preprocessed
	1005	!-- before they are mapped on the LES grid.
	1006	!-- Buildings are mapped on top of the orography by maintaining the roof
	1007	!-- shape of the building. This can be achieved by referencing building on
	1008	!-- top of the maximum terrain height within the area occupied by the
	1009	!-- respective building. As buildings and terrain height are defined PE-wise,
	1010	!-- parallelization of this referencing is required (a building can be
	1011	!-- distributed between different PEs).
	1012	!-- In a first step, determine the number of buildings with different
	1013	!-- building id on each PE. In a next step, all building ids are gathered
	1014	!-- into one array which is present to all PEs. For each building ID,
	1015	!-- the maximum terrain height occupied by the respective building is
	1016	!-- computed and distributed to each PE.
	1017	!-- Finally, for each building id and its respective reference orography,
	1018	!-- builidings are mapped on top.
	1019	!--
	1020	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1021	!-- buildings
	1022	!-- classify the respective surfaces.
	1023	topo_3d = IBSET( topo_3d, 0 )
	1024	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1025	!
[3051]	1026	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1027	!-- pre-calculate an offset value.
[3294]	1028	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1029	!
[2696]	1030	!-- Reference buildings on top of orography. This is not necessary
	1031	!-- if topography is read from ASCII file as no distinction between buildings
	1032	!-- and terrain height can be made. Moreover, this is also not necessary if
	1033	!-- urban-surface and land-surface model are used at the same time.
[2897]	1034	IF ( input_pids_static ) THEN
	1035
	1036	IF ( buildings_f%from_file ) THEN
	1037	num_buildings_l = 0
	1038	num_buildings = 0
[2696]	1039	!
[3925]	1040	!-- Allocate at least one element for building ids and give it an inital
	1041	!-- negative value that will be overwritten later. This, however, is
	1042	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1043	ALLOCATE( build_ids_l(1) )
[3925]	1044	build_ids_l = -1
[2897]	1045	DO i = nxl, nxr
	1046	DO j = nys, nyn
	1047	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1048	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1049	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1050	THEN
	1051	CYCLE
	1052	ELSE
	1053	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1054	!
	1055	!-- Resize array with different local building ids
	1056	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1057	build_ids_l_tmp = build_ids_l
	1058	DEALLOCATE( build_ids_l )
	1059	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1060	build_ids_l(1:num_buildings_l(myid)-1) = &
	1061	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1062	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1063	DEALLOCATE( build_ids_l_tmp )
	1064	ENDIF
	1065	!
[2897]	1066	!-- First occuring building id on PE
	1067	ELSE
	1068	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1069	build_ids_l(1) = building_id_f%var(j,i)
	1070	ENDIF
[2696]	1071	ENDIF
[2897]	1072	ENDDO
[2696]	1073	ENDDO
	1074	!
[2897]	1075	!-- Determine number of different building ids for the entire domain
[2696]	1076	#if defined( __parallel )
[2897]	1077	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1078	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1079	#else
[2897]	1080	num_buildings = num_buildings_l
[2696]	1081	#endif
	1082	!
[2897]	1083	!-- Gather all buildings ids on each PEs.
	1084	!-- First, allocate array encompassing all building ids in model domain.
	1085	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1086	#if defined( __parallel )
	1087	!
[2897]	1088	!-- Allocate array for displacements.
	1089	!-- As each PE may has a different number of buildings, so that
	1090	!-- the block sizes send by each PE may not be equal. Hence,
	1091	!-- information about the respective displacement is required, indicating
	1092	!-- the respective adress where each MPI-task writes into the receive
	1093	!-- buffer array
	1094	ALLOCATE( displace_dum(0:numprocs-1) )
	1095	displace_dum(0) = 0
	1096	DO i = 1, numprocs-1
	1097	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1098	ENDDO
[2696]	1099
[2897]	1100	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1101	num_buildings(myid), &
	1102	MPI_INTEGER, &
	1103	build_ids, &
	1104	num_buildings, &
	1105	displace_dum, &
	1106	MPI_INTEGER, &
	1107	comm2d, ierr )
[2696]	1108
[2897]	1109	DEALLOCATE( displace_dum )
[2696]	1110
	1111	#else
[2897]	1112	build_ids = build_ids_l
[2696]	1113	#endif
	1114
	1115	!
[2897]	1116	!-- Note, in parallel mode building ids can occure mutliple times, as
	1117	!-- each PE has send its own ids. Therefore, sort out building ids which
	1118	!-- appear more than one time.
	1119	num_build = 0
	1120	DO nr = 1, SIZE(build_ids)
[2696]	1121
[2897]	1122	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1123	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1124	CYCLE
	1125	ELSE
	1126	num_build = num_build + 1
	1127	!
	1128	!-- Resize
	1129	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1130	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1131	DEALLOCATE( build_ids_final )
	1132	ALLOCATE( build_ids_final(1:num_build) )
	1133	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1134	build_ids_final(num_build) = build_ids(nr)
	1135	DEALLOCATE( build_ids_final_tmp )
	1136	ENDIF
[2696]	1137	ELSE
	1138	num_build = num_build + 1
	1139	ALLOCATE( build_ids_final(1:num_build) )
	1140	build_ids_final(num_build) = build_ids(nr)
[2897]	1141	ENDIF
	1142	ENDDO
[2696]	1143
	1144	!
[3051]	1145	!-- Determine maximumum terrain height occupied by the respective
	1146	!-- building and temporalily store on oro_max
[2897]	1147	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1148	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1149	oro_max_l = 0.0_wp
[2696]	1150
[2897]	1151	DO nr = 1, SIZE(build_ids_final)
[4159]	1152	oro_max_l(nr) = MAXVAL( &
	1153	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1154	0.0_wp, &
	1155	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1156	build_ids_final(nr) ) )
	1157	ENDDO
[2696]	1158
	1159	#if defined( __parallel )
[2897]	1160	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1161	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1162	MPI_MAX, comm2d, ierr )
	1163	ENDIF
[2696]	1164	#else
[2897]	1165	oro_max = oro_max_l
[2696]	1166	#endif
[3051]	1167	!
	1168	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1169	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1170	!-- exceeds the scalar level the grid box is fully terrain and the
	1171	!-- maximum terrain is set to the zw level.
	1172	!-- terrain or
[3051]	1173	oro_max_l = 0.0
	1174	DO nr = 1, SIZE(build_ids_final)
	1175	DO k = nzb, nzt
	1176	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1177	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1178	ENDDO
[3142]	1179	oro_max(nr) = oro_max_l(nr)
[3051]	1180	ENDDO
[2897]	1181	ENDIF
[2696]	1182	!
[4245]	1183	!-- Allocate array for storing terrain height under buildings
	1184	IF ( buildings_f%from_file ) THEN
	1185	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
	1186	buildings_f%oro_max = buildings_f%fill1
	1187	END IF
	1188	!
[2867]	1189	!-- Map orography as well as buildings onto grid.
[2696]	1190	DO i = nxl, nxr
	1191	DO j = nys, nyn
[2867]	1192	topo_top_index = 0
[3142]	1193	!
	1194	!-- Obtain index in global building_id array
	1195	IF ( buildings_f%from_file ) THEN
	1196	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1197	!
	1198	!-- Determine index where maximum terrain height occupied by
	1199	!-- the respective building height is stored.
	1200	nr = MINLOC( ABS( build_ids_final - &
	1201	building_id_f%var(j,i) ), DIM = 1 )
[4245]	1202	!
	1203	!-- Save grid-indexed oro_max
	1204	buildings_f%oro_max(j,i) = oro_max(nr)
[3142]	1205	ENDIF
	1206	ENDIF
[2696]	1207	DO k = nzb, nzt
	1208	!
	1209	!-- In a first step, if grid point is below or equal the given
	1210	!-- terrain height, grid point is flagged to be of type natural.
	1211	!-- Please note, in case there is also a building which is lower
	1212	!-- than the vertical grid spacing, initialization of surface
	1213	!-- attributes will not be correct as given surface information
	1214	!-- will not be in accordance to the classified grid points.
[4159]	1215	!-- Hence, in this case, also a building flag.
[2747]	1216	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1217	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1218	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1219	topo_top_index = k ! topo_top_index + 1
[2696]	1220	ENDIF
	1221	!
	1222	!-- Set building grid points. Here, only consider 2D buildings.
	1223	!-- 3D buildings require separate treatment.
[2897]	1224	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1225	!
	1226	!-- Fill-up the terrain to the level of maximum orography
	1227	!-- within the building-covered area.
	1228	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1229	!
	1230	!-- Note, oro_max is always on zw level
	1231	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1232	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1233	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1234	ELSEIF ( zu(k) - ocean_offset <= &
	1235	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1236	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1237	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1238	ENDIF
	1239	ENDIF
	1240	ENDIF
	1241	ENDDO
	1242	!
[4159]	1243	!-- Special treatment for non grid-resolved buildings. This case,
	1244	!-- the uppermost terrain grid point is flagged as building as well
	1245	!-- well, even though no building exists at all. However, the
	1246	!-- surface element will be identified as urban-surface and the
	1247	!-- input data provided by the drivers is consistent to the surface
	1248	!-- classification. Else, all non grid-resolved buildings would vanish
	1249	!-- and identified as terrain grid points, which, however, won't be
	1250	!-- consistent with the input data.
	1251	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1252	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1253	DO k = nzb, nzt
	1254	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1255	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1256	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1257	ENDIF
	1258	ENDIF
	1259	ENDDO
	1260	ENDIF
	1261	ENDIF
	1262	!
[2696]	1263	!-- Map 3D buildings onto terrain height.
[2867]	1264	!-- In case of any slopes, map building on top of maximum terrain
	1265	!-- height covered by the building. In other words, extend
	1266	!-- building down to the respective local terrain-surface height.
[2897]	1267	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1268	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1269	!
[3051]	1270	!-- Extend building down to the terrain surface, i.e. fill-up
	1271	!-- surface irregularities below a building. Note, oro_max
	1272	!-- is already a discrete height according to the all-or-nothing
	1273	!-- approach, i.e. grid box is either topography or atmosphere,
	1274	!-- terrain top is defined at upper bound of the grid box.
	1275	!-- Hence, check for zw in this case.
[3115]	1276	!-- Note, do this only for buildings which are surface mounted,
	1277	!-- i.e. building types 1-6. Below bridges, which are represented
	1278	!-- exclusively by building type 7, terrain shape should be
	1279	!-- maintained.
[3855]	1280	IF ( building_type_f%from_file ) THEN
	1281	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1282	DO k = topo_top_index + 1, nzt + 1
[4159]	1283	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1284	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1285	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1286	ENDIF
	1287	ENDDO
	1288	!
	1289	!-- After surface irregularities are smoothen, determine
	1290	!-- lower start index where building starts.
	1291	DO k = nzb, nzt
[4159]	1292	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1293	topo_top_index = k
	1294	ENDDO
	1295	ENDIF
[3115]	1296	ENDIF
[3051]	1297	!
	1298	!-- Finally, map building on top.
[2867]	1299	k2 = 0
	1300	DO k = topo_top_index, nzt + 1
[2796]	1301	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1302	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1303	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1304	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1305	ENDIF
	1306	ENDIF
	1307	k2 = k2 + 1
	1308	ENDDO
	1309	ENDIF
	1310	ENDIF
	1311	ENDDO
	1312	ENDDO
	1313	!
[4265]	1314	!-- Horizontal exchange the oro_max array, which is required to for
	1315	!-- initialization of building-surface properties.
	1316	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
	1317	CALL exchange_horiz_2d( buildings_f%oro_max(:,:), nbgp )
	1318	ENDIF
[4245]	1319	!
[2696]	1320	!-- Deallocate temporary arrays required for processing and reading data
	1321	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1322	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1323	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1324	!
	1325	!-- Topography input via ASCII format.
	1326	ELSE
[3294]	1327	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1328	!
	1329	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1330	!-- and clear all grid points at nzb, where alway a surface is defined.
	1331	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1332	!-- used for masked data output and further processing. Note, in the
	1333	!-- ASCII case no distinction is made between buildings and terrain,
	1334	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1335	topo_3d = IBSET( topo_3d, 0 )
	1336	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1337	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1338	DO i = nxl, nxr
	1339	DO j = nys, nyn
	1340	DO k = nzb, nzt
[3538]	1341	!
	1342	!-- Flag topography for all grid points which are below
	1343	!-- the local topography height.
	1344	!-- Note, each topography is flagged as building.
[2747]	1345	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1346	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1347	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1348	ENDIF
	1349	ENDDO
	1350	ENDDO
	1351	ENDDO
	1352	ENDIF
	1353
	1354	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1355
	1356	IF ( .NOT. bc_ns_cyc ) THEN
	1357	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1358	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1359	ENDIF
	1360
	1361	IF ( .NOT. bc_lr_cyc ) THEN
	1362	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1363	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1364	ENDIF
	1365
	1366	END SUBROUTINE process_topography
	1367
	1368
	1369	! Description:
	1370	! -----------------------------------------------------------------------------!
	1371	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1372	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1373	!> equation on discrete grid cannot be fulfilled in such case.
	1374	!------------------------------------------------------------------------------!
	1375	SUBROUTINE filter_topography( topo_3d )
	1376
	1377	USE control_parameters, &
	1378	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1379
	1380	USE indices, &
	1381	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1382
	1383	USE netcdf_data_input_mod, &
	1384	ONLY: building_id_f, building_type_f
	1385
	1386	USE pegrid
	1387
	1388	IMPLICIT NONE
	1389
[2893]	1390	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1391
[2696]	1392	INTEGER(iwp) :: i !< running index along x-direction
	1393	INTEGER(iwp) :: j !< running index along y-direction
	1394	INTEGER(iwp) :: k !< running index along z-direction
	1395	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1396	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1397	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1398
[2955]	1399	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1400	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1401	!
	1402	!-- Before checking for holes, set lateral boundary conditions for
	1403	!-- topography. After hole-filling, boundary conditions must be set again.
	1404	!-- Several iterations are performed, in order to fill holes which might
	1405	!-- emerge by the filling-algorithm itself.
	1406	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1407	topo_tmp = 0
	1408
	1409	num_hole = 99999
	1410	DO WHILE ( num_hole > 0 )
	1411
	1412	num_hole = 0
	1413	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1414	!
	1415	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1416	!-- variable.
	1417	IF ( building_id_f%from_file ) &
	1418	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1419	IF ( building_type_f%from_file ) &
	1420	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1421
	1422	topo_tmp = topo_3d
	1423	!
	1424	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1425	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1426	!-- boundary and some topographic structure will be filled.
	1427	IF ( .NOT. bc_ns_cyc ) THEN
	1428	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1429	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1430	ENDIF
	1431
	1432	IF ( .NOT. bc_lr_cyc ) THEN
	1433	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1434	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1435	ENDIF
	1436
	1437	num_hole_l = 0
	1438	DO i = nxl, nxr
	1439	DO j = nys, nyn
	1440	DO k = nzb+1, nzt
	1441	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1442	num_wall = 0
	1443	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1444	num_wall = num_wall + 1
	1445	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1446	num_wall = num_wall + 1
	1447	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1448	num_wall = num_wall + 1
	1449	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1450	num_wall = num_wall + 1
	1451	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1452	num_wall = num_wall + 1
	1453	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1454	num_wall = num_wall + 1
	1455
	1456	IF ( num_wall >= 4 ) THEN
	1457	num_hole_l = num_hole_l + 1
	1458	!
[4314]	1459	!-- Clear flag 0 and set special flag ( bit 4) to indicate
[2696]	1460	!-- that new topography point is a result of filtering process.
	1461	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4314]	1462	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
[2696]	1463	!
	1464	!-- If filled grid point is occupied by a building, classify
	1465	!-- it as building grid point.
	1466	IF ( building_type_f%from_file ) THEN
	1467	IF ( building_type_f%var(j,i) /= &
	1468	building_type_f%fill .OR. &
	1469	building_type_f%var(j+1,i) /= &
	1470	building_type_f%fill .OR. &
	1471	building_type_f%var(j-1,i) /= &
	1472	building_type_f%fill .OR. &
	1473	building_type_f%var(j,i+1) /= &
	1474	building_type_f%fill .OR. &
	1475	building_type_f%var(j,i-1) /= &
	1476	building_type_f%fill ) THEN
	1477	!
	1478	!-- Set flag indicating building surfaces
	1479	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1480	!
	1481	!-- Set building_type and ID at this position if not
	1482	!-- already set. This is required for proper
	1483	!-- initialization of urban-surface energy balance
	1484	!-- solver.
	1485	IF ( building_type_f%var(j,i) == &
	1486	building_type_f%fill ) THEN
	1487
	1488	IF ( building_type_f%var(j+1,i) /= &
	1489	building_type_f%fill ) THEN
	1490	building_type_f%var(j,i) = &
	1491	building_type_f%var(j+1,i)
	1492	building_id_f%var(j,i) = &
	1493	building_id_f%var(j+1,i)
	1494	ELSEIF ( building_type_f%var(j-1,i) /= &
	1495	building_type_f%fill ) THEN
	1496	building_type_f%var(j,i) = &
	1497	building_type_f%var(j-1,i)
	1498	building_id_f%var(j,i) = &
	1499	building_id_f%var(j-1,i)
	1500	ELSEIF ( building_type_f%var(j,i+1) /= &
	1501	building_type_f%fill ) THEN
	1502	building_type_f%var(j,i) = &
	1503	building_type_f%var(j,i+1)
	1504	building_id_f%var(j,i) = &
	1505	building_id_f%var(j,i+1)
	1506	ELSEIF ( building_type_f%var(j,i-1) /= &
	1507	building_type_f%fill ) THEN
	1508	building_type_f%var(j,i) = &
	1509	building_type_f%var(j,i-1)
	1510	building_id_f%var(j,i) = &
	1511	building_id_f%var(j,i-1)
	1512	ENDIF
	1513	ENDIF
	1514	ENDIF
	1515	ENDIF
	1516	!
	1517	!-- If filled grid point is already classified as building
	1518	!-- everything is fine, else classify this grid point as
	1519	!-- natural type grid point. This case, values for the
	1520	!-- surface type are already set.
	1521	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1522	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1523	ENDIF
	1524	ENDIF
	1525	ENDIF
	1526	ENDDO
	1527	ENDDO
	1528	ENDDO
	1529	!
	1530	!-- Count the total number of holes, required for informative message.
	1531	#if defined( __parallel )
	1532	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1533	comm2d, ierr )
	1534	#else
	1535	num_hole = num_hole_l
	1536	#endif
[2893]	1537	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1538
[2893]	1539	ENDDO
[2696]	1540	!
[2893]	1541	!-- Create an informative message if any holes were filled.
	1542	IF ( filled ) THEN
	1543	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1544	'resolved by only one grid point ' // &
	1545	'were filled during initialization.'
	1546	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1547	ENDIF
[2696]	1548
	1549	DEALLOCATE( topo_tmp )
	1550	!
	1551	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1552	!-- condition in case of non-cyclic lateral boundaries.
	1553	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1554
	1555	IF ( .NOT. bc_ns_cyc ) THEN
	1556	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1557	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1558	ENDIF
	1559
	1560	IF ( .NOT. bc_lr_cyc ) THEN
	1561	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1562	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1563	ENDIF
[2955]	1564	!
	1565	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1566	IF ( building_id_f%from_file ) &
	1567	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1568	IF ( building_type_f%from_file ) &
	1569	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1570
	1571	END SUBROUTINE filter_topography
	1572
	1573
	1574	! Description:
	1575	! -----------------------------------------------------------------------------!
	1576	!> Reads topography information from file or sets generic topography. Moreover,
	1577	!> all topography-relevant topography arrays are initialized, and grid flags
	1578	!> are set.
	1579	!------------------------------------------------------------------------------!
	1580	SUBROUTINE init_topo( topo )
	1581
	1582	USE arrays_3d, &
	1583	ONLY: zw
	1584
	1585	USE control_parameters, &
	1586	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1587	building_length_y, building_wall_left, building_wall_south, &
	1588	canyon_height, canyon_wall_left, canyon_wall_south, &
	1589	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1590	message_string, topography, topography_grid_convention, &
[2696]	1591	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1592	tunnel_wall_depth
	1593
	1594	USE grid_variables, &
	1595	ONLY: dx, dy
	1596
	1597	USE indices, &
	1598	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1599	nzb, nzt
	1600
	1601	USE kinds
[4189]	1602
	1603	USE netcdf_data_input_mod, &
	1604	ONLY: buildings_f, terrain_height_f
[2696]	1605
	1606	USE pegrid
	1607
	1608	IMPLICIT NONE
	1609
[4386]	1610	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1611	INTEGER(iwp) :: ngp_bx !< grid point number of building size along x
	1612	INTEGER(iwp) :: ngp_by !< grid point number of building size along y
	1613	INTEGER(iwp) :: index_left_bwall !< index for left building wall
	1614	INTEGER(iwp) :: index_right_bwall !< index for right building wall
	1615	INTEGER(iwp) :: index_north_bwall !< index for north building wall
	1616	INTEGER(iwp) :: index_south_bwall !< index for south building wall
	1617	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1618	INTEGER(iwp) :: ngp_cx !< grid point number of canyon size along x
	1619	INTEGER(iwp) :: ngp_cy !< grid point number of canyon size along y
	1620	INTEGER(iwp) :: index_left_cwall !< index for left canyon wall
	1621	INTEGER(iwp) :: index_right_cwall !< index for right canyon wall
	1622	INTEGER(iwp) :: index_north_cwall !< index for north canyon wall
	1623	INTEGER(iwp) :: index_south_cwall !< index for south canyon wall
	1624	INTEGER(iwp) :: i !< index variable along x
	1625	INTEGER(iwp) :: j !< index variable along y
	1626	INTEGER(iwp) :: k !< index variable along z
	1627	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1628	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1629	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1630	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1631	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1632	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1633	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1634	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1635	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1636	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1637	INTEGER(iwp) :: td !< tunnel wall depth
	1638	INTEGER(iwp) :: th !< height of outer tunnel wall
[2696]	1639
	1640	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1641	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1642	!
[4189]	1643	!-- Check for correct setting of the namelist parameter topography. If
	1644	!-- topography information is read from file but topography = 'flat',
[4386]	1645	!-- initialization does not work properly.
[4189]	1646	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1647	TRIM( topography ) /= 'read_from_file' ) THEN
	1648	message_string = 'If topography information is provided (via ' // &
	1649	'Netcdf or ASCII input) topography = ' // &
	1650	'"read_from_file" is required.'
	1651	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1652	ENDIF
	1653	!
[1]	1654	!-- Set outer and inner index arrays for non-flat topography.
	1655	!-- Here consistency checks concerning domain size and periodicity are
	1656	!-- necessary.
	1657	!-- Within this SELECT CASE structure only nzb_local is initialized
	1658	!-- individually depending on the chosen topography type, all other index
	1659	!-- arrays are initialized further below.
	1660	SELECT CASE ( TRIM( topography ) )
	1661
	1662	CASE ( 'flat' )
[2696]	1663	!
[2232]	1664	!-- Initialilize 3D topography array, used later for initializing flags
[4340]	1665	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
	1666
	1667	CASE ( 'closed_channel' )
	1668	!
	1669	!-- Initialilize 3D topography array, used later for initializing flags
	1670	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
[1]	1671
	1672	CASE ( 'single_building' )
	1673	!
	1674	!-- Single rectangular building, by default centered in the middle of the
	1675	!-- total domain
[4386]	1676	ngp_bx = NINT( building_length_x / dx )
	1677	ngp_by = NINT( building_length_y / dy )
[2232]	1678	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1679	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1680	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1681	IF ( building_wall_left == 9999999.9_wp ) THEN
[4386]	1682	building_wall_left = ( nx + 1 - ngp_bx ) / 2 * dx
[1]	1683	ENDIF
[4386]	1684	index_left_bwall = NINT( building_wall_left / dx )
	1685	index_right_bwall = index_left_bwall + ngp_bx
[1]	1686
[1322]	1687	IF ( building_wall_south == 9999999.9_wp ) THEN
[4386]	1688	building_wall_south = ( ny + 1 - ngp_by ) / 2 * dy
[1]	1689	ENDIF
[4386]	1690	index_south_bwall = NINT( building_wall_south / dy )
	1691	index_north_bwall = index_south_bwall + ngp_by
[1]	1692
	1693	!
	1694	!-- Building size has to meet some requirements
[4386]	1695	IF ( ( index_left_bwall < 1 ) .OR. ( index_right_bwall > nx-1 ) .OR. &
	1696	( index_right_bwall < index_left_bwall+3 ) .OR. &
	1697	( index_south_bwall < 1 ) .OR. ( index_north_bwall > ny-1 ) .OR.&
	1698	( index_north_bwall < index_south_bwall+3 ) ) THEN
[274]	1699	WRITE( message_string, * ) 'inconsistent building parameters:', &
[4386]	1700	'&index_left_bwall=', index_left_bwall, &
	1701	'index_right_bwall=', index_right_bwall, &
	1702	'index_south_bwall=', index_south_bwall, &
	1703	'index_north_bwall=', index_north_bwall, &
	1704	'nx=', nx, 'ny=', ny
[254]	1705	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1706	ENDIF
	1707
[2696]	1708	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1709	nzb_local = 0
[1]	1710	!
[1968]	1711	!-- Define the building.
[4386]	1712	IF ( index_left_bwall <= nxr .AND. index_right_bwall >= nxl .AND. &
	1713	index_south_bwall <= nyn .AND. index_north_bwall >= nys ) &
	1714	nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall), &
	1715	MAX(nxl,index_left_bwall):MIN(nxr,index_right_bwall)) = bh
[2232]	1716	!
[2696]	1717	!-- Set bit array on basis of nzb_local
	1718	DO i = nxl, nxr
	1719	DO j = nys, nyn
	1720	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1721	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1722	ENDDO
	1723	ENDDO
[2696]	1724
	1725	DEALLOCATE( nzb_local )
[2232]	1726
[2696]	1727	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1728	!
	1729	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1730	!-- boundary conditions for topography.
	1731	IF ( .NOT. bc_ns_cyc ) THEN
	1732	IF ( nys == 0 ) THEN
	1733	DO i = 1, nbgp
	1734	topo(:,nys-i,:) = topo(:,nys,:)
	1735	ENDDO
	1736	ENDIF
	1737	IF ( nyn == ny ) THEN
	1738	DO i = 1, nbgp
	1739	topo(:,nyn+i,:) = topo(:,nyn,:)
	1740	ENDDO
	1741	ENDIF
	1742	ENDIF
	1743	IF ( .NOT. bc_lr_cyc ) THEN
	1744	IF ( nxl == 0 ) THEN
	1745	DO i = 1, nbgp
	1746	topo(:,:,nxl-i) = topo(:,:,nxl)
	1747	ENDDO
	1748	ENDIF
	1749	IF ( nxr == nx ) THEN
	1750	DO i = 1, nbgp
	1751	topo(:,:,nxr+i) = topo(:,:,nxr)
	1752	ENDDO
	1753	ENDIF
	1754	ENDIF
[2232]	1755
[240]	1756	CASE ( 'single_street_canyon' )
	1757	!
	1758	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1759	!-- The canyon is centered in the other direction by default.
[1322]	1760	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1761	!
	1762	!-- Street canyon in y direction
[4386]	1763	ngp_cx = NINT( canyon_width_x / dx )
[1322]	1764	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[4386]	1765	canyon_wall_left = ( nx + 1 - ngp_cx ) / 2 * dx
[240]	1766	ENDIF
[4386]	1767	index_left_cwall= NINT( canyon_wall_left / dx )
	1768	index_right_cwall= index_left_cwall+ ngp_cx
[1322]	1769	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1770	!
	1771	!-- Street canyon in x direction
[4386]	1772	ngp_cy = NINT( canyon_width_y / dy )
[1322]	1773	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[4386]	1774	canyon_wall_south = ( ny + 1 - ngp_cy ) / 2 * dy
[240]	1775	ENDIF
[4386]	1776	index_south_cwall = NINT( canyon_wall_south / dy )
	1777	index_north_cwall = index_south_cwall + ngp_cy
[2696]	1778
[240]	1779	ELSE
[254]	1780
	1781	message_string = 'no street canyon width given'
	1782	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1783
[240]	1784	ENDIF
	1785
[2232]	1786	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1787	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1788	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1789	dp_level_ind_b = ch
	1790	!
	1791	!-- Street canyon size has to meet some requirements
[1322]	1792	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[4386]	1793	IF ( ( index_left_cwall< 1 ) .OR. ( index_right_cwall> nx-1 ) .OR.&
	1794	( ngp_cx < 3 ) .OR. ( ch < 3 ) ) THEN
[1353]	1795	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[4386]	1796	'&index_left_cwall=', index_left_cwall, &
	1797	' index_right_cwall=', index_right_cwall, &
	1798	' ngp_cx=', ngp_cx, &
[3045]	1799	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1800	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1801	ENDIF
[1322]	1802	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[4386]	1803	IF ( ( index_south_cwall < 1 ) .OR. &
	1804	( index_north_cwall > ny-1 ) .OR. ( ngp_cy < 3 ) .OR. &
[2696]	1805	( ch < 3 ) ) THEN
[1353]	1806	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[4386]	1807	'&index_south_cwall=', index_south_cwall, &
	1808	' index_north_cwall=', index_north_cwall, &
	1809	' ngp_cy=', ngp_cy, &
[3045]	1810	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1811	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1812	ENDIF
	1813	ENDIF
[1353]	1814	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1815	canyon_width_y /= 9999999.9_wp ) THEN
	1816	message_string = 'inconsistent canyon parameters:' // &
[3046]	1817	'&street canyon can only be oriented' // &
[3045]	1818	' either in x- or in y-direction'
[254]	1819	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1820	ENDIF
	1821
[2696]	1822	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	1823	nzb_local = ch
[1322]	1824	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[4386]	1825	IF ( index_left_cwall<= nxr .AND. index_right_cwall>= nxl ) &
	1826	nzb_local(:,MAX(nxl,index_left_cwall+1):MIN(nxr,index_right_cwall-1)) = 0
[1322]	1827	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[4386]	1828	IF ( index_south_cwall <= nyn .AND. index_north_cwall >= nys ) &
	1829	nzb_local(MAX(nys,index_south_cwall+1):MIN(nyn,index_north_cwall-1),:) = 0
[240]	1830	ENDIF
[2232]	1831	!
[2696]	1832	!-- Set bit array on basis of nzb_local
	1833	DO i = nxl, nxr
	1834	DO j = nys, nyn
	1835	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1836	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1837	ENDDO
	1838	ENDDO
[2696]	1839	DEALLOCATE( nzb_local )
[1994]	1840
[2696]	1841	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1842	!
	1843	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1844	!-- boundary conditions for topography.
	1845	IF ( .NOT. bc_ns_cyc ) THEN
	1846	IF ( nys == 0 ) THEN
	1847	DO i = 1, nbgp
	1848	topo(:,nys-i,:) = topo(:,nys,:)
	1849	ENDDO
	1850	ENDIF
	1851	IF ( nyn == ny ) THEN
	1852	DO i = 1, nbgp
	1853	topo(:,nyn+i,:) = topo(:,nyn,:)
	1854	ENDDO
	1855	ENDIF
	1856	ENDIF
	1857	IF ( .NOT. bc_lr_cyc ) THEN
	1858	IF ( nxl == 0 ) THEN
	1859	DO i = 1, nbgp
	1860	topo(:,:,nxl-i) = topo(:,:,nxl)
	1861	ENDDO
	1862	ENDIF
	1863	IF ( nxr == nx ) THEN
	1864	DO i = 1, nbgp
	1865	topo(:,:,nxr+i) = topo(:,:,nxr)
	1866	ENDDO
	1867	ENDIF
	1868	ENDIF
[2232]	1869
	1870	CASE ( 'tunnel' )
	1871
	1872	!
	1873	!-- Tunnel height
	1874	IF ( tunnel_height == 9999999.9_wp ) THEN
	1875	th = zw( INT( 0.2 * nz) )
	1876	ELSE
	1877	th = tunnel_height
	1878	ENDIF
	1879	!
	1880	!-- Tunnel-wall depth
[2696]	1881	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	1882	td = MAX ( dx, dy, dz(1) )
[2232]	1883	ELSE
	1884	td = tunnel_wall_depth
	1885	ENDIF
	1886	!
	1887	!-- Check for tunnel width
	1888	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	1889	tunnel_width_y == 9999999.9_wp ) THEN
	1890	message_string = 'No tunnel width is given. '
[2274]	1891	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	1892	ENDIF
	1893	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	1894	tunnel_width_y /= 9999999.9_wp ) THEN
	1895	message_string = 'Inconsistent tunnel parameters:' // &
	1896	'tunnel can only be oriented' // &
	1897	'either in x- or in y-direction.'
[2274]	1898	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	1899	ENDIF
	1900	!
[4356]	1901	!-- Check for too small tunnel width in x- and y-direction
	1902	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	1903	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) THEN
	1904	message_string = 'tunnel_width_x too small'
	1905	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
	1906	ENDIF
	1907	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
	1908	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) THEN
	1909	message_string = 'tunnel_width_y too small'
	1910	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
	1911	ENDIF
	1912	!
	1913	!-- Check for too large tunnel width.
	1914	!-- Tunnel axis along y.
[2232]	1915	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	1916	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
[4356]	1917	message_string = 'tunnel_width_x too large'
[2274]	1918	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	1919	ENDIF
	1920
	1921	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	1922	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	1923	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	1924	( tunnel_width_x * 0.5_wp - td ) )
	1925	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	1926	( tunnel_width_x * 0.5_wp - td ) )
[2232]	1927
	1928	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	1929	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	1930	tys_in = tys_out
	1931	tye_in = tye_out
	1932	ENDIF
	1933	!
[4356]	1934	!-- Tunnel axis along x.
[2232]	1935	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	1936	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
[4356]	1937	message_string = 'tunnel_width_y too large'
[2274]	1938	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	1939	ENDIF
	1940
	1941	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	1942	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	1943	txs_in = txs_out
	1944	txe_in = txe_out
	1945
	1946	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	1947	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	1948	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	1949	( tunnel_width_y * 0.5_wp - td ) )
[2232]	1950	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	1951	( tunnel_width_y * 0.5_wp - td ) )
	1952	ENDIF
	1953
[2696]	1954	topo = 0
[2232]	1955	DO i = nxl, nxr
	1956	DO j = nys, nyn
	1957	!
	1958	!-- Use heaviside function to model outer tunnel surface
	1959	hv_out = th * 0.5_wp * &
	1960	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	1961	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	1962
	1963	hv_out = hv_out * 0.5_wp * &
	1964	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	1965	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	1966	!
[2232]	1967	!-- Use heaviside function to model inner tunnel surface
	1968	hv_in = ( th - td ) * 0.5_wp * &
	1969	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	1970	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	1971
	1972	hv_in = hv_in * 0.5_wp * &
	1973	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	1974	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	1975	!
	1976	!-- Set flags at x-y-positions without any tunnel surface
	1977	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	1978	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	1979	!
	1980	!-- Set flags at x-y-positions with tunnel surfaces
	1981	ELSE
	1982	DO k = nzb + 1, nzt + 1
	1983	!
	1984	!-- Inner tunnel
	1985	IF ( hv_out - hv_in == th ) THEN
	1986	IF ( zw(k) <= hv_out ) THEN
[2696]	1987	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	1988	ELSE
[2696]	1989	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	1990	ENDIF
	1991	ENDIF
	1992	!
	1993	!-- Lateral tunnel walls
	1994	IF ( hv_out - hv_in == td ) THEN
	1995	IF ( zw(k) <= hv_in ) THEN
[2696]	1996	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	1997	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	1998	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	1999	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	2000	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2001	ENDIF
	2002	ENDIF
	2003	ENDDO
	2004	ENDIF
	2005	ENDDO
	2006	ENDDO
	2007
[2696]	2008	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2009	!
	2010	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2011	!-- boundary conditions for topography.
	2012	IF ( .NOT. bc_ns_cyc ) THEN
	2013	IF ( nys == 0 ) THEN
	2014	DO i = 1, nbgp
	2015	topo(:,nys-i,:) = topo(:,nys,:)
	2016	ENDDO
	2017	ENDIF
	2018	IF ( nyn == ny ) THEN
	2019	DO i = 1, nbgp
	2020	topo(:,nyn+i,:) = topo(:,nyn,:)
	2021	ENDDO
	2022	ENDIF
	2023	ENDIF
	2024	IF ( .NOT. bc_lr_cyc ) THEN
	2025	IF ( nxl == 0 ) THEN
	2026	DO i = 1, nbgp
	2027	topo(:,:,nxl-i) = topo(:,:,nxl)
	2028	ENDDO
	2029	ENDIF
	2030	IF ( nxr == nx ) THEN
	2031	DO i = 1, nbgp
	2032	topo(:,:,nxr+i) = topo(:,:,nxr)
	2033	ENDDO
	2034	ENDIF
	2035	ENDIF
[2232]	2036
[1]	2037	CASE ( 'read_from_file' )
	2038	!
[2696]	2039	!-- Note, topography information have been already read.
	2040	!-- If required, further process topography, i.e. reference buildings on
	2041	!-- top of orography and set temporary 3D topography array, which is
	2042	!-- used later to set grid flags. Calling of this rouinte is also
	2043	!-- required in case of ASCII input, even though no distinction between
	2044	!-- terrain- and building height is made in this case.
	2045	CALL process_topography( topo )
[1968]	2046	!
[2696]	2047	!-- Filter holes resolved by only one grid-point
	2048	CALL filter_topography( topo )
[1968]	2049	!
[2696]	2050	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2051	!-- conditions.
	2052	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2053	!
[4314]	2054	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2055	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2056	IF ( nys == 0 ) THEN
[2696]	2057	DO i = 1, nbgp
	2058	topo(:,nys-i,:) = topo(:,nys,:)
	2059	ENDDO
[2550]	2060	ENDIF
[2696]	2061	IF ( nyn == ny ) THEN
	2062	DO i = 1, nbgp
	2063	topo(:,nyn+i,:) = topo(:,nyn,:)
	2064	ENDDO
	2065	ENDIF
[1942]	2066	ENDIF
[1910]	2067
[1968]	2068	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2069	IF ( nxl == 0 ) THEN
[2696]	2070	DO i = 1, nbgp
	2071	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2072	ENDDO
[2696]	2073	ENDIF
	2074	IF ( nxr == nx ) THEN
	2075	DO i = 1, nbgp
	2076	topo(:,:,nxr+i) = topo(:,:,nxr)
	2077	ENDDO
	2078	ENDIF
[2232]	2079	ENDIF
	2080
[667]	2081
[1]	2082	CASE DEFAULT
[2696]	2083	!
[1]	2084	!-- The DEFAULT case is reached either if the parameter topography
[217]	2085	!-- contains a wrong character string or if the user has defined a special
[1]	2086	!-- case in the user interface. There, the subroutine user_init_grid
	2087	!-- checks which of these two conditions applies.
[2696]	2088	CALL user_init_grid( topo )
	2089	CALL filter_topography( topo )
[1]	2090
	2091	END SELECT
	2092	!
	2093	!-- Consistency checks and index array initialization are only required for
[2696]	2094	!-- non-flat topography.
[1]	2095	IF ( TRIM( topography ) /= 'flat' ) THEN
	2096	!
[2232]	2097	!-- In case of non-flat topography, check whether the convention how to
	2098	!-- define the topography grid has been set correctly, or whether the default
	2099	!-- is applicable. If this is not possible, abort.
	2100	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
[4340]	2101	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
	2102	TRIM( topography ) /= 'single_building' .AND. &
[2232]	2103	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2104	TRIM( topography ) /= 'tunnel' .AND. &
	2105	TRIM( topography ) /= 'read_from_file') THEN
	2106	!-- The default value is not applicable here, because it is only valid
[3045]	2107	!-- for the four standard cases 'single_building',
	2108	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2109	!-- defined in init_grid.
	2110	WRITE( message_string, * ) &
[2696]	2111	'The value for "topography_grid_convention" ', &
[3046]	2112	'is not set. Its default value is & only valid for ', &
[3045]	2113	'"topography" = ''single_building'', ''tunnel'' ', &
[4340]	2114	'''single_street_canyon'', ''closed_channel'' & or ', &
	2115	'''read_from_file''.', &
[3046]	2116	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2117	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2118	ELSE
	2119	!-- The default value is applicable here.
	2120	!-- Set convention according to topography.
	2121	IF ( TRIM( topography ) == 'single_building' .OR. &
	2122	TRIM( topography ) == 'single_street_canyon' ) THEN
	2123	topography_grid_convention = 'cell_edge'
	2124	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2125	TRIM( topography ) == 'tunnel') THEN
	2126	topography_grid_convention = 'cell_center'
	2127	ENDIF
	2128	ENDIF
	2129	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2130	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2131	WRITE( message_string, * ) &
[2696]	2132	'The value for "topography_grid_convention" is ', &
[3046]	2133	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2134	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2135	ENDIF
[1]	2136
[2169]	2137
[217]	2138	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2139	!
[217]	2140	!-- The array nzb_local as defined using the 'cell_edge' convention
	2141	!-- describes the actual total size of topography which is defined at the
	2142	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2143	!-- on the topography walls in y-direction. However, PALM uses individual
	2144	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2145	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2146	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2147	!-- to form the basis for nzb_s_inner.
	2148	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2149	!-- required at this point.
	2150	DO j = nys+1, nyn+1
	2151	DO i = nxl-1, nxr
[2232]	2152	DO k = nzb, nzt+1
[2696]	2153	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2154	BTEST( topo(k,j,i+1), 0 ) ) &
	2155	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2156	ENDDO
	2157	ENDDO
	2158	ENDDO
[2696]	2159	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2160
	2161	DO i = nxl, nxr+1
	2162	DO j = nys-1, nyn
	2163	DO k = nzb, nzt+1
[2696]	2164	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2165	BTEST( topo(k,j+1,i), 0 ) ) &
	2166	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2167	ENDDO
	2168	ENDDO
	2169	ENDDO
[2696]	2170	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2171
[217]	2172	ENDIF
[2696]	2173	ENDIF
[2232]	2174
[1]	2175
[2696]	2176	END SUBROUTINE init_topo
[1]	2177
[2696]	2178	SUBROUTINE set_topo_flags(topo)
[1]	2179
[2696]	2180	USE control_parameters, &
[4294]	2181	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
	2182	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
[1]	2183
[2696]	2184	USE indices, &
[3241]	2185	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4346]	2186	nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
[1]	2187
[2696]	2188	USE kinds
[1]	2189
[2696]	2190	IMPLICIT NONE
[1804]	2191
[2696]	2192	INTEGER(iwp) :: i !< index variable along x
[4168]	2193	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2194	INTEGER(iwp) :: j !< index variable along y
	2195	INTEGER(iwp) :: k !< index variable along z
[1]	2196
[2696]	2197	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2198
[4329]	2199	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2200	wall_flags_static_0 = 0
[2232]	2201	!
[2696]	2202	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2203	!-- Further special flags will be set in following loops.
[2232]	2204	DO i = nxl, nxr
	2205	DO j = nys, nyn
	2206	DO k = nzb, nzt+1
	2207	!
	2208	!-- scalar grid
[4340]	2209	IF ( BTEST( topo(k,j,i), 0 ) ) &
[4329]	2210	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
[2232]	2211	!
[2696]	2212	!-- u grid
[4340]	2213	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2214	BTEST( topo(k,j,i-1), 0 ) ) &
[4329]	2215	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
[2696]	2216	!
[2232]	2217	!-- v grid
[4340]	2218	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2219	BTEST( topo(k,j-1,i), 0 ) ) &
[4329]	2220	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
[2696]	2221
[2232]	2222	ENDDO
[1]	2223
[2232]	2224	DO k = nzb, nzt
[1]	2225	!
[2232]	2226	!-- w grid
[4340]	2227	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2228	BTEST( topo(k+1,j,i), 0 ) ) &
[4329]	2229	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
[2232]	2230	ENDDO
[4340]	2231
	2232	IF ( topography /= 'closed_channel' ) THEN
	2233	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
	2234	ENDIF
[2232]	2235
	2236	ENDDO
	2237	ENDDO
[2696]	2238
[4329]	2239	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
[4346]	2240
[1]	2241	!
[4115]	2242	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2243	!-- basis of flag 24 futher flags will be derived which are used to control
	2244	!-- production of subgrid TKE production near walls.
[4346]	2245
	2246	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2247	wall_flags_total_0 = 0
	2248
[2696]	2249	DO i = nxl, nxr
	2250	DO j = nys, nyn
[2232]	2251	DO k = nzb, nzt+1
[4346]	2252	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
[2232]	2253	ENDDO
	2254	ENDDO
	2255	ENDDO
[4346]	2256
	2257	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2258
	2259	DO i = nxl, nxr
	2260	DO j = nys, nyn
	2261	DO k = nzb, nzt+1
	2262	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
	2263	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
	2264	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
	2265	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
	2266	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
	2267	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
	2268	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
	2269	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
	2270	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
	2271	ENDDO
	2272	ENDDO
	2273	ENDDO
[1]	2274	!
[2232]	2275	!-- Set further special flags
	2276	DO i = nxl, nxr
	2277	DO j = nys, nyn
	2278	DO k = nzb, nzt+1
[1]	2279	!
[2232]	2280	!-- scalar grid, former nzb_diff_s_inner.
	2281	!-- Note, use this flag also to mask topography in diffusion_u and
	2282	!-- diffusion_v along the vertical direction. In case of
	2283	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2284	!-- gradient approach is applied. Please note, in case of u- and v-
	2285	!-- diffuison, a small error is made at edges (on the east side for u,
	2286	!-- at the north side for v), since topography on scalar grid point
	2287	!-- is used instead of topography on u/v-grid. As number of topography grid
	2288	!-- points on uv-grid is different than s-grid, different number of
	2289	!-- surface elements would be required. In order to avoid this,
	2290	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2291	!-- points are not masked within diffusion_u. Tests had shown that the
	2292	!-- effect on the flow is negligible.
	2293	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2294	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2295	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2296	ELSE
[4346]	2297	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2298	ENDIF
[1]	2299
[2232]	2300	ENDDO
	2301	!
	2302	!-- Special flag to control vertical diffusion at model top - former
	2303	!-- nzt_diff
[4346]	2304	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
[2232]	2305	IF ( use_top_fluxes ) &
[4346]	2306	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
[1]	2307
[2696]	2308
[2232]	2309	DO k = nzb+1, nzt
	2310	!
	2311	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2312	!-- for disturb_field and initialization. Do not disturb directly at
	2313	!-- topography, as well as initialize u with zero one grid point outside
	2314	!-- of topography.
[4346]	2315	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2316	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2317	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2318	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
[2232]	2319	!
	2320	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2321	!-- for disturb_field and initialization. Do not disturb directly at
	2322	!-- topography, as well as initialize v with zero one grid point outside
	2323	!-- of topography.
[4346]	2324	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2325	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2326	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2327	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
[2232]	2328	!
	2329	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2330	!-- lpm_sgs_tke
[4346]	2331	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2332	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2333	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2334	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
[2232]	2335	!
	2336	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2337	!-- in production_e
	2338	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2339	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
	2340	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
	2341	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2342	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[2232]	2343	ELSE
[4346]	2344	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2345	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[1]	2346	ENDIF
[2232]	2347	!
	2348	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2349	!-- in production_e
	2350	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2351	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2352	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2353	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2354	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2355	ELSE
[4346]	2356	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2357	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2358	ENDIF
	2359	ENDDO
	2360	!
	2361	!-- Flags indicating downward facing walls
[4340]	2362	DO k = nzb+1, nzt+1
[2232]	2363	!
	2364	!-- Scalar grid
[4346]	2365	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2366	.NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2367	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
[2232]	2368	!
	2369	!-- Downward facing wall on u grid
[4346]	2370	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2371	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
	2372	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
[2232]	2373	!
	2374	!-- Downward facing wall on v grid
[4346]	2375	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2376	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
	2377	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
[2232]	2378	!
	2379	!-- Downward facing wall on w grid
[4346]	2380	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
	2381	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
	2382	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
[2232]	2383	ENDDO
	2384	!
	2385	!-- Flags indicating upward facing walls
	2386	DO k = nzb, nzt
	2387	!
	2388	!-- Upward facing wall on scalar grid
[4346]	2389	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2390	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2391	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
[2232]	2392	!
	2393	!-- Upward facing wall on u grid
[4346]	2394	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2395	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2396	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
[1]	2397
[2696]	2398	!
[2232]	2399	!-- Upward facing wall on v grid
[4346]	2400	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2401	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2402	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
[2696]	2403
[2232]	2404	!
	2405	!-- Upward facing wall on w grid
[4346]	2406	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
	2407	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
	2408	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
[2232]	2409	!
	2410	!-- Special flag on scalar grid, former nzb_s_inner
[4346]	2411	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
	2412	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
	2413	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
	2414	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
[2232]	2415	!
	2416	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2417	!-- flow_statistics
	2418	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2419	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2420	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2421	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[2232]	2422	ELSE
[4346]	2423	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
	2424	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[1]	2425	ENDIF
[2696]	2426
[1]	2427
[2232]	2428	ENDDO
[4346]	2429	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
	2430	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
[4109]	2431	!
	2432	!-- Set flags indicating that topography is close by in horizontal
	2433	!-- direction, i.e. flags that infold the topography. These will be used
	2434	!-- to set advection flags for passive scalars, where due to large
	2435	!-- gradients near buildings stationary numerical oscillations can produce
	2436	!-- unrealistically high concentrations. This is only necessary if
	2437	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2438	!-- only used for passive scalars such as chemical species or aerosols.
	2439	IF ( scalar_advec == 'ws-scheme' ) THEN
	2440	DO k = nzb, nzt
[4346]	2441	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
	2442	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2443	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2444	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2445	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2446	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2447	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2448	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2449	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2450	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2451	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2452	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2453	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
	2454	) ) &
	2455	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
[4109]	2456
	2457	ENDDO
	2458	ENDIF
[2232]	2459	ENDDO
	2460	ENDDO
	2461	!
[2696]	2462	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2463	!-- Natural terrain grid points. Information on the type of the surface is
	2464	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2465	!-- when topography is read from file. In order to run the land-surface model
	2466	!-- also without topography information, set bit 1 explicitely in this case.
[4294]	2467	!--
	2468	!-- Natural terrain grid points
	2469	!-- If no topography is initialized, the land-surface is at k = nzb.
	2470	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
[4329]	2471	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
[4294]	2472	ELSE
	2473	DO i = nxl, nxr
	2474	DO j = nys, nyn
	2475	DO k = nzb, nzt+1
[4189]	2476	!
[4294]	2477	!-- Natural terrain grid point
	2478	IF ( BTEST( topo(k,j,i), 1 ) ) &
[4329]	2479	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
[2696]	2480	ENDDO
	2481	ENDDO
[4294]	2482	ENDDO
[2696]	2483	ENDIF
	2484	!
	2485	!-- Building grid points.
[4294]	2486	DO i = nxl, nxr
	2487	DO j = nys, nyn
	2488	DO k = nzb, nzt+1
	2489	IF ( BTEST( topo(k,j,i), 2 ) ) &
[4329]	2490	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
[2696]	2491	ENDDO
	2492	ENDDO
[4294]	2493	ENDDO
[2696]	2494	!
[4314]	2495	!-- Set flag 4, indicating new topography grid points due to filtering.
	2496	DO i = nxl, nxr
	2497	DO j = nys, nyn
	2498	DO k = nzb, nzt+1
	2499	IF ( BTEST( topo(k,j,i), 4 ) ) &
[4329]	2500	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
[4314]	2501	ENDDO
	2502	ENDDO
	2503	ENDDO
[4346]	2504
	2505	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2506
	2507	DO i = nxl, nxr
	2508	DO j = nys, nyn
	2509	DO k = nzb, nzt+1
	2510	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
	2511	ENDDO
	2512	ENDDO
	2513	ENDDO
[4314]	2514	!
[2232]	2515	!-- Exchange ghost points for wall flags
[4346]	2516	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2517	!
	2518	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2519	!-- boundary conditions for topography.
	2520	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2521	IF ( nys == 0 ) THEN
	2522	DO i = 1, nbgp
[4346]	2523	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
[2696]	2524	ENDDO
	2525	ENDIF
	2526	IF ( nyn == ny ) THEN
	2527	DO i = 1, nbgp
[4346]	2528	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
[2696]	2529	ENDDO
	2530	ENDIF
[2232]	2531	ENDIF
	2532	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2533	IF ( nxl == 0 ) THEN
	2534	DO i = 1, nbgp
[4346]	2535	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
[2696]	2536	ENDDO
[2232]	2537	ENDIF
[2696]	2538	IF ( nxr == nx ) THEN
	2539	DO i = 1, nbgp
[4346]	2540	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
[2232]	2541	ENDDO
[2696]	2542	ENDIF
[2232]	2543	ENDIF
[4168]	2544	!
	2545	!-- Pre-calculate topography top indices (former get_topography_top_index
	2546	!-- function)
	2547	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2548	!
	2549	!-- Uppermost topography index on scalar grid
	2550	ibit = 12
	2551	topo_top_ind(:,:,0) = MAXLOC( &
	2552	MERGE( 1, 0, &
[4346]	2553	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2554	), DIM = 1 &
	2555	) - 1
	2556	!
	2557	!-- Uppermost topography index on u grid
	2558	ibit = 14
	2559	topo_top_ind(:,:,1) = MAXLOC( &
	2560	MERGE( 1, 0, &
[4346]	2561	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2562	), DIM = 1 &
	2563	) - 1
	2564	!
	2565	!-- Uppermost topography index on v grid
	2566	ibit = 16
	2567	topo_top_ind(:,:,2) = MAXLOC( &
	2568	MERGE( 1, 0, &
[4346]	2569	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2570	), DIM = 1 &
	2571	) - 1
	2572	!
	2573	!-- Uppermost topography index on w grid
	2574	ibit = 18
	2575	topo_top_ind(:,:,3) = MAXLOC( &
	2576	MERGE( 1, 0, &
[4346]	2577	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2578	), DIM = 1 &
	2579	) - 1
	2580	!
	2581	!-- Uppermost topography index on scalar outer grid
	2582	ibit = 24
	2583	topo_top_ind(:,:,4) = MAXLOC( &
	2584	MERGE( 1, 0, &
[4346]	2585	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2586	), DIM = 1 &
[4414]	2587	) - 1
	2588
[2696]	2589	END SUBROUTINE set_topo_flags
[114]	2590
	2591
	2592
[4414]	2593

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