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source: palm/trunk/SOURCE/init_grid.f90 @ 4415

Last change on this file since 4415 was 4414, checked in by suehring, 5 years ago
Remove deprecated topography arrays; Move basic initialization of numerics into an extra module interface
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File size: 117.6 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 4414 2020-02-19 20:16:04Z raasch $
[4414]	27	! - Remove deprecated topography arrays nzb_s_inner, nzb_u_inner, etc.
	28	! - Move initialization of boundary conditions and multigrid into an extra
	29	! module interface.
	30	!
	31	! 4386 2020-01-27 15:07:30Z Giersch
[4386]	32	! Allocation statements, comments, naming of variables revised and _wp added to
	33	! real type values
	34	!
	35	! 4360 2020-01-07 11:25:50Z suehring
[4356]	36	! Revise error messages for generic tunnel setup.
	37	!
	38	! 4346 2019-12-18 11:55:56Z motisi
[4346]	39	! Introduction of wall_flags_total_0, which currently sets bits based on static
	40	! topography information used in wall_flags_static_0
	41	!
	42	! 4340 2019-12-16 08:17:03Z Giersch
[4340]	43	! Topography closed channel flow with symmetric boundaries implemented
	44	!
	45	! 4329 2019-12-10 15:46:36Z motisi
[4329]	46	! Renamed wall_flags_0 to wall_flags_static_0
	47	!
	48	! 4328 2019-12-09 18:53:04Z suehring
[4328]	49	! Minor change in nzb_max computation. Commentation added.
	50	!
	51	! 4314 2019-11-29 10:29:20Z suehring
[4314]	52	! Set additional topography flag 4 to mark topography grid points emerged
	53	! from the filtering process.
	54	!
	55	! 4294 2019-11-13 18:34:16Z suehring
[4294]	56	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
	57	! building surfaces in all cases, in order to enable terrain-following output
	58	! also when no land- or urban-surface model is applied.
	59	!
	60	! 4265 2019-10-15 16:16:24Z suehring
[4265]	61	! Bugfix for last commit, exchange oro_max variable only when it is allocated
	62	! (not necessarily the case when topography is input from ASCII file).
	63	!
	64	! 4245 2019-09-30 08:40:37Z pavelkrc
[4245]	65	! Store oro_max (building z-offset) in 2D for building surfaces
	66	!
	67	! 4189 2019-08-26 16:19:38Z suehring
[4189]	68	! - Add check for proper setting of namelist parameter topography
	69	! - Set flag to indicate land surfaces in case no topography is provided
	70	!
	71	! 4182 2019-08-22 15:20:23Z scharf
[4182]	72	! Corrected "Former revisions" section
	73	!
	74	! 4168 2019-08-16 13:50:17Z suehring
[4168]	75	! Pre-calculate topography top index and store it on an array (replaces former
	76	! functions get_topography_top_index)
	77	!
	78	! 4159 2019-08-15 13:31:35Z suehring
[4159]	79	! Revision of topography processing. This was not consistent between 2D and 3D
	80	! buildings.
	81	!
	82	! 4144 2019-08-06 09:11:47Z raasch
[4144]	83	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	84	!
	85	! 4115 2019-07-24 12:50:49Z suehring
[4115]	86	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	87	!
	88	! 4110 2019-07-22 17:05:21Z suehring
[4110]	89	! - Separate initialization of advection flags for momentum and scalars.
	90	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	91	!
	92	! 4109 2019-07-22 17:00:34Z suehring
[3927]	93	! Fix bad commit
	94	!
	95	! 3926 2019-04-23 12:56:42Z suehring
[3925]	96	! Minor bugfix in building mapping when all building IDs in the model domain
	97	! are missing
	98	!
	99	! 3857 2019-04-03 13:00:16Z knoop
[3855]	100	! In projection of non-building 3D objects onto numerical grid remove
	101	! dependency on building_type
	102	!
	103	! 3763 2019-02-25 17:33:49Z suehring
[3763]	104	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	105	! routine as already done in other routines
	106	!
	107	! 3761 2019-02-25 15:31:42Z raasch
[3761]	108	! unused variables removed
	109	!
	110	! 3661 2019-01-08 18:22:50Z suehring
[3661]	111	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	112	! order degradation of advection scheme is handeled directly in advec_ws
	113	!
	114	! 3655 2019-01-07 16:51:22Z knoop
[3538]	115	! Comment added
[2716]	116	!
[4182]	117	! Revision 1.1 1997/08/11 06:17:45 raasch
	118	! Initial revision (Testversion)
	119	!
	120	!
[1]	121	! Description:
[2696]	122	! -----------------------------------------------------------------------------!
[1682]	123	!> Creating grid depending constants
[2696]	124	!> @todo: Rearrange topo flag list
	125	!> @todo: reference 3D buildings on top of orography is not tested and may need
	126	!> further improvement for steep slopes
	127	!> @todo: Use more advanced setting of building type at filled holes
[1]	128	!------------------------------------------------------------------------------!
[1682]	129	SUBROUTINE init_grid
[1]	130
[1320]	131	USE arrays_3d, &
[3857]	132	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[4414]	133
[1353]	134	USE control_parameters, &
[4414]	135	ONLY: constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	136	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	137	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	138	dz_stretch_level_start, ibc_uv_b, message_string, &
[4414]	139	number_stretch_level_end, &
	140	number_stretch_level_start, &
	141	ocean_mode, &
	142	psolver, &
	143	symmetry_flag, &
	144	topography, &
	145	use_surface_fluxes
	146
[1320]	147	USE grid_variables, &
[2232]	148	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[4414]	149
[1320]	150	USE indices, &
[4414]	151	ONLY: nbgp, &
	152	nx, &
	153	nxl, &
	154	nxlg, &
	155	nxr, &
	156	nxrg, &
	157	ny, &
	158	nyn, &
	159	nyng, &
	160	nys, &
	161	nysg, &
	162	nz, &
	163	nzb, &
	164	nzb_diff, &
	165	nzb_max, &
	166	nzt, &
	167	topo_top_ind, &
	168	topo_min_level
	169
[1320]	170	USE kinds
[2696]	171
[1]	172	USE pegrid
	173
[2365]	174	USE vertical_nesting_mod, &
	175	ONLY: vnested, vnest_init_grid
	176
[1]	177	IMPLICIT NONE
	178
[3182]	179	INTEGER(iwp) :: i !< index variable along x
	180	INTEGER(iwp) :: j !< index variable along y
	181	INTEGER(iwp) :: k !< index variable along z
	182	INTEGER(iwp) :: k_top !< topography top index on local PE
	183	INTEGER(iwp) :: n !< loop variable for stretching
	184	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	185	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	186	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[1]	187
[2696]	188	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	189
[3065]	190	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	191	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	192
	193	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	194
[1]	195
	196	!
[709]	197	!-- Calculation of horizontal array bounds including ghost layers
[667]	198	nxlg = nxl - nbgp
	199	nxrg = nxr + nbgp
	200	nysg = nys - nbgp
	201	nyng = nyn + nbgp
[709]	202
[667]	203	!
[1]	204	!-- Allocate grid arrays
[4386]	205	ALLOCATE( x(0:nx) )
	206	ALLOCATE( xu(0:nx) )
	207
[3857]	208	DO i = 0, nx
	209	xu(i) = i * dx
	210	x(i) = i * dx + 0.5_wp * dx
	211	ENDDO
	212
[4386]	213	ALLOCATE( y(0:ny) )
	214	ALLOCATE( yv(0:ny) )
	215
[3857]	216	DO j = 0, ny
	217	yv(j) = j * dy
	218	y(j) = j * dy + 0.5_wp * dy
	219	ENDDO
	220
[4386]	221	ALLOCATE( ddzu(1:nzt+1) )
	222	ALLOCATE( ddzw(1:nzt+1) )
	223	ALLOCATE( dd2zu(1:nzt) )
	224	ALLOCATE( dzu(1:nzt+1) )
	225	ALLOCATE( dzw(1:nzt+1) )
	226	ALLOCATE( zu(nzb:nzt+1) )
	227	ALLOCATE( zw(nzb:nzt+1) )
[1]	228
	229	!
[4386]	230	!-- For constructing an appropriate grid, the vertical grid spacing dz has to
	231	!-- be specified with a non-negative value in the parameter file
[3065]	232	IF ( dz(1) == -1.0_wp ) THEN
[254]	233	message_string = 'missing dz'
	234	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	235	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	236	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	237	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	238	ENDIF
[94]	239
[1]	240	!
[3065]	241	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	242	!-- if it was set by the user
	243	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	244	dz_stretch_level_start(1) = dz_stretch_level
	245	ENDIF
	246
	247	!
	248	!-- Determine number of dz values and stretching levels specified by the
	249	!-- user to allow right controlling of the stretching mechanism and to
[3139]	250	!-- perform error checks. The additional requirement that dz /= dz_max
	251	!-- for counting number of user-specified dz values is necessary. Otherwise
	252	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	253	!-- is used (Attention: The user is not allowed to specify a dz value equal
	254	!-- to the default of dz_max = 999.0).
	255	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	256	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	257	-9999999.9_wp )
	258	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	259	9999999.9_wp )
	260
	261	!
[4386]	262	!-- The number of specified end levels +1 has to be the same as the number
[3065]	263	!-- of specified dz values
	264	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
[4386]	265	WRITE( message_string, * ) 'The number of values for dz = ', &
	266	number_dz, 'has to be the same as& ', &
	267	'the number of values for ', &
	268	'dz_stretch_level_end + 1 = ', &
[3065]	269	number_stretch_level_end+1
	270	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	271	ENDIF
	272
	273	!
[4386]	274	!-- The number of specified start levels has to be the same or one less than
	275	!-- the number of specified dz values
	276	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
[3065]	277	number_dz /= number_stretch_level_start ) THEN
[4386]	278	WRITE( message_string, * ) 'The number of values for dz = ', &
	279	number_dz, 'has to be the same as or one ', &
	280	'more than& the number of values for ', &
	281	'dz_stretch_level_start = ', &
[3065]	282	number_stretch_level_start
	283	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	284	ENDIF
	285
[4386]	286	!-- The number of specified start levels has to be the same or one more than
	287	!-- the number of specified end levels
	288	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
[3065]	289	number_stretch_level_start /= number_stretch_level_end ) THEN
[4386]	290	WRITE( message_string, * ) 'The number of values for ', &
	291	'dz_stretch_level_start = ', &
	292	dz_stretch_level_start, 'has to be the ', &
	293	'same or one more than& the number of ', &
	294	'values for dz_stretch_level_end = ', &
[3065]	295	number_stretch_level_end
	296	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	297	ENDIF
	298
	299	!
	300	!-- Initialize dz for the free atmosphere with the value of dz_max
	301	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	302	number_stretch_level_start /= 0 ) THEN
	303	dz(number_stretch_level_start+1) = dz_max
	304	ENDIF
	305
	306	!
	307	!-- Initialize the stretching factor if (infinitely) stretching in the free
	308	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	309	!-- free atmosphere)
	310	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	311	dz_stretch_factor_array(number_stretch_level_start) = &
	312	dz_stretch_factor
	313	ENDIF
	314
	315	!
	316	!-- Allocation of arrays for stretching
	317	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	318
[3065]	319	!
[4386]	320	!-- Define the vertical grid levels. Start with atmosphere branch
[3294]	321	IF ( .NOT. ocean_mode ) THEN
[3065]	322
[94]	323	!
[3065]	324	!-- The stretching region has to be large enough to allow for a smooth
[4386]	325	!-- transition between two different grid spacings. The number 4 is an
	326	!-- empirical value
[3065]	327	DO n = 1, number_stretch_level_start
	328	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	329	4 * MAX( dz(n),dz(n+1) )
	330	ENDDO
	331
[3066]	332	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	333	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[4386]	334	message_string= 'Each dz_stretch_level_end has to be larger ' // &
[3065]	335	'than its corresponding value for &' // &
	336	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	337	'to allow for smooth grid stretching'
	338	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	339	ENDIF
	340
	341	!
[4386]	342	!-- Stretching must not be applied within the surface layer
[3065]	343	!-- (first two grid points). For the default case dz_stretch_level_start
	344	!-- is negative. Therefore the absolut value is checked here.
[4386]	345	IF ( ANY( ABS( dz_stretch_level_start ) <= dz(1) * 1.5_wp ) ) THEN
	346	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
[3065]	347	'larger than ', dz(1) * 1.5
	348	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	349	ENDIF
	350
	351	!
	352	!-- The stretching has to start and end on a grid level. Therefore
[4386]	353	!-- user-specified values are mapped to the next lowest level. The
	354	!-- calculation of the first level is realized differently just because of
	355	!-- historical reasons (the advanced/new stretching mechanism was realized
	356	!-- in a way that results don't change if the old parameters
	357	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
[3065]	358	IF ( number_stretch_level_start /= 0 ) THEN
	359	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	360	dz(1)/2.0) / dz(1) ) &
	361	* dz(1) + dz(1)/2.0
	362	ENDIF
	363
	364	IF ( number_stretch_level_start > 1 ) THEN
	365	DO n = 2, number_stretch_level_start
	366	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	367	dz(n) ) * dz(n)
	368	ENDDO
	369	ENDIF
	370
	371	IF ( number_stretch_level_end /= 0 ) THEN
	372	DO n = 1, number_stretch_level_end
	373	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	374	dz(n+1) ) * dz(n+1)
	375	ENDDO
	376	ENDIF
[4386]	377
[3065]	378	!
	379	!-- Determine stretching factor if necessary
	380	IF ( number_stretch_level_end >= 1 ) THEN
	381	CALL calculate_stretching_factor( number_stretch_level_end )
	382	ENDIF
	383
	384	!
[94]	385	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	386	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	387	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	388	!-- The second u-level (k=1) corresponds to the top of the
[4386]	389	!-- surface layer. In case of symmetric boundaries (closed channel flow),
[4340]	390	!-- the first grid point is always at z=0.
	391	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. &
	392	topography == 'closed_channel' ) THEN
[1353]	393	zu(0) = 0.0_wp
[667]	394	ELSE
[3065]	395	zu(0) = - dz(1) * 0.5_wp
[667]	396	ENDIF
[3065]	397
	398	zu(1) = dz(1) * 0.5_wp
	399
	400	!
	401	!-- Determine u and v height levels considering the possibility of grid
	402	!-- stretching in several heights.
	403	n = 1
	404	dz_stretch_level_start_index = nzt+1
	405	dz_stretch_level_end_index = nzt+1
	406	dz_stretched = dz(1)
[1]	407
[3065]	408	!-- The default value of dz_stretch_level_start is negative, thus the first
[4386]	409	!-- condition is true even if no stretching shall be applied. Hence, the
	410	!-- second condition is also necessary.
[4340]	411	DO k = 2, nzt+1-symmetry_flag
[3065]	412	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	413	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	414	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	415
	416	IF ( dz(n) > dz(n+1) ) THEN
	417	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	418	ELSE
	419	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	420	ENDIF
	421
	422	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	423	dz_stretch_level_start_index(n) = k-1
	424
[94]	425	ENDIF
[3065]	426
[94]	427	zu(k) = zu(k-1) + dz_stretched
[3065]	428
	429	!
	430	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	431	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	432
	433	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	434	zu(k) = dz_stretch_level_end(n)
	435	dz_stretched = dz(n+1)
	436	dz_stretch_level_end_index(n) = k
	437	n = n + 1
	438	ENDIF
[94]	439	ENDDO
[4340]	440
	441	!
	442	!-- If a closed channel flow is simulated, make sure that grid structure is
	443	!-- the same for both bottom and top boundary. (Hint: Using a different dz
	444	!-- at the bottom and at the top makes no sense due to symmetric boundaries
	445	!-- where dz should be equal. Therefore, different dz at the bottom and top
	446	!-- causes an abort (see check_parameters).)
	447	IF ( topography == 'closed_channel' ) THEN
	448	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
	449	ENDIF
[1]	450
	451	!
[94]	452	!-- Compute the w-levels. They are always staggered half-way between the
[843]	453	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	454	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
[4340]	455	!-- Per default, the top w-level is extrapolated linearly. In case of
	456	!-- a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
	457	!-- (Hint: Using a different dz at the bottom and at the top makes no sense
	458	!-- due to symmetric boundaries where dz should be equal. Therefore,
	459	!-- different dz at the bottom and top causes an abort (see
	460	!-- check_parameters).)
[1353]	461	zw(0) = 0.0_wp
[4340]	462	DO k = 1, nzt-symmetry_flag
[1353]	463	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	464	ENDDO
[4340]	465	IF ( topography == 'closed_channel' ) THEN
	466	zw(nzt) = zw(nzt-1) + dz(1)
	467	zw(nzt+1) = zw(nzt) + dz(1)
	468	ELSE
	469	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
	470	ENDIF
[1]	471
[4386]	472	ELSE !ocean branch
[3065]	473
[1]	474	!
[3065]	475	!-- The stretching region has to be large enough to allow for a smooth
[4386]	476	!-- transition between two different grid spacings. The number 4 is an
	477	!-- empirical value
[3065]	478	DO n = 1, number_stretch_level_start
	479	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	480	4 * MAX( dz(n),dz(n+1) )
	481	ENDDO
	482
[3066]	483	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	484	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[4386]	485	message_string= 'Each dz_stretch_level_end has to be less ' // &
[3065]	486	'than its corresponding value for &' // &
	487	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	488	'to allow for smooth grid stretching'
	489	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	490	ENDIF
	491
	492	!
[3068]	493	!-- Stretching must not be applied close to the surface (last two grid
	494	!-- points). For the default case dz_stretch_level_start is negative.
[4386]	495	IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) ) THEN
	496	WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
	497	'less than ', -dz(1) * 1.5
[3065]	498	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	499	ENDIF
	500
	501	!
	502	!-- The stretching has to start and end on a grid level. Therefore
[4386]	503	!-- user-specified values are mapped to the next highest level. The
	504	!-- calculation of the first level is realized differently just because of
	505	!-- historical reasons (the advanced/new stretching mechanism was realized
	506	!-- in a way that results don't change if the old parameters
	507	!-- dz_stretch_level, dz_stretch_factor and dz_max are used)
[3065]	508	IF ( number_stretch_level_start /= 0 ) THEN
	509	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	510	dz(1)/2.0) / dz(1) ) &
	511	* dz(1) - dz(1)/2.0
	512	ENDIF
	513
	514	IF ( number_stretch_level_start > 1 ) THEN
	515	DO n = 2, number_stretch_level_start
	516	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	517	dz(n) ) * dz(n)
	518	ENDDO
	519	ENDIF
	520
	521	IF ( number_stretch_level_end /= 0 ) THEN
	522	DO n = 1, number_stretch_level_end
	523	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	524	dz(n+1) ) * dz(n+1)
	525	ENDDO
	526	ENDIF
	527
	528	!
	529	!-- Determine stretching factor if necessary
	530	IF ( number_stretch_level_end >= 1 ) THEN
	531	CALL calculate_stretching_factor( number_stretch_level_end )
	532	ENDIF
	533
	534	!
[843]	535	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	536	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	537	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	538	!-- w-level are defined at same height, but staggered from the second level.
[4386]	539	!-- The second u-level (k=1) corresponds to the top of the surface layer.
[3065]	540	!-- z values are negative starting from z=0 (surface)
	541	zu(nzt+1) = dz(1) * 0.5_wp
	542	zu(nzt) = - dz(1) * 0.5_wp
[94]	543
[3065]	544	!
	545	!-- Determine u and v height levels considering the possibility of grid
	546	!-- stretching in several heights.
	547	n = 1
	548	dz_stretch_level_start_index = 0
	549	dz_stretch_level_end_index = 0
	550	dz_stretched = dz(1)
	551
[94]	552	DO k = nzt-1, 0, -1
[3065]	553
	554	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	555	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	556
	557	IF ( dz(n) > dz(n+1) ) THEN
	558	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	559	ELSE
	560	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	561	ENDIF
	562
	563	IF ( dz_stretch_level_start_index(n) == 0 ) &
	564	dz_stretch_level_start_index(n) = k+1
	565
	566	ENDIF
	567
	568	zu(k) = zu(k+1) - dz_stretched
	569
[1418]	570	!
[3065]	571	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	572	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	573
	574	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	575	zu(k) = dz_stretch_level_end(n)
	576	dz_stretched = dz(n+1)
	577	dz_stretch_level_end_index(n) = k
	578	n = n + 1
[94]	579	ENDIF
	580	ENDDO
[3065]	581
[94]	582	!
	583	!-- Compute the w-levels. They are always staggered half-way between the
[843]	584	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	585	!-- at the ground. In this case the first u- and w-level are defined at
	586	!-- same height. The top w-level (nzt+1) is not used but set for
	587	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	588	zw(nzt+1) = dz(1)
[1353]	589	zw(nzt) = 0.0_wp
[94]	590	DO k = 0, nzt
[1353]	591	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	592	ENDDO
	593
[843]	594	!
	595	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	596	!-- at same height.
	597	IF ( ibc_uv_b == 0 ) THEN
	598	zu(0) = zw(0)
	599	ENDIF
	600
[4386]	601	ENDIF !End of defining the vertical grid levels
[94]	602
	603	!
[1]	604	!-- Compute grid lengths.
	605	DO k = 1, nzt+1
	606	dzu(k) = zu(k) - zu(k-1)
[1353]	607	ddzu(k) = 1.0_wp / dzu(k)
[1]	608	dzw(k) = zw(k) - zw(k-1)
[1353]	609	ddzw(k) = 1.0_wp / dzw(k)
[1]	610	ENDDO
	611
	612	DO k = 1, nzt
[1353]	613	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	614	ENDDO
[667]	615
	616	!
[709]	617	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	618	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	619	!-- is only dz/2, but should be dz. Therefore, an additional array
	620	!-- containing with appropriate grid information is created for these
	621	!-- solvers.
[1575]	622	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	623	ALLOCATE( ddzu_pres(1:nzt+1) )
	624	ddzu_pres = ddzu
[864]	625	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	626	ENDIF
	627
	628	!
	629	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	630	ddx = 1.0_wp / dx
	631	ddy = 1.0_wp / dy
[1]	632	dx2 = dx * dx
	633	dy2 = dy * dy
[1353]	634	ddx2 = 1.0_wp / dx2
	635	ddy2 = 1.0_wp / dy2
[1]	636
	637	!
[2696]	638	!-- Allocate 3D array to set topography
	639	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	640	topo = 0
	641	!
[4386]	642	!-- Initialize topography by generic topography or read topography from file.
[2696]	643	CALL init_topo( topo )
	644	!
	645	!-- Set flags to mask topography on the grid.
[4414]	646	CALL set_topo_flags( topo )
[2696]	647
	648	!
	649	!-- Determine the maximum level of topography. It is used for
	650	!-- steering the degradation of order of the applied advection scheme,
[4328]	651	!-- as well in the lpm.
[2696]	652	k_top = 0
	653	DO i = nxl, nxr
	654	DO j = nys, nyn
	655	DO k = nzb, nzt + 1
[4109]	656	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	657	ENDDO
	658	ENDDO
[1]	659	ENDDO
[2696]	660	#if defined( __parallel )
[4328]	661	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, &
[2696]	662	MPI_MAX, comm2d, ierr )
	663	#else
[4328]	664	nzb_max = k_top
[2696]	665	#endif
[1]	666	!
[4328]	667	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
	668	!-- Further, in case topography extents up to the model top, limit to nzt.
	669	nzb_max = MIN( nzb_max+1, nzt )
	670	!
[2968]	671	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	672	!-- there is elevated topography, however, the lowest topography will be higher.
	673	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	674	!-- temperature, surface pressure and density, etc. .
	675	topo_min_level = 0
	676	#if defined( __parallel )
[4168]	677	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	678	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	679	#else
[4168]	680	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	681	#endif
[3182]	682
[2696]	683	!
[2968]	684	!-- Check topography for consistency with model domain. Therefore, use
	685	!-- maximum and minium topography-top indices. Note, minimum topography top
	686	!-- index is already calculated.
[2696]	687	IF ( TRIM( topography ) /= 'flat' ) THEN
	688	#if defined( __parallel )
[4168]	689	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	690	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	691	#else
[4168]	692	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	693	#endif
[2968]	694	nzb_local_min = topo_min_level
[2696]	695	!
	696	!-- Consistency checks
	697	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	698	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	699	' model domain', &
[3046]	700	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	701	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	702	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	703	ENDIF
	704	ENDIF
[1]	705	!
[19]	706	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	707	!-- form (which does not use surface fluxes) is applied
[1691]	708	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	709	nzb_diff = nzb + 2
	710	ELSE
	711	nzb_diff = nzb + 1
	712	ENDIF
	713
[4414]	714	IF ( TRIM( topography ) /= 'flat' ) THEN
[2696]	715	!
[4414]	716	!-- Allocate and set the arrays containing the topography height (for output
	717	!-- reasons only).
	718	IF ( nxr == nx .AND. nyn /= ny ) THEN
	719	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	720	zw_w_inner(nxl:nxr+1,nys:nyn) )
	721	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	722	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	723	zw_w_inner(nxl:nxr,nys:nyn+1) )
	724	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	725	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	726	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	727	ELSE
	728	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	729	zw_w_inner(nxl:nxr,nys:nyn) )
[2696]	730	ENDIF
[1]	731
[4414]	732	zu_s_inner = 0.0_wp
	733	zw_w_inner = 0.0_wp
[1]	734	!
[4414]	735	!-- Determine local topography height on scalar and w-grid. Note, setting
	736	!-- lateral boundary values is not necessary, realized via wall_flags_static_0
	737	!-- array. Further, please note that loop bounds are different from
	738	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	739	!-- use intrinsic lbound and ubound functions to infer array bounds.
	740	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	741	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
[2696]	742	!
[4414]	743	!-- Topography height on scalar grid. Therefore, determine index of
	744	!-- upward-facing surface element on scalar grid.
	745	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	746	!
[4414]	747	!-- Topography height on w grid. Therefore, determine index of
	748	!-- upward-facing surface element on w grid.
	749	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
	750	ENDDO
[2696]	751	ENDDO
	752	ENDIF
	753	!
	754	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	755	!-- coarse grid
	756	IF ( vnested ) CALL vnest_init_grid
	757
	758	END SUBROUTINE init_grid
	759
[3065]	760
[2696]	761	! Description:
	762	! -----------------------------------------------------------------------------!
[3065]	763	!> Calculation of the stretching factor through an iterative method. Ideas were
	764	!> taken from the paper "Regional stretched grid generation and its application
	765	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	766	!> system of equations has two variables (r,l) but four requirements
	767	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	768	!> results into an overdetermined system.
	769	!------------------------------------------------------------------------------!
	770	SUBROUTINE calculate_stretching_factor( number_end )
	771
	772	USE control_parameters, &
[3241]	773	ONLY: dz, dz_stretch_factor_array, &
[3065]	774	dz_stretch_level_end, dz_stretch_level_start, message_string
	775
	776	USE kinds
	777
	778	IMPLICIT NONE
	779
	780	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	781	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	782	INTEGER(iwp) :: n !< loop variable for stretching
	783
	784	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	785
	786	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	787	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	788	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	789	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	790	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	791	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	792	REAL(wp) :: numerator !< numerator of the quotient
	793	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	794	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	795
[3068]	796	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	797
[4386]	798	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06_wp !< interval for sampling possible stretching factors
	799	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88_wp !< lowest possible stretching factor
	800	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12_wp !< highest possible stretching factor
[3065]	801
	802
[3068]	803	l = 0
	804	DO n = 1, number_end
	805
	806	iterations = 1
[4386]	807	stretch_factor_1 = 1.0_wp
	808	stretch_factor_2 = 1.0_wp
	809	delta_total_old = 1.0_wp
[3065]	810
[4386]	811	!
	812	!-- First branch for stretching from rough to fine
[3068]	813	IF ( dz(n) > dz(n+1) ) THEN
	814	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	815
[4386]	816	stretch_factor_1 = 1.0_wp - iterations * stretch_factor_interval
	817	distance = ABS( dz_stretch_level_end(n) - &
	818	dz_stretch_level_start(n) )
	819	numerator = distance*stretch_factor_1/dz(n) + &
[3068]	820	stretch_factor_1 - distance/dz(n)
	821
[4386]	822	IF ( numerator > 0.0_wp ) THEN
	823	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
[3068]	824	l_rounded = NINT( l )
	825	delta_l = ABS( l_rounded - l ) / l
	826	ENDIF
	827
	828	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	829
[4386]	830	delta_stretch_factor = ABS( stretch_factor_1 - &
	831	stretch_factor_2 ) / &
[3068]	832	stretch_factor_2
	833
	834	delta_total_new = delta_l + delta_stretch_factor
[3065]	835
	836	!
[4386]	837	!-- stretch_factor_1 is taken to guarantee that the stretching
	838	!-- procedure ends as close as possible to dz_stretch_level_end.
	839	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	840	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	841	IF (delta_total_new < delta_total_old) THEN
	842	dz_stretch_factor_array(n) = stretch_factor_1
	843	dz_stretch_factor_array_2(n) = stretch_factor_2
	844	delta_total_old = delta_total_new
	845	ENDIF
	846
	847	iterations = iterations + 1
	848
	849	ENDDO
[4386]	850
	851	!
	852	!-- Second branch for stretching from fine to rough
[3068]	853	ELSEIF ( dz(n) < dz(n+1) ) THEN
	854	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	855
[4386]	856	stretch_factor_1 = 1.0_wp + iterations * stretch_factor_interval
	857	distance = ABS( dz_stretch_level_end(n) - &
[3068]	858	dz_stretch_level_start(n) )
[4386]	859	numerator = distance*stretch_factor_1/dz(n) + &
[3068]	860	stretch_factor_1 - distance/dz(n)
	861
[4386]	862	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
[3068]	863	l_rounded = NINT( l )
	864	delta_l = ABS( l_rounded - l ) / l
	865
	866	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	867
[4386]	868	delta_stretch_factor = ABS( stretch_factor_1 - &
	869	stretch_factor_2 ) / &
[3068]	870	stretch_factor_2
	871
	872	delta_total_new = delta_l + delta_stretch_factor
	873
[3065]	874	!
[4386]	875	!-- stretch_factor_1 is taken to guarantee that the stretching
	876	!-- procedure ends as close as possible to dz_stretch_level_end.
	877	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	878	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	879	IF (delta_total_new < delta_total_old) THEN
	880	dz_stretch_factor_array(n) = stretch_factor_1
	881	dz_stretch_factor_array_2(n) = stretch_factor_2
	882	delta_total_old = delta_total_new
	883	ENDIF
[3065]	884
[3068]	885	iterations = iterations + 1
	886	ENDDO
	887
	888	ELSE
	889	message_string= 'Two adjacent values of dz must be different'
	890	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	891
	892	ENDIF
	893
	894	!
	895	!-- Check if also the second stretching factor fits into the allowed
	896	!-- interval. If not, print a warning for the user.
	897	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	898	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	899	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	900	dz_stretch_factor_array_2(n), ' which is',&
	901	' responsible for exactly reaching& dz =',&
	902	dz(n+1), 'after a specific amount of', &
	903	' grid levels& exceeds the upper', &
	904	' limit =', stretch_factor_upper_limit, &
	905	' &or lower limit = ', &
	906	stretch_factor_lower_limit
	907	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	908
	909	ENDIF
	910	ENDDO
[3065]	911
	912	END SUBROUTINE calculate_stretching_factor
	913
	914
	915	! Description:
	916	! -----------------------------------------------------------------------------!
[2696]	917	!> Set temporary topography flags and reference buildings on top of underlying
	918	!> orography.
	919	!------------------------------------------------------------------------------!
	920	SUBROUTINE process_topography( topo_3d )
	921
	922	USE arrays_3d, &
[2747]	923	ONLY: zu, zw
[2696]	924
	925	USE control_parameters, &
[3294]	926	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	927
	928	USE indices, &
	929	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	930	nzt
	931
	932	USE netcdf_data_input_mod, &
[3115]	933	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	934	terrain_height_f
	935
	936	USE kinds
	937
	938	USE pegrid
	939
	940	IMPLICIT NONE
	941
[2867]	942	INTEGER(iwp) :: i !< running index along x-direction
	943	INTEGER(iwp) :: j !< running index along y-direction
	944	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	945	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	946	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	947	INTEGER(iwp) :: num_build !< counter for number of buildings
	948	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	949
	950	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
	951	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	952	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	953	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	954	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	955	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	956
	957	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	958	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	959
	960	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	961
	962	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	963	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	964	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	965	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	966
	967	!
[3103]	968	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	969	!-- is non-zero, all grid points of the lower vertical grid levels might be
	970	!-- entirely below the surface, meaning a waste of computational resources.
	971	!-- In order to avoid this, remove the lowest terrain height. Please note,
	972	!-- in case of a nested run, the global minimum from all parent and childs
	973	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	974	IF ( input_pids_static ) THEN
[4159]	975
[3200]	976	#if defined( __parallel )
[3103]	977	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	978	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	979	#else
	980	oro_min = MINVAL( terrain_height_f%var )
	981	#endif
[3103]	982	terrain_height_f%var = terrain_height_f%var - oro_min
	983	!
	984	!-- Give an informative message that terrain height is referenced to zero
	985	IF ( oro_min > 0.0_wp ) THEN
	986	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	987	'downwards by ', oro_min, 'meter(s) to save ' // &
	988	'computational resources.'
	989	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	990	ENDIF
	991	ENDIF
	992
	993	!
[2696]	994	!-- In the following, buildings and orography are further preprocessed
	995	!-- before they are mapped on the LES grid.
	996	!-- Buildings are mapped on top of the orography by maintaining the roof
	997	!-- shape of the building. This can be achieved by referencing building on
	998	!-- top of the maximum terrain height within the area occupied by the
	999	!-- respective building. As buildings and terrain height are defined PE-wise,
	1000	!-- parallelization of this referencing is required (a building can be
	1001	!-- distributed between different PEs).
	1002	!-- In a first step, determine the number of buildings with different
	1003	!-- building id on each PE. In a next step, all building ids are gathered
	1004	!-- into one array which is present to all PEs. For each building ID,
	1005	!-- the maximum terrain height occupied by the respective building is
	1006	!-- computed and distributed to each PE.
	1007	!-- Finally, for each building id and its respective reference orography,
	1008	!-- builidings are mapped on top.
	1009	!--
	1010	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1011	!-- buildings
	1012	!-- classify the respective surfaces.
	1013	topo_3d = IBSET( topo_3d, 0 )
	1014	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1015	!
[3051]	1016	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1017	!-- pre-calculate an offset value.
[3294]	1018	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1019	!
[2696]	1020	!-- Reference buildings on top of orography. This is not necessary
	1021	!-- if topography is read from ASCII file as no distinction between buildings
	1022	!-- and terrain height can be made. Moreover, this is also not necessary if
	1023	!-- urban-surface and land-surface model are used at the same time.
[2897]	1024	IF ( input_pids_static ) THEN
	1025
	1026	IF ( buildings_f%from_file ) THEN
	1027	num_buildings_l = 0
	1028	num_buildings = 0
[2696]	1029	!
[3925]	1030	!-- Allocate at least one element for building ids and give it an inital
	1031	!-- negative value that will be overwritten later. This, however, is
	1032	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1033	ALLOCATE( build_ids_l(1) )
[3925]	1034	build_ids_l = -1
[2897]	1035	DO i = nxl, nxr
	1036	DO j = nys, nyn
	1037	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1038	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1039	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1040	THEN
	1041	CYCLE
	1042	ELSE
	1043	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1044	!
	1045	!-- Resize array with different local building ids
	1046	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1047	build_ids_l_tmp = build_ids_l
	1048	DEALLOCATE( build_ids_l )
	1049	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1050	build_ids_l(1:num_buildings_l(myid)-1) = &
	1051	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1052	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1053	DEALLOCATE( build_ids_l_tmp )
	1054	ENDIF
	1055	!
[2897]	1056	!-- First occuring building id on PE
	1057	ELSE
	1058	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1059	build_ids_l(1) = building_id_f%var(j,i)
	1060	ENDIF
[2696]	1061	ENDIF
[2897]	1062	ENDDO
[2696]	1063	ENDDO
	1064	!
[2897]	1065	!-- Determine number of different building ids for the entire domain
[2696]	1066	#if defined( __parallel )
[2897]	1067	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1068	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1069	#else
[2897]	1070	num_buildings = num_buildings_l
[2696]	1071	#endif
	1072	!
[2897]	1073	!-- Gather all buildings ids on each PEs.
	1074	!-- First, allocate array encompassing all building ids in model domain.
	1075	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1076	#if defined( __parallel )
	1077	!
[2897]	1078	!-- Allocate array for displacements.
	1079	!-- As each PE may has a different number of buildings, so that
	1080	!-- the block sizes send by each PE may not be equal. Hence,
	1081	!-- information about the respective displacement is required, indicating
	1082	!-- the respective adress where each MPI-task writes into the receive
	1083	!-- buffer array
	1084	ALLOCATE( displace_dum(0:numprocs-1) )
	1085	displace_dum(0) = 0
	1086	DO i = 1, numprocs-1
	1087	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1088	ENDDO
[2696]	1089
[2897]	1090	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1091	num_buildings(myid), &
	1092	MPI_INTEGER, &
	1093	build_ids, &
	1094	num_buildings, &
	1095	displace_dum, &
	1096	MPI_INTEGER, &
	1097	comm2d, ierr )
[2696]	1098
[2897]	1099	DEALLOCATE( displace_dum )
[2696]	1100
	1101	#else
[2897]	1102	build_ids = build_ids_l
[2696]	1103	#endif
	1104
	1105	!
[2897]	1106	!-- Note, in parallel mode building ids can occure mutliple times, as
	1107	!-- each PE has send its own ids. Therefore, sort out building ids which
	1108	!-- appear more than one time.
	1109	num_build = 0
	1110	DO nr = 1, SIZE(build_ids)
[2696]	1111
[2897]	1112	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1113	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1114	CYCLE
	1115	ELSE
	1116	num_build = num_build + 1
	1117	!
	1118	!-- Resize
	1119	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1120	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1121	DEALLOCATE( build_ids_final )
	1122	ALLOCATE( build_ids_final(1:num_build) )
	1123	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1124	build_ids_final(num_build) = build_ids(nr)
	1125	DEALLOCATE( build_ids_final_tmp )
	1126	ENDIF
[2696]	1127	ELSE
	1128	num_build = num_build + 1
	1129	ALLOCATE( build_ids_final(1:num_build) )
	1130	build_ids_final(num_build) = build_ids(nr)
[2897]	1131	ENDIF
	1132	ENDDO
[2696]	1133
	1134	!
[3051]	1135	!-- Determine maximumum terrain height occupied by the respective
	1136	!-- building and temporalily store on oro_max
[2897]	1137	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1138	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1139	oro_max_l = 0.0_wp
[2696]	1140
[2897]	1141	DO nr = 1, SIZE(build_ids_final)
[4159]	1142	oro_max_l(nr) = MAXVAL( &
	1143	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1144	0.0_wp, &
	1145	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1146	build_ids_final(nr) ) )
	1147	ENDDO
[2696]	1148
	1149	#if defined( __parallel )
[2897]	1150	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1151	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1152	MPI_MAX, comm2d, ierr )
	1153	ENDIF
[2696]	1154	#else
[2897]	1155	oro_max = oro_max_l
[2696]	1156	#endif
[3051]	1157	!
	1158	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1159	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1160	!-- exceeds the scalar level the grid box is fully terrain and the
	1161	!-- maximum terrain is set to the zw level.
	1162	!-- terrain or
[3051]	1163	oro_max_l = 0.0
	1164	DO nr = 1, SIZE(build_ids_final)
	1165	DO k = nzb, nzt
	1166	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1167	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1168	ENDDO
[3142]	1169	oro_max(nr) = oro_max_l(nr)
[3051]	1170	ENDDO
[2897]	1171	ENDIF
[2696]	1172	!
[4245]	1173	!-- Allocate array for storing terrain height under buildings
	1174	IF ( buildings_f%from_file ) THEN
	1175	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
	1176	buildings_f%oro_max = buildings_f%fill1
	1177	END IF
	1178	!
[2867]	1179	!-- Map orography as well as buildings onto grid.
[2696]	1180	DO i = nxl, nxr
	1181	DO j = nys, nyn
[2867]	1182	topo_top_index = 0
[3142]	1183	!
	1184	!-- Obtain index in global building_id array
	1185	IF ( buildings_f%from_file ) THEN
	1186	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1187	!
	1188	!-- Determine index where maximum terrain height occupied by
	1189	!-- the respective building height is stored.
	1190	nr = MINLOC( ABS( build_ids_final - &
	1191	building_id_f%var(j,i) ), DIM = 1 )
[4245]	1192	!
	1193	!-- Save grid-indexed oro_max
	1194	buildings_f%oro_max(j,i) = oro_max(nr)
[3142]	1195	ENDIF
	1196	ENDIF
[2696]	1197	DO k = nzb, nzt
	1198	!
	1199	!-- In a first step, if grid point is below or equal the given
	1200	!-- terrain height, grid point is flagged to be of type natural.
	1201	!-- Please note, in case there is also a building which is lower
	1202	!-- than the vertical grid spacing, initialization of surface
	1203	!-- attributes will not be correct as given surface information
	1204	!-- will not be in accordance to the classified grid points.
[4159]	1205	!-- Hence, in this case, also a building flag.
[2747]	1206	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1207	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1208	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1209	topo_top_index = k ! topo_top_index + 1
[2696]	1210	ENDIF
	1211	!
	1212	!-- Set building grid points. Here, only consider 2D buildings.
	1213	!-- 3D buildings require separate treatment.
[2897]	1214	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1215	!
	1216	!-- Fill-up the terrain to the level of maximum orography
	1217	!-- within the building-covered area.
	1218	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1219	!
	1220	!-- Note, oro_max is always on zw level
	1221	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1222	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1223	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1224	ELSEIF ( zu(k) - ocean_offset <= &
	1225	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1226	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1227	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1228	ENDIF
	1229	ENDIF
	1230	ENDIF
	1231	ENDDO
	1232	!
[4159]	1233	!-- Special treatment for non grid-resolved buildings. This case,
	1234	!-- the uppermost terrain grid point is flagged as building as well
	1235	!-- well, even though no building exists at all. However, the
	1236	!-- surface element will be identified as urban-surface and the
	1237	!-- input data provided by the drivers is consistent to the surface
	1238	!-- classification. Else, all non grid-resolved buildings would vanish
	1239	!-- and identified as terrain grid points, which, however, won't be
	1240	!-- consistent with the input data.
	1241	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1242	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1243	DO k = nzb, nzt
	1244	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1245	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1246	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1247	ENDIF
	1248	ENDIF
	1249	ENDDO
	1250	ENDIF
	1251	ENDIF
	1252	!
[2696]	1253	!-- Map 3D buildings onto terrain height.
[2867]	1254	!-- In case of any slopes, map building on top of maximum terrain
	1255	!-- height covered by the building. In other words, extend
	1256	!-- building down to the respective local terrain-surface height.
[2897]	1257	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1258	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1259	!
[3051]	1260	!-- Extend building down to the terrain surface, i.e. fill-up
	1261	!-- surface irregularities below a building. Note, oro_max
	1262	!-- is already a discrete height according to the all-or-nothing
	1263	!-- approach, i.e. grid box is either topography or atmosphere,
	1264	!-- terrain top is defined at upper bound of the grid box.
	1265	!-- Hence, check for zw in this case.
[3115]	1266	!-- Note, do this only for buildings which are surface mounted,
	1267	!-- i.e. building types 1-6. Below bridges, which are represented
	1268	!-- exclusively by building type 7, terrain shape should be
	1269	!-- maintained.
[3855]	1270	IF ( building_type_f%from_file ) THEN
	1271	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1272	DO k = topo_top_index + 1, nzt + 1
[4159]	1273	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1274	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1275	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1276	ENDIF
	1277	ENDDO
	1278	!
	1279	!-- After surface irregularities are smoothen, determine
	1280	!-- lower start index where building starts.
	1281	DO k = nzb, nzt
[4159]	1282	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1283	topo_top_index = k
	1284	ENDDO
	1285	ENDIF
[3115]	1286	ENDIF
[3051]	1287	!
	1288	!-- Finally, map building on top.
[2867]	1289	k2 = 0
	1290	DO k = topo_top_index, nzt + 1
[2796]	1291	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1292	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1293	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1294	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1295	ENDIF
	1296	ENDIF
	1297	k2 = k2 + 1
	1298	ENDDO
	1299	ENDIF
	1300	ENDIF
	1301	ENDDO
	1302	ENDDO
	1303	!
[4265]	1304	!-- Horizontal exchange the oro_max array, which is required to for
	1305	!-- initialization of building-surface properties.
	1306	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
	1307	CALL exchange_horiz_2d( buildings_f%oro_max(:,:), nbgp )
	1308	ENDIF
[4245]	1309	!
[2696]	1310	!-- Deallocate temporary arrays required for processing and reading data
	1311	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1312	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1313	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1314	!
	1315	!-- Topography input via ASCII format.
	1316	ELSE
[3294]	1317	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1318	!
	1319	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1320	!-- and clear all grid points at nzb, where alway a surface is defined.
	1321	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1322	!-- used for masked data output and further processing. Note, in the
	1323	!-- ASCII case no distinction is made between buildings and terrain,
	1324	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1325	topo_3d = IBSET( topo_3d, 0 )
	1326	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1327	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1328	DO i = nxl, nxr
	1329	DO j = nys, nyn
	1330	DO k = nzb, nzt
[3538]	1331	!
	1332	!-- Flag topography for all grid points which are below
	1333	!-- the local topography height.
	1334	!-- Note, each topography is flagged as building.
[2747]	1335	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1336	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1337	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1338	ENDIF
	1339	ENDDO
	1340	ENDDO
	1341	ENDDO
	1342	ENDIF
	1343
	1344	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1345
	1346	IF ( .NOT. bc_ns_cyc ) THEN
	1347	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1348	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1349	ENDIF
	1350
	1351	IF ( .NOT. bc_lr_cyc ) THEN
	1352	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1353	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1354	ENDIF
	1355
	1356	END SUBROUTINE process_topography
	1357
	1358
	1359	! Description:
	1360	! -----------------------------------------------------------------------------!
	1361	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1362	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1363	!> equation on discrete grid cannot be fulfilled in such case.
	1364	!------------------------------------------------------------------------------!
	1365	SUBROUTINE filter_topography( topo_3d )
	1366
	1367	USE control_parameters, &
	1368	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1369
	1370	USE indices, &
	1371	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1372
	1373	USE netcdf_data_input_mod, &
	1374	ONLY: building_id_f, building_type_f
	1375
	1376	USE pegrid
	1377
	1378	IMPLICIT NONE
	1379
[2893]	1380	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1381
[2696]	1382	INTEGER(iwp) :: i !< running index along x-direction
	1383	INTEGER(iwp) :: j !< running index along y-direction
	1384	INTEGER(iwp) :: k !< running index along z-direction
	1385	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1386	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1387	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1388
[2955]	1389	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1390	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1391	!
	1392	!-- Before checking for holes, set lateral boundary conditions for
	1393	!-- topography. After hole-filling, boundary conditions must be set again.
	1394	!-- Several iterations are performed, in order to fill holes which might
	1395	!-- emerge by the filling-algorithm itself.
	1396	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1397	topo_tmp = 0
	1398
	1399	num_hole = 99999
	1400	DO WHILE ( num_hole > 0 )
	1401
	1402	num_hole = 0
	1403	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1404	!
	1405	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1406	!-- variable.
	1407	IF ( building_id_f%from_file ) &
	1408	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1409	IF ( building_type_f%from_file ) &
	1410	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1411
	1412	topo_tmp = topo_3d
	1413	!
	1414	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1415	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1416	!-- boundary and some topographic structure will be filled.
	1417	IF ( .NOT. bc_ns_cyc ) THEN
	1418	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1419	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1420	ENDIF
	1421
	1422	IF ( .NOT. bc_lr_cyc ) THEN
	1423	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1424	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1425	ENDIF
	1426
	1427	num_hole_l = 0
	1428	DO i = nxl, nxr
	1429	DO j = nys, nyn
	1430	DO k = nzb+1, nzt
	1431	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1432	num_wall = 0
	1433	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1434	num_wall = num_wall + 1
	1435	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1436	num_wall = num_wall + 1
	1437	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1438	num_wall = num_wall + 1
	1439	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1440	num_wall = num_wall + 1
	1441	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1442	num_wall = num_wall + 1
	1443	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1444	num_wall = num_wall + 1
	1445
	1446	IF ( num_wall >= 4 ) THEN
	1447	num_hole_l = num_hole_l + 1
	1448	!
[4314]	1449	!-- Clear flag 0 and set special flag ( bit 4) to indicate
[2696]	1450	!-- that new topography point is a result of filtering process.
	1451	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4314]	1452	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
[2696]	1453	!
	1454	!-- If filled grid point is occupied by a building, classify
	1455	!-- it as building grid point.
	1456	IF ( building_type_f%from_file ) THEN
	1457	IF ( building_type_f%var(j,i) /= &
	1458	building_type_f%fill .OR. &
	1459	building_type_f%var(j+1,i) /= &
	1460	building_type_f%fill .OR. &
	1461	building_type_f%var(j-1,i) /= &
	1462	building_type_f%fill .OR. &
	1463	building_type_f%var(j,i+1) /= &
	1464	building_type_f%fill .OR. &
	1465	building_type_f%var(j,i-1) /= &
	1466	building_type_f%fill ) THEN
	1467	!
	1468	!-- Set flag indicating building surfaces
	1469	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1470	!
	1471	!-- Set building_type and ID at this position if not
	1472	!-- already set. This is required for proper
	1473	!-- initialization of urban-surface energy balance
	1474	!-- solver.
	1475	IF ( building_type_f%var(j,i) == &
	1476	building_type_f%fill ) THEN
	1477
	1478	IF ( building_type_f%var(j+1,i) /= &
	1479	building_type_f%fill ) THEN
	1480	building_type_f%var(j,i) = &
	1481	building_type_f%var(j+1,i)
	1482	building_id_f%var(j,i) = &
	1483	building_id_f%var(j+1,i)
	1484	ELSEIF ( building_type_f%var(j-1,i) /= &
	1485	building_type_f%fill ) THEN
	1486	building_type_f%var(j,i) = &
	1487	building_type_f%var(j-1,i)
	1488	building_id_f%var(j,i) = &
	1489	building_id_f%var(j-1,i)
	1490	ELSEIF ( building_type_f%var(j,i+1) /= &
	1491	building_type_f%fill ) THEN
	1492	building_type_f%var(j,i) = &
	1493	building_type_f%var(j,i+1)
	1494	building_id_f%var(j,i) = &
	1495	building_id_f%var(j,i+1)
	1496	ELSEIF ( building_type_f%var(j,i-1) /= &
	1497	building_type_f%fill ) THEN
	1498	building_type_f%var(j,i) = &
	1499	building_type_f%var(j,i-1)
	1500	building_id_f%var(j,i) = &
	1501	building_id_f%var(j,i-1)
	1502	ENDIF
	1503	ENDIF
	1504	ENDIF
	1505	ENDIF
	1506	!
	1507	!-- If filled grid point is already classified as building
	1508	!-- everything is fine, else classify this grid point as
	1509	!-- natural type grid point. This case, values for the
	1510	!-- surface type are already set.
	1511	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1512	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1513	ENDIF
	1514	ENDIF
	1515	ENDIF
	1516	ENDDO
	1517	ENDDO
	1518	ENDDO
	1519	!
	1520	!-- Count the total number of holes, required for informative message.
	1521	#if defined( __parallel )
	1522	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1523	comm2d, ierr )
	1524	#else
	1525	num_hole = num_hole_l
	1526	#endif
[2893]	1527	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1528
[2893]	1529	ENDDO
[2696]	1530	!
[2893]	1531	!-- Create an informative message if any holes were filled.
	1532	IF ( filled ) THEN
	1533	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1534	'resolved by only one grid point ' // &
	1535	'were filled during initialization.'
	1536	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1537	ENDIF
[2696]	1538
	1539	DEALLOCATE( topo_tmp )
	1540	!
	1541	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1542	!-- condition in case of non-cyclic lateral boundaries.
	1543	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1544
	1545	IF ( .NOT. bc_ns_cyc ) THEN
	1546	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1547	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1548	ENDIF
	1549
	1550	IF ( .NOT. bc_lr_cyc ) THEN
	1551	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1552	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1553	ENDIF
[2955]	1554	!
	1555	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1556	IF ( building_id_f%from_file ) &
	1557	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1558	IF ( building_type_f%from_file ) &
	1559	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1560
	1561	END SUBROUTINE filter_topography
	1562
	1563
	1564	! Description:
	1565	! -----------------------------------------------------------------------------!
	1566	!> Reads topography information from file or sets generic topography. Moreover,
	1567	!> all topography-relevant topography arrays are initialized, and grid flags
	1568	!> are set.
	1569	!------------------------------------------------------------------------------!
	1570	SUBROUTINE init_topo( topo )
	1571
	1572	USE arrays_3d, &
	1573	ONLY: zw
	1574
	1575	USE control_parameters, &
	1576	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1577	building_length_y, building_wall_left, building_wall_south, &
	1578	canyon_height, canyon_wall_left, canyon_wall_south, &
	1579	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1580	message_string, topography, topography_grid_convention, &
[2696]	1581	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1582	tunnel_wall_depth
	1583
	1584	USE grid_variables, &
	1585	ONLY: dx, dy
	1586
	1587	USE indices, &
	1588	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1589	nzb, nzt
	1590
	1591	USE kinds
[4189]	1592
	1593	USE netcdf_data_input_mod, &
	1594	ONLY: buildings_f, terrain_height_f
[2696]	1595
	1596	USE pegrid
	1597
	1598	IMPLICIT NONE
	1599
[4386]	1600	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1601	INTEGER(iwp) :: ngp_bx !< grid point number of building size along x
	1602	INTEGER(iwp) :: ngp_by !< grid point number of building size along y
	1603	INTEGER(iwp) :: index_left_bwall !< index for left building wall
	1604	INTEGER(iwp) :: index_right_bwall !< index for right building wall
	1605	INTEGER(iwp) :: index_north_bwall !< index for north building wall
	1606	INTEGER(iwp) :: index_south_bwall !< index for south building wall
	1607	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1608	INTEGER(iwp) :: ngp_cx !< grid point number of canyon size along x
	1609	INTEGER(iwp) :: ngp_cy !< grid point number of canyon size along y
	1610	INTEGER(iwp) :: index_left_cwall !< index for left canyon wall
	1611	INTEGER(iwp) :: index_right_cwall !< index for right canyon wall
	1612	INTEGER(iwp) :: index_north_cwall !< index for north canyon wall
	1613	INTEGER(iwp) :: index_south_cwall !< index for south canyon wall
	1614	INTEGER(iwp) :: i !< index variable along x
	1615	INTEGER(iwp) :: j !< index variable along y
	1616	INTEGER(iwp) :: k !< index variable along z
	1617	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1618	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1619	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1620	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1621	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1622	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1623	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1624	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1625	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1626	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1627	INTEGER(iwp) :: td !< tunnel wall depth
	1628	INTEGER(iwp) :: th !< height of outer tunnel wall
[2696]	1629
	1630	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1631	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1632	!
[4189]	1633	!-- Check for correct setting of the namelist parameter topography. If
	1634	!-- topography information is read from file but topography = 'flat',
[4386]	1635	!-- initialization does not work properly.
[4189]	1636	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1637	TRIM( topography ) /= 'read_from_file' ) THEN
	1638	message_string = 'If topography information is provided (via ' // &
	1639	'Netcdf or ASCII input) topography = ' // &
	1640	'"read_from_file" is required.'
	1641	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1642	ENDIF
	1643	!
[1]	1644	!-- Set outer and inner index arrays for non-flat topography.
	1645	!-- Here consistency checks concerning domain size and periodicity are
	1646	!-- necessary.
	1647	!-- Within this SELECT CASE structure only nzb_local is initialized
	1648	!-- individually depending on the chosen topography type, all other index
	1649	!-- arrays are initialized further below.
	1650	SELECT CASE ( TRIM( topography ) )
	1651
	1652	CASE ( 'flat' )
[2696]	1653	!
[2232]	1654	!-- Initialilize 3D topography array, used later for initializing flags
[4340]	1655	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
	1656
	1657	CASE ( 'closed_channel' )
	1658	!
	1659	!-- Initialilize 3D topography array, used later for initializing flags
	1660	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
[1]	1661
	1662	CASE ( 'single_building' )
	1663	!
	1664	!-- Single rectangular building, by default centered in the middle of the
	1665	!-- total domain
[4386]	1666	ngp_bx = NINT( building_length_x / dx )
	1667	ngp_by = NINT( building_length_y / dy )
[2232]	1668	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1669	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1670	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1671	IF ( building_wall_left == 9999999.9_wp ) THEN
[4386]	1672	building_wall_left = ( nx + 1 - ngp_bx ) / 2 * dx
[1]	1673	ENDIF
[4386]	1674	index_left_bwall = NINT( building_wall_left / dx )
	1675	index_right_bwall = index_left_bwall + ngp_bx
[1]	1676
[1322]	1677	IF ( building_wall_south == 9999999.9_wp ) THEN
[4386]	1678	building_wall_south = ( ny + 1 - ngp_by ) / 2 * dy
[1]	1679	ENDIF
[4386]	1680	index_south_bwall = NINT( building_wall_south / dy )
	1681	index_north_bwall = index_south_bwall + ngp_by
[1]	1682
	1683	!
	1684	!-- Building size has to meet some requirements
[4386]	1685	IF ( ( index_left_bwall < 1 ) .OR. ( index_right_bwall > nx-1 ) .OR. &
	1686	( index_right_bwall < index_left_bwall+3 ) .OR. &
	1687	( index_south_bwall < 1 ) .OR. ( index_north_bwall > ny-1 ) .OR.&
	1688	( index_north_bwall < index_south_bwall+3 ) ) THEN
[274]	1689	WRITE( message_string, * ) 'inconsistent building parameters:', &
[4386]	1690	'&index_left_bwall=', index_left_bwall, &
	1691	'index_right_bwall=', index_right_bwall, &
	1692	'index_south_bwall=', index_south_bwall, &
	1693	'index_north_bwall=', index_north_bwall, &
	1694	'nx=', nx, 'ny=', ny
[254]	1695	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1696	ENDIF
	1697
[2696]	1698	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1699	nzb_local = 0
[1]	1700	!
[1968]	1701	!-- Define the building.
[4386]	1702	IF ( index_left_bwall <= nxr .AND. index_right_bwall >= nxl .AND. &
	1703	index_south_bwall <= nyn .AND. index_north_bwall >= nys ) &
	1704	nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall), &
	1705	MAX(nxl,index_left_bwall):MIN(nxr,index_right_bwall)) = bh
[2232]	1706	!
[2696]	1707	!-- Set bit array on basis of nzb_local
	1708	DO i = nxl, nxr
	1709	DO j = nys, nyn
	1710	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1711	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1712	ENDDO
	1713	ENDDO
[2696]	1714
	1715	DEALLOCATE( nzb_local )
[2232]	1716
[2696]	1717	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1718	!
	1719	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1720	!-- boundary conditions for topography.
	1721	IF ( .NOT. bc_ns_cyc ) THEN
	1722	IF ( nys == 0 ) THEN
	1723	DO i = 1, nbgp
	1724	topo(:,nys-i,:) = topo(:,nys,:)
	1725	ENDDO
	1726	ENDIF
	1727	IF ( nyn == ny ) THEN
	1728	DO i = 1, nbgp
	1729	topo(:,nyn+i,:) = topo(:,nyn,:)
	1730	ENDDO
	1731	ENDIF
	1732	ENDIF
	1733	IF ( .NOT. bc_lr_cyc ) THEN
	1734	IF ( nxl == 0 ) THEN
	1735	DO i = 1, nbgp
	1736	topo(:,:,nxl-i) = topo(:,:,nxl)
	1737	ENDDO
	1738	ENDIF
	1739	IF ( nxr == nx ) THEN
	1740	DO i = 1, nbgp
	1741	topo(:,:,nxr+i) = topo(:,:,nxr)
	1742	ENDDO
	1743	ENDIF
	1744	ENDIF
[2232]	1745
[240]	1746	CASE ( 'single_street_canyon' )
	1747	!
	1748	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1749	!-- The canyon is centered in the other direction by default.
[1322]	1750	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1751	!
	1752	!-- Street canyon in y direction
[4386]	1753	ngp_cx = NINT( canyon_width_x / dx )
[1322]	1754	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[4386]	1755	canyon_wall_left = ( nx + 1 - ngp_cx ) / 2 * dx
[240]	1756	ENDIF
[4386]	1757	index_left_cwall= NINT( canyon_wall_left / dx )
	1758	index_right_cwall= index_left_cwall+ ngp_cx
[1322]	1759	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1760	!
	1761	!-- Street canyon in x direction
[4386]	1762	ngp_cy = NINT( canyon_width_y / dy )
[1322]	1763	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[4386]	1764	canyon_wall_south = ( ny + 1 - ngp_cy ) / 2 * dy
[240]	1765	ENDIF
[4386]	1766	index_south_cwall = NINT( canyon_wall_south / dy )
	1767	index_north_cwall = index_south_cwall + ngp_cy
[2696]	1768
[240]	1769	ELSE
[254]	1770
	1771	message_string = 'no street canyon width given'
	1772	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1773
[240]	1774	ENDIF
	1775
[2232]	1776	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1777	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1778	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1779	dp_level_ind_b = ch
	1780	!
	1781	!-- Street canyon size has to meet some requirements
[1322]	1782	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[4386]	1783	IF ( ( index_left_cwall< 1 ) .OR. ( index_right_cwall> nx-1 ) .OR.&
	1784	( ngp_cx < 3 ) .OR. ( ch < 3 ) ) THEN
[1353]	1785	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[4386]	1786	'&index_left_cwall=', index_left_cwall, &
	1787	' index_right_cwall=', index_right_cwall, &
	1788	' ngp_cx=', ngp_cx, &
[3045]	1789	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1790	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1791	ENDIF
[1322]	1792	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[4386]	1793	IF ( ( index_south_cwall < 1 ) .OR. &
	1794	( index_north_cwall > ny-1 ) .OR. ( ngp_cy < 3 ) .OR. &
[2696]	1795	( ch < 3 ) ) THEN
[1353]	1796	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[4386]	1797	'&index_south_cwall=', index_south_cwall, &
	1798	' index_north_cwall=', index_north_cwall, &
	1799	' ngp_cy=', ngp_cy, &
[3045]	1800	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1801	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1802	ENDIF
	1803	ENDIF
[1353]	1804	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1805	canyon_width_y /= 9999999.9_wp ) THEN
	1806	message_string = 'inconsistent canyon parameters:' // &
[3046]	1807	'&street canyon can only be oriented' // &
[3045]	1808	' either in x- or in y-direction'
[254]	1809	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1810	ENDIF
	1811
[2696]	1812	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	1813	nzb_local = ch
[1322]	1814	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[4386]	1815	IF ( index_left_cwall<= nxr .AND. index_right_cwall>= nxl ) &
	1816	nzb_local(:,MAX(nxl,index_left_cwall+1):MIN(nxr,index_right_cwall-1)) = 0
[1322]	1817	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[4386]	1818	IF ( index_south_cwall <= nyn .AND. index_north_cwall >= nys ) &
	1819	nzb_local(MAX(nys,index_south_cwall+1):MIN(nyn,index_north_cwall-1),:) = 0
[240]	1820	ENDIF
[2232]	1821	!
[2696]	1822	!-- Set bit array on basis of nzb_local
	1823	DO i = nxl, nxr
	1824	DO j = nys, nyn
	1825	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1826	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1827	ENDDO
	1828	ENDDO
[2696]	1829	DEALLOCATE( nzb_local )
[1994]	1830
[2696]	1831	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1832	!
	1833	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1834	!-- boundary conditions for topography.
	1835	IF ( .NOT. bc_ns_cyc ) THEN
	1836	IF ( nys == 0 ) THEN
	1837	DO i = 1, nbgp
	1838	topo(:,nys-i,:) = topo(:,nys,:)
	1839	ENDDO
	1840	ENDIF
	1841	IF ( nyn == ny ) THEN
	1842	DO i = 1, nbgp
	1843	topo(:,nyn+i,:) = topo(:,nyn,:)
	1844	ENDDO
	1845	ENDIF
	1846	ENDIF
	1847	IF ( .NOT. bc_lr_cyc ) THEN
	1848	IF ( nxl == 0 ) THEN
	1849	DO i = 1, nbgp
	1850	topo(:,:,nxl-i) = topo(:,:,nxl)
	1851	ENDDO
	1852	ENDIF
	1853	IF ( nxr == nx ) THEN
	1854	DO i = 1, nbgp
	1855	topo(:,:,nxr+i) = topo(:,:,nxr)
	1856	ENDDO
	1857	ENDIF
	1858	ENDIF
[2232]	1859
	1860	CASE ( 'tunnel' )
	1861
	1862	!
	1863	!-- Tunnel height
	1864	IF ( tunnel_height == 9999999.9_wp ) THEN
	1865	th = zw( INT( 0.2 * nz) )
	1866	ELSE
	1867	th = tunnel_height
	1868	ENDIF
	1869	!
	1870	!-- Tunnel-wall depth
[2696]	1871	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	1872	td = MAX ( dx, dy, dz(1) )
[2232]	1873	ELSE
	1874	td = tunnel_wall_depth
	1875	ENDIF
	1876	!
	1877	!-- Check for tunnel width
	1878	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	1879	tunnel_width_y == 9999999.9_wp ) THEN
	1880	message_string = 'No tunnel width is given. '
[2274]	1881	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	1882	ENDIF
	1883	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	1884	tunnel_width_y /= 9999999.9_wp ) THEN
	1885	message_string = 'Inconsistent tunnel parameters:' // &
	1886	'tunnel can only be oriented' // &
	1887	'either in x- or in y-direction.'
[2274]	1888	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	1889	ENDIF
	1890	!
[4356]	1891	!-- Check for too small tunnel width in x- and y-direction
	1892	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	1893	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) THEN
	1894	message_string = 'tunnel_width_x too small'
	1895	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
	1896	ENDIF
	1897	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
	1898	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) THEN
	1899	message_string = 'tunnel_width_y too small'
	1900	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
	1901	ENDIF
	1902	!
	1903	!-- Check for too large tunnel width.
	1904	!-- Tunnel axis along y.
[2232]	1905	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	1906	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
[4356]	1907	message_string = 'tunnel_width_x too large'
[2274]	1908	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	1909	ENDIF
	1910
	1911	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	1912	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	1913	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	1914	( tunnel_width_x * 0.5_wp - td ) )
	1915	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	1916	( tunnel_width_x * 0.5_wp - td ) )
[2232]	1917
	1918	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	1919	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	1920	tys_in = tys_out
	1921	tye_in = tye_out
	1922	ENDIF
	1923	!
[4356]	1924	!-- Tunnel axis along x.
[2232]	1925	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	1926	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
[4356]	1927	message_string = 'tunnel_width_y too large'
[2274]	1928	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	1929	ENDIF
	1930
	1931	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	1932	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	1933	txs_in = txs_out
	1934	txe_in = txe_out
	1935
	1936	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	1937	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	1938	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	1939	( tunnel_width_y * 0.5_wp - td ) )
[2232]	1940	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	1941	( tunnel_width_y * 0.5_wp - td ) )
	1942	ENDIF
	1943
[2696]	1944	topo = 0
[2232]	1945	DO i = nxl, nxr
	1946	DO j = nys, nyn
	1947	!
	1948	!-- Use heaviside function to model outer tunnel surface
	1949	hv_out = th * 0.5_wp * &
	1950	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	1951	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	1952
	1953	hv_out = hv_out * 0.5_wp * &
	1954	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	1955	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	1956	!
[2232]	1957	!-- Use heaviside function to model inner tunnel surface
	1958	hv_in = ( th - td ) * 0.5_wp * &
	1959	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	1960	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	1961
	1962	hv_in = hv_in * 0.5_wp * &
	1963	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	1964	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	1965	!
	1966	!-- Set flags at x-y-positions without any tunnel surface
	1967	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	1968	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	1969	!
	1970	!-- Set flags at x-y-positions with tunnel surfaces
	1971	ELSE
	1972	DO k = nzb + 1, nzt + 1
	1973	!
	1974	!-- Inner tunnel
	1975	IF ( hv_out - hv_in == th ) THEN
	1976	IF ( zw(k) <= hv_out ) THEN
[2696]	1977	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	1978	ELSE
[2696]	1979	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	1980	ENDIF
	1981	ENDIF
	1982	!
	1983	!-- Lateral tunnel walls
	1984	IF ( hv_out - hv_in == td ) THEN
	1985	IF ( zw(k) <= hv_in ) THEN
[2696]	1986	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	1987	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	1988	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	1989	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	1990	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	1991	ENDIF
	1992	ENDIF
	1993	ENDDO
	1994	ENDIF
	1995	ENDDO
	1996	ENDDO
	1997
[2696]	1998	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1999	!
	2000	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2001	!-- boundary conditions for topography.
	2002	IF ( .NOT. bc_ns_cyc ) THEN
	2003	IF ( nys == 0 ) THEN
	2004	DO i = 1, nbgp
	2005	topo(:,nys-i,:) = topo(:,nys,:)
	2006	ENDDO
	2007	ENDIF
	2008	IF ( nyn == ny ) THEN
	2009	DO i = 1, nbgp
	2010	topo(:,nyn+i,:) = topo(:,nyn,:)
	2011	ENDDO
	2012	ENDIF
	2013	ENDIF
	2014	IF ( .NOT. bc_lr_cyc ) THEN
	2015	IF ( nxl == 0 ) THEN
	2016	DO i = 1, nbgp
	2017	topo(:,:,nxl-i) = topo(:,:,nxl)
	2018	ENDDO
	2019	ENDIF
	2020	IF ( nxr == nx ) THEN
	2021	DO i = 1, nbgp
	2022	topo(:,:,nxr+i) = topo(:,:,nxr)
	2023	ENDDO
	2024	ENDIF
	2025	ENDIF
[2232]	2026
[1]	2027	CASE ( 'read_from_file' )
	2028	!
[2696]	2029	!-- Note, topography information have been already read.
	2030	!-- If required, further process topography, i.e. reference buildings on
	2031	!-- top of orography and set temporary 3D topography array, which is
	2032	!-- used later to set grid flags. Calling of this rouinte is also
	2033	!-- required in case of ASCII input, even though no distinction between
	2034	!-- terrain- and building height is made in this case.
	2035	CALL process_topography( topo )
[1968]	2036	!
[2696]	2037	!-- Filter holes resolved by only one grid-point
	2038	CALL filter_topography( topo )
[1968]	2039	!
[2696]	2040	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2041	!-- conditions.
	2042	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2043	!
[4314]	2044	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2045	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2046	IF ( nys == 0 ) THEN
[2696]	2047	DO i = 1, nbgp
	2048	topo(:,nys-i,:) = topo(:,nys,:)
	2049	ENDDO
[2550]	2050	ENDIF
[2696]	2051	IF ( nyn == ny ) THEN
	2052	DO i = 1, nbgp
	2053	topo(:,nyn+i,:) = topo(:,nyn,:)
	2054	ENDDO
	2055	ENDIF
[1942]	2056	ENDIF
[1910]	2057
[1968]	2058	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2059	IF ( nxl == 0 ) THEN
[2696]	2060	DO i = 1, nbgp
	2061	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2062	ENDDO
[2696]	2063	ENDIF
	2064	IF ( nxr == nx ) THEN
	2065	DO i = 1, nbgp
	2066	topo(:,:,nxr+i) = topo(:,:,nxr)
	2067	ENDDO
	2068	ENDIF
[2232]	2069	ENDIF
	2070
[667]	2071
[1]	2072	CASE DEFAULT
[2696]	2073	!
[1]	2074	!-- The DEFAULT case is reached either if the parameter topography
[217]	2075	!-- contains a wrong character string or if the user has defined a special
[1]	2076	!-- case in the user interface. There, the subroutine user_init_grid
	2077	!-- checks which of these two conditions applies.
[2696]	2078	CALL user_init_grid( topo )
	2079	CALL filter_topography( topo )
[1]	2080
	2081	END SELECT
	2082	!
	2083	!-- Consistency checks and index array initialization are only required for
[2696]	2084	!-- non-flat topography.
[1]	2085	IF ( TRIM( topography ) /= 'flat' ) THEN
	2086	!
[2232]	2087	!-- In case of non-flat topography, check whether the convention how to
	2088	!-- define the topography grid has been set correctly, or whether the default
	2089	!-- is applicable. If this is not possible, abort.
	2090	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
[4340]	2091	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
	2092	TRIM( topography ) /= 'single_building' .AND. &
[2232]	2093	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2094	TRIM( topography ) /= 'tunnel' .AND. &
	2095	TRIM( topography ) /= 'read_from_file') THEN
	2096	!-- The default value is not applicable here, because it is only valid
[3045]	2097	!-- for the four standard cases 'single_building',
	2098	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2099	!-- defined in init_grid.
	2100	WRITE( message_string, * ) &
[2696]	2101	'The value for "topography_grid_convention" ', &
[3046]	2102	'is not set. Its default value is & only valid for ', &
[3045]	2103	'"topography" = ''single_building'', ''tunnel'' ', &
[4340]	2104	'''single_street_canyon'', ''closed_channel'' & or ', &
	2105	'''read_from_file''.', &
[3046]	2106	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2107	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2108	ELSE
	2109	!-- The default value is applicable here.
	2110	!-- Set convention according to topography.
	2111	IF ( TRIM( topography ) == 'single_building' .OR. &
	2112	TRIM( topography ) == 'single_street_canyon' ) THEN
	2113	topography_grid_convention = 'cell_edge'
	2114	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2115	TRIM( topography ) == 'tunnel') THEN
	2116	topography_grid_convention = 'cell_center'
	2117	ENDIF
	2118	ENDIF
	2119	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2120	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2121	WRITE( message_string, * ) &
[2696]	2122	'The value for "topography_grid_convention" is ', &
[3046]	2123	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2124	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2125	ENDIF
[1]	2126
[2169]	2127
[217]	2128	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2129	!
[217]	2130	!-- The array nzb_local as defined using the 'cell_edge' convention
	2131	!-- describes the actual total size of topography which is defined at the
	2132	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2133	!-- on the topography walls in y-direction. However, PALM uses individual
	2134	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2135	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2136	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2137	!-- to form the basis for nzb_s_inner.
	2138	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2139	!-- required at this point.
	2140	DO j = nys+1, nyn+1
	2141	DO i = nxl-1, nxr
[2232]	2142	DO k = nzb, nzt+1
[2696]	2143	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2144	BTEST( topo(k,j,i+1), 0 ) ) &
	2145	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2146	ENDDO
	2147	ENDDO
	2148	ENDDO
[2696]	2149	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2150
	2151	DO i = nxl, nxr+1
	2152	DO j = nys-1, nyn
	2153	DO k = nzb, nzt+1
[2696]	2154	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2155	BTEST( topo(k,j+1,i), 0 ) ) &
	2156	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2157	ENDDO
	2158	ENDDO
	2159	ENDDO
[2696]	2160	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2161
[217]	2162	ENDIF
[2696]	2163	ENDIF
[2232]	2164
[1]	2165
[2696]	2166	END SUBROUTINE init_topo
[1]	2167
[2696]	2168	SUBROUTINE set_topo_flags(topo)
[1]	2169
[2696]	2170	USE control_parameters, &
[4294]	2171	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
	2172	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
[1]	2173
[2696]	2174	USE indices, &
[3241]	2175	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4346]	2176	nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
[1]	2177
[2696]	2178	USE kinds
[1]	2179
[2696]	2180	IMPLICIT NONE
[1804]	2181
[2696]	2182	INTEGER(iwp) :: i !< index variable along x
[4168]	2183	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2184	INTEGER(iwp) :: j !< index variable along y
	2185	INTEGER(iwp) :: k !< index variable along z
[1]	2186
[2696]	2187	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2188
[4329]	2189	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2190	wall_flags_static_0 = 0
[2232]	2191	!
[2696]	2192	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2193	!-- Further special flags will be set in following loops.
[2232]	2194	DO i = nxl, nxr
	2195	DO j = nys, nyn
	2196	DO k = nzb, nzt+1
	2197	!
	2198	!-- scalar grid
[4340]	2199	IF ( BTEST( topo(k,j,i), 0 ) ) &
[4329]	2200	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
[2232]	2201	!
[2696]	2202	!-- u grid
[4340]	2203	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2204	BTEST( topo(k,j,i-1), 0 ) ) &
[4329]	2205	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
[2696]	2206	!
[2232]	2207	!-- v grid
[4340]	2208	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2209	BTEST( topo(k,j-1,i), 0 ) ) &
[4329]	2210	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
[2696]	2211
[2232]	2212	ENDDO
[1]	2213
[2232]	2214	DO k = nzb, nzt
[1]	2215	!
[2232]	2216	!-- w grid
[4340]	2217	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2218	BTEST( topo(k+1,j,i), 0 ) ) &
[4329]	2219	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
[2232]	2220	ENDDO
[4340]	2221
	2222	IF ( topography /= 'closed_channel' ) THEN
	2223	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
	2224	ENDIF
[2232]	2225
	2226	ENDDO
	2227	ENDDO
[2696]	2228
[4329]	2229	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
[4346]	2230
[1]	2231	!
[4115]	2232	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2233	!-- basis of flag 24 futher flags will be derived which are used to control
	2234	!-- production of subgrid TKE production near walls.
[4346]	2235
	2236	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2237	wall_flags_total_0 = 0
	2238
[2696]	2239	DO i = nxl, nxr
	2240	DO j = nys, nyn
[2232]	2241	DO k = nzb, nzt+1
[4346]	2242	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
[2232]	2243	ENDDO
	2244	ENDDO
	2245	ENDDO
[4346]	2246
	2247	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2248
	2249	DO i = nxl, nxr
	2250	DO j = nys, nyn
	2251	DO k = nzb, nzt+1
	2252	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
	2253	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
	2254	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
	2255	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
	2256	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
	2257	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
	2258	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
	2259	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
	2260	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
	2261	ENDDO
	2262	ENDDO
	2263	ENDDO
[1]	2264	!
[2232]	2265	!-- Set further special flags
	2266	DO i = nxl, nxr
	2267	DO j = nys, nyn
	2268	DO k = nzb, nzt+1
[1]	2269	!
[2232]	2270	!-- scalar grid, former nzb_diff_s_inner.
	2271	!-- Note, use this flag also to mask topography in diffusion_u and
	2272	!-- diffusion_v along the vertical direction. In case of
	2273	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2274	!-- gradient approach is applied. Please note, in case of u- and v-
	2275	!-- diffuison, a small error is made at edges (on the east side for u,
	2276	!-- at the north side for v), since topography on scalar grid point
	2277	!-- is used instead of topography on u/v-grid. As number of topography grid
	2278	!-- points on uv-grid is different than s-grid, different number of
	2279	!-- surface elements would be required. In order to avoid this,
	2280	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2281	!-- points are not masked within diffusion_u. Tests had shown that the
	2282	!-- effect on the flow is negligible.
	2283	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2284	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2285	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2286	ELSE
[4346]	2287	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2288	ENDIF
[1]	2289
[2232]	2290	ENDDO
	2291	!
	2292	!-- Special flag to control vertical diffusion at model top - former
	2293	!-- nzt_diff
[4346]	2294	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
[2232]	2295	IF ( use_top_fluxes ) &
[4346]	2296	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
[1]	2297
[2696]	2298
[2232]	2299	DO k = nzb+1, nzt
	2300	!
	2301	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2302	!-- for disturb_field and initialization. Do not disturb directly at
	2303	!-- topography, as well as initialize u with zero one grid point outside
	2304	!-- of topography.
[4346]	2305	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2306	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2307	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2308	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
[2232]	2309	!
	2310	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2311	!-- for disturb_field and initialization. Do not disturb directly at
	2312	!-- topography, as well as initialize v with zero one grid point outside
	2313	!-- of topography.
[4346]	2314	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2315	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2316	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2317	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
[2232]	2318	!
	2319	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2320	!-- lpm_sgs_tke
[4346]	2321	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2322	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2323	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2324	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
[2232]	2325	!
	2326	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2327	!-- in production_e
	2328	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2329	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
	2330	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
	2331	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2332	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[2232]	2333	ELSE
[4346]	2334	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2335	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[1]	2336	ENDIF
[2232]	2337	!
	2338	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2339	!-- in production_e
	2340	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2341	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2342	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2343	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2344	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2345	ELSE
[4346]	2346	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2347	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2348	ENDIF
	2349	ENDDO
	2350	!
	2351	!-- Flags indicating downward facing walls
[4340]	2352	DO k = nzb+1, nzt+1
[2232]	2353	!
	2354	!-- Scalar grid
[4346]	2355	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2356	.NOT. 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), 13 )
[2232]	2358	!
	2359	!-- Downward facing wall on u grid
[4346]	2360	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2361	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
	2362	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
[2232]	2363	!
	2364	!-- Downward facing wall on v grid
[4346]	2365	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2366	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
	2367	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
[2232]	2368	!
	2369	!-- Downward facing wall on w grid
[4346]	2370	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
	2371	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
	2372	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
[2232]	2373	ENDDO
	2374	!
	2375	!-- Flags indicating upward facing walls
	2376	DO k = nzb, nzt
	2377	!
	2378	!-- Upward facing wall on scalar grid
[4346]	2379	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2380	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2381	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
[2232]	2382	!
	2383	!-- Upward facing wall on u grid
[4346]	2384	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2385	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2386	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
[1]	2387
[2696]	2388	!
[2232]	2389	!-- Upward facing wall on v grid
[4346]	2390	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2391	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2392	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
[2696]	2393
[2232]	2394	!
	2395	!-- Upward facing wall on w grid
[4346]	2396	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
	2397	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
	2398	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
[2232]	2399	!
	2400	!-- Special flag on scalar grid, former nzb_s_inner
[4346]	2401	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
	2402	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
	2403	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
	2404	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
[2232]	2405	!
	2406	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2407	!-- flow_statistics
	2408	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2409	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2410	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2411	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[2232]	2412	ELSE
[4346]	2413	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
	2414	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[1]	2415	ENDIF
[2696]	2416
[1]	2417
[2232]	2418	ENDDO
[4346]	2419	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
	2420	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
[4109]	2421	!
	2422	!-- Set flags indicating that topography is close by in horizontal
	2423	!-- direction, i.e. flags that infold the topography. These will be used
	2424	!-- to set advection flags for passive scalars, where due to large
	2425	!-- gradients near buildings stationary numerical oscillations can produce
	2426	!-- unrealistically high concentrations. This is only necessary if
	2427	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2428	!-- only used for passive scalars such as chemical species or aerosols.
	2429	IF ( scalar_advec == 'ws-scheme' ) THEN
	2430	DO k = nzb, nzt
[4346]	2431	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
	2432	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2433	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2434	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2435	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2436	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2437	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2438	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2439	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2440	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2441	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2442	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2443	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
	2444	) ) &
	2445	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
[4109]	2446
	2447	ENDDO
	2448	ENDIF
[2232]	2449	ENDDO
	2450	ENDDO
	2451	!
[2696]	2452	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2453	!-- Natural terrain grid points. Information on the type of the surface is
	2454	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2455	!-- when topography is read from file. In order to run the land-surface model
	2456	!-- also without topography information, set bit 1 explicitely in this case.
[4294]	2457	!--
	2458	!-- Natural terrain grid points
	2459	!-- If no topography is initialized, the land-surface is at k = nzb.
	2460	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
[4329]	2461	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
[4294]	2462	ELSE
	2463	DO i = nxl, nxr
	2464	DO j = nys, nyn
	2465	DO k = nzb, nzt+1
[4189]	2466	!
[4294]	2467	!-- Natural terrain grid point
	2468	IF ( BTEST( topo(k,j,i), 1 ) ) &
[4329]	2469	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
[2696]	2470	ENDDO
	2471	ENDDO
[4294]	2472	ENDDO
[2696]	2473	ENDIF
	2474	!
	2475	!-- Building grid points.
[4294]	2476	DO i = nxl, nxr
	2477	DO j = nys, nyn
	2478	DO k = nzb, nzt+1
	2479	IF ( BTEST( topo(k,j,i), 2 ) ) &
[4329]	2480	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
[2696]	2481	ENDDO
	2482	ENDDO
[4294]	2483	ENDDO
[2696]	2484	!
[4314]	2485	!-- Set flag 4, indicating new topography grid points due to filtering.
	2486	DO i = nxl, nxr
	2487	DO j = nys, nyn
	2488	DO k = nzb, nzt+1
	2489	IF ( BTEST( topo(k,j,i), 4 ) ) &
[4329]	2490	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
[4314]	2491	ENDDO
	2492	ENDDO
	2493	ENDDO
[4346]	2494
	2495	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2496
	2497	DO i = nxl, nxr
	2498	DO j = nys, nyn
	2499	DO k = nzb, nzt+1
	2500	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
	2501	ENDDO
	2502	ENDDO
	2503	ENDDO
[4314]	2504	!
[2232]	2505	!-- Exchange ghost points for wall flags
[4346]	2506	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2507	!
	2508	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2509	!-- boundary conditions for topography.
	2510	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2511	IF ( nys == 0 ) THEN
	2512	DO i = 1, nbgp
[4346]	2513	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
[2696]	2514	ENDDO
	2515	ENDIF
	2516	IF ( nyn == ny ) THEN
	2517	DO i = 1, nbgp
[4346]	2518	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
[2696]	2519	ENDDO
	2520	ENDIF
[2232]	2521	ENDIF
	2522	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2523	IF ( nxl == 0 ) THEN
	2524	DO i = 1, nbgp
[4346]	2525	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
[2696]	2526	ENDDO
[2232]	2527	ENDIF
[2696]	2528	IF ( nxr == nx ) THEN
	2529	DO i = 1, nbgp
[4346]	2530	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
[2232]	2531	ENDDO
[2696]	2532	ENDIF
[2232]	2533	ENDIF
[4168]	2534	!
	2535	!-- Pre-calculate topography top indices (former get_topography_top_index
	2536	!-- function)
	2537	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2538	!
	2539	!-- Uppermost topography index on scalar grid
	2540	ibit = 12
	2541	topo_top_ind(:,:,0) = MAXLOC( &
	2542	MERGE( 1, 0, &
[4346]	2543	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2544	), DIM = 1 &
	2545	) - 1
	2546	!
	2547	!-- Uppermost topography index on u grid
	2548	ibit = 14
	2549	topo_top_ind(:,:,1) = MAXLOC( &
	2550	MERGE( 1, 0, &
[4346]	2551	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2552	), DIM = 1 &
	2553	) - 1
	2554	!
	2555	!-- Uppermost topography index on v grid
	2556	ibit = 16
	2557	topo_top_ind(:,:,2) = MAXLOC( &
	2558	MERGE( 1, 0, &
[4346]	2559	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2560	), DIM = 1 &
	2561	) - 1
	2562	!
	2563	!-- Uppermost topography index on w grid
	2564	ibit = 18
	2565	topo_top_ind(:,:,3) = MAXLOC( &
	2566	MERGE( 1, 0, &
[4346]	2567	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2568	), DIM = 1 &
	2569	) - 1
	2570	!
	2571	!-- Uppermost topography index on scalar outer grid
	2572	ibit = 24
	2573	topo_top_ind(:,:,4) = MAXLOC( &
	2574	MERGE( 1, 0, &
[4346]	2575	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2576	), DIM = 1 &
[4414]	2577	) - 1
	2578
[2696]	2579	END SUBROUTINE set_topo_flags
[114]	2580
	2581
	2582
[4414]	2583

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