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source: palm/trunk/SOURCE/init_grid.f90 @ 4372

Last change on this file since 4372 was 4360, checked in by suehring, 5 years ago
Bugfix in output of time-averaged plant-canopy quanities; Output of plant-canopy data only where tall canopy is defined; land-surface model: fix wrong location strings; tests: update urban test case; all source code files: copyright update
Property svn:keywords set to `Id`
File size: 123.2 KB

Rev	Line
[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 4360 2020-01-07 11:25:50Z banzhafs $
[4356]	27	! Revise error messages for generic tunnel setup.
	28	!
	29	! 4346 2019-12-18 11:55:56Z motisi
[4346]	30	! Introduction of wall_flags_total_0, which currently sets bits based on static
	31	! topography information used in wall_flags_static_0
	32	!
	33	! 4340 2019-12-16 08:17:03Z Giersch
[4340]	34	! Topography closed channel flow with symmetric boundaries implemented
	35	!
	36	! 4329 2019-12-10 15:46:36Z motisi
[4329]	37	! Renamed wall_flags_0 to wall_flags_static_0
	38	!
	39	! 4328 2019-12-09 18:53:04Z suehring
[4328]	40	! Minor change in nzb_max computation. Commentation added.
	41	!
	42	! 4314 2019-11-29 10:29:20Z suehring
[4314]	43	! Set additional topography flag 4 to mark topography grid points emerged
	44	! from the filtering process.
	45	!
	46	! 4294 2019-11-13 18:34:16Z suehring
[4294]	47	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
	48	! building surfaces in all cases, in order to enable terrain-following output
	49	! also when no land- or urban-surface model is applied.
	50	!
	51	! 4265 2019-10-15 16:16:24Z suehring
[4265]	52	! Bugfix for last commit, exchange oro_max variable only when it is allocated
	53	! (not necessarily the case when topography is input from ASCII file).
	54	!
	55	! 4245 2019-09-30 08:40:37Z pavelkrc
[4245]	56	! Store oro_max (building z-offset) in 2D for building surfaces
	57	!
	58	! 4189 2019-08-26 16:19:38Z suehring
[4189]	59	! - Add check for proper setting of namelist parameter topography
	60	! - Set flag to indicate land surfaces in case no topography is provided
	61	!
	62	! 4182 2019-08-22 15:20:23Z scharf
[4182]	63	! Corrected "Former revisions" section
	64	!
	65	! 4168 2019-08-16 13:50:17Z suehring
[4168]	66	! Pre-calculate topography top index and store it on an array (replaces former
	67	! functions get_topography_top_index)
	68	!
	69	! 4159 2019-08-15 13:31:35Z suehring
[4159]	70	! Revision of topography processing. This was not consistent between 2D and 3D
	71	! buildings.
	72	!
	73	! 4144 2019-08-06 09:11:47Z raasch
[4144]	74	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	75	!
	76	! 4115 2019-07-24 12:50:49Z suehring
[4115]	77	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	78	!
	79	! 4110 2019-07-22 17:05:21Z suehring
[4110]	80	! - Separate initialization of advection flags for momentum and scalars.
	81	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	82	!
	83	! 4109 2019-07-22 17:00:34Z suehring
[3927]	84	! Fix bad commit
	85	!
	86	! 3926 2019-04-23 12:56:42Z suehring
[3925]	87	! Minor bugfix in building mapping when all building IDs in the model domain
	88	! are missing
	89	!
	90	! 3857 2019-04-03 13:00:16Z knoop
[3855]	91	! In projection of non-building 3D objects onto numerical grid remove
	92	! dependency on building_type
	93	!
	94	! 3763 2019-02-25 17:33:49Z suehring
[3763]	95	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	96	! routine as already done in other routines
	97	!
	98	! 3761 2019-02-25 15:31:42Z raasch
[3761]	99	! unused variables removed
	100	!
	101	! 3661 2019-01-08 18:22:50Z suehring
[3661]	102	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	103	! order degradation of advection scheme is handeled directly in advec_ws
	104	!
	105	! 3655 2019-01-07 16:51:22Z knoop
[3538]	106	! Comment added
[2716]	107	!
[4182]	108	! Revision 1.1 1997/08/11 06:17:45 raasch
	109	! Initial revision (Testversion)
	110	!
	111	!
[1]	112	! Description:
[2696]	113	! -----------------------------------------------------------------------------!
[1682]	114	!> Creating grid depending constants
[2696]	115	!> @todo: Rearrange topo flag list
	116	!> @todo: reference 3D buildings on top of orography is not tested and may need
	117	!> further improvement for steep slopes
	118	!> @todo: Use more advanced setting of building type at filled holes
[1]	119	!------------------------------------------------------------------------------!
[1682]	120	SUBROUTINE init_grid
	121
[1942]	122	USE advec_ws, &
[4109]	123	ONLY: ws_init_flags_momentum, ws_init_flags_scalar
[1]	124
[1320]	125	USE arrays_3d, &
[3857]	126	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[1320]	127
[1353]	128	USE control_parameters, &
[3761]	129	ONLY: bc_lr_cyc, bc_ns_cyc, &
[4109]	130	bc_dirichlet_l, &
	131	bc_dirichlet_n, &
	132	bc_dirichlet_r, &
	133	bc_dirichlet_s, &
	134	bc_radiation_l, &
	135	bc_radiation_n, &
	136	bc_radiation_r, &
	137	bc_radiation_s, &
[3241]	138	constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	139	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	140	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	141	dz_stretch_level_start, ibc_uv_b, message_string, &
[3182]	142	momentum_advec, number_stretch_level_end, &
[3294]	143	number_stretch_level_start, ocean_mode, psolver, scalar_advec, &
[4340]	144	symmetry_flag, topography, use_surface_fluxes
[2021]	145
[1320]	146	USE grid_variables, &
[2232]	147	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[1320]	148
	149	USE indices, &
[4109]	150	ONLY: advc_flags_m, &
	151	advc_flags_s, &
	152	nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
[2232]	153	nzb, nzb_diff, nzb_diff_s_inner, nzb_diff_s_outer, &
	154	nzb_max, nzb_s_inner, nzb_s_outer, nzb_u_inner, &
[1845]	155	nzb_u_outer, nzb_v_inner, nzb_v_outer, nzb_w_inner, &
[4168]	156	nzb_w_outer, nzt, topo_top_ind, topo_min_level
[1320]	157
	158	USE kinds
[2696]	159
[1]	160	USE pegrid
	161
[2696]	162	USE poismg_noopt_mod
	163
[2232]	164	USE surface_mod, &
[4168]	165	ONLY: init_bc
[2232]	166
[2365]	167	USE vertical_nesting_mod, &
	168	ONLY: vnested, vnest_init_grid
	169
[1]	170	IMPLICIT NONE
	171
[3182]	172	INTEGER(iwp) :: i !< index variable along x
	173	INTEGER(iwp) :: j !< index variable along y
	174	INTEGER(iwp) :: k !< index variable along z
	175	INTEGER(iwp) :: k_top !< topography top index on local PE
	176	INTEGER(iwp) :: n !< loop variable for stretching
	177	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	178	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	179	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[2232]	180
[3065]	181	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	182	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_tmp !< dummy to calculate topography indices on u- and v-grid
[1]	183
[2696]	184	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	185
[3065]	186	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	187	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	188
	189	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	190
[1]	191
	192	!
[709]	193	!-- Calculation of horizontal array bounds including ghost layers
[667]	194	nxlg = nxl - nbgp
	195	nxrg = nxr + nbgp
	196	nysg = nys - nbgp
	197	nyng = nyn + nbgp
[709]	198
[667]	199	!
[1]	200	!-- Allocate grid arrays
[3857]	201	ALLOCATE( x(0:nx), xu(0:nx) )
	202	DO i = 0, nx
	203	xu(i) = i * dx
	204	x(i) = i * dx + 0.5_wp * dx
	205	ENDDO
	206
	207	ALLOCATE( y(0:ny), yv(0:ny) )
	208	DO j = 0, ny
	209	yv(j) = j * dy
	210	y(j) = j * dy + 0.5_wp * dy
	211	ENDDO
	212
	213	!
	214	!-- Allocate grid arrays
[1353]	215	ALLOCATE( ddzu(1:nzt+1), ddzw(1:nzt+1), dd2zu(1:nzt), dzu(1:nzt+1), &
[2696]	216	dzw(1:nzt+1), zu(nzb:nzt+1), zw(nzb:nzt+1) )
[1]	217
	218	!
	219	!-- Compute height of u-levels from constant grid length and dz stretch factors
[3065]	220	IF ( dz(1) == -1.0_wp ) THEN
[254]	221	message_string = 'missing dz'
	222	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	223	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	224	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	225	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	226	ENDIF
[94]	227
[1]	228	!
[3065]	229	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	230	!-- if it was set by the user
	231	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	232	dz_stretch_level_start(1) = dz_stretch_level
	233	ENDIF
	234
	235	!
	236	!-- Determine number of dz values and stretching levels specified by the
	237	!-- user to allow right controlling of the stretching mechanism and to
[3139]	238	!-- perform error checks. The additional requirement that dz /= dz_max
	239	!-- for counting number of user-specified dz values is necessary. Otherwise
	240	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	241	!-- is used (Attention: The user is not allowed to specify a dz value equal
	242	!-- to the default of dz_max = 999.0).
	243	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	244	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	245	-9999999.9_wp )
	246	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	247	9999999.9_wp )
	248
	249	!
	250	!-- The number of specified end levels +1 has to be the same than the number
	251	!-- of specified dz values
	252	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
	253	WRITE( message_string, * ) 'The number of values for dz = ', &
	254	number_dz, 'has to be the same than& ', &
	255	'the number of values for ', &
	256	'dz_stretch_level_end + 1 = ', &
	257	number_stretch_level_end+1
	258	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	259	ENDIF
	260
	261	!
	262	!-- The number of specified start levels has to be the same or one less than
	263	!-- the number of specified dz values
	264	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
	265	number_dz /= number_stretch_level_start ) THEN
	266	WRITE( message_string, * ) 'The number of values for dz = ', &
	267	number_dz, 'has to be the same or one ', &
	268	'more than& the number of values for ', &
	269	'dz_stretch_level_start = ', &
	270	number_stretch_level_start
	271	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	272	ENDIF
	273
	274	!-- The number of specified start levels has to be the same or one more than
	275	!-- the number of specified end levels
	276	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
	277	number_stretch_level_start /= number_stretch_level_end ) THEN
	278	WRITE( message_string, * ) 'The number of values for ', &
	279	'dz_stretch_level_start = ', &
	280	dz_stretch_level_start, 'has to be the ',&
	281	'same or one more than& the number of ', &
	282	'values for dz_stretch_level_end = ', &
	283	number_stretch_level_end
	284	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	285	ENDIF
	286
	287	!
	288	!-- Initialize dz for the free atmosphere with the value of dz_max
	289	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	290	number_stretch_level_start /= 0 ) THEN
	291	dz(number_stretch_level_start+1) = dz_max
	292	ENDIF
	293
	294	!
	295	!-- Initialize the stretching factor if (infinitely) stretching in the free
	296	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	297	!-- free atmosphere)
	298	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	299	dz_stretch_factor_array(number_stretch_level_start) = &
	300	dz_stretch_factor
	301	ENDIF
	302
	303	!
	304	!-- Allocation of arrays for stretching
	305	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	306
[3065]	307	!
[94]	308	!-- Define the vertical grid levels
[3294]	309	IF ( .NOT. ocean_mode ) THEN
[3065]	310
[94]	311	!
[3065]	312	!-- The stretching region has to be large enough to allow for a smooth
	313	!-- transition between two different grid spacings
	314	DO n = 1, number_stretch_level_start
	315	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	316	4 * MAX( dz(n),dz(n+1) )
	317	ENDDO
	318
[3066]	319	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	320	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	321	message_string= 'Eeach dz_stretch_level_end has to be larger ' // &
	322	'than its corresponding value for &' // &
	323	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	324	'to allow for smooth grid stretching'
	325	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	326	ENDIF
	327
	328	!
	329	!-- Stretching must not be applied within the prandtl_layer
	330	!-- (first two grid points). For the default case dz_stretch_level_start
	331	!-- is negative. Therefore the absolut value is checked here.
	332	IF ( ANY( ABS( dz_stretch_level_start ) < dz(1) * 1.5_wp ) ) THEN
	333	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	334	'larger than ', dz(1) * 1.5
	335	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	336	ENDIF
	337
	338	!
	339	!-- The stretching has to start and end on a grid level. Therefore
	340	!-- user-specified values have to ''interpolate'' to the next lowest level
	341	IF ( number_stretch_level_start /= 0 ) THEN
	342	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	343	dz(1)/2.0) / dz(1) ) &
	344	* dz(1) + dz(1)/2.0
	345	ENDIF
	346
	347	IF ( number_stretch_level_start > 1 ) THEN
	348	DO n = 2, number_stretch_level_start
	349	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	350	dz(n) ) * dz(n)
	351	ENDDO
	352	ENDIF
	353
	354	IF ( number_stretch_level_end /= 0 ) THEN
	355	DO n = 1, number_stretch_level_end
	356	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	357	dz(n+1) ) * dz(n+1)
	358	ENDDO
	359	ENDIF
	360
	361	!
	362	!-- Determine stretching factor if necessary
	363	IF ( number_stretch_level_end >= 1 ) THEN
	364	CALL calculate_stretching_factor( number_stretch_level_end )
	365	ENDIF
	366
	367	!
[94]	368	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	369	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	370	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	371	!-- The second u-level (k=1) corresponds to the top of the
[4340]	372	!-- Prandtl-layer. In case of symmetric boundaries (closed channel flow),
	373	!-- the first grid point is always at z=0.
	374	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. &
	375	topography == 'closed_channel' ) THEN
[1353]	376	zu(0) = 0.0_wp
[667]	377	ELSE
[3065]	378	zu(0) = - dz(1) * 0.5_wp
[667]	379	ENDIF
[3065]	380
	381	zu(1) = dz(1) * 0.5_wp
	382
	383	!
	384	!-- Determine u and v height levels considering the possibility of grid
	385	!-- stretching in several heights.
	386	n = 1
	387	dz_stretch_level_start_index = nzt+1
	388	dz_stretch_level_end_index = nzt+1
	389	dz_stretched = dz(1)
[1]	390
[3065]	391	!-- The default value of dz_stretch_level_start is negative, thus the first
	392	!-- condition is always true. Hence, the second condition is necessary.
[4340]	393	DO k = 2, nzt+1-symmetry_flag
[3065]	394	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	395	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	396	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	397
	398	IF ( dz(n) > dz(n+1) ) THEN
	399	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	400	ELSE
	401	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	402	ENDIF
	403
	404	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	405	dz_stretch_level_start_index(n) = k-1
	406
[94]	407	ENDIF
[3065]	408
[94]	409	zu(k) = zu(k-1) + dz_stretched
[3065]	410
	411	!
	412	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	413	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	414
	415	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	416	zu(k) = dz_stretch_level_end(n)
	417	dz_stretched = dz(n+1)
	418	dz_stretch_level_end_index(n) = k
	419	n = n + 1
	420	ENDIF
[94]	421	ENDDO
[4340]	422
	423	!
	424	!-- If a closed channel flow is simulated, make sure that grid structure is
	425	!-- the same for both bottom and top boundary. (Hint: Using a different dz
	426	!-- at the bottom and at the top makes no sense due to symmetric boundaries
	427	!-- where dz should be equal. Therefore, different dz at the bottom and top
	428	!-- causes an abort (see check_parameters).)
	429	IF ( topography == 'closed_channel' ) THEN
	430	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
	431	ENDIF
[1]	432
	433	!
[94]	434	!-- Compute the w-levels. They are always staggered half-way between the
[843]	435	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	436	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
[4340]	437	!-- Per default, the top w-level is extrapolated linearly. In case of
	438	!-- a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
	439	!-- (Hint: Using a different dz at the bottom and at the top makes no sense
	440	!-- due to symmetric boundaries where dz should be equal. Therefore,
	441	!-- different dz at the bottom and top causes an abort (see
	442	!-- check_parameters).)
[1353]	443	zw(0) = 0.0_wp
[4340]	444	DO k = 1, nzt-symmetry_flag
[1353]	445	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	446	ENDDO
[4340]	447	IF ( topography == 'closed_channel' ) THEN
	448	zw(nzt) = zw(nzt-1) + dz(1)
	449	zw(nzt+1) = zw(nzt) + dz(1)
	450	ELSE
	451	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
	452	ENDIF
[1]	453
[94]	454	ELSE
[3065]	455
[1]	456	!
[3065]	457	!-- The stretching region has to be large enough to allow for a smooth
	458	!-- transition between two different grid spacings
	459	DO n = 1, number_stretch_level_start
	460	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	461	4 * MAX( dz(n),dz(n+1) )
	462	ENDDO
	463
[3066]	464	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	465	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	466	message_string= 'Eeach dz_stretch_level_end has to be less ' // &
	467	'than its corresponding value for &' // &
	468	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	469	'to allow for smooth grid stretching'
	470	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	471	ENDIF
	472
	473	!
[3068]	474	!-- Stretching must not be applied close to the surface (last two grid
	475	!-- points). For the default case dz_stretch_level_start is negative.
	476	IF ( ANY( dz_stretch_level_start > - dz(1) * 1.5_wp ) ) THEN
[3065]	477	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	478	'less than ', dz(1) * 1.5
	479	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	480	ENDIF
	481
	482	!
	483	!-- The stretching has to start and end on a grid level. Therefore
	484	!-- user-specified values have to ''interpolate'' to the next highest level
	485	IF ( number_stretch_level_start /= 0 ) THEN
	486	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	487	dz(1)/2.0) / dz(1) ) &
	488	* dz(1) - dz(1)/2.0
	489	ENDIF
	490
	491	IF ( number_stretch_level_start > 1 ) THEN
	492	DO n = 2, number_stretch_level_start
	493	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	494	dz(n) ) * dz(n)
	495	ENDDO
	496	ENDIF
	497
	498	IF ( number_stretch_level_end /= 0 ) THEN
	499	DO n = 1, number_stretch_level_end
	500	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	501	dz(n+1) ) * dz(n+1)
	502	ENDDO
	503	ENDIF
	504
	505	!
	506	!-- Determine stretching factor if necessary
	507	IF ( number_stretch_level_end >= 1 ) THEN
	508	CALL calculate_stretching_factor( number_stretch_level_end )
	509	ENDIF
	510
	511	!
[843]	512	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	513	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	514	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	515	!-- w-level are defined at same height, but staggered from the second level.
	516	!-- The second u-level (k=1) corresponds to the top of the Prandtl-layer.
[3065]	517	!-- z values are negative starting from z=0 (surface)
	518	zu(nzt+1) = dz(1) * 0.5_wp
	519	zu(nzt) = - dz(1) * 0.5_wp
[94]	520
[3065]	521	!
	522	!-- Determine u and v height levels considering the possibility of grid
	523	!-- stretching in several heights.
	524	n = 1
	525	dz_stretch_level_start_index = 0
	526	dz_stretch_level_end_index = 0
	527	dz_stretched = dz(1)
	528
[94]	529	DO k = nzt-1, 0, -1
[3065]	530
	531	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	532	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	533
	534	IF ( dz(n) > dz(n+1) ) THEN
	535	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	536	ELSE
	537	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	538	ENDIF
	539
	540	IF ( dz_stretch_level_start_index(n) == 0 ) &
	541	dz_stretch_level_start_index(n) = k+1
	542
	543	ENDIF
	544
	545	zu(k) = zu(k+1) - dz_stretched
	546
[1418]	547	!
[3065]	548	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	549	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	550
	551	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	552	zu(k) = dz_stretch_level_end(n)
	553	dz_stretched = dz(n+1)
	554	dz_stretch_level_end_index(n) = k
	555	n = n + 1
[94]	556	ENDIF
	557	ENDDO
[3065]	558
[94]	559	!
	560	!-- Compute the w-levels. They are always staggered half-way between the
[843]	561	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	562	!-- at the ground. In this case the first u- and w-level are defined at
	563	!-- same height. The top w-level (nzt+1) is not used but set for
	564	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	565	zw(nzt+1) = dz(1)
[1353]	566	zw(nzt) = 0.0_wp
[94]	567	DO k = 0, nzt
[1353]	568	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	569	ENDDO
	570
[843]	571	!
	572	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	573	!-- at same height.
	574	IF ( ibc_uv_b == 0 ) THEN
	575	zu(0) = zw(0)
	576	ENDIF
	577
[94]	578	ENDIF
	579
	580	!
[1]	581	!-- Compute grid lengths.
	582	DO k = 1, nzt+1
	583	dzu(k) = zu(k) - zu(k-1)
[1353]	584	ddzu(k) = 1.0_wp / dzu(k)
[1]	585	dzw(k) = zw(k) - zw(k-1)
[1353]	586	ddzw(k) = 1.0_wp / dzw(k)
[1]	587	ENDDO
	588
	589	DO k = 1, nzt
[1353]	590	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	591	ENDDO
[667]	592
	593	!
[709]	594	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	595	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	596	!-- is only dz/2, but should be dz. Therefore, an additional array
	597	!-- containing with appropriate grid information is created for these
	598	!-- solvers.
[1575]	599	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	600	ALLOCATE( ddzu_pres(1:nzt+1) )
	601	ddzu_pres = ddzu
[864]	602	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	603	ENDIF
	604
	605	!
	606	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	607	ddx = 1.0_wp / dx
	608	ddy = 1.0_wp / dy
[1]	609	dx2 = dx * dx
	610	dy2 = dy * dy
[1353]	611	ddx2 = 1.0_wp / dx2
	612	ddy2 = 1.0_wp / dy2
[1]	613
	614	!
[2696]	615	!-- Allocate 3D array to set topography
	616	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	617	topo = 0
	618	!
	619	!-- Initialize topography by generic topography or read from topography from file.
	620	CALL init_topo( topo )
	621	!
	622	!-- Set flags to mask topography on the grid.
	623	CALL set_topo_flags( topo )
	624	!
	625	!-- Calculate wall flag arrays for the multigrid method.
	626	!-- Please note, wall flags are only applied in the non-optimized version.
[4109]	627	IF ( psolver == 'multigrid_noopt' ) CALL poismg_noopt_init
[2696]	628
	629	!
	630	!-- Init flags for ws-scheme to degrade order of the numerics near walls, i.e.
[4109]	631	!-- to decrease the numerical stencil appropriately. The order of the scheme
	632	!-- is degraded near solid walls as well as near non-cyclic inflow and outflow
	633	!-- boundaries. Do this separately for momentum and scalars.
	634	IF ( momentum_advec == 'ws-scheme' ) THEN
	635	ALLOCATE( advc_flags_m(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	636	CALL ws_init_flags_momentum
	637	ENDIF
	638	IF ( scalar_advec == 'ws-scheme' ) THEN
	639	ALLOCATE( advc_flags_s(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	640	advc_flags_s = 0
	641
	642	CALL ws_init_flags_scalar( bc_dirichlet_l .OR. bc_radiation_l, &
	643	bc_dirichlet_n .OR. bc_radiation_n, &
	644	bc_dirichlet_r .OR. bc_radiation_r, &
	645	bc_dirichlet_s .OR. bc_radiation_s, &
	646	advc_flags_s )
	647	ENDIF
[2696]	648
	649	!
	650	!-- Determine the maximum level of topography. It is used for
	651	!-- steering the degradation of order of the applied advection scheme,
[4328]	652	!-- as well in the lpm.
[2696]	653	k_top = 0
	654	DO i = nxl, nxr
	655	DO j = nys, nyn
	656	DO k = nzb, nzt + 1
[4109]	657	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	658	ENDDO
	659	ENDDO
[1]	660	ENDDO
[2696]	661	#if defined( __parallel )
[4328]	662	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, &
[2696]	663	MPI_MAX, comm2d, ierr )
	664	#else
[4328]	665	nzb_max = k_top
[2696]	666	#endif
[1]	667	!
[4328]	668	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
	669	!-- Further, in case topography extents up to the model top, limit to nzt.
	670	nzb_max = MIN( nzb_max+1, nzt )
	671	!
[2968]	672	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	673	!-- there is elevated topography, however, the lowest topography will be higher.
	674	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	675	!-- temperature, surface pressure and density, etc. .
	676	topo_min_level = 0
	677	#if defined( __parallel )
[4168]	678	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	679	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	680	#else
[4168]	681	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	682	#endif
	683	!
[2696]	684	!-- Initialize boundary conditions via surface type
	685	CALL init_bc
[3182]	686
[2696]	687	!
	688	!-- Allocate and set topography height arrays required for data output
	689	IF ( TRIM( topography ) /= 'flat' ) THEN
	690	!
	691	!-- Allocate and set the arrays containing the topography height
	692	IF ( nxr == nx .AND. nyn /= ny ) THEN
	693	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	694	zw_w_inner(nxl:nxr+1,nys:nyn) )
	695	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	696	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	697	zw_w_inner(nxl:nxr,nys:nyn+1) )
	698	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	699	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	700	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	701	ELSE
	702	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	703	zw_w_inner(nxl:nxr,nys:nyn) )
	704	ENDIF
	705
	706	zu_s_inner = 0.0_wp
	707	zw_w_inner = 0.0_wp
	708	!
	709	!-- Determine local topography height on scalar and w-grid. Note, setting
[4329]	710	!-- lateral boundary values is not necessary, realized via wall_flags_static_0
[2696]	711	!-- array. Further, please note that loop bounds are different from
	712	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	713	!-- use intrinsic lbound and ubound functions to infer array bounds.
	714	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	715	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
	716	!
	717	!-- Topography height on scalar grid. Therefore, determine index of
	718	!-- upward-facing surface element on scalar grid.
[4168]	719	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	720	!
	721	!-- Topography height on w grid. Therefore, determine index of
	722	!-- upward-facing surface element on w grid.
[4168]	723	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
[2696]	724	ENDDO
	725	ENDDO
	726	ENDIF
	727
	728	!
	729	!-- In the following, calculate 2D index arrays. Note, these will be removed
	730	!-- soon.
[1]	731	!-- Allocate outer and inner index arrays for topography and set
[2232]	732	!-- defaults.
[2696]	733	ALLOCATE( nzb_s_inner(nysg:nyng,nxlg:nxrg), &
	734	nzb_s_outer(nysg:nyng,nxlg:nxrg), &
	735	nzb_u_inner(nysg:nyng,nxlg:nxrg), &
	736	nzb_u_outer(nysg:nyng,nxlg:nxrg), &
	737	nzb_v_inner(nysg:nyng,nxlg:nxrg), &
	738	nzb_v_outer(nysg:nyng,nxlg:nxrg), &
	739	nzb_w_inner(nysg:nyng,nxlg:nxrg), &
	740	nzb_w_outer(nysg:nyng,nxlg:nxrg), &
	741	nzb_diff_s_inner(nysg:nyng,nxlg:nxrg), &
	742	nzb_diff_s_outer(nysg:nyng,nxlg:nxrg), &
	743	nzb_local(nysg:nyng,nxlg:nxrg), &
	744	nzb_tmp(nysg:nyng,nxlg:nxrg) )
	745	!
	746	!-- Initialize 2D-index arrays. Note, these will be removed soon!
[4168]	747	nzb_local(nys:nyn,nxl:nxr) = topo_top_ind(nys:nyn,nxl:nxr,0)
[2696]	748	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2968]	749	!
	750	!-- Check topography for consistency with model domain. Therefore, use
	751	!-- maximum and minium topography-top indices. Note, minimum topography top
	752	!-- index is already calculated.
[2696]	753	IF ( TRIM( topography ) /= 'flat' ) THEN
	754	#if defined( __parallel )
[4168]	755	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	756	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	757	#else
[4168]	758	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	759	#endif
[2968]	760	nzb_local_min = topo_min_level
[2696]	761	!
	762	!-- Consistency checks
	763	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	764	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	765	' model domain', &
[3046]	766	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	767	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	768	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	769	ENDIF
	770	ENDIF
[1]	771
	772	nzb_s_inner = nzb; nzb_s_outer = nzb
	773	nzb_u_inner = nzb; nzb_u_outer = nzb
	774	nzb_v_inner = nzb; nzb_v_outer = nzb
	775	nzb_w_inner = nzb; nzb_w_outer = nzb
	776
	777	!
[19]	778	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	779	!-- form (which does not use surface fluxes) is applied
[1691]	780	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	781	nzb_diff = nzb + 2
	782	ELSE
	783	nzb_diff = nzb + 1
	784	ENDIF
	785
	786	nzb_diff_s_inner = nzb_diff; nzb_diff_s_outer = nzb_diff
[2696]	787	!
	788	!-- Set Neumann conditions for topography. Will be removed soon.
	789	IF ( .NOT. bc_ns_cyc ) THEN
	790	IF ( nys == 0 ) THEN
[2927]	791	DO i = 1, nbgp
	792	nzb_local(nys-i,:) = nzb_local(nys,:)
	793	ENDDO
[2696]	794	ELSEIF ( nyn == ny ) THEN
[2927]	795	DO i = 1, nbgp
	796	nzb_local(ny+i,:) = nzb_local(ny,:)
	797	ENDDO
[2696]	798	ENDIF
	799	ENDIF
[1]	800
[2696]	801	IF ( .NOT. bc_lr_cyc ) THEN
	802	IF ( nxl == 0 ) THEN
[2927]	803	DO i = 1, nbgp
	804	nzb_local(:,nxl-i) = nzb_local(:,nxl)
	805	ENDDO
[2696]	806	ELSEIF ( nxr == nx ) THEN
[2927]	807	DO i = 1, nbgp
	808	nzb_local(:,nx+i) = nzb_local(:,nx)
	809	ENDDO
[2696]	810	ENDIF
	811	ENDIF
[1]	812	!
[2696]	813	!-- Initialization of 2D index arrays, will be removed soon!
	814	!-- Initialize nzb_s_inner and nzb_w_inner
	815	nzb_s_inner = nzb_local
	816	nzb_w_inner = nzb_local
	817
	818	!
	819	!-- Initialize remaining index arrays:
	820	!-- first pre-initialize them with nzb_s_inner...
	821	nzb_u_inner = nzb_s_inner
	822	nzb_u_outer = nzb_s_inner
	823	nzb_v_inner = nzb_s_inner
	824	nzb_v_outer = nzb_s_inner
	825	nzb_w_outer = nzb_s_inner
	826	nzb_s_outer = nzb_s_inner
	827
	828	!
	829	!-- nzb_s_outer:
	830	!-- extend nzb_local east-/westwards first, then north-/southwards
	831	nzb_tmp = nzb_local
	832	DO j = nys, nyn
	833	DO i = nxl, nxr
	834	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i), &
	835	nzb_local(j,i+1) )
	836	ENDDO
	837	ENDDO
	838
	839	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	840
	841	DO i = nxl, nxr
	842	DO j = nys, nyn
	843	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	844	nzb_tmp(j+1,i) )
	845	ENDDO
	846	!
	847	!-- non-cyclic boundary conditions (overwritten by call of
	848	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	849	IF ( nys == 0 ) THEN
	850	j = -1
	851	nzb_s_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	852	ENDIF
	853	IF ( nyn == ny ) THEN
	854	j = ny + 1
	855	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	856	ENDIF
	857	ENDDO
	858	!
	859	!-- nzb_w_outer:
	860	!-- identical to nzb_s_outer
	861	nzb_w_outer = nzb_s_outer
	862	!
	863	!-- nzb_u_inner:
	864	!-- extend nzb_local rightwards only
	865	nzb_tmp = nzb_local
	866	DO j = nys, nyn
	867	DO i = nxl, nxr
	868	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i) )
	869	ENDDO
	870	ENDDO
	871
	872	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	873
	874	nzb_u_inner = nzb_tmp
	875	!
	876	!-- nzb_u_outer:
	877	!-- extend current nzb_tmp (nzb_u_inner) north-/southwards
	878	DO i = nxl, nxr
	879	DO j = nys, nyn
	880	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	881	nzb_tmp(j+1,i) )
	882	ENDDO
	883	!
	884	!-- non-cyclic boundary conditions (overwritten by call of
	885	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	886	IF ( nys == 0 ) THEN
	887	j = -1
	888	nzb_u_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	889	ENDIF
	890	IF ( nyn == ny ) THEN
	891	j = ny + 1
	892	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	893	ENDIF
	894	ENDDO
	895
	896	!
	897	!-- nzb_v_inner:
	898	!-- extend nzb_local northwards only
	899	nzb_tmp = nzb_local
	900	DO i = nxl, nxr
	901	DO j = nys, nyn
	902	nzb_tmp(j,i) = MAX( nzb_local(j-1,i), nzb_local(j,i) )
	903	ENDDO
	904	ENDDO
	905
	906	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	907	nzb_v_inner = nzb_tmp
	908
	909	!
	910	!-- nzb_v_outer:
	911	!-- extend current nzb_tmp (nzb_v_inner) right-/leftwards
	912	DO j = nys, nyn
	913	DO i = nxl, nxr
	914	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i), &
	915	nzb_tmp(j,i+1) )
	916	ENDDO
	917	!
	918	!-- non-cyclic boundary conditions (overwritten by call of
	919	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	920	IF ( nxl == 0 ) THEN
	921	i = -1
	922	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i+1), nzb_tmp(j,i) )
	923	ENDIF
	924	IF ( nxr == nx ) THEN
	925	i = nx + 1
	926	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i) )
	927	ENDIF
	928	ENDDO
	929
	930	!
	931	!-- Exchange of lateral boundary values (parallel computers) and cyclic
	932	!-- boundary conditions, if applicable.
	933	!-- Since nzb_s_inner and nzb_w_inner are derived directly from nzb_local
	934	!-- they do not require exchange and are not included here.
	935	CALL exchange_horiz_2d_int( nzb_u_inner, nys, nyn, nxl, nxr, nbgp )
	936	CALL exchange_horiz_2d_int( nzb_u_outer, nys, nyn, nxl, nxr, nbgp )
	937	CALL exchange_horiz_2d_int( nzb_v_inner, nys, nyn, nxl, nxr, nbgp )
	938	CALL exchange_horiz_2d_int( nzb_v_outer, nys, nyn, nxl, nxr, nbgp )
	939	CALL exchange_horiz_2d_int( nzb_w_outer, nys, nyn, nxl, nxr, nbgp )
	940	CALL exchange_horiz_2d_int( nzb_s_outer, nys, nyn, nxl, nxr, nbgp )
	941
	942	!
	943	!-- Set the individual index arrays which define the k index from which on
	944	!-- the usual finite difference form (which does not use surface fluxes) is
	945	!-- applied
	946	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	947	nzb_diff_s_inner = nzb_s_inner + 2
	948	nzb_diff_s_outer = nzb_s_outer + 2
	949	ELSE
	950	nzb_diff_s_inner = nzb_s_inner + 1
	951	nzb_diff_s_outer = nzb_s_outer + 1
	952	ENDIF
	953	!
	954	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	955	!-- coarse grid
	956	IF ( vnested ) CALL vnest_init_grid
	957
	958	END SUBROUTINE init_grid
	959
[3065]	960
[2696]	961	! Description:
	962	! -----------------------------------------------------------------------------!
[3065]	963	!> Calculation of the stretching factor through an iterative method. Ideas were
	964	!> taken from the paper "Regional stretched grid generation and its application
	965	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	966	!> system of equations has two variables (r,l) but four requirements
	967	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	968	!> results into an overdetermined system.
	969	!------------------------------------------------------------------------------!
	970	SUBROUTINE calculate_stretching_factor( number_end )
	971
	972	USE control_parameters, &
[3241]	973	ONLY: dz, dz_stretch_factor_array, &
[3065]	974	dz_stretch_level_end, dz_stretch_level_start, message_string
	975
	976	USE kinds
	977
	978	IMPLICIT NONE
	979
	980	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	981	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	982	INTEGER(iwp) :: n !< loop variable for stretching
	983
	984	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	985
	986	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	987	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	988	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	989	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	990	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	991	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	992	REAL(wp) :: numerator !< numerator of the quotient
	993	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	994	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	995
[3068]	996	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	997
[3065]	998	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06 !< interval for sampling possible stretching factors
	999	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88 !< lowest possible stretching factor
	1000	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12 !< highest possible stretching factor
	1001
	1002
[3068]	1003	l = 0
	1004	DO n = 1, number_end
	1005
	1006	iterations = 1
	1007	stretch_factor_1 = 1.0
	1008	stretch_factor_2 = 1.0
	1009	delta_total_old = 1.0
[3065]	1010
[3068]	1011	IF ( dz(n) > dz(n+1) ) THEN
	1012	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	1013
	1014	stretch_factor_1 = 1.0 - iterations * stretch_factor_interval
	1015	distance = ABS( dz_stretch_level_end(n) - &
	1016	dz_stretch_level_start(n) )
	1017	numerator = distance*stretch_factor_1/dz(n) + &
	1018	stretch_factor_1 - distance/dz(n)
	1019
	1020	IF ( numerator > 0.0 ) THEN
	1021	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1022	l_rounded = NINT( l )
	1023	delta_l = ABS( l_rounded - l ) / l
	1024	ENDIF
	1025
	1026	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	1027
	1028	delta_stretch_factor = ABS( stretch_factor_1 - &
	1029	stretch_factor_2 ) / &
	1030	stretch_factor_2
	1031
	1032	delta_total_new = delta_l + delta_stretch_factor
[3065]	1033
	1034	!
	1035	!-- stretch_factor_1 is taken to guarantee that the stretching
	1036	!-- procedure ends as close as possible to dz_stretch_level_end.
	1037	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1038	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1039	IF (delta_total_new < delta_total_old) THEN
	1040	dz_stretch_factor_array(n) = stretch_factor_1
	1041	dz_stretch_factor_array_2(n) = stretch_factor_2
	1042	delta_total_old = delta_total_new
	1043	ENDIF
	1044
	1045	iterations = iterations + 1
	1046
	1047	ENDDO
	1048
	1049	ELSEIF ( dz(n) < dz(n+1) ) THEN
	1050	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	1051
	1052	stretch_factor_1 = 1.0 + iterations * stretch_factor_interval
	1053	distance = ABS( dz_stretch_level_end(n) - &
	1054	dz_stretch_level_start(n) )
	1055	numerator = distance*stretch_factor_1/dz(n) + &
	1056	stretch_factor_1 - distance/dz(n)
	1057
	1058	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1059	l_rounded = NINT( l )
	1060	delta_l = ABS( l_rounded - l ) / l
	1061
	1062	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	1063
[3068]	1064	delta_stretch_factor = ABS( stretch_factor_1 - &
	1065	stretch_factor_2 ) / &
	1066	stretch_factor_2
	1067
	1068	delta_total_new = delta_l + delta_stretch_factor
	1069
[3065]	1070	!
	1071	!-- stretch_factor_1 is taken to guarantee that the stretching
	1072	!-- procedure ends as close as possible to dz_stretch_level_end.
	1073	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1074	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1075	IF (delta_total_new < delta_total_old) THEN
	1076	dz_stretch_factor_array(n) = stretch_factor_1
	1077	dz_stretch_factor_array_2(n) = stretch_factor_2
	1078	delta_total_old = delta_total_new
	1079	ENDIF
[3065]	1080
[3068]	1081	iterations = iterations + 1
	1082	ENDDO
	1083
	1084	ELSE
	1085	message_string= 'Two adjacent values of dz must be different'
	1086	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	1087
	1088	ENDIF
	1089
	1090	!
	1091	!-- Check if also the second stretching factor fits into the allowed
	1092	!-- interval. If not, print a warning for the user.
	1093	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	1094	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	1095	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	1096	dz_stretch_factor_array_2(n), ' which is',&
	1097	' responsible for exactly reaching& dz =',&
	1098	dz(n+1), 'after a specific amount of', &
	1099	' grid levels& exceeds the upper', &
	1100	' limit =', stretch_factor_upper_limit, &
	1101	' &or lower limit = ', &
	1102	stretch_factor_lower_limit
	1103	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	1104
	1105	ENDIF
	1106	ENDDO
[3065]	1107
	1108	END SUBROUTINE calculate_stretching_factor
	1109
	1110
	1111	! Description:
	1112	! -----------------------------------------------------------------------------!
[2696]	1113	!> Set temporary topography flags and reference buildings on top of underlying
	1114	!> orography.
	1115	!------------------------------------------------------------------------------!
	1116	SUBROUTINE process_topography( topo_3d )
	1117
	1118	USE arrays_3d, &
[2747]	1119	ONLY: zu, zw
[2696]	1120
	1121	USE control_parameters, &
[3294]	1122	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	1123
	1124	USE indices, &
	1125	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	1126	nzt
	1127
	1128	USE netcdf_data_input_mod, &
[3115]	1129	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	1130	terrain_height_f
	1131
	1132	USE kinds
	1133
	1134	USE pegrid
	1135
	1136	IMPLICIT NONE
	1137
[2867]	1138	INTEGER(iwp) :: i !< running index along x-direction
	1139	INTEGER(iwp) :: j !< running index along y-direction
	1140	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	1141	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	1142	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	1143	INTEGER(iwp) :: num_build !< counter for number of buildings
	1144	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	1145
	1146	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
	1147	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	1148	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	1149	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	1150	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	1151	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	1152
	1153	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	1154	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	1155
	1156	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	1157
	1158	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	1159	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	1160	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	1161	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	1162
	1163	!
[3103]	1164	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	1165	!-- is non-zero, all grid points of the lower vertical grid levels might be
	1166	!-- entirely below the surface, meaning a waste of computational resources.
	1167	!-- In order to avoid this, remove the lowest terrain height. Please note,
	1168	!-- in case of a nested run, the global minimum from all parent and childs
	1169	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	1170	IF ( input_pids_static ) THEN
[4159]	1171
[3200]	1172	#if defined( __parallel )
[3103]	1173	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	1174	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	1175	#else
	1176	oro_min = MINVAL( terrain_height_f%var )
	1177	#endif
[3103]	1178	terrain_height_f%var = terrain_height_f%var - oro_min
	1179	!
	1180	!-- Give an informative message that terrain height is referenced to zero
	1181	IF ( oro_min > 0.0_wp ) THEN
	1182	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	1183	'downwards by ', oro_min, 'meter(s) to save ' // &
	1184	'computational resources.'
	1185	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	1186	ENDIF
	1187	ENDIF
	1188
	1189	!
[2696]	1190	!-- In the following, buildings and orography are further preprocessed
	1191	!-- before they are mapped on the LES grid.
	1192	!-- Buildings are mapped on top of the orography by maintaining the roof
	1193	!-- shape of the building. This can be achieved by referencing building on
	1194	!-- top of the maximum terrain height within the area occupied by the
	1195	!-- respective building. As buildings and terrain height are defined PE-wise,
	1196	!-- parallelization of this referencing is required (a building can be
	1197	!-- distributed between different PEs).
	1198	!-- In a first step, determine the number of buildings with different
	1199	!-- building id on each PE. In a next step, all building ids are gathered
	1200	!-- into one array which is present to all PEs. For each building ID,
	1201	!-- the maximum terrain height occupied by the respective building is
	1202	!-- computed and distributed to each PE.
	1203	!-- Finally, for each building id and its respective reference orography,
	1204	!-- builidings are mapped on top.
	1205	!--
	1206	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1207	!-- buildings
	1208	!-- classify the respective surfaces.
	1209	topo_3d = IBSET( topo_3d, 0 )
	1210	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1211	!
[3051]	1212	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1213	!-- pre-calculate an offset value.
[3294]	1214	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1215	!
[2696]	1216	!-- Reference buildings on top of orography. This is not necessary
	1217	!-- if topography is read from ASCII file as no distinction between buildings
	1218	!-- and terrain height can be made. Moreover, this is also not necessary if
	1219	!-- urban-surface and land-surface model are used at the same time.
[2897]	1220	IF ( input_pids_static ) THEN
	1221
	1222	IF ( buildings_f%from_file ) THEN
	1223	num_buildings_l = 0
	1224	num_buildings = 0
[2696]	1225	!
[3925]	1226	!-- Allocate at least one element for building ids and give it an inital
	1227	!-- negative value that will be overwritten later. This, however, is
	1228	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1229	ALLOCATE( build_ids_l(1) )
[3925]	1230	build_ids_l = -1
[2897]	1231	DO i = nxl, nxr
	1232	DO j = nys, nyn
	1233	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1234	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1235	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1236	THEN
	1237	CYCLE
	1238	ELSE
	1239	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1240	!
	1241	!-- Resize array with different local building ids
	1242	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1243	build_ids_l_tmp = build_ids_l
	1244	DEALLOCATE( build_ids_l )
	1245	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1246	build_ids_l(1:num_buildings_l(myid)-1) = &
	1247	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1248	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1249	DEALLOCATE( build_ids_l_tmp )
	1250	ENDIF
	1251	!
[2897]	1252	!-- First occuring building id on PE
	1253	ELSE
	1254	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1255	build_ids_l(1) = building_id_f%var(j,i)
	1256	ENDIF
[2696]	1257	ENDIF
[2897]	1258	ENDDO
[2696]	1259	ENDDO
	1260	!
[2897]	1261	!-- Determine number of different building ids for the entire domain
[2696]	1262	#if defined( __parallel )
[2897]	1263	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1264	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1265	#else
[2897]	1266	num_buildings = num_buildings_l
[2696]	1267	#endif
	1268	!
[2897]	1269	!-- Gather all buildings ids on each PEs.
	1270	!-- First, allocate array encompassing all building ids in model domain.
	1271	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1272	#if defined( __parallel )
	1273	!
[2897]	1274	!-- Allocate array for displacements.
	1275	!-- As each PE may has a different number of buildings, so that
	1276	!-- the block sizes send by each PE may not be equal. Hence,
	1277	!-- information about the respective displacement is required, indicating
	1278	!-- the respective adress where each MPI-task writes into the receive
	1279	!-- buffer array
	1280	ALLOCATE( displace_dum(0:numprocs-1) )
	1281	displace_dum(0) = 0
	1282	DO i = 1, numprocs-1
	1283	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1284	ENDDO
[2696]	1285
[2897]	1286	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1287	num_buildings(myid), &
	1288	MPI_INTEGER, &
	1289	build_ids, &
	1290	num_buildings, &
	1291	displace_dum, &
	1292	MPI_INTEGER, &
	1293	comm2d, ierr )
[2696]	1294
[2897]	1295	DEALLOCATE( displace_dum )
[2696]	1296
	1297	#else
[2897]	1298	build_ids = build_ids_l
[2696]	1299	#endif
	1300
	1301	!
[2897]	1302	!-- Note, in parallel mode building ids can occure mutliple times, as
	1303	!-- each PE has send its own ids. Therefore, sort out building ids which
	1304	!-- appear more than one time.
	1305	num_build = 0
	1306	DO nr = 1, SIZE(build_ids)
[2696]	1307
[2897]	1308	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1309	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1310	CYCLE
	1311	ELSE
	1312	num_build = num_build + 1
	1313	!
	1314	!-- Resize
	1315	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1316	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1317	DEALLOCATE( build_ids_final )
	1318	ALLOCATE( build_ids_final(1:num_build) )
	1319	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1320	build_ids_final(num_build) = build_ids(nr)
	1321	DEALLOCATE( build_ids_final_tmp )
	1322	ENDIF
[2696]	1323	ELSE
	1324	num_build = num_build + 1
	1325	ALLOCATE( build_ids_final(1:num_build) )
	1326	build_ids_final(num_build) = build_ids(nr)
[2897]	1327	ENDIF
	1328	ENDDO
[2696]	1329
	1330	!
[3051]	1331	!-- Determine maximumum terrain height occupied by the respective
	1332	!-- building and temporalily store on oro_max
[2897]	1333	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1334	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1335	oro_max_l = 0.0_wp
[2696]	1336
[2897]	1337	DO nr = 1, SIZE(build_ids_final)
[4159]	1338	oro_max_l(nr) = MAXVAL( &
	1339	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1340	0.0_wp, &
	1341	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1342	build_ids_final(nr) ) )
	1343	ENDDO
[2696]	1344
	1345	#if defined( __parallel )
[2897]	1346	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1347	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1348	MPI_MAX, comm2d, ierr )
	1349	ENDIF
[2696]	1350	#else
[2897]	1351	oro_max = oro_max_l
[2696]	1352	#endif
[3051]	1353	!
	1354	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1355	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1356	!-- exceeds the scalar level the grid box is fully terrain and the
	1357	!-- maximum terrain is set to the zw level.
	1358	!-- terrain or
[3051]	1359	oro_max_l = 0.0
	1360	DO nr = 1, SIZE(build_ids_final)
	1361	DO k = nzb, nzt
	1362	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1363	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1364	ENDDO
[3142]	1365	oro_max(nr) = oro_max_l(nr)
[3051]	1366	ENDDO
[2897]	1367	ENDIF
[2696]	1368	!
[4245]	1369	!-- Allocate array for storing terrain height under buildings
	1370	IF ( buildings_f%from_file ) THEN
	1371	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
	1372	buildings_f%oro_max = buildings_f%fill1
	1373	END IF
	1374	!
[2867]	1375	!-- Map orography as well as buildings onto grid.
[2696]	1376	DO i = nxl, nxr
	1377	DO j = nys, nyn
[2867]	1378	topo_top_index = 0
[3142]	1379	!
	1380	!-- Obtain index in global building_id array
	1381	IF ( buildings_f%from_file ) THEN
	1382	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1383	!
	1384	!-- Determine index where maximum terrain height occupied by
	1385	!-- the respective building height is stored.
	1386	nr = MINLOC( ABS( build_ids_final - &
	1387	building_id_f%var(j,i) ), DIM = 1 )
[4245]	1388	!
	1389	!-- Save grid-indexed oro_max
	1390	buildings_f%oro_max(j,i) = oro_max(nr)
[3142]	1391	ENDIF
	1392	ENDIF
[2696]	1393	DO k = nzb, nzt
	1394	!
	1395	!-- In a first step, if grid point is below or equal the given
	1396	!-- terrain height, grid point is flagged to be of type natural.
	1397	!-- Please note, in case there is also a building which is lower
	1398	!-- than the vertical grid spacing, initialization of surface
	1399	!-- attributes will not be correct as given surface information
	1400	!-- will not be in accordance to the classified grid points.
[4159]	1401	!-- Hence, in this case, also a building flag.
[2747]	1402	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1403	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1404	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1405	topo_top_index = k ! topo_top_index + 1
[2696]	1406	ENDIF
	1407	!
	1408	!-- Set building grid points. Here, only consider 2D buildings.
	1409	!-- 3D buildings require separate treatment.
[2897]	1410	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1411	!
	1412	!-- Fill-up the terrain to the level of maximum orography
	1413	!-- within the building-covered area.
	1414	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1415	!
	1416	!-- Note, oro_max is always on zw level
	1417	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1418	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1419	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1420	ELSEIF ( zu(k) - ocean_offset <= &
	1421	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1422	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1423	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1424	ENDIF
	1425	ENDIF
	1426	ENDIF
	1427	ENDDO
	1428	!
[4159]	1429	!-- Special treatment for non grid-resolved buildings. This case,
	1430	!-- the uppermost terrain grid point is flagged as building as well
	1431	!-- well, even though no building exists at all. However, the
	1432	!-- surface element will be identified as urban-surface and the
	1433	!-- input data provided by the drivers is consistent to the surface
	1434	!-- classification. Else, all non grid-resolved buildings would vanish
	1435	!-- and identified as terrain grid points, which, however, won't be
	1436	!-- consistent with the input data.
	1437	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1438	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1439	DO k = nzb, nzt
	1440	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1441	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1442	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1443	ENDIF
	1444	ENDIF
	1445	ENDDO
	1446	ENDIF
	1447	ENDIF
	1448	!
[2696]	1449	!-- Map 3D buildings onto terrain height.
[2867]	1450	!-- In case of any slopes, map building on top of maximum terrain
	1451	!-- height covered by the building. In other words, extend
	1452	!-- building down to the respective local terrain-surface height.
[2897]	1453	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1454	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1455	!
[3051]	1456	!-- Extend building down to the terrain surface, i.e. fill-up
	1457	!-- surface irregularities below a building. Note, oro_max
	1458	!-- is already a discrete height according to the all-or-nothing
	1459	!-- approach, i.e. grid box is either topography or atmosphere,
	1460	!-- terrain top is defined at upper bound of the grid box.
	1461	!-- Hence, check for zw in this case.
[3115]	1462	!-- Note, do this only for buildings which are surface mounted,
	1463	!-- i.e. building types 1-6. Below bridges, which are represented
	1464	!-- exclusively by building type 7, terrain shape should be
	1465	!-- maintained.
[3855]	1466	IF ( building_type_f%from_file ) THEN
	1467	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1468	DO k = topo_top_index + 1, nzt + 1
[4159]	1469	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1470	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1471	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1472	ENDIF
	1473	ENDDO
	1474	!
	1475	!-- After surface irregularities are smoothen, determine
	1476	!-- lower start index where building starts.
	1477	DO k = nzb, nzt
[4159]	1478	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1479	topo_top_index = k
	1480	ENDDO
	1481	ENDIF
[3115]	1482	ENDIF
[3051]	1483	!
	1484	!-- Finally, map building on top.
[2867]	1485	k2 = 0
	1486	DO k = topo_top_index, nzt + 1
[2796]	1487	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1488	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1489	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1490	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1491	ENDIF
	1492	ENDIF
	1493	k2 = k2 + 1
	1494	ENDDO
	1495	ENDIF
	1496	ENDIF
	1497	ENDDO
	1498	ENDDO
	1499	!
[4265]	1500	!-- Horizontal exchange the oro_max array, which is required to for
	1501	!-- initialization of building-surface properties.
	1502	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
	1503	CALL exchange_horiz_2d( buildings_f%oro_max(:,:), nbgp )
	1504	ENDIF
[4245]	1505	!
[2696]	1506	!-- Deallocate temporary arrays required for processing and reading data
	1507	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1508	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1509	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1510	!
	1511	!-- Topography input via ASCII format.
	1512	ELSE
[3294]	1513	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1514	!
	1515	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1516	!-- and clear all grid points at nzb, where alway a surface is defined.
	1517	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1518	!-- used for masked data output and further processing. Note, in the
	1519	!-- ASCII case no distinction is made between buildings and terrain,
	1520	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1521	topo_3d = IBSET( topo_3d, 0 )
	1522	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1523	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1524	DO i = nxl, nxr
	1525	DO j = nys, nyn
	1526	DO k = nzb, nzt
[3538]	1527	!
	1528	!-- Flag topography for all grid points which are below
	1529	!-- the local topography height.
	1530	!-- Note, each topography is flagged as building.
[2747]	1531	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1532	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1533	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1534	ENDIF
	1535	ENDDO
	1536	ENDDO
	1537	ENDDO
	1538	ENDIF
	1539
	1540	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1541
	1542	IF ( .NOT. bc_ns_cyc ) THEN
	1543	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1544	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1545	ENDIF
	1546
	1547	IF ( .NOT. bc_lr_cyc ) THEN
	1548	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1549	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1550	ENDIF
	1551
	1552	END SUBROUTINE process_topography
	1553
	1554
	1555	! Description:
	1556	! -----------------------------------------------------------------------------!
	1557	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1558	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1559	!> equation on discrete grid cannot be fulfilled in such case.
	1560	!------------------------------------------------------------------------------!
	1561	SUBROUTINE filter_topography( topo_3d )
	1562
	1563	USE control_parameters, &
	1564	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1565
	1566	USE indices, &
	1567	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1568
	1569	USE netcdf_data_input_mod, &
	1570	ONLY: building_id_f, building_type_f
	1571
	1572	USE pegrid
	1573
	1574	IMPLICIT NONE
	1575
[2893]	1576	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1577
[2696]	1578	INTEGER(iwp) :: i !< running index along x-direction
	1579	INTEGER(iwp) :: j !< running index along y-direction
	1580	INTEGER(iwp) :: k !< running index along z-direction
	1581	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1582	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1583	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1584
[2955]	1585	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1586	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1587	!
	1588	!-- Before checking for holes, set lateral boundary conditions for
	1589	!-- topography. After hole-filling, boundary conditions must be set again.
	1590	!-- Several iterations are performed, in order to fill holes which might
	1591	!-- emerge by the filling-algorithm itself.
	1592	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1593	topo_tmp = 0
	1594
	1595	num_hole = 99999
	1596	DO WHILE ( num_hole > 0 )
	1597
	1598	num_hole = 0
	1599	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1600	!
	1601	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1602	!-- variable.
	1603	IF ( building_id_f%from_file ) &
	1604	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1605	IF ( building_type_f%from_file ) &
	1606	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1607
	1608	topo_tmp = topo_3d
	1609	!
	1610	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1611	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1612	!-- boundary and some topographic structure will be filled.
	1613	IF ( .NOT. bc_ns_cyc ) THEN
	1614	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1615	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1616	ENDIF
	1617
	1618	IF ( .NOT. bc_lr_cyc ) THEN
	1619	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1620	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1621	ENDIF
	1622
	1623	num_hole_l = 0
	1624	DO i = nxl, nxr
	1625	DO j = nys, nyn
	1626	DO k = nzb+1, nzt
	1627	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1628	num_wall = 0
	1629	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1630	num_wall = num_wall + 1
	1631	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1632	num_wall = num_wall + 1
	1633	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1634	num_wall = num_wall + 1
	1635	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1636	num_wall = num_wall + 1
	1637	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1638	num_wall = num_wall + 1
	1639	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1640	num_wall = num_wall + 1
	1641
	1642	IF ( num_wall >= 4 ) THEN
	1643	num_hole_l = num_hole_l + 1
	1644	!
[4314]	1645	!-- Clear flag 0 and set special flag ( bit 4) to indicate
[2696]	1646	!-- that new topography point is a result of filtering process.
	1647	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4314]	1648	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
[2696]	1649	!
	1650	!-- If filled grid point is occupied by a building, classify
	1651	!-- it as building grid point.
	1652	IF ( building_type_f%from_file ) THEN
	1653	IF ( building_type_f%var(j,i) /= &
	1654	building_type_f%fill .OR. &
	1655	building_type_f%var(j+1,i) /= &
	1656	building_type_f%fill .OR. &
	1657	building_type_f%var(j-1,i) /= &
	1658	building_type_f%fill .OR. &
	1659	building_type_f%var(j,i+1) /= &
	1660	building_type_f%fill .OR. &
	1661	building_type_f%var(j,i-1) /= &
	1662	building_type_f%fill ) THEN
	1663	!
	1664	!-- Set flag indicating building surfaces
	1665	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1666	!
	1667	!-- Set building_type and ID at this position if not
	1668	!-- already set. This is required for proper
	1669	!-- initialization of urban-surface energy balance
	1670	!-- solver.
	1671	IF ( building_type_f%var(j,i) == &
	1672	building_type_f%fill ) THEN
	1673
	1674	IF ( building_type_f%var(j+1,i) /= &
	1675	building_type_f%fill ) THEN
	1676	building_type_f%var(j,i) = &
	1677	building_type_f%var(j+1,i)
	1678	building_id_f%var(j,i) = &
	1679	building_id_f%var(j+1,i)
	1680	ELSEIF ( building_type_f%var(j-1,i) /= &
	1681	building_type_f%fill ) THEN
	1682	building_type_f%var(j,i) = &
	1683	building_type_f%var(j-1,i)
	1684	building_id_f%var(j,i) = &
	1685	building_id_f%var(j-1,i)
	1686	ELSEIF ( building_type_f%var(j,i+1) /= &
	1687	building_type_f%fill ) THEN
	1688	building_type_f%var(j,i) = &
	1689	building_type_f%var(j,i+1)
	1690	building_id_f%var(j,i) = &
	1691	building_id_f%var(j,i+1)
	1692	ELSEIF ( building_type_f%var(j,i-1) /= &
	1693	building_type_f%fill ) THEN
	1694	building_type_f%var(j,i) = &
	1695	building_type_f%var(j,i-1)
	1696	building_id_f%var(j,i) = &
	1697	building_id_f%var(j,i-1)
	1698	ENDIF
	1699	ENDIF
	1700	ENDIF
	1701	ENDIF
	1702	!
	1703	!-- If filled grid point is already classified as building
	1704	!-- everything is fine, else classify this grid point as
	1705	!-- natural type grid point. This case, values for the
	1706	!-- surface type are already set.
	1707	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1708	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1709	ENDIF
	1710	ENDIF
	1711	ENDIF
	1712	ENDDO
	1713	ENDDO
	1714	ENDDO
	1715	!
	1716	!-- Count the total number of holes, required for informative message.
	1717	#if defined( __parallel )
	1718	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1719	comm2d, ierr )
	1720	#else
	1721	num_hole = num_hole_l
	1722	#endif
[2893]	1723	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1724
[2893]	1725	ENDDO
[2696]	1726	!
[2893]	1727	!-- Create an informative message if any holes were filled.
	1728	IF ( filled ) THEN
	1729	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1730	'resolved by only one grid point ' // &
	1731	'were filled during initialization.'
	1732	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1733	ENDIF
[2696]	1734
	1735	DEALLOCATE( topo_tmp )
	1736	!
	1737	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1738	!-- condition in case of non-cyclic lateral boundaries.
	1739	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1740
	1741	IF ( .NOT. bc_ns_cyc ) THEN
	1742	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1743	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1744	ENDIF
	1745
	1746	IF ( .NOT. bc_lr_cyc ) THEN
	1747	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1748	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1749	ENDIF
[2955]	1750	!
	1751	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1752	IF ( building_id_f%from_file ) &
	1753	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1754	IF ( building_type_f%from_file ) &
	1755	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1756
	1757	END SUBROUTINE filter_topography
	1758
	1759
	1760	! Description:
	1761	! -----------------------------------------------------------------------------!
	1762	!> Reads topography information from file or sets generic topography. Moreover,
	1763	!> all topography-relevant topography arrays are initialized, and grid flags
	1764	!> are set.
	1765	!------------------------------------------------------------------------------!
	1766	SUBROUTINE init_topo( topo )
	1767
	1768	USE arrays_3d, &
	1769	ONLY: zw
	1770
	1771	USE control_parameters, &
	1772	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1773	building_length_y, building_wall_left, building_wall_south, &
	1774	canyon_height, canyon_wall_left, canyon_wall_south, &
	1775	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1776	message_string, topography, topography_grid_convention, &
[2696]	1777	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1778	tunnel_wall_depth
	1779
	1780	USE grid_variables, &
	1781	ONLY: dx, dy
	1782
	1783	USE indices, &
	1784	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1785	nzb, nzt
	1786
	1787	USE kinds
[4189]	1788
	1789	USE netcdf_data_input_mod, &
	1790	ONLY: buildings_f, terrain_height_f
[2696]	1791
	1792	USE pegrid
	1793
	1794	IMPLICIT NONE
	1795
	1796	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1797	INTEGER(iwp) :: blx !< grid point number of building size along x
	1798	INTEGER(iwp) :: bly !< grid point number of building size along y
	1799	INTEGER(iwp) :: bxl !< index for left building wall
	1800	INTEGER(iwp) :: bxr !< index for right building wall
	1801	INTEGER(iwp) :: byn !< index for north building wall
	1802	INTEGER(iwp) :: bys !< index for south building wall
	1803	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1804	INTEGER(iwp) :: cwx !< grid point number of canyon size along x
	1805	INTEGER(iwp) :: cwy !< grid point number of canyon size along y
	1806	INTEGER(iwp) :: cxl !< index for left canyon wall
	1807	INTEGER(iwp) :: cxr !< index for right canyon wall
	1808	INTEGER(iwp) :: cyn !< index for north canyon wall
	1809	INTEGER(iwp) :: cys !< index for south canyon wall
	1810	INTEGER(iwp) :: i !< index variable along x
	1811	INTEGER(iwp) :: j !< index variable along y
	1812	INTEGER(iwp) :: k !< index variable along z
	1813	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1814	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1815	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1816	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1817	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1818	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1819	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1820	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1821	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1822	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1823	INTEGER(iwp) :: td !< tunnel wall depth
	1824	INTEGER(iwp) :: th !< height of outer tunnel wall
	1825
	1826	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1827	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1828	!
[4189]	1829	!-- Check for correct setting of the namelist parameter topography. If
	1830	!-- topography information is read from file but topography = 'flat',
	1831	!-- initialization does not properly.
	1832	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1833	TRIM( topography ) /= 'read_from_file' ) THEN
	1834	message_string = 'If topography information is provided (via ' // &
	1835	'Netcdf or ASCII input) topography = ' // &
	1836	'"read_from_file" is required.'
	1837	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1838	ENDIF
	1839	!
[1]	1840	!-- Set outer and inner index arrays for non-flat topography.
	1841	!-- Here consistency checks concerning domain size and periodicity are
	1842	!-- necessary.
	1843	!-- Within this SELECT CASE structure only nzb_local is initialized
	1844	!-- individually depending on the chosen topography type, all other index
	1845	!-- arrays are initialized further below.
	1846	SELECT CASE ( TRIM( topography ) )
	1847
	1848	CASE ( 'flat' )
[2696]	1849	!
[2232]	1850	!-- Initialilize 3D topography array, used later for initializing flags
[4340]	1851	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
	1852
	1853	CASE ( 'closed_channel' )
	1854	!
	1855	!-- Initialilize 3D topography array, used later for initializing flags
	1856	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
[1]	1857
	1858	CASE ( 'single_building' )
	1859	!
	1860	!-- Single rectangular building, by default centered in the middle of the
	1861	!-- total domain
	1862	blx = NINT( building_length_x / dx )
	1863	bly = NINT( building_length_y / dy )
[2232]	1864	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1865	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1866	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1867	IF ( building_wall_left == 9999999.9_wp ) THEN
[1]	1868	building_wall_left = ( nx + 1 - blx ) / 2 * dx
	1869	ENDIF
	1870	bxl = NINT( building_wall_left / dx )
	1871	bxr = bxl + blx
	1872
[1322]	1873	IF ( building_wall_south == 9999999.9_wp ) THEN
[2696]	1874	building_wall_south = ( ny + 1 - bly ) / 2 * dy
[1]	1875	ENDIF
	1876	bys = NINT( building_wall_south / dy )
	1877	byn = bys + bly
	1878
	1879	!
	1880	!-- Building size has to meet some requirements
[2696]	1881	IF ( ( bxl < 1 ) .OR. ( bxr > nx-1 ) .OR. ( bxr < bxl+3 ) .OR. &
[1]	1882	( bys < 1 ) .OR. ( byn > ny-1 ) .OR. ( byn < bys+3 ) ) THEN
[274]	1883	WRITE( message_string, * ) 'inconsistent building parameters:', &
[3046]	1884	'&bxl=', bxl, 'bxr=', bxr, 'bys=', bys, &
[274]	1885	'byn=', byn, 'nx=', nx, 'ny=', ny
[254]	1886	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1887	ENDIF
	1888
[2696]	1889	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1890	nzb_local = 0
[1]	1891	!
[1968]	1892	!-- Define the building.
	1893	IF ( bxl <= nxr .AND. bxr >= nxl .AND. &
[2696]	1894	bys <= nyn .AND. byn >= nys ) &
[1968]	1895	nzb_local(MAX(nys,bys):MIN(nyn,byn),MAX(nxl,bxl):MIN(nxr,bxr)) = bh
[2232]	1896	!
[2696]	1897	!-- Set bit array on basis of nzb_local
	1898	DO i = nxl, nxr
	1899	DO j = nys, nyn
	1900	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1901	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1902	ENDDO
	1903	ENDDO
[2696]	1904
	1905	DEALLOCATE( nzb_local )
[2232]	1906
[2696]	1907	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1908	!
	1909	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1910	!-- boundary conditions for topography.
	1911	IF ( .NOT. bc_ns_cyc ) THEN
	1912	IF ( nys == 0 ) THEN
	1913	DO i = 1, nbgp
	1914	topo(:,nys-i,:) = topo(:,nys,:)
	1915	ENDDO
	1916	ENDIF
	1917	IF ( nyn == ny ) THEN
	1918	DO i = 1, nbgp
	1919	topo(:,nyn+i,:) = topo(:,nyn,:)
	1920	ENDDO
	1921	ENDIF
	1922	ENDIF
	1923	IF ( .NOT. bc_lr_cyc ) THEN
	1924	IF ( nxl == 0 ) THEN
	1925	DO i = 1, nbgp
	1926	topo(:,:,nxl-i) = topo(:,:,nxl)
	1927	ENDDO
	1928	ENDIF
	1929	IF ( nxr == nx ) THEN
	1930	DO i = 1, nbgp
	1931	topo(:,:,nxr+i) = topo(:,:,nxr)
	1932	ENDDO
	1933	ENDIF
	1934	ENDIF
[2232]	1935
[240]	1936	CASE ( 'single_street_canyon' )
	1937	!
	1938	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1939	!-- The canyon is centered in the other direction by default.
[1322]	1940	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1941	!
	1942	!-- Street canyon in y direction
	1943	cwx = NINT( canyon_width_x / dx )
[1322]	1944	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[240]	1945	canyon_wall_left = ( nx + 1 - cwx ) / 2 * dx
	1946	ENDIF
	1947	cxl = NINT( canyon_wall_left / dx )
	1948	cxr = cxl + cwx
[1322]	1949	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1950	!
	1951	!-- Street canyon in x direction
	1952	cwy = NINT( canyon_width_y / dy )
[1322]	1953	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[240]	1954	canyon_wall_south = ( ny + 1 - cwy ) / 2 * dy
	1955	ENDIF
	1956	cys = NINT( canyon_wall_south / dy )
	1957	cyn = cys + cwy
[2696]	1958
[240]	1959	ELSE
[254]	1960
	1961	message_string = 'no street canyon width given'
	1962	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1963
[240]	1964	ENDIF
	1965
[2232]	1966	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1967	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1968	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1969	dp_level_ind_b = ch
	1970	!
	1971	!-- Street canyon size has to meet some requirements
[1322]	1972	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1353]	1973	IF ( ( cxl < 1 ) .OR. ( cxr > nx-1 ) .OR. ( cwx < 3 ) .OR. &
[2696]	1974	( ch < 3 ) ) THEN
[1353]	1975	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1976	'&cxl=', cxl, ' cxr=', cxr, &
[3045]	1977	' cwx=', cwx, &
	1978	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1979	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1980	ENDIF
[1322]	1981	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1353]	1982	IF ( ( cys < 1 ) .OR. ( cyn > ny-1 ) .OR. ( cwy < 3 ) .OR. &
[2696]	1983	( ch < 3 ) ) THEN
[1353]	1984	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1985	'&cys=', cys, ' cyn=', cyn, &
[3045]	1986	' cwy=', cwy, &
	1987	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1988	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1989	ENDIF
	1990	ENDIF
[1353]	1991	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1992	canyon_width_y /= 9999999.9_wp ) THEN
	1993	message_string = 'inconsistent canyon parameters:' // &
[3046]	1994	'&street canyon can only be oriented' // &
[3045]	1995	' either in x- or in y-direction'
[254]	1996	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1997	ENDIF
	1998
[2696]	1999	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	2000	nzb_local = ch
[1322]	2001	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1968]	2002	IF ( cxl <= nxr .AND. cxr >= nxl ) &
	2003	nzb_local(:,MAX(nxl,cxl+1):MIN(nxr,cxr-1)) = 0
[1322]	2004	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1968]	2005	IF ( cys <= nyn .AND. cyn >= nys ) &
	2006	nzb_local(MAX(nys,cys+1):MIN(nyn,cyn-1),:) = 0
[240]	2007	ENDIF
[2232]	2008	!
[2696]	2009	!-- Set bit array on basis of nzb_local
	2010	DO i = nxl, nxr
	2011	DO j = nys, nyn
	2012	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	2013	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	2014	ENDDO
	2015	ENDDO
[2696]	2016	DEALLOCATE( nzb_local )
[1994]	2017
[2696]	2018	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2019	!
	2020	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2021	!-- boundary conditions for topography.
	2022	IF ( .NOT. bc_ns_cyc ) THEN
	2023	IF ( nys == 0 ) THEN
	2024	DO i = 1, nbgp
	2025	topo(:,nys-i,:) = topo(:,nys,:)
	2026	ENDDO
	2027	ENDIF
	2028	IF ( nyn == ny ) THEN
	2029	DO i = 1, nbgp
	2030	topo(:,nyn+i,:) = topo(:,nyn,:)
	2031	ENDDO
	2032	ENDIF
	2033	ENDIF
	2034	IF ( .NOT. bc_lr_cyc ) THEN
	2035	IF ( nxl == 0 ) THEN
	2036	DO i = 1, nbgp
	2037	topo(:,:,nxl-i) = topo(:,:,nxl)
	2038	ENDDO
	2039	ENDIF
	2040	IF ( nxr == nx ) THEN
	2041	DO i = 1, nbgp
	2042	topo(:,:,nxr+i) = topo(:,:,nxr)
	2043	ENDDO
	2044	ENDIF
	2045	ENDIF
[2232]	2046
	2047	CASE ( 'tunnel' )
	2048
	2049	!
	2050	!-- Tunnel height
	2051	IF ( tunnel_height == 9999999.9_wp ) THEN
	2052	th = zw( INT( 0.2 * nz) )
	2053	ELSE
	2054	th = tunnel_height
	2055	ENDIF
	2056	!
	2057	!-- Tunnel-wall depth
[2696]	2058	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	2059	td = MAX ( dx, dy, dz(1) )
[2232]	2060	ELSE
	2061	td = tunnel_wall_depth
	2062	ENDIF
	2063	!
	2064	!-- Check for tunnel width
	2065	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	2066	tunnel_width_y == 9999999.9_wp ) THEN
	2067	message_string = 'No tunnel width is given. '
[2274]	2068	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	2069	ENDIF
	2070	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2071	tunnel_width_y /= 9999999.9_wp ) THEN
	2072	message_string = 'Inconsistent tunnel parameters:' // &
	2073	'tunnel can only be oriented' // &
	2074	'either in x- or in y-direction.'
[2274]	2075	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	2076	ENDIF
	2077	!
[4356]	2078	!-- Check for too small tunnel width in x- and y-direction
	2079	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2080	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) THEN
	2081	message_string = 'tunnel_width_x too small'
	2082	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
	2083	ENDIF
	2084	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
	2085	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) THEN
	2086	message_string = 'tunnel_width_y too small'
	2087	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
	2088	ENDIF
	2089	!
	2090	!-- Check for too large tunnel width.
	2091	!-- Tunnel axis along y.
[2232]	2092	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	2093	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
[4356]	2094	message_string = 'tunnel_width_x too large'
[2274]	2095	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	2096	ENDIF
	2097
	2098	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	2099	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	2100	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	2101	( tunnel_width_x * 0.5_wp - td ) )
	2102	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	2103	( tunnel_width_x * 0.5_wp - td ) )
[2232]	2104
	2105	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	2106	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	2107	tys_in = tys_out
	2108	tye_in = tye_out
	2109	ENDIF
	2110	!
[4356]	2111	!-- Tunnel axis along x.
[2232]	2112	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	2113	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
[4356]	2114	message_string = 'tunnel_width_y too large'
[2274]	2115	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	2116	ENDIF
	2117
	2118	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	2119	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	2120	txs_in = txs_out
	2121	txe_in = txe_out
	2122
	2123	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	2124	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	2125	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	2126	( tunnel_width_y * 0.5_wp - td ) )
[2232]	2127	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	2128	( tunnel_width_y * 0.5_wp - td ) )
	2129	ENDIF
	2130
[2696]	2131	topo = 0
[2232]	2132	DO i = nxl, nxr
	2133	DO j = nys, nyn
	2134	!
	2135	!-- Use heaviside function to model outer tunnel surface
	2136	hv_out = th * 0.5_wp * &
	2137	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	2138	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	2139
	2140	hv_out = hv_out * 0.5_wp * &
	2141	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	2142	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	2143	!
[2232]	2144	!-- Use heaviside function to model inner tunnel surface
	2145	hv_in = ( th - td ) * 0.5_wp * &
	2146	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	2147	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	2148
	2149	hv_in = hv_in * 0.5_wp * &
	2150	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	2151	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	2152	!
	2153	!-- Set flags at x-y-positions without any tunnel surface
	2154	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	2155	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	2156	!
	2157	!-- Set flags at x-y-positions with tunnel surfaces
	2158	ELSE
	2159	DO k = nzb + 1, nzt + 1
	2160	!
	2161	!-- Inner tunnel
	2162	IF ( hv_out - hv_in == th ) THEN
	2163	IF ( zw(k) <= hv_out ) THEN
[2696]	2164	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2165	ELSE
[2696]	2166	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2167	ENDIF
	2168	ENDIF
	2169	!
	2170	!-- Lateral tunnel walls
	2171	IF ( hv_out - hv_in == td ) THEN
	2172	IF ( zw(k) <= hv_in ) THEN
[2696]	2173	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2174	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	2175	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2176	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	2177	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2178	ENDIF
	2179	ENDIF
	2180	ENDDO
	2181	ENDIF
	2182	ENDDO
	2183	ENDDO
	2184
[2696]	2185	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2186	!
	2187	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2188	!-- boundary conditions for topography.
	2189	IF ( .NOT. bc_ns_cyc ) THEN
	2190	IF ( nys == 0 ) THEN
	2191	DO i = 1, nbgp
	2192	topo(:,nys-i,:) = topo(:,nys,:)
	2193	ENDDO
	2194	ENDIF
	2195	IF ( nyn == ny ) THEN
	2196	DO i = 1, nbgp
	2197	topo(:,nyn+i,:) = topo(:,nyn,:)
	2198	ENDDO
	2199	ENDIF
	2200	ENDIF
	2201	IF ( .NOT. bc_lr_cyc ) THEN
	2202	IF ( nxl == 0 ) THEN
	2203	DO i = 1, nbgp
	2204	topo(:,:,nxl-i) = topo(:,:,nxl)
	2205	ENDDO
	2206	ENDIF
	2207	IF ( nxr == nx ) THEN
	2208	DO i = 1, nbgp
	2209	topo(:,:,nxr+i) = topo(:,:,nxr)
	2210	ENDDO
	2211	ENDIF
	2212	ENDIF
[2232]	2213
[1]	2214	CASE ( 'read_from_file' )
	2215	!
[2696]	2216	!-- Note, topography information have been already read.
	2217	!-- If required, further process topography, i.e. reference buildings on
	2218	!-- top of orography and set temporary 3D topography array, which is
	2219	!-- used later to set grid flags. Calling of this rouinte is also
	2220	!-- required in case of ASCII input, even though no distinction between
	2221	!-- terrain- and building height is made in this case.
	2222	CALL process_topography( topo )
[1968]	2223	!
[2696]	2224	!-- Filter holes resolved by only one grid-point
	2225	CALL filter_topography( topo )
[1968]	2226	!
[2696]	2227	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2228	!-- conditions.
	2229	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2230	!
[4314]	2231	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2232	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2233	IF ( nys == 0 ) THEN
[2696]	2234	DO i = 1, nbgp
	2235	topo(:,nys-i,:) = topo(:,nys,:)
	2236	ENDDO
[2550]	2237	ENDIF
[2696]	2238	IF ( nyn == ny ) THEN
	2239	DO i = 1, nbgp
	2240	topo(:,nyn+i,:) = topo(:,nyn,:)
	2241	ENDDO
	2242	ENDIF
[1942]	2243	ENDIF
[1910]	2244
[1968]	2245	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2246	IF ( nxl == 0 ) THEN
[2696]	2247	DO i = 1, nbgp
	2248	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2249	ENDDO
[2696]	2250	ENDIF
	2251	IF ( nxr == nx ) THEN
	2252	DO i = 1, nbgp
	2253	topo(:,:,nxr+i) = topo(:,:,nxr)
	2254	ENDDO
	2255	ENDIF
[2232]	2256	ENDIF
	2257
[667]	2258
[1]	2259	CASE DEFAULT
[2696]	2260	!
[1]	2261	!-- The DEFAULT case is reached either if the parameter topography
[217]	2262	!-- contains a wrong character string or if the user has defined a special
[1]	2263	!-- case in the user interface. There, the subroutine user_init_grid
	2264	!-- checks which of these two conditions applies.
[2696]	2265	CALL user_init_grid( topo )
	2266	CALL filter_topography( topo )
[1]	2267
	2268	END SELECT
	2269	!
	2270	!-- Consistency checks and index array initialization are only required for
[2696]	2271	!-- non-flat topography.
[1]	2272	IF ( TRIM( topography ) /= 'flat' ) THEN
	2273	!
[2232]	2274	!-- In case of non-flat topography, check whether the convention how to
	2275	!-- define the topography grid has been set correctly, or whether the default
	2276	!-- is applicable. If this is not possible, abort.
	2277	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
[4340]	2278	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
	2279	TRIM( topography ) /= 'single_building' .AND. &
[2232]	2280	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2281	TRIM( topography ) /= 'tunnel' .AND. &
	2282	TRIM( topography ) /= 'read_from_file') THEN
	2283	!-- The default value is not applicable here, because it is only valid
[3045]	2284	!-- for the four standard cases 'single_building',
	2285	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2286	!-- defined in init_grid.
	2287	WRITE( message_string, * ) &
[2696]	2288	'The value for "topography_grid_convention" ', &
[3046]	2289	'is not set. Its default value is & only valid for ', &
[3045]	2290	'"topography" = ''single_building'', ''tunnel'' ', &
[4340]	2291	'''single_street_canyon'', ''closed_channel'' & or ', &
	2292	'''read_from_file''.', &
[3046]	2293	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2294	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2295	ELSE
	2296	!-- The default value is applicable here.
	2297	!-- Set convention according to topography.
	2298	IF ( TRIM( topography ) == 'single_building' .OR. &
	2299	TRIM( topography ) == 'single_street_canyon' ) THEN
	2300	topography_grid_convention = 'cell_edge'
	2301	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2302	TRIM( topography ) == 'tunnel') THEN
	2303	topography_grid_convention = 'cell_center'
	2304	ENDIF
	2305	ENDIF
	2306	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2307	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2308	WRITE( message_string, * ) &
[2696]	2309	'The value for "topography_grid_convention" is ', &
[3046]	2310	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2311	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2312	ENDIF
[1]	2313
[2169]	2314
[217]	2315	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2316	!
[217]	2317	!-- The array nzb_local as defined using the 'cell_edge' convention
	2318	!-- describes the actual total size of topography which is defined at the
	2319	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2320	!-- on the topography walls in y-direction. However, PALM uses individual
	2321	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2322	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2323	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2324	!-- to form the basis for nzb_s_inner.
	2325	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2326	!-- required at this point.
	2327	DO j = nys+1, nyn+1
	2328	DO i = nxl-1, nxr
[2232]	2329	DO k = nzb, nzt+1
[2696]	2330	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2331	BTEST( topo(k,j,i+1), 0 ) ) &
	2332	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2333	ENDDO
	2334	ENDDO
	2335	ENDDO
[2696]	2336	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2337
	2338	DO i = nxl, nxr+1
	2339	DO j = nys-1, nyn
	2340	DO k = nzb, nzt+1
[2696]	2341	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2342	BTEST( topo(k,j+1,i), 0 ) ) &
	2343	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2344	ENDDO
	2345	ENDDO
	2346	ENDDO
[2696]	2347	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2348
[217]	2349	ENDIF
[2696]	2350	ENDIF
[2232]	2351
[1]	2352
[2696]	2353	END SUBROUTINE init_topo
[1]	2354
[2696]	2355	SUBROUTINE set_topo_flags(topo)
[1]	2356
[2696]	2357	USE control_parameters, &
[4294]	2358	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
	2359	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
[1]	2360
[2696]	2361	USE indices, &
[3241]	2362	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4346]	2363	nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
[1]	2364
[2696]	2365	USE kinds
[1]	2366
[2696]	2367	IMPLICIT NONE
[1804]	2368
[2696]	2369	INTEGER(iwp) :: i !< index variable along x
[4168]	2370	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2371	INTEGER(iwp) :: j !< index variable along y
	2372	INTEGER(iwp) :: k !< index variable along z
[1]	2373
[2696]	2374	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2375
[4329]	2376	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2377	wall_flags_static_0 = 0
[2232]	2378	!
[2696]	2379	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2380	!-- Further special flags will be set in following loops.
[2232]	2381	DO i = nxl, nxr
	2382	DO j = nys, nyn
	2383	DO k = nzb, nzt+1
	2384	!
	2385	!-- scalar grid
[4340]	2386	IF ( BTEST( topo(k,j,i), 0 ) ) &
[4329]	2387	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
[2232]	2388	!
[2696]	2389	!-- u grid
[4340]	2390	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2391	BTEST( topo(k,j,i-1), 0 ) ) &
[4329]	2392	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
[2696]	2393	!
[2232]	2394	!-- v grid
[4340]	2395	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2396	BTEST( topo(k,j-1,i), 0 ) ) &
[4329]	2397	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
[2696]	2398
[2232]	2399	ENDDO
[1]	2400
[2232]	2401	DO k = nzb, nzt
[1]	2402	!
[2232]	2403	!-- w grid
[4340]	2404	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2405	BTEST( topo(k+1,j,i), 0 ) ) &
[4329]	2406	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
[2232]	2407	ENDDO
[4340]	2408
	2409	IF ( topography /= 'closed_channel' ) THEN
	2410	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
	2411	ENDIF
[2232]	2412
	2413	ENDDO
	2414	ENDDO
[2696]	2415
[4329]	2416	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
[4346]	2417
[1]	2418	!
[4115]	2419	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2420	!-- basis of flag 24 futher flags will be derived which are used to control
	2421	!-- production of subgrid TKE production near walls.
[4346]	2422
	2423	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2424	wall_flags_total_0 = 0
	2425
[2696]	2426	DO i = nxl, nxr
	2427	DO j = nys, nyn
[2232]	2428	DO k = nzb, nzt+1
[4346]	2429	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
[2232]	2430	ENDDO
	2431	ENDDO
	2432	ENDDO
[4346]	2433
	2434	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2435
	2436	DO i = nxl, nxr
	2437	DO j = nys, nyn
	2438	DO k = nzb, nzt+1
	2439	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
	2440	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
	2441	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
	2442	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
	2443	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
	2444	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
	2445	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
	2446	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
	2447	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
	2448	ENDDO
	2449	ENDDO
	2450	ENDDO
[1]	2451	!
[2232]	2452	!-- Set further special flags
	2453	DO i = nxl, nxr
	2454	DO j = nys, nyn
	2455	DO k = nzb, nzt+1
[1]	2456	!
[2232]	2457	!-- scalar grid, former nzb_diff_s_inner.
	2458	!-- Note, use this flag also to mask topography in diffusion_u and
	2459	!-- diffusion_v along the vertical direction. In case of
	2460	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2461	!-- gradient approach is applied. Please note, in case of u- and v-
	2462	!-- diffuison, a small error is made at edges (on the east side for u,
	2463	!-- at the north side for v), since topography on scalar grid point
	2464	!-- is used instead of topography on u/v-grid. As number of topography grid
	2465	!-- points on uv-grid is different than s-grid, different number of
	2466	!-- surface elements would be required. In order to avoid this,
	2467	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2468	!-- points are not masked within diffusion_u. Tests had shown that the
	2469	!-- effect on the flow is negligible.
	2470	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2471	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2472	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2473	ELSE
[4346]	2474	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2475	ENDIF
[1]	2476
[2232]	2477	ENDDO
	2478	!
	2479	!-- Special flag to control vertical diffusion at model top - former
	2480	!-- nzt_diff
[4346]	2481	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
[2232]	2482	IF ( use_top_fluxes ) &
[4346]	2483	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
[1]	2484
[2696]	2485
[2232]	2486	DO k = nzb+1, nzt
	2487	!
	2488	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2489	!-- for disturb_field and initialization. Do not disturb directly at
	2490	!-- topography, as well as initialize u with zero one grid point outside
	2491	!-- of topography.
[4346]	2492	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2493	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2494	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2495	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
[2232]	2496	!
	2497	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2498	!-- for disturb_field and initialization. Do not disturb directly at
	2499	!-- topography, as well as initialize v with zero one grid point outside
	2500	!-- of topography.
[4346]	2501	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2502	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2503	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2504	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
[2232]	2505	!
	2506	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2507	!-- lpm_sgs_tke
[4346]	2508	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2509	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2510	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2511	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
[2232]	2512	!
	2513	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2514	!-- in production_e
	2515	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2516	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
	2517	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
	2518	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2519	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[2232]	2520	ELSE
[4346]	2521	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2522	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[1]	2523	ENDIF
[2232]	2524	!
	2525	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2526	!-- in production_e
	2527	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2528	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2529	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2530	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2531	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2532	ELSE
[4346]	2533	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2534	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2535	ENDIF
	2536	ENDDO
	2537	!
	2538	!-- Flags indicating downward facing walls
[4340]	2539	DO k = nzb+1, nzt+1
[2232]	2540	!
	2541	!-- Scalar grid
[4346]	2542	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2543	.NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2544	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
[2232]	2545	!
	2546	!-- Downward facing wall on u grid
[4346]	2547	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2548	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
	2549	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
[2232]	2550	!
	2551	!-- Downward facing wall on v grid
[4346]	2552	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2553	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
	2554	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
[2232]	2555	!
	2556	!-- Downward facing wall on w grid
[4346]	2557	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
	2558	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
	2559	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
[2232]	2560	ENDDO
	2561	!
	2562	!-- Flags indicating upward facing walls
	2563	DO k = nzb, nzt
	2564	!
	2565	!-- Upward facing wall on scalar grid
[4346]	2566	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2567	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2568	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
[2232]	2569	!
	2570	!-- Upward facing wall on u grid
[4346]	2571	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2572	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2573	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
[1]	2574
[2696]	2575	!
[2232]	2576	!-- Upward facing wall on v grid
[4346]	2577	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2578	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2579	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
[2696]	2580
[2232]	2581	!
	2582	!-- Upward facing wall on w grid
[4346]	2583	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
	2584	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
	2585	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
[2232]	2586	!
	2587	!-- Special flag on scalar grid, former nzb_s_inner
[4346]	2588	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
	2589	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
	2590	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
	2591	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
[2232]	2592	!
	2593	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2594	!-- flow_statistics
	2595	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2596	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2597	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2598	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[2232]	2599	ELSE
[4346]	2600	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
	2601	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[1]	2602	ENDIF
[2696]	2603
[1]	2604
[2232]	2605	ENDDO
[4346]	2606	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
	2607	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
[4109]	2608	!
	2609	!-- Set flags indicating that topography is close by in horizontal
	2610	!-- direction, i.e. flags that infold the topography. These will be used
	2611	!-- to set advection flags for passive scalars, where due to large
	2612	!-- gradients near buildings stationary numerical oscillations can produce
	2613	!-- unrealistically high concentrations. This is only necessary if
	2614	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2615	!-- only used for passive scalars such as chemical species or aerosols.
	2616	IF ( scalar_advec == 'ws-scheme' ) THEN
	2617	DO k = nzb, nzt
[4346]	2618	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
	2619	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2620	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2621	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2622	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2623	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2624	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2625	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2626	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2627	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2628	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2629	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2630	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
	2631	) ) &
	2632	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
[4109]	2633
	2634	ENDDO
	2635	ENDIF
[2232]	2636	ENDDO
	2637	ENDDO
	2638	!
[2696]	2639	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2640	!-- Natural terrain grid points. Information on the type of the surface is
	2641	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2642	!-- when topography is read from file. In order to run the land-surface model
	2643	!-- also without topography information, set bit 1 explicitely in this case.
[4294]	2644	!--
	2645	!-- Natural terrain grid points
	2646	!-- If no topography is initialized, the land-surface is at k = nzb.
	2647	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
[4329]	2648	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
[4294]	2649	ELSE
	2650	DO i = nxl, nxr
	2651	DO j = nys, nyn
	2652	DO k = nzb, nzt+1
[4189]	2653	!
[4294]	2654	!-- Natural terrain grid point
	2655	IF ( BTEST( topo(k,j,i), 1 ) ) &
[4329]	2656	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
[2696]	2657	ENDDO
	2658	ENDDO
[4294]	2659	ENDDO
[2696]	2660	ENDIF
	2661	!
	2662	!-- Building grid points.
[4294]	2663	DO i = nxl, nxr
	2664	DO j = nys, nyn
	2665	DO k = nzb, nzt+1
	2666	IF ( BTEST( topo(k,j,i), 2 ) ) &
[4329]	2667	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
[2696]	2668	ENDDO
	2669	ENDDO
[4294]	2670	ENDDO
[2696]	2671	!
[4314]	2672	!-- Set flag 4, indicating new topography grid points due to filtering.
	2673	DO i = nxl, nxr
	2674	DO j = nys, nyn
	2675	DO k = nzb, nzt+1
	2676	IF ( BTEST( topo(k,j,i), 4 ) ) &
[4329]	2677	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
[4314]	2678	ENDDO
	2679	ENDDO
	2680	ENDDO
[4346]	2681
	2682	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2683
	2684	DO i = nxl, nxr
	2685	DO j = nys, nyn
	2686	DO k = nzb, nzt+1
	2687	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
	2688	ENDDO
	2689	ENDDO
	2690	ENDDO
[4314]	2691	!
[2232]	2692	!-- Exchange ghost points for wall flags
[4346]	2693	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2694	!
	2695	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2696	!-- boundary conditions for topography.
	2697	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2698	IF ( nys == 0 ) THEN
	2699	DO i = 1, nbgp
[4346]	2700	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
[2696]	2701	ENDDO
	2702	ENDIF
	2703	IF ( nyn == ny ) THEN
	2704	DO i = 1, nbgp
[4346]	2705	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
[2696]	2706	ENDDO
	2707	ENDIF
[2232]	2708	ENDIF
	2709	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2710	IF ( nxl == 0 ) THEN
	2711	DO i = 1, nbgp
[4346]	2712	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
[2696]	2713	ENDDO
[2232]	2714	ENDIF
[2696]	2715	IF ( nxr == nx ) THEN
	2716	DO i = 1, nbgp
[4346]	2717	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
[2232]	2718	ENDDO
[2696]	2719	ENDIF
[2232]	2720	ENDIF
[4168]	2721	!
	2722	!-- Pre-calculate topography top indices (former get_topography_top_index
	2723	!-- function)
	2724	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2725	!
	2726	!-- Uppermost topography index on scalar grid
	2727	ibit = 12
	2728	topo_top_ind(:,:,0) = MAXLOC( &
	2729	MERGE( 1, 0, &
[4346]	2730	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2731	), DIM = 1 &
	2732	) - 1
	2733	!
	2734	!-- Uppermost topography index on u grid
	2735	ibit = 14
	2736	topo_top_ind(:,:,1) = MAXLOC( &
	2737	MERGE( 1, 0, &
[4346]	2738	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2739	), DIM = 1 &
	2740	) - 1
	2741	!
	2742	!-- Uppermost topography index on v grid
	2743	ibit = 16
	2744	topo_top_ind(:,:,2) = MAXLOC( &
	2745	MERGE( 1, 0, &
[4346]	2746	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2747	), DIM = 1 &
	2748	) - 1
	2749	!
	2750	!-- Uppermost topography index on w grid
	2751	ibit = 18
	2752	topo_top_ind(:,:,3) = MAXLOC( &
	2753	MERGE( 1, 0, &
[4346]	2754	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2755	), DIM = 1 &
	2756	) - 1
	2757	!
	2758	!-- Uppermost topography index on scalar outer grid
	2759	ibit = 24
	2760	topo_top_ind(:,:,4) = MAXLOC( &
	2761	MERGE( 1, 0, &
[4346]	2762	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2763	), DIM = 1 &
	2764	) - 1
[4346]	2765
[2696]	2766	END SUBROUTINE set_topo_flags
[114]	2767
	2768
	2769

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