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source: palm/trunk/SOURCE/init_grid.f90 @ 4346

Last change on this file since 4346 was 4346, checked in by motisi, 4 years ago
Introduction of wall_flags_total_0, which currently sets bits based on static topography information used in wall_flags_static_0
Property svn:keywords set to `Id`
File size: 123.1 KB

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[1682]	1	!> @file init_grid.f90
[2000]	2	!------------------------------------------------------------------------------!
[2696]	3	! This file is part of the PALM model system.
[1036]	4	!
[2000]	5	! PALM is free software: you can redistribute it and/or modify it under the
	6	! terms of the GNU General Public License as published by the Free Software
	7	! Foundation, either version 3 of the License, or (at your option) any later
	8	! version.
[1036]	9	!
	10	! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
	11	! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
	12	! A PARTICULAR PURPOSE. See the GNU General Public License for more details.
	13	!
	14	! You should have received a copy of the GNU General Public License along with
	15	! PALM. If not, see <http://www.gnu.org/licenses/>.
	16	!
[3655]	17	! Copyright 1997-2019 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 4346 2019-12-18 11:55:56Z motisi $
[4346]	27	! Introduction of wall_flags_total_0, which currently sets bits based on static
	28	! topography information used in wall_flags_static_0
	29	!
	30	! 4340 2019-12-16 08:17:03Z Giersch
[4340]	31	! Topography closed channel flow with symmetric boundaries implemented
	32	!
	33	! 4329 2019-12-10 15:46:36Z motisi
[4329]	34	! Renamed wall_flags_0 to wall_flags_static_0
	35	!
	36	! 4328 2019-12-09 18:53:04Z suehring
[4328]	37	! Minor change in nzb_max computation. Commentation added.
	38	!
	39	! 4314 2019-11-29 10:29:20Z suehring
[4314]	40	! Set additional topography flag 4 to mark topography grid points emerged
	41	! from the filtering process.
	42	!
	43	! 4294 2019-11-13 18:34:16Z suehring
[4294]	44	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
	45	! building surfaces in all cases, in order to enable terrain-following output
	46	! also when no land- or urban-surface model is applied.
	47	!
	48	! 4265 2019-10-15 16:16:24Z suehring
[4265]	49	! Bugfix for last commit, exchange oro_max variable only when it is allocated
	50	! (not necessarily the case when topography is input from ASCII file).
	51	!
	52	! 4245 2019-09-30 08:40:37Z pavelkrc
[4245]	53	! Store oro_max (building z-offset) in 2D for building surfaces
	54	!
	55	! 4189 2019-08-26 16:19:38Z suehring
[4189]	56	! - Add check for proper setting of namelist parameter topography
	57	! - Set flag to indicate land surfaces in case no topography is provided
	58	!
	59	! 4182 2019-08-22 15:20:23Z scharf
[4182]	60	! Corrected "Former revisions" section
	61	!
	62	! 4168 2019-08-16 13:50:17Z suehring
[4168]	63	! Pre-calculate topography top index and store it on an array (replaces former
	64	! functions get_topography_top_index)
	65	!
	66	! 4159 2019-08-15 13:31:35Z suehring
[4159]	67	! Revision of topography processing. This was not consistent between 2D and 3D
	68	! buildings.
	69	!
	70	! 4144 2019-08-06 09:11:47Z raasch
[4144]	71	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	72	!
	73	! 4115 2019-07-24 12:50:49Z suehring
[4115]	74	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	75	!
	76	! 4110 2019-07-22 17:05:21Z suehring
[4110]	77	! - Separate initialization of advection flags for momentum and scalars.
	78	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	79	!
	80	! 4109 2019-07-22 17:00:34Z suehring
[3927]	81	! Fix bad commit
	82	!
	83	! 3926 2019-04-23 12:56:42Z suehring
[3925]	84	! Minor bugfix in building mapping when all building IDs in the model domain
	85	! are missing
	86	!
	87	! 3857 2019-04-03 13:00:16Z knoop
[3855]	88	! In projection of non-building 3D objects onto numerical grid remove
	89	! dependency on building_type
	90	!
	91	! 3763 2019-02-25 17:33:49Z suehring
[3763]	92	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	93	! routine as already done in other routines
	94	!
	95	! 3761 2019-02-25 15:31:42Z raasch
[3761]	96	! unused variables removed
	97	!
	98	! 3661 2019-01-08 18:22:50Z suehring
[3661]	99	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	100	! order degradation of advection scheme is handeled directly in advec_ws
	101	!
	102	! 3655 2019-01-07 16:51:22Z knoop
[3538]	103	! Comment added
[2716]	104	!
[4182]	105	! Revision 1.1 1997/08/11 06:17:45 raasch
	106	! Initial revision (Testversion)
	107	!
	108	!
[1]	109	! Description:
[2696]	110	! -----------------------------------------------------------------------------!
[1682]	111	!> Creating grid depending constants
[2696]	112	!> @todo: Rearrange topo flag list
	113	!> @todo: reference 3D buildings on top of orography is not tested and may need
	114	!> further improvement for steep slopes
	115	!> @todo: Use more advanced setting of building type at filled holes
[1]	116	!------------------------------------------------------------------------------!
[1682]	117	SUBROUTINE init_grid
	118
[1942]	119	USE advec_ws, &
[4109]	120	ONLY: ws_init_flags_momentum, ws_init_flags_scalar
[1]	121
[1320]	122	USE arrays_3d, &
[3857]	123	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[1320]	124
[1353]	125	USE control_parameters, &
[3761]	126	ONLY: bc_lr_cyc, bc_ns_cyc, &
[4109]	127	bc_dirichlet_l, &
	128	bc_dirichlet_n, &
	129	bc_dirichlet_r, &
	130	bc_dirichlet_s, &
	131	bc_radiation_l, &
	132	bc_radiation_n, &
	133	bc_radiation_r, &
	134	bc_radiation_s, &
[3241]	135	constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	136	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	137	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	138	dz_stretch_level_start, ibc_uv_b, message_string, &
[3182]	139	momentum_advec, number_stretch_level_end, &
[3294]	140	number_stretch_level_start, ocean_mode, psolver, scalar_advec, &
[4340]	141	symmetry_flag, topography, use_surface_fluxes
[2021]	142
[1320]	143	USE grid_variables, &
[2232]	144	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[1320]	145
	146	USE indices, &
[4109]	147	ONLY: advc_flags_m, &
	148	advc_flags_s, &
	149	nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
[2232]	150	nzb, nzb_diff, nzb_diff_s_inner, nzb_diff_s_outer, &
	151	nzb_max, nzb_s_inner, nzb_s_outer, nzb_u_inner, &
[1845]	152	nzb_u_outer, nzb_v_inner, nzb_v_outer, nzb_w_inner, &
[4168]	153	nzb_w_outer, nzt, topo_top_ind, topo_min_level
[1320]	154
	155	USE kinds
[2696]	156
[1]	157	USE pegrid
	158
[2696]	159	USE poismg_noopt_mod
	160
[2232]	161	USE surface_mod, &
[4168]	162	ONLY: init_bc
[2232]	163
[2365]	164	USE vertical_nesting_mod, &
	165	ONLY: vnested, vnest_init_grid
	166
[1]	167	IMPLICIT NONE
	168
[3182]	169	INTEGER(iwp) :: i !< index variable along x
	170	INTEGER(iwp) :: j !< index variable along y
	171	INTEGER(iwp) :: k !< index variable along z
	172	INTEGER(iwp) :: k_top !< topography top index on local PE
	173	INTEGER(iwp) :: n !< loop variable for stretching
	174	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	175	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	176	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[2232]	177
[3065]	178	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	179	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_tmp !< dummy to calculate topography indices on u- and v-grid
[1]	180
[2696]	181	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	182
[3065]	183	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	184	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	185
	186	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	187
[1]	188
	189	!
[709]	190	!-- Calculation of horizontal array bounds including ghost layers
[667]	191	nxlg = nxl - nbgp
	192	nxrg = nxr + nbgp
	193	nysg = nys - nbgp
	194	nyng = nyn + nbgp
[709]	195
[667]	196	!
[1]	197	!-- Allocate grid arrays
[3857]	198	ALLOCATE( x(0:nx), xu(0:nx) )
	199	DO i = 0, nx
	200	xu(i) = i * dx
	201	x(i) = i * dx + 0.5_wp * dx
	202	ENDDO
	203
	204	ALLOCATE( y(0:ny), yv(0:ny) )
	205	DO j = 0, ny
	206	yv(j) = j * dy
	207	y(j) = j * dy + 0.5_wp * dy
	208	ENDDO
	209
	210	!
	211	!-- Allocate grid arrays
[1353]	212	ALLOCATE( ddzu(1:nzt+1), ddzw(1:nzt+1), dd2zu(1:nzt), dzu(1:nzt+1), &
[2696]	213	dzw(1:nzt+1), zu(nzb:nzt+1), zw(nzb:nzt+1) )
[1]	214
	215	!
	216	!-- Compute height of u-levels from constant grid length and dz stretch factors
[3065]	217	IF ( dz(1) == -1.0_wp ) THEN
[254]	218	message_string = 'missing dz'
	219	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	220	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	221	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	222	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	223	ENDIF
[94]	224
[1]	225	!
[3065]	226	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	227	!-- if it was set by the user
	228	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	229	dz_stretch_level_start(1) = dz_stretch_level
	230	ENDIF
	231
	232	!
	233	!-- Determine number of dz values and stretching levels specified by the
	234	!-- user to allow right controlling of the stretching mechanism and to
[3139]	235	!-- perform error checks. The additional requirement that dz /= dz_max
	236	!-- for counting number of user-specified dz values is necessary. Otherwise
	237	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	238	!-- is used (Attention: The user is not allowed to specify a dz value equal
	239	!-- to the default of dz_max = 999.0).
	240	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	241	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	242	-9999999.9_wp )
	243	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	244	9999999.9_wp )
	245
	246	!
	247	!-- The number of specified end levels +1 has to be the same than the number
	248	!-- of specified dz values
	249	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
	250	WRITE( message_string, * ) 'The number of values for dz = ', &
	251	number_dz, 'has to be the same than& ', &
	252	'the number of values for ', &
	253	'dz_stretch_level_end + 1 = ', &
	254	number_stretch_level_end+1
	255	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	256	ENDIF
	257
	258	!
	259	!-- The number of specified start levels has to be the same or one less than
	260	!-- the number of specified dz values
	261	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
	262	number_dz /= number_stretch_level_start ) THEN
	263	WRITE( message_string, * ) 'The number of values for dz = ', &
	264	number_dz, 'has to be the same or one ', &
	265	'more than& the number of values for ', &
	266	'dz_stretch_level_start = ', &
	267	number_stretch_level_start
	268	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	269	ENDIF
	270
	271	!-- The number of specified start levels has to be the same or one more than
	272	!-- the number of specified end levels
	273	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
	274	number_stretch_level_start /= number_stretch_level_end ) THEN
	275	WRITE( message_string, * ) 'The number of values for ', &
	276	'dz_stretch_level_start = ', &
	277	dz_stretch_level_start, 'has to be the ',&
	278	'same or one more than& the number of ', &
	279	'values for dz_stretch_level_end = ', &
	280	number_stretch_level_end
	281	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	282	ENDIF
	283
	284	!
	285	!-- Initialize dz for the free atmosphere with the value of dz_max
	286	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	287	number_stretch_level_start /= 0 ) THEN
	288	dz(number_stretch_level_start+1) = dz_max
	289	ENDIF
	290
	291	!
	292	!-- Initialize the stretching factor if (infinitely) stretching in the free
	293	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	294	!-- free atmosphere)
	295	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	296	dz_stretch_factor_array(number_stretch_level_start) = &
	297	dz_stretch_factor
	298	ENDIF
	299
	300	!
	301	!-- Allocation of arrays for stretching
	302	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	303
[3065]	304	!
[94]	305	!-- Define the vertical grid levels
[3294]	306	IF ( .NOT. ocean_mode ) THEN
[3065]	307
[94]	308	!
[3065]	309	!-- The stretching region has to be large enough to allow for a smooth
	310	!-- transition between two different grid spacings
	311	DO n = 1, number_stretch_level_start
	312	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	313	4 * MAX( dz(n),dz(n+1) )
	314	ENDDO
	315
[3066]	316	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	317	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	318	message_string= 'Eeach dz_stretch_level_end has to be larger ' // &
	319	'than its corresponding value for &' // &
	320	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	321	'to allow for smooth grid stretching'
	322	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	323	ENDIF
	324
	325	!
	326	!-- Stretching must not be applied within the prandtl_layer
	327	!-- (first two grid points). For the default case dz_stretch_level_start
	328	!-- is negative. Therefore the absolut value is checked here.
	329	IF ( ANY( ABS( dz_stretch_level_start ) < dz(1) * 1.5_wp ) ) THEN
	330	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	331	'larger than ', dz(1) * 1.5
	332	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	333	ENDIF
	334
	335	!
	336	!-- The stretching has to start and end on a grid level. Therefore
	337	!-- user-specified values have to ''interpolate'' to the next lowest level
	338	IF ( number_stretch_level_start /= 0 ) THEN
	339	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	340	dz(1)/2.0) / dz(1) ) &
	341	* dz(1) + dz(1)/2.0
	342	ENDIF
	343
	344	IF ( number_stretch_level_start > 1 ) THEN
	345	DO n = 2, number_stretch_level_start
	346	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	347	dz(n) ) * dz(n)
	348	ENDDO
	349	ENDIF
	350
	351	IF ( number_stretch_level_end /= 0 ) THEN
	352	DO n = 1, number_stretch_level_end
	353	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	354	dz(n+1) ) * dz(n+1)
	355	ENDDO
	356	ENDIF
	357
	358	!
	359	!-- Determine stretching factor if necessary
	360	IF ( number_stretch_level_end >= 1 ) THEN
	361	CALL calculate_stretching_factor( number_stretch_level_end )
	362	ENDIF
	363
	364	!
[94]	365	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	366	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	367	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	368	!-- The second u-level (k=1) corresponds to the top of the
[4340]	369	!-- Prandtl-layer. In case of symmetric boundaries (closed channel flow),
	370	!-- the first grid point is always at z=0.
	371	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR. &
	372	topography == 'closed_channel' ) THEN
[1353]	373	zu(0) = 0.0_wp
[667]	374	ELSE
[3065]	375	zu(0) = - dz(1) * 0.5_wp
[667]	376	ENDIF
[3065]	377
	378	zu(1) = dz(1) * 0.5_wp
	379
	380	!
	381	!-- Determine u and v height levels considering the possibility of grid
	382	!-- stretching in several heights.
	383	n = 1
	384	dz_stretch_level_start_index = nzt+1
	385	dz_stretch_level_end_index = nzt+1
	386	dz_stretched = dz(1)
[1]	387
[3065]	388	!-- The default value of dz_stretch_level_start is negative, thus the first
	389	!-- condition is always true. Hence, the second condition is necessary.
[4340]	390	DO k = 2, nzt+1-symmetry_flag
[3065]	391	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	392	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	393	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	394
	395	IF ( dz(n) > dz(n+1) ) THEN
	396	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	397	ELSE
	398	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	399	ENDIF
	400
	401	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	402	dz_stretch_level_start_index(n) = k-1
	403
[94]	404	ENDIF
[3065]	405
[94]	406	zu(k) = zu(k-1) + dz_stretched
[3065]	407
	408	!
	409	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	410	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	411
	412	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	413	zu(k) = dz_stretch_level_end(n)
	414	dz_stretched = dz(n+1)
	415	dz_stretch_level_end_index(n) = k
	416	n = n + 1
	417	ENDIF
[94]	418	ENDDO
[4340]	419
	420	!
	421	!-- If a closed channel flow is simulated, make sure that grid structure is
	422	!-- the same for both bottom and top boundary. (Hint: Using a different dz
	423	!-- at the bottom and at the top makes no sense due to symmetric boundaries
	424	!-- where dz should be equal. Therefore, different dz at the bottom and top
	425	!-- causes an abort (see check_parameters).)
	426	IF ( topography == 'closed_channel' ) THEN
	427	zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
	428	ENDIF
[1]	429
	430	!
[94]	431	!-- Compute the w-levels. They are always staggered half-way between the
[843]	432	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	433	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
[4340]	434	!-- Per default, the top w-level is extrapolated linearly. In case of
	435	!-- a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
	436	!-- (Hint: Using a different dz at the bottom and at the top makes no sense
	437	!-- due to symmetric boundaries where dz should be equal. Therefore,
	438	!-- different dz at the bottom and top causes an abort (see
	439	!-- check_parameters).)
[1353]	440	zw(0) = 0.0_wp
[4340]	441	DO k = 1, nzt-symmetry_flag
[1353]	442	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	443	ENDDO
[4340]	444	IF ( topography == 'closed_channel' ) THEN
	445	zw(nzt) = zw(nzt-1) + dz(1)
	446	zw(nzt+1) = zw(nzt) + dz(1)
	447	ELSE
	448	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
	449	ENDIF
[1]	450
[94]	451	ELSE
[3065]	452
[1]	453	!
[3065]	454	!-- The stretching region has to be large enough to allow for a smooth
	455	!-- transition between two different grid spacings
	456	DO n = 1, number_stretch_level_start
	457	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	458	4 * MAX( dz(n),dz(n+1) )
	459	ENDDO
	460
[3066]	461	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	462	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	463	message_string= 'Eeach dz_stretch_level_end has to be less ' // &
	464	'than its corresponding value for &' // &
	465	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	466	'to allow for smooth grid stretching'
	467	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	468	ENDIF
	469
	470	!
[3068]	471	!-- Stretching must not be applied close to the surface (last two grid
	472	!-- points). For the default case dz_stretch_level_start is negative.
	473	IF ( ANY( dz_stretch_level_start > - dz(1) * 1.5_wp ) ) THEN
[3065]	474	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	475	'less than ', dz(1) * 1.5
	476	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	477	ENDIF
	478
	479	!
	480	!-- The stretching has to start and end on a grid level. Therefore
	481	!-- user-specified values have to ''interpolate'' to the next highest level
	482	IF ( number_stretch_level_start /= 0 ) THEN
	483	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	484	dz(1)/2.0) / dz(1) ) &
	485	* dz(1) - dz(1)/2.0
	486	ENDIF
	487
	488	IF ( number_stretch_level_start > 1 ) THEN
	489	DO n = 2, number_stretch_level_start
	490	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	491	dz(n) ) * dz(n)
	492	ENDDO
	493	ENDIF
	494
	495	IF ( number_stretch_level_end /= 0 ) THEN
	496	DO n = 1, number_stretch_level_end
	497	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	498	dz(n+1) ) * dz(n+1)
	499	ENDDO
	500	ENDIF
	501
	502	!
	503	!-- Determine stretching factor if necessary
	504	IF ( number_stretch_level_end >= 1 ) THEN
	505	CALL calculate_stretching_factor( number_stretch_level_end )
	506	ENDIF
	507
	508	!
[843]	509	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	510	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	511	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	512	!-- w-level are defined at same height, but staggered from the second level.
	513	!-- The second u-level (k=1) corresponds to the top of the Prandtl-layer.
[3065]	514	!-- z values are negative starting from z=0 (surface)
	515	zu(nzt+1) = dz(1) * 0.5_wp
	516	zu(nzt) = - dz(1) * 0.5_wp
[94]	517
[3065]	518	!
	519	!-- Determine u and v height levels considering the possibility of grid
	520	!-- stretching in several heights.
	521	n = 1
	522	dz_stretch_level_start_index = 0
	523	dz_stretch_level_end_index = 0
	524	dz_stretched = dz(1)
	525
[94]	526	DO k = nzt-1, 0, -1
[3065]	527
	528	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	529	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	530
	531	IF ( dz(n) > dz(n+1) ) THEN
	532	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	533	ELSE
	534	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	535	ENDIF
	536
	537	IF ( dz_stretch_level_start_index(n) == 0 ) &
	538	dz_stretch_level_start_index(n) = k+1
	539
	540	ENDIF
	541
	542	zu(k) = zu(k+1) - dz_stretched
	543
[1418]	544	!
[3065]	545	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	546	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	547
	548	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	549	zu(k) = dz_stretch_level_end(n)
	550	dz_stretched = dz(n+1)
	551	dz_stretch_level_end_index(n) = k
	552	n = n + 1
[94]	553	ENDIF
	554	ENDDO
[3065]	555
[94]	556	!
	557	!-- Compute the w-levels. They are always staggered half-way between the
[843]	558	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	559	!-- at the ground. In this case the first u- and w-level are defined at
	560	!-- same height. The top w-level (nzt+1) is not used but set for
	561	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	562	zw(nzt+1) = dz(1)
[1353]	563	zw(nzt) = 0.0_wp
[94]	564	DO k = 0, nzt
[1353]	565	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	566	ENDDO
	567
[843]	568	!
	569	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	570	!-- at same height.
	571	IF ( ibc_uv_b == 0 ) THEN
	572	zu(0) = zw(0)
	573	ENDIF
	574
[94]	575	ENDIF
	576
	577	!
[1]	578	!-- Compute grid lengths.
	579	DO k = 1, nzt+1
	580	dzu(k) = zu(k) - zu(k-1)
[1353]	581	ddzu(k) = 1.0_wp / dzu(k)
[1]	582	dzw(k) = zw(k) - zw(k-1)
[1353]	583	ddzw(k) = 1.0_wp / dzw(k)
[1]	584	ENDDO
	585
	586	DO k = 1, nzt
[1353]	587	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	588	ENDDO
[667]	589
	590	!
[709]	591	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	592	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	593	!-- is only dz/2, but should be dz. Therefore, an additional array
	594	!-- containing with appropriate grid information is created for these
	595	!-- solvers.
[1575]	596	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	597	ALLOCATE( ddzu_pres(1:nzt+1) )
	598	ddzu_pres = ddzu
[864]	599	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	600	ENDIF
	601
	602	!
	603	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	604	ddx = 1.0_wp / dx
	605	ddy = 1.0_wp / dy
[1]	606	dx2 = dx * dx
	607	dy2 = dy * dy
[1353]	608	ddx2 = 1.0_wp / dx2
	609	ddy2 = 1.0_wp / dy2
[1]	610
	611	!
[2696]	612	!-- Allocate 3D array to set topography
	613	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	614	topo = 0
	615	!
	616	!-- Initialize topography by generic topography or read from topography from file.
	617	CALL init_topo( topo )
	618	!
	619	!-- Set flags to mask topography on the grid.
	620	CALL set_topo_flags( topo )
	621	!
	622	!-- Calculate wall flag arrays for the multigrid method.
	623	!-- Please note, wall flags are only applied in the non-optimized version.
[4109]	624	IF ( psolver == 'multigrid_noopt' ) CALL poismg_noopt_init
[2696]	625
	626	!
	627	!-- Init flags for ws-scheme to degrade order of the numerics near walls, i.e.
[4109]	628	!-- to decrease the numerical stencil appropriately. The order of the scheme
	629	!-- is degraded near solid walls as well as near non-cyclic inflow and outflow
	630	!-- boundaries. Do this separately for momentum and scalars.
	631	IF ( momentum_advec == 'ws-scheme' ) THEN
	632	ALLOCATE( advc_flags_m(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	633	CALL ws_init_flags_momentum
	634	ENDIF
	635	IF ( scalar_advec == 'ws-scheme' ) THEN
	636	ALLOCATE( advc_flags_s(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	637	advc_flags_s = 0
	638
	639	CALL ws_init_flags_scalar( bc_dirichlet_l .OR. bc_radiation_l, &
	640	bc_dirichlet_n .OR. bc_radiation_n, &
	641	bc_dirichlet_r .OR. bc_radiation_r, &
	642	bc_dirichlet_s .OR. bc_radiation_s, &
	643	advc_flags_s )
	644	ENDIF
[2696]	645
	646	!
	647	!-- Determine the maximum level of topography. It is used for
	648	!-- steering the degradation of order of the applied advection scheme,
[4328]	649	!-- as well in the lpm.
[2696]	650	k_top = 0
	651	DO i = nxl, nxr
	652	DO j = nys, nyn
	653	DO k = nzb, nzt + 1
[4109]	654	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	655	ENDDO
	656	ENDDO
[1]	657	ENDDO
[2696]	658	#if defined( __parallel )
[4328]	659	CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, &
[2696]	660	MPI_MAX, comm2d, ierr )
	661	#else
[4328]	662	nzb_max = k_top
[2696]	663	#endif
[1]	664	!
[4328]	665	!-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
	666	!-- Further, in case topography extents up to the model top, limit to nzt.
	667	nzb_max = MIN( nzb_max+1, nzt )
	668	!
[2968]	669	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	670	!-- there is elevated topography, however, the lowest topography will be higher.
	671	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	672	!-- temperature, surface pressure and density, etc. .
	673	topo_min_level = 0
	674	#if defined( __parallel )
[4168]	675	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	676	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	677	#else
[4168]	678	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	679	#endif
	680	!
[2696]	681	!-- Initialize boundary conditions via surface type
	682	CALL init_bc
[3182]	683
[2696]	684	!
	685	!-- Allocate and set topography height arrays required for data output
	686	IF ( TRIM( topography ) /= 'flat' ) THEN
	687	!
	688	!-- Allocate and set the arrays containing the topography height
	689	IF ( nxr == nx .AND. nyn /= ny ) THEN
	690	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	691	zw_w_inner(nxl:nxr+1,nys:nyn) )
	692	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	693	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	694	zw_w_inner(nxl:nxr,nys:nyn+1) )
	695	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	696	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	697	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	698	ELSE
	699	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	700	zw_w_inner(nxl:nxr,nys:nyn) )
	701	ENDIF
	702
	703	zu_s_inner = 0.0_wp
	704	zw_w_inner = 0.0_wp
	705	!
	706	!-- Determine local topography height on scalar and w-grid. Note, setting
[4329]	707	!-- lateral boundary values is not necessary, realized via wall_flags_static_0
[2696]	708	!-- array. Further, please note that loop bounds are different from
	709	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	710	!-- use intrinsic lbound and ubound functions to infer array bounds.
	711	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	712	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
	713	!
	714	!-- Topography height on scalar grid. Therefore, determine index of
	715	!-- upward-facing surface element on scalar grid.
[4168]	716	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	717	!
	718	!-- Topography height on w grid. Therefore, determine index of
	719	!-- upward-facing surface element on w grid.
[4168]	720	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
[2696]	721	ENDDO
	722	ENDDO
	723	ENDIF
	724
	725	!
	726	!-- In the following, calculate 2D index arrays. Note, these will be removed
	727	!-- soon.
[1]	728	!-- Allocate outer and inner index arrays for topography and set
[2232]	729	!-- defaults.
[2696]	730	ALLOCATE( nzb_s_inner(nysg:nyng,nxlg:nxrg), &
	731	nzb_s_outer(nysg:nyng,nxlg:nxrg), &
	732	nzb_u_inner(nysg:nyng,nxlg:nxrg), &
	733	nzb_u_outer(nysg:nyng,nxlg:nxrg), &
	734	nzb_v_inner(nysg:nyng,nxlg:nxrg), &
	735	nzb_v_outer(nysg:nyng,nxlg:nxrg), &
	736	nzb_w_inner(nysg:nyng,nxlg:nxrg), &
	737	nzb_w_outer(nysg:nyng,nxlg:nxrg), &
	738	nzb_diff_s_inner(nysg:nyng,nxlg:nxrg), &
	739	nzb_diff_s_outer(nysg:nyng,nxlg:nxrg), &
	740	nzb_local(nysg:nyng,nxlg:nxrg), &
	741	nzb_tmp(nysg:nyng,nxlg:nxrg) )
	742	!
	743	!-- Initialize 2D-index arrays. Note, these will be removed soon!
[4168]	744	nzb_local(nys:nyn,nxl:nxr) = topo_top_ind(nys:nyn,nxl:nxr,0)
[2696]	745	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2968]	746	!
	747	!-- Check topography for consistency with model domain. Therefore, use
	748	!-- maximum and minium topography-top indices. Note, minimum topography top
	749	!-- index is already calculated.
[2696]	750	IF ( TRIM( topography ) /= 'flat' ) THEN
	751	#if defined( __parallel )
[4168]	752	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	753	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	754	#else
[4168]	755	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	756	#endif
[2968]	757	nzb_local_min = topo_min_level
[2696]	758	!
	759	!-- Consistency checks
	760	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	761	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	762	' model domain', &
[3046]	763	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	764	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	765	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	766	ENDIF
	767	ENDIF
[1]	768
	769	nzb_s_inner = nzb; nzb_s_outer = nzb
	770	nzb_u_inner = nzb; nzb_u_outer = nzb
	771	nzb_v_inner = nzb; nzb_v_outer = nzb
	772	nzb_w_inner = nzb; nzb_w_outer = nzb
	773
	774	!
[19]	775	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	776	!-- form (which does not use surface fluxes) is applied
[1691]	777	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	778	nzb_diff = nzb + 2
	779	ELSE
	780	nzb_diff = nzb + 1
	781	ENDIF
	782
	783	nzb_diff_s_inner = nzb_diff; nzb_diff_s_outer = nzb_diff
[2696]	784	!
	785	!-- Set Neumann conditions for topography. Will be removed soon.
	786	IF ( .NOT. bc_ns_cyc ) THEN
	787	IF ( nys == 0 ) THEN
[2927]	788	DO i = 1, nbgp
	789	nzb_local(nys-i,:) = nzb_local(nys,:)
	790	ENDDO
[2696]	791	ELSEIF ( nyn == ny ) THEN
[2927]	792	DO i = 1, nbgp
	793	nzb_local(ny+i,:) = nzb_local(ny,:)
	794	ENDDO
[2696]	795	ENDIF
	796	ENDIF
[1]	797
[2696]	798	IF ( .NOT. bc_lr_cyc ) THEN
	799	IF ( nxl == 0 ) THEN
[2927]	800	DO i = 1, nbgp
	801	nzb_local(:,nxl-i) = nzb_local(:,nxl)
	802	ENDDO
[2696]	803	ELSEIF ( nxr == nx ) THEN
[2927]	804	DO i = 1, nbgp
	805	nzb_local(:,nx+i) = nzb_local(:,nx)
	806	ENDDO
[2696]	807	ENDIF
	808	ENDIF
[1]	809	!
[2696]	810	!-- Initialization of 2D index arrays, will be removed soon!
	811	!-- Initialize nzb_s_inner and nzb_w_inner
	812	nzb_s_inner = nzb_local
	813	nzb_w_inner = nzb_local
	814
	815	!
	816	!-- Initialize remaining index arrays:
	817	!-- first pre-initialize them with nzb_s_inner...
	818	nzb_u_inner = nzb_s_inner
	819	nzb_u_outer = nzb_s_inner
	820	nzb_v_inner = nzb_s_inner
	821	nzb_v_outer = nzb_s_inner
	822	nzb_w_outer = nzb_s_inner
	823	nzb_s_outer = nzb_s_inner
	824
	825	!
	826	!-- nzb_s_outer:
	827	!-- extend nzb_local east-/westwards first, then north-/southwards
	828	nzb_tmp = nzb_local
	829	DO j = nys, nyn
	830	DO i = nxl, nxr
	831	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i), &
	832	nzb_local(j,i+1) )
	833	ENDDO
	834	ENDDO
	835
	836	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	837
	838	DO i = nxl, nxr
	839	DO j = nys, nyn
	840	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	841	nzb_tmp(j+1,i) )
	842	ENDDO
	843	!
	844	!-- non-cyclic boundary conditions (overwritten by call of
	845	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	846	IF ( nys == 0 ) THEN
	847	j = -1
	848	nzb_s_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	849	ENDIF
	850	IF ( nyn == ny ) THEN
	851	j = ny + 1
	852	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	853	ENDIF
	854	ENDDO
	855	!
	856	!-- nzb_w_outer:
	857	!-- identical to nzb_s_outer
	858	nzb_w_outer = nzb_s_outer
	859	!
	860	!-- nzb_u_inner:
	861	!-- extend nzb_local rightwards only
	862	nzb_tmp = nzb_local
	863	DO j = nys, nyn
	864	DO i = nxl, nxr
	865	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i) )
	866	ENDDO
	867	ENDDO
	868
	869	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	870
	871	nzb_u_inner = nzb_tmp
	872	!
	873	!-- nzb_u_outer:
	874	!-- extend current nzb_tmp (nzb_u_inner) north-/southwards
	875	DO i = nxl, nxr
	876	DO j = nys, nyn
	877	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	878	nzb_tmp(j+1,i) )
	879	ENDDO
	880	!
	881	!-- non-cyclic boundary conditions (overwritten by call of
	882	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	883	IF ( nys == 0 ) THEN
	884	j = -1
	885	nzb_u_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	886	ENDIF
	887	IF ( nyn == ny ) THEN
	888	j = ny + 1
	889	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	890	ENDIF
	891	ENDDO
	892
	893	!
	894	!-- nzb_v_inner:
	895	!-- extend nzb_local northwards only
	896	nzb_tmp = nzb_local
	897	DO i = nxl, nxr
	898	DO j = nys, nyn
	899	nzb_tmp(j,i) = MAX( nzb_local(j-1,i), nzb_local(j,i) )
	900	ENDDO
	901	ENDDO
	902
	903	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	904	nzb_v_inner = nzb_tmp
	905
	906	!
	907	!-- nzb_v_outer:
	908	!-- extend current nzb_tmp (nzb_v_inner) right-/leftwards
	909	DO j = nys, nyn
	910	DO i = nxl, nxr
	911	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i), &
	912	nzb_tmp(j,i+1) )
	913	ENDDO
	914	!
	915	!-- non-cyclic boundary conditions (overwritten by call of
	916	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	917	IF ( nxl == 0 ) THEN
	918	i = -1
	919	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i+1), nzb_tmp(j,i) )
	920	ENDIF
	921	IF ( nxr == nx ) THEN
	922	i = nx + 1
	923	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i) )
	924	ENDIF
	925	ENDDO
	926
	927	!
	928	!-- Exchange of lateral boundary values (parallel computers) and cyclic
	929	!-- boundary conditions, if applicable.
	930	!-- Since nzb_s_inner and nzb_w_inner are derived directly from nzb_local
	931	!-- they do not require exchange and are not included here.
	932	CALL exchange_horiz_2d_int( nzb_u_inner, nys, nyn, nxl, nxr, nbgp )
	933	CALL exchange_horiz_2d_int( nzb_u_outer, nys, nyn, nxl, nxr, nbgp )
	934	CALL exchange_horiz_2d_int( nzb_v_inner, nys, nyn, nxl, nxr, nbgp )
	935	CALL exchange_horiz_2d_int( nzb_v_outer, nys, nyn, nxl, nxr, nbgp )
	936	CALL exchange_horiz_2d_int( nzb_w_outer, nys, nyn, nxl, nxr, nbgp )
	937	CALL exchange_horiz_2d_int( nzb_s_outer, nys, nyn, nxl, nxr, nbgp )
	938
	939	!
	940	!-- Set the individual index arrays which define the k index from which on
	941	!-- the usual finite difference form (which does not use surface fluxes) is
	942	!-- applied
	943	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	944	nzb_diff_s_inner = nzb_s_inner + 2
	945	nzb_diff_s_outer = nzb_s_outer + 2
	946	ELSE
	947	nzb_diff_s_inner = nzb_s_inner + 1
	948	nzb_diff_s_outer = nzb_s_outer + 1
	949	ENDIF
	950	!
	951	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	952	!-- coarse grid
	953	IF ( vnested ) CALL vnest_init_grid
	954
	955	END SUBROUTINE init_grid
	956
[3065]	957
[2696]	958	! Description:
	959	! -----------------------------------------------------------------------------!
[3065]	960	!> Calculation of the stretching factor through an iterative method. Ideas were
	961	!> taken from the paper "Regional stretched grid generation and its application
	962	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	963	!> system of equations has two variables (r,l) but four requirements
	964	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	965	!> results into an overdetermined system.
	966	!------------------------------------------------------------------------------!
	967	SUBROUTINE calculate_stretching_factor( number_end )
	968
	969	USE control_parameters, &
[3241]	970	ONLY: dz, dz_stretch_factor_array, &
[3065]	971	dz_stretch_level_end, dz_stretch_level_start, message_string
	972
	973	USE kinds
	974
	975	IMPLICIT NONE
	976
	977	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	978	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	979	INTEGER(iwp) :: n !< loop variable for stretching
	980
	981	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	982
	983	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	984	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	985	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	986	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	987	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	988	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	989	REAL(wp) :: numerator !< numerator of the quotient
	990	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	991	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	992
[3068]	993	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	994
[3065]	995	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06 !< interval for sampling possible stretching factors
	996	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88 !< lowest possible stretching factor
	997	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12 !< highest possible stretching factor
	998
	999
[3068]	1000	l = 0
	1001	DO n = 1, number_end
	1002
	1003	iterations = 1
	1004	stretch_factor_1 = 1.0
	1005	stretch_factor_2 = 1.0
	1006	delta_total_old = 1.0
[3065]	1007
[3068]	1008	IF ( dz(n) > dz(n+1) ) THEN
	1009	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	1010
	1011	stretch_factor_1 = 1.0 - iterations * stretch_factor_interval
	1012	distance = ABS( dz_stretch_level_end(n) - &
	1013	dz_stretch_level_start(n) )
	1014	numerator = distance*stretch_factor_1/dz(n) + &
	1015	stretch_factor_1 - distance/dz(n)
	1016
	1017	IF ( numerator > 0.0 ) THEN
	1018	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1019	l_rounded = NINT( l )
	1020	delta_l = ABS( l_rounded - l ) / l
	1021	ENDIF
	1022
	1023	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	1024
	1025	delta_stretch_factor = ABS( stretch_factor_1 - &
	1026	stretch_factor_2 ) / &
	1027	stretch_factor_2
	1028
	1029	delta_total_new = delta_l + delta_stretch_factor
[3065]	1030
	1031	!
	1032	!-- stretch_factor_1 is taken to guarantee that the stretching
	1033	!-- procedure ends as close as possible to dz_stretch_level_end.
	1034	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1035	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1036	IF (delta_total_new < delta_total_old) THEN
	1037	dz_stretch_factor_array(n) = stretch_factor_1
	1038	dz_stretch_factor_array_2(n) = stretch_factor_2
	1039	delta_total_old = delta_total_new
	1040	ENDIF
	1041
	1042	iterations = iterations + 1
	1043
	1044	ENDDO
	1045
	1046	ELSEIF ( dz(n) < dz(n+1) ) THEN
	1047	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	1048
	1049	stretch_factor_1 = 1.0 + iterations * stretch_factor_interval
	1050	distance = ABS( dz_stretch_level_end(n) - &
	1051	dz_stretch_level_start(n) )
	1052	numerator = distance*stretch_factor_1/dz(n) + &
	1053	stretch_factor_1 - distance/dz(n)
	1054
	1055	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1056	l_rounded = NINT( l )
	1057	delta_l = ABS( l_rounded - l ) / l
	1058
	1059	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	1060
[3068]	1061	delta_stretch_factor = ABS( stretch_factor_1 - &
	1062	stretch_factor_2 ) / &
	1063	stretch_factor_2
	1064
	1065	delta_total_new = delta_l + delta_stretch_factor
	1066
[3065]	1067	!
	1068	!-- stretch_factor_1 is taken to guarantee that the stretching
	1069	!-- procedure ends as close as possible to dz_stretch_level_end.
	1070	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1071	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1072	IF (delta_total_new < delta_total_old) THEN
	1073	dz_stretch_factor_array(n) = stretch_factor_1
	1074	dz_stretch_factor_array_2(n) = stretch_factor_2
	1075	delta_total_old = delta_total_new
	1076	ENDIF
[3065]	1077
[3068]	1078	iterations = iterations + 1
	1079	ENDDO
	1080
	1081	ELSE
	1082	message_string= 'Two adjacent values of dz must be different'
	1083	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	1084
	1085	ENDIF
	1086
	1087	!
	1088	!-- Check if also the second stretching factor fits into the allowed
	1089	!-- interval. If not, print a warning for the user.
	1090	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	1091	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	1092	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	1093	dz_stretch_factor_array_2(n), ' which is',&
	1094	' responsible for exactly reaching& dz =',&
	1095	dz(n+1), 'after a specific amount of', &
	1096	' grid levels& exceeds the upper', &
	1097	' limit =', stretch_factor_upper_limit, &
	1098	' &or lower limit = ', &
	1099	stretch_factor_lower_limit
	1100	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	1101
	1102	ENDIF
	1103	ENDDO
[3065]	1104
	1105	END SUBROUTINE calculate_stretching_factor
	1106
	1107
	1108	! Description:
	1109	! -----------------------------------------------------------------------------!
[2696]	1110	!> Set temporary topography flags and reference buildings on top of underlying
	1111	!> orography.
	1112	!------------------------------------------------------------------------------!
	1113	SUBROUTINE process_topography( topo_3d )
	1114
	1115	USE arrays_3d, &
[2747]	1116	ONLY: zu, zw
[2696]	1117
	1118	USE control_parameters, &
[3294]	1119	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	1120
	1121	USE indices, &
	1122	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	1123	nzt
	1124
	1125	USE netcdf_data_input_mod, &
[3115]	1126	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	1127	terrain_height_f
	1128
	1129	USE kinds
	1130
	1131	USE pegrid
	1132
	1133	IMPLICIT NONE
	1134
[2867]	1135	INTEGER(iwp) :: i !< running index along x-direction
	1136	INTEGER(iwp) :: j !< running index along y-direction
	1137	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	1138	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	1139	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	1140	INTEGER(iwp) :: num_build !< counter for number of buildings
	1141	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	1142
	1143	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
	1144	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	1145	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	1146	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	1147	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	1148	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	1149
	1150	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	1151	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	1152
	1153	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	1154
	1155	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	1156	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	1157	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	1158	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	1159
	1160	!
[3103]	1161	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	1162	!-- is non-zero, all grid points of the lower vertical grid levels might be
	1163	!-- entirely below the surface, meaning a waste of computational resources.
	1164	!-- In order to avoid this, remove the lowest terrain height. Please note,
	1165	!-- in case of a nested run, the global minimum from all parent and childs
	1166	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	1167	IF ( input_pids_static ) THEN
[4159]	1168
[3200]	1169	#if defined( __parallel )
[3103]	1170	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	1171	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	1172	#else
	1173	oro_min = MINVAL( terrain_height_f%var )
	1174	#endif
[3103]	1175	terrain_height_f%var = terrain_height_f%var - oro_min
	1176	!
	1177	!-- Give an informative message that terrain height is referenced to zero
	1178	IF ( oro_min > 0.0_wp ) THEN
	1179	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	1180	'downwards by ', oro_min, 'meter(s) to save ' // &
	1181	'computational resources.'
	1182	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	1183	ENDIF
	1184	ENDIF
	1185
	1186	!
[2696]	1187	!-- In the following, buildings and orography are further preprocessed
	1188	!-- before they are mapped on the LES grid.
	1189	!-- Buildings are mapped on top of the orography by maintaining the roof
	1190	!-- shape of the building. This can be achieved by referencing building on
	1191	!-- top of the maximum terrain height within the area occupied by the
	1192	!-- respective building. As buildings and terrain height are defined PE-wise,
	1193	!-- parallelization of this referencing is required (a building can be
	1194	!-- distributed between different PEs).
	1195	!-- In a first step, determine the number of buildings with different
	1196	!-- building id on each PE. In a next step, all building ids are gathered
	1197	!-- into one array which is present to all PEs. For each building ID,
	1198	!-- the maximum terrain height occupied by the respective building is
	1199	!-- computed and distributed to each PE.
	1200	!-- Finally, for each building id and its respective reference orography,
	1201	!-- builidings are mapped on top.
	1202	!--
	1203	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1204	!-- buildings
	1205	!-- classify the respective surfaces.
	1206	topo_3d = IBSET( topo_3d, 0 )
	1207	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1208	!
[3051]	1209	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1210	!-- pre-calculate an offset value.
[3294]	1211	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1212	!
[2696]	1213	!-- Reference buildings on top of orography. This is not necessary
	1214	!-- if topography is read from ASCII file as no distinction between buildings
	1215	!-- and terrain height can be made. Moreover, this is also not necessary if
	1216	!-- urban-surface and land-surface model are used at the same time.
[2897]	1217	IF ( input_pids_static ) THEN
	1218
	1219	IF ( buildings_f%from_file ) THEN
	1220	num_buildings_l = 0
	1221	num_buildings = 0
[2696]	1222	!
[3925]	1223	!-- Allocate at least one element for building ids and give it an inital
	1224	!-- negative value that will be overwritten later. This, however, is
	1225	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1226	ALLOCATE( build_ids_l(1) )
[3925]	1227	build_ids_l = -1
[2897]	1228	DO i = nxl, nxr
	1229	DO j = nys, nyn
	1230	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1231	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1232	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1233	THEN
	1234	CYCLE
	1235	ELSE
	1236	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1237	!
	1238	!-- Resize array with different local building ids
	1239	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1240	build_ids_l_tmp = build_ids_l
	1241	DEALLOCATE( build_ids_l )
	1242	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1243	build_ids_l(1:num_buildings_l(myid)-1) = &
	1244	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1245	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1246	DEALLOCATE( build_ids_l_tmp )
	1247	ENDIF
	1248	!
[2897]	1249	!-- First occuring building id on PE
	1250	ELSE
	1251	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1252	build_ids_l(1) = building_id_f%var(j,i)
	1253	ENDIF
[2696]	1254	ENDIF
[2897]	1255	ENDDO
[2696]	1256	ENDDO
	1257	!
[2897]	1258	!-- Determine number of different building ids for the entire domain
[2696]	1259	#if defined( __parallel )
[2897]	1260	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1261	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1262	#else
[2897]	1263	num_buildings = num_buildings_l
[2696]	1264	#endif
	1265	!
[2897]	1266	!-- Gather all buildings ids on each PEs.
	1267	!-- First, allocate array encompassing all building ids in model domain.
	1268	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1269	#if defined( __parallel )
	1270	!
[2897]	1271	!-- Allocate array for displacements.
	1272	!-- As each PE may has a different number of buildings, so that
	1273	!-- the block sizes send by each PE may not be equal. Hence,
	1274	!-- information about the respective displacement is required, indicating
	1275	!-- the respective adress where each MPI-task writes into the receive
	1276	!-- buffer array
	1277	ALLOCATE( displace_dum(0:numprocs-1) )
	1278	displace_dum(0) = 0
	1279	DO i = 1, numprocs-1
	1280	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1281	ENDDO
[2696]	1282
[2897]	1283	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1284	num_buildings(myid), &
	1285	MPI_INTEGER, &
	1286	build_ids, &
	1287	num_buildings, &
	1288	displace_dum, &
	1289	MPI_INTEGER, &
	1290	comm2d, ierr )
[2696]	1291
[2897]	1292	DEALLOCATE( displace_dum )
[2696]	1293
	1294	#else
[2897]	1295	build_ids = build_ids_l
[2696]	1296	#endif
	1297
	1298	!
[2897]	1299	!-- Note, in parallel mode building ids can occure mutliple times, as
	1300	!-- each PE has send its own ids. Therefore, sort out building ids which
	1301	!-- appear more than one time.
	1302	num_build = 0
	1303	DO nr = 1, SIZE(build_ids)
[2696]	1304
[2897]	1305	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1306	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1307	CYCLE
	1308	ELSE
	1309	num_build = num_build + 1
	1310	!
	1311	!-- Resize
	1312	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1313	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1314	DEALLOCATE( build_ids_final )
	1315	ALLOCATE( build_ids_final(1:num_build) )
	1316	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1317	build_ids_final(num_build) = build_ids(nr)
	1318	DEALLOCATE( build_ids_final_tmp )
	1319	ENDIF
[2696]	1320	ELSE
	1321	num_build = num_build + 1
	1322	ALLOCATE( build_ids_final(1:num_build) )
	1323	build_ids_final(num_build) = build_ids(nr)
[2897]	1324	ENDIF
	1325	ENDDO
[2696]	1326
	1327	!
[3051]	1328	!-- Determine maximumum terrain height occupied by the respective
	1329	!-- building and temporalily store on oro_max
[2897]	1330	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1331	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1332	oro_max_l = 0.0_wp
[2696]	1333
[2897]	1334	DO nr = 1, SIZE(build_ids_final)
[4159]	1335	oro_max_l(nr) = MAXVAL( &
	1336	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1337	0.0_wp, &
	1338	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1339	build_ids_final(nr) ) )
	1340	ENDDO
[2696]	1341
	1342	#if defined( __parallel )
[2897]	1343	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1344	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1345	MPI_MAX, comm2d, ierr )
	1346	ENDIF
[2696]	1347	#else
[2897]	1348	oro_max = oro_max_l
[2696]	1349	#endif
[3051]	1350	!
	1351	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1352	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1353	!-- exceeds the scalar level the grid box is fully terrain and the
	1354	!-- maximum terrain is set to the zw level.
	1355	!-- terrain or
[3051]	1356	oro_max_l = 0.0
	1357	DO nr = 1, SIZE(build_ids_final)
	1358	DO k = nzb, nzt
	1359	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1360	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1361	ENDDO
[3142]	1362	oro_max(nr) = oro_max_l(nr)
[3051]	1363	ENDDO
[2897]	1364	ENDIF
[2696]	1365	!
[4245]	1366	!-- Allocate array for storing terrain height under buildings
	1367	IF ( buildings_f%from_file ) THEN
	1368	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
	1369	buildings_f%oro_max = buildings_f%fill1
	1370	END IF
	1371	!
[2867]	1372	!-- Map orography as well as buildings onto grid.
[2696]	1373	DO i = nxl, nxr
	1374	DO j = nys, nyn
[2867]	1375	topo_top_index = 0
[3142]	1376	!
	1377	!-- Obtain index in global building_id array
	1378	IF ( buildings_f%from_file ) THEN
	1379	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1380	!
	1381	!-- Determine index where maximum terrain height occupied by
	1382	!-- the respective building height is stored.
	1383	nr = MINLOC( ABS( build_ids_final - &
	1384	building_id_f%var(j,i) ), DIM = 1 )
[4245]	1385	!
	1386	!-- Save grid-indexed oro_max
	1387	buildings_f%oro_max(j,i) = oro_max(nr)
[3142]	1388	ENDIF
	1389	ENDIF
[2696]	1390	DO k = nzb, nzt
	1391	!
	1392	!-- In a first step, if grid point is below or equal the given
	1393	!-- terrain height, grid point is flagged to be of type natural.
	1394	!-- Please note, in case there is also a building which is lower
	1395	!-- than the vertical grid spacing, initialization of surface
	1396	!-- attributes will not be correct as given surface information
	1397	!-- will not be in accordance to the classified grid points.
[4159]	1398	!-- Hence, in this case, also a building flag.
[2747]	1399	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1400	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1401	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1402	topo_top_index = k ! topo_top_index + 1
[2696]	1403	ENDIF
	1404	!
	1405	!-- Set building grid points. Here, only consider 2D buildings.
	1406	!-- 3D buildings require separate treatment.
[2897]	1407	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1408	!
	1409	!-- Fill-up the terrain to the level of maximum orography
	1410	!-- within the building-covered area.
	1411	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1412	!
	1413	!-- Note, oro_max is always on zw level
	1414	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1415	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1416	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1417	ELSEIF ( zu(k) - ocean_offset <= &
	1418	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1419	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1420	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1421	ENDIF
	1422	ENDIF
	1423	ENDIF
	1424	ENDDO
	1425	!
[4159]	1426	!-- Special treatment for non grid-resolved buildings. This case,
	1427	!-- the uppermost terrain grid point is flagged as building as well
	1428	!-- well, even though no building exists at all. However, the
	1429	!-- surface element will be identified as urban-surface and the
	1430	!-- input data provided by the drivers is consistent to the surface
	1431	!-- classification. Else, all non grid-resolved buildings would vanish
	1432	!-- and identified as terrain grid points, which, however, won't be
	1433	!-- consistent with the input data.
	1434	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1435	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1436	DO k = nzb, nzt
	1437	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1438	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1439	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1440	ENDIF
	1441	ENDIF
	1442	ENDDO
	1443	ENDIF
	1444	ENDIF
	1445	!
[2696]	1446	!-- Map 3D buildings onto terrain height.
[2867]	1447	!-- In case of any slopes, map building on top of maximum terrain
	1448	!-- height covered by the building. In other words, extend
	1449	!-- building down to the respective local terrain-surface height.
[2897]	1450	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1451	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1452	!
[3051]	1453	!-- Extend building down to the terrain surface, i.e. fill-up
	1454	!-- surface irregularities below a building. Note, oro_max
	1455	!-- is already a discrete height according to the all-or-nothing
	1456	!-- approach, i.e. grid box is either topography or atmosphere,
	1457	!-- terrain top is defined at upper bound of the grid box.
	1458	!-- Hence, check for zw in this case.
[3115]	1459	!-- Note, do this only for buildings which are surface mounted,
	1460	!-- i.e. building types 1-6. Below bridges, which are represented
	1461	!-- exclusively by building type 7, terrain shape should be
	1462	!-- maintained.
[3855]	1463	IF ( building_type_f%from_file ) THEN
	1464	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1465	DO k = topo_top_index + 1, nzt + 1
[4159]	1466	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1467	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1468	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1469	ENDIF
	1470	ENDDO
	1471	!
	1472	!-- After surface irregularities are smoothen, determine
	1473	!-- lower start index where building starts.
	1474	DO k = nzb, nzt
[4159]	1475	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1476	topo_top_index = k
	1477	ENDDO
	1478	ENDIF
[3115]	1479	ENDIF
[3051]	1480	!
	1481	!-- Finally, map building on top.
[2867]	1482	k2 = 0
	1483	DO k = topo_top_index, nzt + 1
[2796]	1484	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1485	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1486	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1487	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1488	ENDIF
	1489	ENDIF
	1490	k2 = k2 + 1
	1491	ENDDO
	1492	ENDIF
	1493	ENDIF
	1494	ENDDO
	1495	ENDDO
	1496	!
[4265]	1497	!-- Horizontal exchange the oro_max array, which is required to for
	1498	!-- initialization of building-surface properties.
	1499	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
	1500	CALL exchange_horiz_2d( buildings_f%oro_max(:,:), nbgp )
	1501	ENDIF
[4245]	1502	!
[2696]	1503	!-- Deallocate temporary arrays required for processing and reading data
	1504	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1505	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1506	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1507	!
	1508	!-- Topography input via ASCII format.
	1509	ELSE
[3294]	1510	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1511	!
	1512	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1513	!-- and clear all grid points at nzb, where alway a surface is defined.
	1514	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1515	!-- used for masked data output and further processing. Note, in the
	1516	!-- ASCII case no distinction is made between buildings and terrain,
	1517	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1518	topo_3d = IBSET( topo_3d, 0 )
	1519	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1520	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1521	DO i = nxl, nxr
	1522	DO j = nys, nyn
	1523	DO k = nzb, nzt
[3538]	1524	!
	1525	!-- Flag topography for all grid points which are below
	1526	!-- the local topography height.
	1527	!-- Note, each topography is flagged as building.
[2747]	1528	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1529	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1530	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1531	ENDIF
	1532	ENDDO
	1533	ENDDO
	1534	ENDDO
	1535	ENDIF
	1536
	1537	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1538
	1539	IF ( .NOT. bc_ns_cyc ) THEN
	1540	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1541	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1542	ENDIF
	1543
	1544	IF ( .NOT. bc_lr_cyc ) THEN
	1545	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1546	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1547	ENDIF
	1548
	1549	END SUBROUTINE process_topography
	1550
	1551
	1552	! Description:
	1553	! -----------------------------------------------------------------------------!
	1554	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1555	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1556	!> equation on discrete grid cannot be fulfilled in such case.
	1557	!------------------------------------------------------------------------------!
	1558	SUBROUTINE filter_topography( topo_3d )
	1559
	1560	USE control_parameters, &
	1561	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1562
	1563	USE indices, &
	1564	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1565
	1566	USE netcdf_data_input_mod, &
	1567	ONLY: building_id_f, building_type_f
	1568
	1569	USE pegrid
	1570
	1571	IMPLICIT NONE
	1572
[2893]	1573	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1574
[2696]	1575	INTEGER(iwp) :: i !< running index along x-direction
	1576	INTEGER(iwp) :: j !< running index along y-direction
	1577	INTEGER(iwp) :: k !< running index along z-direction
	1578	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1579	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1580	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1581
[2955]	1582	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1583	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1584	!
	1585	!-- Before checking for holes, set lateral boundary conditions for
	1586	!-- topography. After hole-filling, boundary conditions must be set again.
	1587	!-- Several iterations are performed, in order to fill holes which might
	1588	!-- emerge by the filling-algorithm itself.
	1589	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1590	topo_tmp = 0
	1591
	1592	num_hole = 99999
	1593	DO WHILE ( num_hole > 0 )
	1594
	1595	num_hole = 0
	1596	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1597	!
	1598	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1599	!-- variable.
	1600	IF ( building_id_f%from_file ) &
	1601	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1602	IF ( building_type_f%from_file ) &
	1603	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1604
	1605	topo_tmp = topo_3d
	1606	!
	1607	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1608	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1609	!-- boundary and some topographic structure will be filled.
	1610	IF ( .NOT. bc_ns_cyc ) THEN
	1611	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1612	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1613	ENDIF
	1614
	1615	IF ( .NOT. bc_lr_cyc ) THEN
	1616	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1617	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1618	ENDIF
	1619
	1620	num_hole_l = 0
	1621	DO i = nxl, nxr
	1622	DO j = nys, nyn
	1623	DO k = nzb+1, nzt
	1624	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1625	num_wall = 0
	1626	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1627	num_wall = num_wall + 1
	1628	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1629	num_wall = num_wall + 1
	1630	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1631	num_wall = num_wall + 1
	1632	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1633	num_wall = num_wall + 1
	1634	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1635	num_wall = num_wall + 1
	1636	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1637	num_wall = num_wall + 1
	1638
	1639	IF ( num_wall >= 4 ) THEN
	1640	num_hole_l = num_hole_l + 1
	1641	!
[4314]	1642	!-- Clear flag 0 and set special flag ( bit 4) to indicate
[2696]	1643	!-- that new topography point is a result of filtering process.
	1644	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4314]	1645	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
[2696]	1646	!
	1647	!-- If filled grid point is occupied by a building, classify
	1648	!-- it as building grid point.
	1649	IF ( building_type_f%from_file ) THEN
	1650	IF ( building_type_f%var(j,i) /= &
	1651	building_type_f%fill .OR. &
	1652	building_type_f%var(j+1,i) /= &
	1653	building_type_f%fill .OR. &
	1654	building_type_f%var(j-1,i) /= &
	1655	building_type_f%fill .OR. &
	1656	building_type_f%var(j,i+1) /= &
	1657	building_type_f%fill .OR. &
	1658	building_type_f%var(j,i-1) /= &
	1659	building_type_f%fill ) THEN
	1660	!
	1661	!-- Set flag indicating building surfaces
	1662	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1663	!
	1664	!-- Set building_type and ID at this position if not
	1665	!-- already set. This is required for proper
	1666	!-- initialization of urban-surface energy balance
	1667	!-- solver.
	1668	IF ( building_type_f%var(j,i) == &
	1669	building_type_f%fill ) THEN
	1670
	1671	IF ( building_type_f%var(j+1,i) /= &
	1672	building_type_f%fill ) THEN
	1673	building_type_f%var(j,i) = &
	1674	building_type_f%var(j+1,i)
	1675	building_id_f%var(j,i) = &
	1676	building_id_f%var(j+1,i)
	1677	ELSEIF ( building_type_f%var(j-1,i) /= &
	1678	building_type_f%fill ) THEN
	1679	building_type_f%var(j,i) = &
	1680	building_type_f%var(j-1,i)
	1681	building_id_f%var(j,i) = &
	1682	building_id_f%var(j-1,i)
	1683	ELSEIF ( building_type_f%var(j,i+1) /= &
	1684	building_type_f%fill ) THEN
	1685	building_type_f%var(j,i) = &
	1686	building_type_f%var(j,i+1)
	1687	building_id_f%var(j,i) = &
	1688	building_id_f%var(j,i+1)
	1689	ELSEIF ( building_type_f%var(j,i-1) /= &
	1690	building_type_f%fill ) THEN
	1691	building_type_f%var(j,i) = &
	1692	building_type_f%var(j,i-1)
	1693	building_id_f%var(j,i) = &
	1694	building_id_f%var(j,i-1)
	1695	ENDIF
	1696	ENDIF
	1697	ENDIF
	1698	ENDIF
	1699	!
	1700	!-- If filled grid point is already classified as building
	1701	!-- everything is fine, else classify this grid point as
	1702	!-- natural type grid point. This case, values for the
	1703	!-- surface type are already set.
	1704	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1705	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1706	ENDIF
	1707	ENDIF
	1708	ENDIF
	1709	ENDDO
	1710	ENDDO
	1711	ENDDO
	1712	!
	1713	!-- Count the total number of holes, required for informative message.
	1714	#if defined( __parallel )
	1715	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1716	comm2d, ierr )
	1717	#else
	1718	num_hole = num_hole_l
	1719	#endif
[2893]	1720	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1721
[2893]	1722	ENDDO
[2696]	1723	!
[2893]	1724	!-- Create an informative message if any holes were filled.
	1725	IF ( filled ) THEN
	1726	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1727	'resolved by only one grid point ' // &
	1728	'were filled during initialization.'
	1729	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1730	ENDIF
[2696]	1731
	1732	DEALLOCATE( topo_tmp )
	1733	!
	1734	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1735	!-- condition in case of non-cyclic lateral boundaries.
	1736	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1737
	1738	IF ( .NOT. bc_ns_cyc ) THEN
	1739	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1740	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1741	ENDIF
	1742
	1743	IF ( .NOT. bc_lr_cyc ) THEN
	1744	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1745	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1746	ENDIF
[2955]	1747	!
	1748	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1749	IF ( building_id_f%from_file ) &
	1750	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1751	IF ( building_type_f%from_file ) &
	1752	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1753
	1754	END SUBROUTINE filter_topography
	1755
	1756
	1757	! Description:
	1758	! -----------------------------------------------------------------------------!
	1759	!> Reads topography information from file or sets generic topography. Moreover,
	1760	!> all topography-relevant topography arrays are initialized, and grid flags
	1761	!> are set.
	1762	!------------------------------------------------------------------------------!
	1763	SUBROUTINE init_topo( topo )
	1764
	1765	USE arrays_3d, &
	1766	ONLY: zw
	1767
	1768	USE control_parameters, &
	1769	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1770	building_length_y, building_wall_left, building_wall_south, &
	1771	canyon_height, canyon_wall_left, canyon_wall_south, &
	1772	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1773	message_string, topography, topography_grid_convention, &
[2696]	1774	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1775	tunnel_wall_depth
	1776
	1777	USE grid_variables, &
	1778	ONLY: dx, dy
	1779
	1780	USE indices, &
	1781	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1782	nzb, nzt
	1783
	1784	USE kinds
[4189]	1785
	1786	USE netcdf_data_input_mod, &
	1787	ONLY: buildings_f, terrain_height_f
[2696]	1788
	1789	USE pegrid
	1790
	1791	IMPLICIT NONE
	1792
	1793	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1794	INTEGER(iwp) :: blx !< grid point number of building size along x
	1795	INTEGER(iwp) :: bly !< grid point number of building size along y
	1796	INTEGER(iwp) :: bxl !< index for left building wall
	1797	INTEGER(iwp) :: bxr !< index for right building wall
	1798	INTEGER(iwp) :: byn !< index for north building wall
	1799	INTEGER(iwp) :: bys !< index for south building wall
	1800	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1801	INTEGER(iwp) :: cwx !< grid point number of canyon size along x
	1802	INTEGER(iwp) :: cwy !< grid point number of canyon size along y
	1803	INTEGER(iwp) :: cxl !< index for left canyon wall
	1804	INTEGER(iwp) :: cxr !< index for right canyon wall
	1805	INTEGER(iwp) :: cyn !< index for north canyon wall
	1806	INTEGER(iwp) :: cys !< index for south canyon wall
	1807	INTEGER(iwp) :: i !< index variable along x
	1808	INTEGER(iwp) :: j !< index variable along y
	1809	INTEGER(iwp) :: k !< index variable along z
	1810	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1811	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1812	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1813	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1814	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1815	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1816	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1817	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1818	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1819	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1820	INTEGER(iwp) :: td !< tunnel wall depth
	1821	INTEGER(iwp) :: th !< height of outer tunnel wall
	1822
	1823	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1824	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1825	!
[4189]	1826	!-- Check for correct setting of the namelist parameter topography. If
	1827	!-- topography information is read from file but topography = 'flat',
	1828	!-- initialization does not properly.
	1829	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1830	TRIM( topography ) /= 'read_from_file' ) THEN
	1831	message_string = 'If topography information is provided (via ' // &
	1832	'Netcdf or ASCII input) topography = ' // &
	1833	'"read_from_file" is required.'
	1834	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1835	ENDIF
	1836	!
[1]	1837	!-- Set outer and inner index arrays for non-flat topography.
	1838	!-- Here consistency checks concerning domain size and periodicity are
	1839	!-- necessary.
	1840	!-- Within this SELECT CASE structure only nzb_local is initialized
	1841	!-- individually depending on the chosen topography type, all other index
	1842	!-- arrays are initialized further below.
	1843	SELECT CASE ( TRIM( topography ) )
	1844
	1845	CASE ( 'flat' )
[2696]	1846	!
[2232]	1847	!-- Initialilize 3D topography array, used later for initializing flags
[4340]	1848	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
	1849
	1850	CASE ( 'closed_channel' )
	1851	!
	1852	!-- Initialilize 3D topography array, used later for initializing flags
	1853	topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
[1]	1854
	1855	CASE ( 'single_building' )
	1856	!
	1857	!-- Single rectangular building, by default centered in the middle of the
	1858	!-- total domain
	1859	blx = NINT( building_length_x / dx )
	1860	bly = NINT( building_length_y / dy )
[2232]	1861	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1862	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1863	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1864	IF ( building_wall_left == 9999999.9_wp ) THEN
[1]	1865	building_wall_left = ( nx + 1 - blx ) / 2 * dx
	1866	ENDIF
	1867	bxl = NINT( building_wall_left / dx )
	1868	bxr = bxl + blx
	1869
[1322]	1870	IF ( building_wall_south == 9999999.9_wp ) THEN
[2696]	1871	building_wall_south = ( ny + 1 - bly ) / 2 * dy
[1]	1872	ENDIF
	1873	bys = NINT( building_wall_south / dy )
	1874	byn = bys + bly
	1875
	1876	!
	1877	!-- Building size has to meet some requirements
[2696]	1878	IF ( ( bxl < 1 ) .OR. ( bxr > nx-1 ) .OR. ( bxr < bxl+3 ) .OR. &
[1]	1879	( bys < 1 ) .OR. ( byn > ny-1 ) .OR. ( byn < bys+3 ) ) THEN
[274]	1880	WRITE( message_string, * ) 'inconsistent building parameters:', &
[3046]	1881	'&bxl=', bxl, 'bxr=', bxr, 'bys=', bys, &
[274]	1882	'byn=', byn, 'nx=', nx, 'ny=', ny
[254]	1883	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1884	ENDIF
	1885
[2696]	1886	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1887	nzb_local = 0
[1]	1888	!
[1968]	1889	!-- Define the building.
	1890	IF ( bxl <= nxr .AND. bxr >= nxl .AND. &
[2696]	1891	bys <= nyn .AND. byn >= nys ) &
[1968]	1892	nzb_local(MAX(nys,bys):MIN(nyn,byn),MAX(nxl,bxl):MIN(nxr,bxr)) = bh
[2232]	1893	!
[2696]	1894	!-- Set bit array on basis of nzb_local
	1895	DO i = nxl, nxr
	1896	DO j = nys, nyn
	1897	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1898	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1899	ENDDO
	1900	ENDDO
[2696]	1901
	1902	DEALLOCATE( nzb_local )
[2232]	1903
[2696]	1904	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1905	!
	1906	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1907	!-- boundary conditions for topography.
	1908	IF ( .NOT. bc_ns_cyc ) THEN
	1909	IF ( nys == 0 ) THEN
	1910	DO i = 1, nbgp
	1911	topo(:,nys-i,:) = topo(:,nys,:)
	1912	ENDDO
	1913	ENDIF
	1914	IF ( nyn == ny ) THEN
	1915	DO i = 1, nbgp
	1916	topo(:,nyn+i,:) = topo(:,nyn,:)
	1917	ENDDO
	1918	ENDIF
	1919	ENDIF
	1920	IF ( .NOT. bc_lr_cyc ) THEN
	1921	IF ( nxl == 0 ) THEN
	1922	DO i = 1, nbgp
	1923	topo(:,:,nxl-i) = topo(:,:,nxl)
	1924	ENDDO
	1925	ENDIF
	1926	IF ( nxr == nx ) THEN
	1927	DO i = 1, nbgp
	1928	topo(:,:,nxr+i) = topo(:,:,nxr)
	1929	ENDDO
	1930	ENDIF
	1931	ENDIF
[2232]	1932
[240]	1933	CASE ( 'single_street_canyon' )
	1934	!
	1935	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1936	!-- The canyon is centered in the other direction by default.
[1322]	1937	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1938	!
	1939	!-- Street canyon in y direction
	1940	cwx = NINT( canyon_width_x / dx )
[1322]	1941	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[240]	1942	canyon_wall_left = ( nx + 1 - cwx ) / 2 * dx
	1943	ENDIF
	1944	cxl = NINT( canyon_wall_left / dx )
	1945	cxr = cxl + cwx
[1322]	1946	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1947	!
	1948	!-- Street canyon in x direction
	1949	cwy = NINT( canyon_width_y / dy )
[1322]	1950	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[240]	1951	canyon_wall_south = ( ny + 1 - cwy ) / 2 * dy
	1952	ENDIF
	1953	cys = NINT( canyon_wall_south / dy )
	1954	cyn = cys + cwy
[2696]	1955
[240]	1956	ELSE
[254]	1957
	1958	message_string = 'no street canyon width given'
	1959	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1960
[240]	1961	ENDIF
	1962
[2232]	1963	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1964	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1965	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1966	dp_level_ind_b = ch
	1967	!
	1968	!-- Street canyon size has to meet some requirements
[1322]	1969	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1353]	1970	IF ( ( cxl < 1 ) .OR. ( cxr > nx-1 ) .OR. ( cwx < 3 ) .OR. &
[2696]	1971	( ch < 3 ) ) THEN
[1353]	1972	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1973	'&cxl=', cxl, ' cxr=', cxr, &
[3045]	1974	' cwx=', cwx, &
	1975	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1976	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1977	ENDIF
[1322]	1978	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1353]	1979	IF ( ( cys < 1 ) .OR. ( cyn > ny-1 ) .OR. ( cwy < 3 ) .OR. &
[2696]	1980	( ch < 3 ) ) THEN
[1353]	1981	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1982	'&cys=', cys, ' cyn=', cyn, &
[3045]	1983	' cwy=', cwy, &
	1984	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1985	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1986	ENDIF
	1987	ENDIF
[1353]	1988	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1989	canyon_width_y /= 9999999.9_wp ) THEN
	1990	message_string = 'inconsistent canyon parameters:' // &
[3046]	1991	'&street canyon can only be oriented' // &
[3045]	1992	' either in x- or in y-direction'
[254]	1993	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1994	ENDIF
	1995
[2696]	1996	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	1997	nzb_local = ch
[1322]	1998	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1968]	1999	IF ( cxl <= nxr .AND. cxr >= nxl ) &
	2000	nzb_local(:,MAX(nxl,cxl+1):MIN(nxr,cxr-1)) = 0
[1322]	2001	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1968]	2002	IF ( cys <= nyn .AND. cyn >= nys ) &
	2003	nzb_local(MAX(nys,cys+1):MIN(nyn,cyn-1),:) = 0
[240]	2004	ENDIF
[2232]	2005	!
[2696]	2006	!-- Set bit array on basis of nzb_local
	2007	DO i = nxl, nxr
	2008	DO j = nys, nyn
	2009	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	2010	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	2011	ENDDO
	2012	ENDDO
[2696]	2013	DEALLOCATE( nzb_local )
[1994]	2014
[2696]	2015	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2016	!
	2017	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2018	!-- boundary conditions for topography.
	2019	IF ( .NOT. bc_ns_cyc ) THEN
	2020	IF ( nys == 0 ) THEN
	2021	DO i = 1, nbgp
	2022	topo(:,nys-i,:) = topo(:,nys,:)
	2023	ENDDO
	2024	ENDIF
	2025	IF ( nyn == ny ) THEN
	2026	DO i = 1, nbgp
	2027	topo(:,nyn+i,:) = topo(:,nyn,:)
	2028	ENDDO
	2029	ENDIF
	2030	ENDIF
	2031	IF ( .NOT. bc_lr_cyc ) THEN
	2032	IF ( nxl == 0 ) THEN
	2033	DO i = 1, nbgp
	2034	topo(:,:,nxl-i) = topo(:,:,nxl)
	2035	ENDDO
	2036	ENDIF
	2037	IF ( nxr == nx ) THEN
	2038	DO i = 1, nbgp
	2039	topo(:,:,nxr+i) = topo(:,:,nxr)
	2040	ENDDO
	2041	ENDIF
	2042	ENDIF
[2232]	2043
	2044	CASE ( 'tunnel' )
	2045
	2046	!
	2047	!-- Tunnel height
	2048	IF ( tunnel_height == 9999999.9_wp ) THEN
	2049	th = zw( INT( 0.2 * nz) )
	2050	ELSE
	2051	th = tunnel_height
	2052	ENDIF
	2053	!
	2054	!-- Tunnel-wall depth
[2696]	2055	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	2056	td = MAX ( dx, dy, dz(1) )
[2232]	2057	ELSE
	2058	td = tunnel_wall_depth
	2059	ENDIF
	2060	!
	2061	!-- Check for tunnel width
	2062	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	2063	tunnel_width_y == 9999999.9_wp ) THEN
	2064	message_string = 'No tunnel width is given. '
[2274]	2065	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	2066	ENDIF
	2067	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2068	tunnel_width_y /= 9999999.9_wp ) THEN
	2069	message_string = 'Inconsistent tunnel parameters:' // &
	2070	'tunnel can only be oriented' // &
	2071	'either in x- or in y-direction.'
[2274]	2072	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	2073	ENDIF
	2074	!
	2075	!-- Tunnel axis along y
	2076	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	2077	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
	2078	message_string = 'Tunnel width too large'
[2274]	2079	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	2080	ENDIF
	2081
	2082	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	2083	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	2084	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	2085	( tunnel_width_x * 0.5_wp - td ) )
	2086	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	2087	( tunnel_width_x * 0.5_wp - td ) )
[2232]	2088
	2089	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	2090	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	2091	tys_in = tys_out
	2092	tye_in = tye_out
	2093	ENDIF
[2696]	2094	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2095	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) &
	2096	THEN
[2232]	2097	message_string = 'Tunnel width too small'
[2274]	2098	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
[2232]	2099	ENDIF
	2100	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
[2696]	2101	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) &
	2102	THEN
[2232]	2103	message_string = 'Tunnel width too small'
[2274]	2104	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
[2232]	2105	ENDIF
	2106	!
	2107	!-- Tunnel axis along x
	2108	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	2109	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
	2110	message_string = 'Tunnel width too large'
[2274]	2111	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	2112	ENDIF
	2113
	2114	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	2115	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	2116	txs_in = txs_out
	2117	txe_in = txe_out
	2118
	2119	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	2120	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	2121	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	2122	( tunnel_width_y * 0.5_wp - td ) )
[2232]	2123	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	2124	( tunnel_width_y * 0.5_wp - td ) )
	2125	ENDIF
	2126
[2696]	2127	topo = 0
[2232]	2128	DO i = nxl, nxr
	2129	DO j = nys, nyn
	2130	!
	2131	!-- Use heaviside function to model outer tunnel surface
	2132	hv_out = th * 0.5_wp * &
	2133	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	2134	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	2135
	2136	hv_out = hv_out * 0.5_wp * &
	2137	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	2138	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	2139	!
[2232]	2140	!-- Use heaviside function to model inner tunnel surface
	2141	hv_in = ( th - td ) * 0.5_wp * &
	2142	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	2143	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	2144
	2145	hv_in = hv_in * 0.5_wp * &
	2146	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	2147	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	2148	!
	2149	!-- Set flags at x-y-positions without any tunnel surface
	2150	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	2151	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	2152	!
	2153	!-- Set flags at x-y-positions with tunnel surfaces
	2154	ELSE
	2155	DO k = nzb + 1, nzt + 1
	2156	!
	2157	!-- Inner tunnel
	2158	IF ( hv_out - hv_in == th ) THEN
	2159	IF ( zw(k) <= hv_out ) THEN
[2696]	2160	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2161	ELSE
[2696]	2162	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2163	ENDIF
	2164	ENDIF
	2165	!
	2166	!-- Lateral tunnel walls
	2167	IF ( hv_out - hv_in == td ) THEN
	2168	IF ( zw(k) <= hv_in ) THEN
[2696]	2169	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2170	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	2171	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2172	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	2173	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2174	ENDIF
	2175	ENDIF
	2176	ENDDO
	2177	ENDIF
	2178	ENDDO
	2179	ENDDO
	2180
[2696]	2181	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2182	!
	2183	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2184	!-- boundary conditions for topography.
	2185	IF ( .NOT. bc_ns_cyc ) THEN
	2186	IF ( nys == 0 ) THEN
	2187	DO i = 1, nbgp
	2188	topo(:,nys-i,:) = topo(:,nys,:)
	2189	ENDDO
	2190	ENDIF
	2191	IF ( nyn == ny ) THEN
	2192	DO i = 1, nbgp
	2193	topo(:,nyn+i,:) = topo(:,nyn,:)
	2194	ENDDO
	2195	ENDIF
	2196	ENDIF
	2197	IF ( .NOT. bc_lr_cyc ) THEN
	2198	IF ( nxl == 0 ) THEN
	2199	DO i = 1, nbgp
	2200	topo(:,:,nxl-i) = topo(:,:,nxl)
	2201	ENDDO
	2202	ENDIF
	2203	IF ( nxr == nx ) THEN
	2204	DO i = 1, nbgp
	2205	topo(:,:,nxr+i) = topo(:,:,nxr)
	2206	ENDDO
	2207	ENDIF
	2208	ENDIF
[2232]	2209
[1]	2210	CASE ( 'read_from_file' )
	2211	!
[2696]	2212	!-- Note, topography information have been already read.
	2213	!-- If required, further process topography, i.e. reference buildings on
	2214	!-- top of orography and set temporary 3D topography array, which is
	2215	!-- used later to set grid flags. Calling of this rouinte is also
	2216	!-- required in case of ASCII input, even though no distinction between
	2217	!-- terrain- and building height is made in this case.
	2218	CALL process_topography( topo )
[1968]	2219	!
[2696]	2220	!-- Filter holes resolved by only one grid-point
	2221	CALL filter_topography( topo )
[1968]	2222	!
[2696]	2223	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2224	!-- conditions.
	2225	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2226	!
[4314]	2227	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2228	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2229	IF ( nys == 0 ) THEN
[2696]	2230	DO i = 1, nbgp
	2231	topo(:,nys-i,:) = topo(:,nys,:)
	2232	ENDDO
[2550]	2233	ENDIF
[2696]	2234	IF ( nyn == ny ) THEN
	2235	DO i = 1, nbgp
	2236	topo(:,nyn+i,:) = topo(:,nyn,:)
	2237	ENDDO
	2238	ENDIF
[1942]	2239	ENDIF
[1910]	2240
[1968]	2241	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2242	IF ( nxl == 0 ) THEN
[2696]	2243	DO i = 1, nbgp
	2244	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2245	ENDDO
[2696]	2246	ENDIF
	2247	IF ( nxr == nx ) THEN
	2248	DO i = 1, nbgp
	2249	topo(:,:,nxr+i) = topo(:,:,nxr)
	2250	ENDDO
	2251	ENDIF
[2232]	2252	ENDIF
	2253
[667]	2254
[1]	2255	CASE DEFAULT
[2696]	2256	!
[1]	2257	!-- The DEFAULT case is reached either if the parameter topography
[217]	2258	!-- contains a wrong character string or if the user has defined a special
[1]	2259	!-- case in the user interface. There, the subroutine user_init_grid
	2260	!-- checks which of these two conditions applies.
[2696]	2261	CALL user_init_grid( topo )
	2262	CALL filter_topography( topo )
[1]	2263
	2264	END SELECT
	2265	!
	2266	!-- Consistency checks and index array initialization are only required for
[2696]	2267	!-- non-flat topography.
[1]	2268	IF ( TRIM( topography ) /= 'flat' ) THEN
	2269	!
[2232]	2270	!-- In case of non-flat topography, check whether the convention how to
	2271	!-- define the topography grid has been set correctly, or whether the default
	2272	!-- is applicable. If this is not possible, abort.
	2273	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
[4340]	2274	IF ( TRIM( topography ) /= 'closed_channel' .AND. &
	2275	TRIM( topography ) /= 'single_building' .AND. &
[2232]	2276	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2277	TRIM( topography ) /= 'tunnel' .AND. &
	2278	TRIM( topography ) /= 'read_from_file') THEN
	2279	!-- The default value is not applicable here, because it is only valid
[3045]	2280	!-- for the four standard cases 'single_building',
	2281	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2282	!-- defined in init_grid.
	2283	WRITE( message_string, * ) &
[2696]	2284	'The value for "topography_grid_convention" ', &
[3046]	2285	'is not set. Its default value is & only valid for ', &
[3045]	2286	'"topography" = ''single_building'', ''tunnel'' ', &
[4340]	2287	'''single_street_canyon'', ''closed_channel'' & or ', &
	2288	'''read_from_file''.', &
[3046]	2289	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2290	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2291	ELSE
	2292	!-- The default value is applicable here.
	2293	!-- Set convention according to topography.
	2294	IF ( TRIM( topography ) == 'single_building' .OR. &
	2295	TRIM( topography ) == 'single_street_canyon' ) THEN
	2296	topography_grid_convention = 'cell_edge'
	2297	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2298	TRIM( topography ) == 'tunnel') THEN
	2299	topography_grid_convention = 'cell_center'
	2300	ENDIF
	2301	ENDIF
	2302	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2303	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2304	WRITE( message_string, * ) &
[2696]	2305	'The value for "topography_grid_convention" is ', &
[3046]	2306	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2307	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2308	ENDIF
[1]	2309
[2169]	2310
[217]	2311	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2312	!
[217]	2313	!-- The array nzb_local as defined using the 'cell_edge' convention
	2314	!-- describes the actual total size of topography which is defined at the
	2315	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2316	!-- on the topography walls in y-direction. However, PALM uses individual
	2317	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2318	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2319	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2320	!-- to form the basis for nzb_s_inner.
	2321	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2322	!-- required at this point.
	2323	DO j = nys+1, nyn+1
	2324	DO i = nxl-1, nxr
[2232]	2325	DO k = nzb, nzt+1
[2696]	2326	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2327	BTEST( topo(k,j,i+1), 0 ) ) &
	2328	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2329	ENDDO
	2330	ENDDO
	2331	ENDDO
[2696]	2332	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2333
	2334	DO i = nxl, nxr+1
	2335	DO j = nys-1, nyn
	2336	DO k = nzb, nzt+1
[2696]	2337	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2338	BTEST( topo(k,j+1,i), 0 ) ) &
	2339	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2340	ENDDO
	2341	ENDDO
	2342	ENDDO
[2696]	2343	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2344
[217]	2345	ENDIF
[2696]	2346	ENDIF
[2232]	2347
[1]	2348
[2696]	2349	END SUBROUTINE init_topo
[1]	2350
[2696]	2351	SUBROUTINE set_topo_flags(topo)
[1]	2352
[2696]	2353	USE control_parameters, &
[4294]	2354	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
	2355	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
[1]	2356
[2696]	2357	USE indices, &
[3241]	2358	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4346]	2359	nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
[1]	2360
[2696]	2361	USE kinds
[1]	2362
[2696]	2363	IMPLICIT NONE
[1804]	2364
[2696]	2365	INTEGER(iwp) :: i !< index variable along x
[4168]	2366	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2367	INTEGER(iwp) :: j !< index variable along y
	2368	INTEGER(iwp) :: k !< index variable along z
[1]	2369
[2696]	2370	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2371
[4329]	2372	ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2373	wall_flags_static_0 = 0
[2232]	2374	!
[2696]	2375	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2376	!-- Further special flags will be set in following loops.
[2232]	2377	DO i = nxl, nxr
	2378	DO j = nys, nyn
	2379	DO k = nzb, nzt+1
	2380	!
	2381	!-- scalar grid
[4340]	2382	IF ( BTEST( topo(k,j,i), 0 ) ) &
[4329]	2383	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
[2232]	2384	!
[2696]	2385	!-- u grid
[4340]	2386	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2387	BTEST( topo(k,j,i-1), 0 ) ) &
[4329]	2388	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
[2696]	2389	!
[2232]	2390	!-- v grid
[4340]	2391	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2392	BTEST( topo(k,j-1,i), 0 ) ) &
[4329]	2393	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
[2696]	2394
[2232]	2395	ENDDO
[1]	2396
[2232]	2397	DO k = nzb, nzt
[1]	2398	!
[2232]	2399	!-- w grid
[4340]	2400	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2401	BTEST( topo(k+1,j,i), 0 ) ) &
[4329]	2402	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
[2232]	2403	ENDDO
[4340]	2404
	2405	IF ( topography /= 'closed_channel' ) THEN
	2406	wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
	2407	ENDIF
[2232]	2408
	2409	ENDDO
	2410	ENDDO
[2696]	2411
[4329]	2412	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
[4346]	2413
[1]	2414	!
[4115]	2415	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2416	!-- basis of flag 24 futher flags will be derived which are used to control
	2417	!-- production of subgrid TKE production near walls.
[4346]	2418
	2419	ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2420	wall_flags_total_0 = 0
	2421
[2696]	2422	DO i = nxl, nxr
	2423	DO j = nys, nyn
[2232]	2424	DO k = nzb, nzt+1
[4346]	2425	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
[2232]	2426	ENDDO
	2427	ENDDO
	2428	ENDDO
[4346]	2429
	2430	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2431
	2432	DO i = nxl, nxr
	2433	DO j = nys, nyn
	2434	DO k = nzb, nzt+1
	2435	IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 ) .AND. &
	2436	BTEST( wall_flags_total_0(k,j+1,i), 0 ) .AND. &
	2437	BTEST( wall_flags_total_0(k,j,i-1), 0 ) .AND. &
	2438	BTEST( wall_flags_total_0(k,j,i+1), 0 ) .AND. &
	2439	BTEST( wall_flags_total_0(k,j-1,i-1), 0 ) .AND. &
	2440	BTEST( wall_flags_total_0(k,j+1,i-1), 0 ) .AND. &
	2441	BTEST( wall_flags_total_0(k,j-1,i+1), 0 ) .AND. &
	2442	BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) ) &
	2443	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
	2444	ENDDO
	2445	ENDDO
	2446	ENDDO
[1]	2447	!
[2232]	2448	!-- Set further special flags
	2449	DO i = nxl, nxr
	2450	DO j = nys, nyn
	2451	DO k = nzb, nzt+1
[1]	2452	!
[2232]	2453	!-- scalar grid, former nzb_diff_s_inner.
	2454	!-- Note, use this flag also to mask topography in diffusion_u and
	2455	!-- diffusion_v along the vertical direction. In case of
	2456	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2457	!-- gradient approach is applied. Please note, in case of u- and v-
	2458	!-- diffuison, a small error is made at edges (on the east side for u,
	2459	!-- at the north side for v), since topography on scalar grid point
	2460	!-- is used instead of topography on u/v-grid. As number of topography grid
	2461	!-- points on uv-grid is different than s-grid, different number of
	2462	!-- surface elements would be required. In order to avoid this,
	2463	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2464	!-- points are not masked within diffusion_u. Tests had shown that the
	2465	!-- effect on the flow is negligible.
	2466	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2467	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2468	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2469	ELSE
[4346]	2470	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
[2232]	2471	ENDIF
[1]	2472
[2232]	2473	ENDDO
	2474	!
	2475	!-- Special flag to control vertical diffusion at model top - former
	2476	!-- nzt_diff
[4346]	2477	wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
[2232]	2478	IF ( use_top_fluxes ) &
[4346]	2479	wall_flags_total_0(nzt+1,j,i) = IBCLR( wall_flags_total_0(nzt+1,j,i), 9 )
[1]	2480
[2696]	2481
[2232]	2482	DO k = nzb+1, nzt
	2483	!
	2484	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2485	!-- for disturb_field and initialization. Do not disturb directly at
	2486	!-- topography, as well as initialize u with zero one grid point outside
	2487	!-- of topography.
[4346]	2488	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2489	BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2490	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2491	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
[2232]	2492	!
	2493	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2494	!-- for disturb_field and initialization. Do not disturb directly at
	2495	!-- topography, as well as initialize v with zero one grid point outside
	2496	!-- of topography.
[4346]	2497	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2498	BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2499	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2500	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
[2232]	2501	!
	2502	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2503	!-- lpm_sgs_tke
[4346]	2504	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2505	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2506	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2507	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
[2232]	2508	!
	2509	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2510	!-- in production_e
	2511	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2512	IF ( BTEST( wall_flags_total_0(k,j,i), 24 ) .AND. &
	2513	BTEST( wall_flags_total_0(k-1,j,i), 24 ) .AND. &
	2514	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2515	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[2232]	2516	ELSE
[4346]	2517	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2518	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
[1]	2519	ENDIF
[2232]	2520	!
	2521	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2522	!-- in production_e
	2523	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2524	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2525	BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2526	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2527	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2528	ELSE
[4346]	2529	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2530	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
[2232]	2531	ENDIF
	2532	ENDDO
	2533	!
	2534	!-- Flags indicating downward facing walls
[4340]	2535	DO k = nzb+1, nzt+1
[2232]	2536	!
	2537	!-- Scalar grid
[4346]	2538	IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 ) .AND. &
	2539	.NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) ) &
	2540	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
[2232]	2541	!
	2542	!-- Downward facing wall on u grid
[4346]	2543	IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 ) .AND. &
	2544	.NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) ) &
	2545	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
[2232]	2546	!
	2547	!-- Downward facing wall on v grid
[4346]	2548	IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 ) .AND. &
	2549	.NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) ) &
	2550	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
[2232]	2551	!
	2552	!-- Downward facing wall on w grid
[4346]	2553	IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 ) .AND. &
	2554	.NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) ) &
	2555	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
[2232]	2556	ENDDO
	2557	!
	2558	!-- Flags indicating upward facing walls
	2559	DO k = nzb, nzt
	2560	!
	2561	!-- Upward facing wall on scalar grid
[4346]	2562	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2563	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2564	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
[2232]	2565	!
	2566	!-- Upward facing wall on u grid
[4346]	2567	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 1 ) .AND. &
	2568	BTEST( wall_flags_total_0(k+1,j,i), 1 ) ) &
	2569	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
[1]	2570
[2696]	2571	!
[2232]	2572	!-- Upward facing wall on v grid
[4346]	2573	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 2 ) .AND. &
	2574	BTEST( wall_flags_total_0(k+1,j,i), 2 ) ) &
	2575	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
[2696]	2576
[2232]	2577	!
	2578	!-- Upward facing wall on w grid
[4346]	2579	IF ( .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) .AND. &
	2580	BTEST( wall_flags_total_0(k+1,j,i), 3 ) ) &
	2581	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
[2232]	2582	!
	2583	!-- Special flag on scalar grid, former nzb_s_inner
[4346]	2584	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .OR. &
	2585	BTEST( wall_flags_total_0(k,j,i), 12 ) .OR. &
	2586	BTEST( wall_flags_total_0(k,j,i), 13 ) ) &
	2587	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
[2232]	2588	!
	2589	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2590	!-- flow_statistics
	2591	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[4346]	2592	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. &
	2593	BTEST( wall_flags_total_0(k+1,j,i), 0 ) ) &
	2594	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[2232]	2595	ELSE
[4346]	2596	IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) ) &
	2597	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
[1]	2598	ENDIF
[2696]	2599
[1]	2600
[2232]	2601	ENDDO
[4346]	2602	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 22 )
	2603	wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
[4109]	2604	!
	2605	!-- Set flags indicating that topography is close by in horizontal
	2606	!-- direction, i.e. flags that infold the topography. These will be used
	2607	!-- to set advection flags for passive scalars, where due to large
	2608	!-- gradients near buildings stationary numerical oscillations can produce
	2609	!-- unrealistically high concentrations. This is only necessary if
	2610	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2611	!-- only used for passive scalars such as chemical species or aerosols.
	2612	IF ( scalar_advec == 'ws-scheme' ) THEN
	2613	DO k = nzb, nzt
[4346]	2614	IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) .AND. ( &
	2615	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2616	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2617	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2618	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2619	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2620	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2621	ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2622	ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2623	ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2624	ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2625	ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2626	ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) ) &
	2627	) ) &
	2628	wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
[4109]	2629
	2630	ENDDO
	2631	ENDIF
[2232]	2632	ENDDO
	2633	ENDDO
	2634	!
[2696]	2635	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2636	!-- Natural terrain grid points. Information on the type of the surface is
	2637	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2638	!-- when topography is read from file. In order to run the land-surface model
	2639	!-- also without topography information, set bit 1 explicitely in this case.
[4294]	2640	!--
	2641	!-- Natural terrain grid points
	2642	!-- If no topography is initialized, the land-surface is at k = nzb.
	2643	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
[4329]	2644	wall_flags_static_0(nzb,:,:) = IBSET( wall_flags_static_0(nzb,:,:), 5 )
[4294]	2645	ELSE
	2646	DO i = nxl, nxr
	2647	DO j = nys, nyn
	2648	DO k = nzb, nzt+1
[4189]	2649	!
[4294]	2650	!-- Natural terrain grid point
	2651	IF ( BTEST( topo(k,j,i), 1 ) ) &
[4329]	2652	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
[2696]	2653	ENDDO
	2654	ENDDO
[4294]	2655	ENDDO
[2696]	2656	ENDIF
	2657	!
	2658	!-- Building grid points.
[4294]	2659	DO i = nxl, nxr
	2660	DO j = nys, nyn
	2661	DO k = nzb, nzt+1
	2662	IF ( BTEST( topo(k,j,i), 2 ) ) &
[4329]	2663	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
[2696]	2664	ENDDO
	2665	ENDDO
[4294]	2666	ENDDO
[2696]	2667	!
[4314]	2668	!-- Set flag 4, indicating new topography grid points due to filtering.
	2669	DO i = nxl, nxr
	2670	DO j = nys, nyn
	2671	DO k = nzb, nzt+1
	2672	IF ( BTEST( topo(k,j,i), 4 ) ) &
[4329]	2673	wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
[4314]	2674	ENDDO
	2675	ENDDO
	2676	ENDDO
[4346]	2677
	2678	CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
	2679
	2680	DO i = nxl, nxr
	2681	DO j = nys, nyn
	2682	DO k = nzb, nzt+1
	2683	wall_flags_total_0(k,j,i) = IOR( wall_flags_total_0(k,j,i), wall_flags_static_0(k,j,i) )
	2684	ENDDO
	2685	ENDDO
	2686	ENDDO
[4314]	2687	!
[2232]	2688	!-- Exchange ghost points for wall flags
[4346]	2689	CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2690	!
	2691	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2692	!-- boundary conditions for topography.
	2693	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2694	IF ( nys == 0 ) THEN
	2695	DO i = 1, nbgp
[4346]	2696	wall_flags_total_0(:,nys-i,:) = wall_flags_total_0(:,nys,:)
[2696]	2697	ENDDO
	2698	ENDIF
	2699	IF ( nyn == ny ) THEN
	2700	DO i = 1, nbgp
[4346]	2701	wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
[2696]	2702	ENDDO
	2703	ENDIF
[2232]	2704	ENDIF
	2705	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2706	IF ( nxl == 0 ) THEN
	2707	DO i = 1, nbgp
[4346]	2708	wall_flags_total_0(:,:,nxl-i) = wall_flags_total_0(:,:,nxl)
[2696]	2709	ENDDO
[2232]	2710	ENDIF
[2696]	2711	IF ( nxr == nx ) THEN
	2712	DO i = 1, nbgp
[4346]	2713	wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
[2232]	2714	ENDDO
[2696]	2715	ENDIF
[2232]	2716	ENDIF
[4168]	2717	!
	2718	!-- Pre-calculate topography top indices (former get_topography_top_index
	2719	!-- function)
	2720	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2721	!
	2722	!-- Uppermost topography index on scalar grid
	2723	ibit = 12
	2724	topo_top_ind(:,:,0) = MAXLOC( &
	2725	MERGE( 1, 0, &
[4346]	2726	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2727	), DIM = 1 &
	2728	) - 1
	2729	!
	2730	!-- Uppermost topography index on u grid
	2731	ibit = 14
	2732	topo_top_ind(:,:,1) = MAXLOC( &
	2733	MERGE( 1, 0, &
[4346]	2734	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2735	), DIM = 1 &
	2736	) - 1
	2737	!
	2738	!-- Uppermost topography index on v grid
	2739	ibit = 16
	2740	topo_top_ind(:,:,2) = MAXLOC( &
	2741	MERGE( 1, 0, &
[4346]	2742	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2743	), DIM = 1 &
	2744	) - 1
	2745	!
	2746	!-- Uppermost topography index on w grid
	2747	ibit = 18
	2748	topo_top_ind(:,:,3) = MAXLOC( &
	2749	MERGE( 1, 0, &
[4346]	2750	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2751	), DIM = 1 &
	2752	) - 1
	2753	!
	2754	!-- Uppermost topography index on scalar outer grid
	2755	ibit = 24
	2756	topo_top_ind(:,:,4) = MAXLOC( &
	2757	MERGE( 1, 0, &
[4346]	2758	BTEST( wall_flags_total_0(:,:,:), ibit ) &
[4168]	2759	), DIM = 1 &
	2760	) - 1
[4346]	2761
[2696]	2762	END SUBROUTINE set_topo_flags
[114]	2763
	2764
	2765

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