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source: palm/trunk/SOURCE/init_grid.f90 @ 4231

Last change on this file since 4231 was 4189, checked in by suehring, 5 years ago
init_grid: Add check for proper setting of namelist parameter topography; Set bit flag to indicate land surfaces in case no topography is provided
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File size: 117.9 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 4189 2019-08-26 16:19:38Z suehring $
[4189]	27	! - Add check for proper setting of namelist parameter topography
	28	! - Set flag to indicate land surfaces in case no topography is provided
	29	!
	30	! 4182 2019-08-22 15:20:23Z scharf
[4182]	31	! Corrected "Former revisions" section
	32	!
	33	! 4168 2019-08-16 13:50:17Z suehring
[4168]	34	! Pre-calculate topography top index and store it on an array (replaces former
	35	! functions get_topography_top_index)
	36	!
	37	! 4159 2019-08-15 13:31:35Z suehring
[4159]	38	! Revision of topography processing. This was not consistent between 2D and 3D
	39	! buildings.
	40	!
	41	! 4144 2019-08-06 09:11:47Z raasch
[4144]	42	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	43	!
	44	! 4115 2019-07-24 12:50:49Z suehring
[4115]	45	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	46	!
	47	! 4110 2019-07-22 17:05:21Z suehring
[4110]	48	! - Separate initialization of advection flags for momentum and scalars.
	49	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	50	!
	51	! 4109 2019-07-22 17:00:34Z suehring
[3927]	52	! Fix bad commit
	53	!
	54	! 3926 2019-04-23 12:56:42Z suehring
[3925]	55	! Minor bugfix in building mapping when all building IDs in the model domain
	56	! are missing
	57	!
	58	! 3857 2019-04-03 13:00:16Z knoop
[3855]	59	! In projection of non-building 3D objects onto numerical grid remove
	60	! dependency on building_type
	61	!
	62	! 3763 2019-02-25 17:33:49Z suehring
[3763]	63	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	64	! routine as already done in other routines
	65	!
	66	! 3761 2019-02-25 15:31:42Z raasch
[3761]	67	! unused variables removed
	68	!
	69	! 3661 2019-01-08 18:22:50Z suehring
[3661]	70	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	71	! order degradation of advection scheme is handeled directly in advec_ws
	72	!
	73	! 3655 2019-01-07 16:51:22Z knoop
[3538]	74	! Comment added
[2716]	75	!
[4182]	76	! Revision 1.1 1997/08/11 06:17:45 raasch
	77	! Initial revision (Testversion)
	78	!
	79	!
[1]	80	! Description:
[2696]	81	! -----------------------------------------------------------------------------!
[1682]	82	!> Creating grid depending constants
[2696]	83	!> @todo: Rearrange topo flag list
	84	!> @todo: reference 3D buildings on top of orography is not tested and may need
	85	!> further improvement for steep slopes
	86	!> @todo: Use more advanced setting of building type at filled holes
[1]	87	!------------------------------------------------------------------------------!
[1682]	88	SUBROUTINE init_grid
	89
[1942]	90	USE advec_ws, &
[4109]	91	ONLY: ws_init_flags_momentum, ws_init_flags_scalar
[1]	92
[1320]	93	USE arrays_3d, &
[3857]	94	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[1320]	95
[1353]	96	USE control_parameters, &
[3761]	97	ONLY: bc_lr_cyc, bc_ns_cyc, &
[4109]	98	bc_dirichlet_l, &
	99	bc_dirichlet_n, &
	100	bc_dirichlet_r, &
	101	bc_dirichlet_s, &
	102	bc_radiation_l, &
	103	bc_radiation_n, &
	104	bc_radiation_r, &
	105	bc_radiation_s, &
[3241]	106	constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	107	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	108	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	109	dz_stretch_level_start, ibc_uv_b, message_string, &
[3182]	110	momentum_advec, number_stretch_level_end, &
[3294]	111	number_stretch_level_start, ocean_mode, psolver, scalar_advec, &
[3241]	112	topography, use_surface_fluxes
[2021]	113
[1320]	114	USE grid_variables, &
[2232]	115	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[1320]	116
	117	USE indices, &
[4109]	118	ONLY: advc_flags_m, &
	119	advc_flags_s, &
	120	nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
[2232]	121	nzb, nzb_diff, nzb_diff_s_inner, nzb_diff_s_outer, &
	122	nzb_max, nzb_s_inner, nzb_s_outer, nzb_u_inner, &
[1845]	123	nzb_u_outer, nzb_v_inner, nzb_v_outer, nzb_w_inner, &
[4168]	124	nzb_w_outer, nzt, topo_top_ind, topo_min_level
[1320]	125
	126	USE kinds
[2696]	127
[1]	128	USE pegrid
	129
[2696]	130	USE poismg_noopt_mod
	131
[2232]	132	USE surface_mod, &
[4168]	133	ONLY: init_bc
[2232]	134
[2365]	135	USE vertical_nesting_mod, &
	136	ONLY: vnested, vnest_init_grid
	137
[1]	138	IMPLICIT NONE
	139
[3182]	140	INTEGER(iwp) :: i !< index variable along x
	141	INTEGER(iwp) :: j !< index variable along y
	142	INTEGER(iwp) :: k !< index variable along z
	143	INTEGER(iwp) :: k_top !< topography top index on local PE
	144	INTEGER(iwp) :: n !< loop variable for stretching
	145	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	146	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	147	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[2232]	148
[3065]	149	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	150	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_tmp !< dummy to calculate topography indices on u- and v-grid
[1]	151
[2696]	152	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	153
[3065]	154	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	155	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	156
	157	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	158
[1]	159
	160	!
[709]	161	!-- Calculation of horizontal array bounds including ghost layers
[667]	162	nxlg = nxl - nbgp
	163	nxrg = nxr + nbgp
	164	nysg = nys - nbgp
	165	nyng = nyn + nbgp
[709]	166
[667]	167	!
[1]	168	!-- Allocate grid arrays
[3857]	169	ALLOCATE( x(0:nx), xu(0:nx) )
	170	DO i = 0, nx
	171	xu(i) = i * dx
	172	x(i) = i * dx + 0.5_wp * dx
	173	ENDDO
	174
	175	ALLOCATE( y(0:ny), yv(0:ny) )
	176	DO j = 0, ny
	177	yv(j) = j * dy
	178	y(j) = j * dy + 0.5_wp * dy
	179	ENDDO
	180
	181	!
	182	!-- Allocate grid arrays
[1353]	183	ALLOCATE( ddzu(1:nzt+1), ddzw(1:nzt+1), dd2zu(1:nzt), dzu(1:nzt+1), &
[2696]	184	dzw(1:nzt+1), zu(nzb:nzt+1), zw(nzb:nzt+1) )
[1]	185
	186	!
	187	!-- Compute height of u-levels from constant grid length and dz stretch factors
[3065]	188	IF ( dz(1) == -1.0_wp ) THEN
[254]	189	message_string = 'missing dz'
	190	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	191	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	192	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	193	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	194	ENDIF
[94]	195
[1]	196	!
[3065]	197	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	198	!-- if it was set by the user
	199	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	200	dz_stretch_level_start(1) = dz_stretch_level
	201	ENDIF
	202
	203	!
	204	!-- Determine number of dz values and stretching levels specified by the
	205	!-- user to allow right controlling of the stretching mechanism and to
[3139]	206	!-- perform error checks. The additional requirement that dz /= dz_max
	207	!-- for counting number of user-specified dz values is necessary. Otherwise
	208	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	209	!-- is used (Attention: The user is not allowed to specify a dz value equal
	210	!-- to the default of dz_max = 999.0).
	211	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	212	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	213	-9999999.9_wp )
	214	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	215	9999999.9_wp )
	216
	217	!
	218	!-- The number of specified end levels +1 has to be the same than the number
	219	!-- of specified dz values
	220	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
	221	WRITE( message_string, * ) 'The number of values for dz = ', &
	222	number_dz, 'has to be the same than& ', &
	223	'the number of values for ', &
	224	'dz_stretch_level_end + 1 = ', &
	225	number_stretch_level_end+1
	226	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	227	ENDIF
	228
	229	!
	230	!-- The number of specified start levels has to be the same or one less than
	231	!-- the number of specified dz values
	232	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
	233	number_dz /= number_stretch_level_start ) THEN
	234	WRITE( message_string, * ) 'The number of values for dz = ', &
	235	number_dz, 'has to be the same or one ', &
	236	'more than& the number of values for ', &
	237	'dz_stretch_level_start = ', &
	238	number_stretch_level_start
	239	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	240	ENDIF
	241
	242	!-- The number of specified start levels has to be the same or one more than
	243	!-- the number of specified end levels
	244	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
	245	number_stretch_level_start /= number_stretch_level_end ) THEN
	246	WRITE( message_string, * ) 'The number of values for ', &
	247	'dz_stretch_level_start = ', &
	248	dz_stretch_level_start, 'has to be the ',&
	249	'same or one more than& the number of ', &
	250	'values for dz_stretch_level_end = ', &
	251	number_stretch_level_end
	252	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	253	ENDIF
	254
	255	!
	256	!-- Initialize dz for the free atmosphere with the value of dz_max
	257	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	258	number_stretch_level_start /= 0 ) THEN
	259	dz(number_stretch_level_start+1) = dz_max
	260	ENDIF
	261
	262	!
	263	!-- Initialize the stretching factor if (infinitely) stretching in the free
	264	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	265	!-- free atmosphere)
	266	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	267	dz_stretch_factor_array(number_stretch_level_start) = &
	268	dz_stretch_factor
	269	ENDIF
	270
	271	!
	272	!-- Allocation of arrays for stretching
	273	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	274
[3065]	275	!
[94]	276	!-- Define the vertical grid levels
[3294]	277	IF ( .NOT. ocean_mode ) THEN
[3065]	278
[94]	279	!
[3065]	280	!-- The stretching region has to be large enough to allow for a smooth
	281	!-- transition between two different grid spacings
	282	DO n = 1, number_stretch_level_start
	283	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	284	4 * MAX( dz(n),dz(n+1) )
	285	ENDDO
	286
[3066]	287	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	288	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	289	message_string= 'Eeach dz_stretch_level_end has to be larger ' // &
	290	'than its corresponding value for &' // &
	291	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	292	'to allow for smooth grid stretching'
	293	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	294	ENDIF
	295
	296	!
	297	!-- Stretching must not be applied within the prandtl_layer
	298	!-- (first two grid points). For the default case dz_stretch_level_start
	299	!-- is negative. Therefore the absolut value is checked here.
	300	IF ( ANY( ABS( dz_stretch_level_start ) < dz(1) * 1.5_wp ) ) THEN
	301	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	302	'larger than ', dz(1) * 1.5
	303	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	304	ENDIF
	305
	306	!
	307	!-- The stretching has to start and end on a grid level. Therefore
	308	!-- user-specified values have to ''interpolate'' to the next lowest level
	309	IF ( number_stretch_level_start /= 0 ) THEN
	310	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	311	dz(1)/2.0) / dz(1) ) &
	312	* dz(1) + dz(1)/2.0
	313	ENDIF
	314
	315	IF ( number_stretch_level_start > 1 ) THEN
	316	DO n = 2, number_stretch_level_start
	317	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	318	dz(n) ) * dz(n)
	319	ENDDO
	320	ENDIF
	321
	322	IF ( number_stretch_level_end /= 0 ) THEN
	323	DO n = 1, number_stretch_level_end
	324	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	325	dz(n+1) ) * dz(n+1)
	326	ENDDO
	327	ENDIF
	328
	329	!
	330	!-- Determine stretching factor if necessary
	331	IF ( number_stretch_level_end >= 1 ) THEN
	332	CALL calculate_stretching_factor( number_stretch_level_end )
	333	ENDIF
	334
	335	!
[94]	336	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	337	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	338	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	339	!-- The second u-level (k=1) corresponds to the top of the
[94]	340	!-- Prandtl-layer.
[667]	341	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 ) THEN
[1353]	342	zu(0) = 0.0_wp
[667]	343	ELSE
[3065]	344	zu(0) = - dz(1) * 0.5_wp
[667]	345	ENDIF
[3065]	346
	347	zu(1) = dz(1) * 0.5_wp
	348
	349	!
	350	!-- Determine u and v height levels considering the possibility of grid
	351	!-- stretching in several heights.
	352	n = 1
	353	dz_stretch_level_start_index = nzt+1
	354	dz_stretch_level_end_index = nzt+1
	355	dz_stretched = dz(1)
[1]	356
[3065]	357	!-- The default value of dz_stretch_level_start is negative, thus the first
	358	!-- condition is always true. Hence, the second condition is necessary.
[94]	359	DO k = 2, nzt+1
[3065]	360	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	361	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	362	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	363
	364	IF ( dz(n) > dz(n+1) ) THEN
	365	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	366	ELSE
	367	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	368	ENDIF
	369
	370	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	371	dz_stretch_level_start_index(n) = k-1
	372
[94]	373	ENDIF
[3065]	374
[94]	375	zu(k) = zu(k-1) + dz_stretched
[3065]	376
	377	!
	378	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	379	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	380
	381	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	382	zu(k) = dz_stretch_level_end(n)
	383	dz_stretched = dz(n+1)
	384	dz_stretch_level_end_index(n) = k
	385	n = n + 1
	386	ENDIF
[94]	387	ENDDO
[1]	388
	389	!
[94]	390	!-- Compute the w-levels. They are always staggered half-way between the
[843]	391	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	392	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
	393	!-- The top w-level is extrapolated linearly.
[1353]	394	zw(0) = 0.0_wp
[94]	395	DO k = 1, nzt
[1353]	396	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	397	ENDDO
[1353]	398	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
[1]	399
[94]	400	ELSE
[3065]	401
[1]	402	!
[3065]	403	!-- The stretching region has to be large enough to allow for a smooth
	404	!-- transition between two different grid spacings
	405	DO n = 1, number_stretch_level_start
	406	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	407	4 * MAX( dz(n),dz(n+1) )
	408	ENDDO
	409
[3066]	410	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	411	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	412	message_string= 'Eeach dz_stretch_level_end has to be less ' // &
	413	'than its corresponding value for &' // &
	414	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	415	'to allow for smooth grid stretching'
	416	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	417	ENDIF
	418
	419	!
[3068]	420	!-- Stretching must not be applied close to the surface (last two grid
	421	!-- points). For the default case dz_stretch_level_start is negative.
	422	IF ( ANY( dz_stretch_level_start > - dz(1) * 1.5_wp ) ) THEN
[3065]	423	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	424	'less than ', dz(1) * 1.5
	425	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	426	ENDIF
	427
	428	!
	429	!-- The stretching has to start and end on a grid level. Therefore
	430	!-- user-specified values have to ''interpolate'' to the next highest level
	431	IF ( number_stretch_level_start /= 0 ) THEN
	432	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	433	dz(1)/2.0) / dz(1) ) &
	434	* dz(1) - dz(1)/2.0
	435	ENDIF
	436
	437	IF ( number_stretch_level_start > 1 ) THEN
	438	DO n = 2, number_stretch_level_start
	439	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	440	dz(n) ) * dz(n)
	441	ENDDO
	442	ENDIF
	443
	444	IF ( number_stretch_level_end /= 0 ) THEN
	445	DO n = 1, number_stretch_level_end
	446	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	447	dz(n+1) ) * dz(n+1)
	448	ENDDO
	449	ENDIF
	450
	451	!
	452	!-- Determine stretching factor if necessary
	453	IF ( number_stretch_level_end >= 1 ) THEN
	454	CALL calculate_stretching_factor( number_stretch_level_end )
	455	ENDIF
	456
	457	!
[843]	458	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	459	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	460	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	461	!-- w-level are defined at same height, but staggered from the second level.
	462	!-- The second u-level (k=1) corresponds to the top of the Prandtl-layer.
[3065]	463	!-- z values are negative starting from z=0 (surface)
	464	zu(nzt+1) = dz(1) * 0.5_wp
	465	zu(nzt) = - dz(1) * 0.5_wp
[94]	466
[3065]	467	!
	468	!-- Determine u and v height levels considering the possibility of grid
	469	!-- stretching in several heights.
	470	n = 1
	471	dz_stretch_level_start_index = 0
	472	dz_stretch_level_end_index = 0
	473	dz_stretched = dz(1)
	474
[94]	475	DO k = nzt-1, 0, -1
[3065]	476
	477	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	478	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	479
	480	IF ( dz(n) > dz(n+1) ) THEN
	481	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	482	ELSE
	483	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	484	ENDIF
	485
	486	IF ( dz_stretch_level_start_index(n) == 0 ) &
	487	dz_stretch_level_start_index(n) = k+1
	488
	489	ENDIF
	490
	491	zu(k) = zu(k+1) - dz_stretched
	492
[1418]	493	!
[3065]	494	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	495	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	496
	497	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	498	zu(k) = dz_stretch_level_end(n)
	499	dz_stretched = dz(n+1)
	500	dz_stretch_level_end_index(n) = k
	501	n = n + 1
[94]	502	ENDIF
	503	ENDDO
[3065]	504
[94]	505	!
	506	!-- Compute the w-levels. They are always staggered half-way between the
[843]	507	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	508	!-- at the ground. In this case the first u- and w-level are defined at
	509	!-- same height. The top w-level (nzt+1) is not used but set for
	510	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	511	zw(nzt+1) = dz(1)
[1353]	512	zw(nzt) = 0.0_wp
[94]	513	DO k = 0, nzt
[1353]	514	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	515	ENDDO
	516
[843]	517	!
	518	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	519	!-- at same height.
	520	IF ( ibc_uv_b == 0 ) THEN
	521	zu(0) = zw(0)
	522	ENDIF
	523
[94]	524	ENDIF
	525
	526	!
[1]	527	!-- Compute grid lengths.
	528	DO k = 1, nzt+1
	529	dzu(k) = zu(k) - zu(k-1)
[1353]	530	ddzu(k) = 1.0_wp / dzu(k)
[1]	531	dzw(k) = zw(k) - zw(k-1)
[1353]	532	ddzw(k) = 1.0_wp / dzw(k)
[1]	533	ENDDO
	534
	535	DO k = 1, nzt
[1353]	536	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	537	ENDDO
[667]	538
	539	!
[709]	540	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	541	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	542	!-- is only dz/2, but should be dz. Therefore, an additional array
	543	!-- containing with appropriate grid information is created for these
	544	!-- solvers.
[1575]	545	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	546	ALLOCATE( ddzu_pres(1:nzt+1) )
	547	ddzu_pres = ddzu
[864]	548	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	549	ENDIF
	550
	551	!
	552	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	553	ddx = 1.0_wp / dx
	554	ddy = 1.0_wp / dy
[1]	555	dx2 = dx * dx
	556	dy2 = dy * dy
[1353]	557	ddx2 = 1.0_wp / dx2
	558	ddy2 = 1.0_wp / dy2
[1]	559
	560	!
[2696]	561	!-- Allocate 3D array to set topography
	562	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	563	topo = 0
	564	!
	565	!-- Initialize topography by generic topography or read from topography from file.
	566	CALL init_topo( topo )
	567	!
	568	!-- Set flags to mask topography on the grid.
	569	CALL set_topo_flags( topo )
	570	!
	571	!-- Calculate wall flag arrays for the multigrid method.
	572	!-- Please note, wall flags are only applied in the non-optimized version.
[4109]	573	IF ( psolver == 'multigrid_noopt' ) CALL poismg_noopt_init
[2696]	574
	575	!
	576	!-- Init flags for ws-scheme to degrade order of the numerics near walls, i.e.
[4109]	577	!-- to decrease the numerical stencil appropriately. The order of the scheme
	578	!-- is degraded near solid walls as well as near non-cyclic inflow and outflow
	579	!-- boundaries. Do this separately for momentum and scalars.
	580	IF ( momentum_advec == 'ws-scheme' ) THEN
	581	ALLOCATE( advc_flags_m(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	582	CALL ws_init_flags_momentum
	583	ENDIF
	584	IF ( scalar_advec == 'ws-scheme' ) THEN
	585	ALLOCATE( advc_flags_s(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	586	advc_flags_s = 0
	587
	588	CALL ws_init_flags_scalar( bc_dirichlet_l .OR. bc_radiation_l, &
	589	bc_dirichlet_n .OR. bc_radiation_n, &
	590	bc_dirichlet_r .OR. bc_radiation_r, &
	591	bc_dirichlet_s .OR. bc_radiation_s, &
	592	advc_flags_s )
	593	ENDIF
[2696]	594
	595	!
	596	!-- Determine the maximum level of topography. It is used for
	597	!-- steering the degradation of order of the applied advection scheme,
	598	!-- as well in the lpm.
	599	k_top = 0
	600	DO i = nxl, nxr
	601	DO j = nys, nyn
	602	DO k = nzb, nzt + 1
[4109]	603	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	604	ENDDO
	605	ENDDO
[1]	606	ENDDO
[2696]	607	#if defined( __parallel )
	608	CALL MPI_ALLREDUCE( k_top + 1, nzb_max, 1, MPI_INTEGER, & !is +1 really necessary here?
	609	MPI_MAX, comm2d, ierr )
	610	#else
	611	nzb_max = k_top + 1
	612	#endif
	613	!
[3661]	614	!-- If topography extents up to the model top, limit nzb_max to nzt.
[3182]	615	nzb_max = MIN( nzb_max, nzt )
[1]	616	!
[2968]	617	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	618	!-- there is elevated topography, however, the lowest topography will be higher.
	619	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	620	!-- temperature, surface pressure and density, etc. .
	621	topo_min_level = 0
	622	#if defined( __parallel )
[4168]	623	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	624	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	625	#else
[4168]	626	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	627	#endif
	628	!
[2696]	629	!-- Initialize boundary conditions via surface type
	630	CALL init_bc
[3182]	631
[2696]	632	!
	633	!-- Allocate and set topography height arrays required for data output
	634	IF ( TRIM( topography ) /= 'flat' ) THEN
	635	!
	636	!-- Allocate and set the arrays containing the topography height
	637	IF ( nxr == nx .AND. nyn /= ny ) THEN
	638	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	639	zw_w_inner(nxl:nxr+1,nys:nyn) )
	640	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	641	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	642	zw_w_inner(nxl:nxr,nys:nyn+1) )
	643	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	644	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	645	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	646	ELSE
	647	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	648	zw_w_inner(nxl:nxr,nys:nyn) )
	649	ENDIF
	650
	651	zu_s_inner = 0.0_wp
	652	zw_w_inner = 0.0_wp
	653	!
	654	!-- Determine local topography height on scalar and w-grid. Note, setting
	655	!-- lateral boundary values is not necessary, realized via wall_flags_0
	656	!-- array. Further, please note that loop bounds are different from
	657	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	658	!-- use intrinsic lbound and ubound functions to infer array bounds.
	659	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	660	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
	661	!
	662	!-- Topography height on scalar grid. Therefore, determine index of
	663	!-- upward-facing surface element on scalar grid.
[4168]	664	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	665	!
	666	!-- Topography height on w grid. Therefore, determine index of
	667	!-- upward-facing surface element on w grid.
[4168]	668	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
[2696]	669	ENDDO
	670	ENDDO
	671	ENDIF
	672
	673	!
	674	!-- In the following, calculate 2D index arrays. Note, these will be removed
	675	!-- soon.
[1]	676	!-- Allocate outer and inner index arrays for topography and set
[2232]	677	!-- defaults.
[2696]	678	ALLOCATE( nzb_s_inner(nysg:nyng,nxlg:nxrg), &
	679	nzb_s_outer(nysg:nyng,nxlg:nxrg), &
	680	nzb_u_inner(nysg:nyng,nxlg:nxrg), &
	681	nzb_u_outer(nysg:nyng,nxlg:nxrg), &
	682	nzb_v_inner(nysg:nyng,nxlg:nxrg), &
	683	nzb_v_outer(nysg:nyng,nxlg:nxrg), &
	684	nzb_w_inner(nysg:nyng,nxlg:nxrg), &
	685	nzb_w_outer(nysg:nyng,nxlg:nxrg), &
	686	nzb_diff_s_inner(nysg:nyng,nxlg:nxrg), &
	687	nzb_diff_s_outer(nysg:nyng,nxlg:nxrg), &
	688	nzb_local(nysg:nyng,nxlg:nxrg), &
	689	nzb_tmp(nysg:nyng,nxlg:nxrg) )
	690	!
	691	!-- Initialize 2D-index arrays. Note, these will be removed soon!
[4168]	692	nzb_local(nys:nyn,nxl:nxr) = topo_top_ind(nys:nyn,nxl:nxr,0)
[2696]	693	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2968]	694	!
	695	!-- Check topography for consistency with model domain. Therefore, use
	696	!-- maximum and minium topography-top indices. Note, minimum topography top
	697	!-- index is already calculated.
[2696]	698	IF ( TRIM( topography ) /= 'flat' ) THEN
	699	#if defined( __parallel )
[4168]	700	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	701	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	702	#else
[4168]	703	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	704	#endif
[2968]	705	nzb_local_min = topo_min_level
[2696]	706	!
	707	!-- Consistency checks
	708	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	709	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	710	' model domain', &
[3046]	711	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	712	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	713	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	714	ENDIF
	715	ENDIF
[1]	716
	717	nzb_s_inner = nzb; nzb_s_outer = nzb
	718	nzb_u_inner = nzb; nzb_u_outer = nzb
	719	nzb_v_inner = nzb; nzb_v_outer = nzb
	720	nzb_w_inner = nzb; nzb_w_outer = nzb
	721
	722	!
[19]	723	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	724	!-- form (which does not use surface fluxes) is applied
[1691]	725	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	726	nzb_diff = nzb + 2
	727	ELSE
	728	nzb_diff = nzb + 1
	729	ENDIF
	730
	731	nzb_diff_s_inner = nzb_diff; nzb_diff_s_outer = nzb_diff
[2696]	732	!
	733	!-- Set Neumann conditions for topography. Will be removed soon.
	734	IF ( .NOT. bc_ns_cyc ) THEN
	735	IF ( nys == 0 ) THEN
[2927]	736	DO i = 1, nbgp
	737	nzb_local(nys-i,:) = nzb_local(nys,:)
	738	ENDDO
[2696]	739	ELSEIF ( nyn == ny ) THEN
[2927]	740	DO i = 1, nbgp
	741	nzb_local(ny+i,:) = nzb_local(ny,:)
	742	ENDDO
[2696]	743	ENDIF
	744	ENDIF
[1]	745
[2696]	746	IF ( .NOT. bc_lr_cyc ) THEN
	747	IF ( nxl == 0 ) THEN
[2927]	748	DO i = 1, nbgp
	749	nzb_local(:,nxl-i) = nzb_local(:,nxl)
	750	ENDDO
[2696]	751	ELSEIF ( nxr == nx ) THEN
[2927]	752	DO i = 1, nbgp
	753	nzb_local(:,nx+i) = nzb_local(:,nx)
	754	ENDDO
[2696]	755	ENDIF
	756	ENDIF
[1]	757	!
[2696]	758	!-- Initialization of 2D index arrays, will be removed soon!
	759	!-- Initialize nzb_s_inner and nzb_w_inner
	760	nzb_s_inner = nzb_local
	761	nzb_w_inner = nzb_local
	762
	763	!
	764	!-- Initialize remaining index arrays:
	765	!-- first pre-initialize them with nzb_s_inner...
	766	nzb_u_inner = nzb_s_inner
	767	nzb_u_outer = nzb_s_inner
	768	nzb_v_inner = nzb_s_inner
	769	nzb_v_outer = nzb_s_inner
	770	nzb_w_outer = nzb_s_inner
	771	nzb_s_outer = nzb_s_inner
	772
	773	!
	774	!-- nzb_s_outer:
	775	!-- extend nzb_local east-/westwards first, then north-/southwards
	776	nzb_tmp = nzb_local
	777	DO j = nys, nyn
	778	DO i = nxl, nxr
	779	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i), &
	780	nzb_local(j,i+1) )
	781	ENDDO
	782	ENDDO
	783
	784	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	785
	786	DO i = nxl, nxr
	787	DO j = nys, nyn
	788	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	789	nzb_tmp(j+1,i) )
	790	ENDDO
	791	!
	792	!-- non-cyclic boundary conditions (overwritten by call of
	793	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	794	IF ( nys == 0 ) THEN
	795	j = -1
	796	nzb_s_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	797	ENDIF
	798	IF ( nyn == ny ) THEN
	799	j = ny + 1
	800	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	801	ENDIF
	802	ENDDO
	803	!
	804	!-- nzb_w_outer:
	805	!-- identical to nzb_s_outer
	806	nzb_w_outer = nzb_s_outer
	807	!
	808	!-- nzb_u_inner:
	809	!-- extend nzb_local rightwards only
	810	nzb_tmp = nzb_local
	811	DO j = nys, nyn
	812	DO i = nxl, nxr
	813	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i) )
	814	ENDDO
	815	ENDDO
	816
	817	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	818
	819	nzb_u_inner = nzb_tmp
	820	!
	821	!-- nzb_u_outer:
	822	!-- extend current nzb_tmp (nzb_u_inner) north-/southwards
	823	DO i = nxl, nxr
	824	DO j = nys, nyn
	825	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	826	nzb_tmp(j+1,i) )
	827	ENDDO
	828	!
	829	!-- non-cyclic boundary conditions (overwritten by call of
	830	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	831	IF ( nys == 0 ) THEN
	832	j = -1
	833	nzb_u_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	834	ENDIF
	835	IF ( nyn == ny ) THEN
	836	j = ny + 1
	837	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	838	ENDIF
	839	ENDDO
	840
	841	!
	842	!-- nzb_v_inner:
	843	!-- extend nzb_local northwards only
	844	nzb_tmp = nzb_local
	845	DO i = nxl, nxr
	846	DO j = nys, nyn
	847	nzb_tmp(j,i) = MAX( nzb_local(j-1,i), nzb_local(j,i) )
	848	ENDDO
	849	ENDDO
	850
	851	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	852	nzb_v_inner = nzb_tmp
	853
	854	!
	855	!-- nzb_v_outer:
	856	!-- extend current nzb_tmp (nzb_v_inner) right-/leftwards
	857	DO j = nys, nyn
	858	DO i = nxl, nxr
	859	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i), &
	860	nzb_tmp(j,i+1) )
	861	ENDDO
	862	!
	863	!-- non-cyclic boundary conditions (overwritten by call of
	864	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	865	IF ( nxl == 0 ) THEN
	866	i = -1
	867	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i+1), nzb_tmp(j,i) )
	868	ENDIF
	869	IF ( nxr == nx ) THEN
	870	i = nx + 1
	871	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i) )
	872	ENDIF
	873	ENDDO
	874
	875	!
	876	!-- Exchange of lateral boundary values (parallel computers) and cyclic
	877	!-- boundary conditions, if applicable.
	878	!-- Since nzb_s_inner and nzb_w_inner are derived directly from nzb_local
	879	!-- they do not require exchange and are not included here.
	880	CALL exchange_horiz_2d_int( nzb_u_inner, nys, nyn, nxl, nxr, nbgp )
	881	CALL exchange_horiz_2d_int( nzb_u_outer, nys, nyn, nxl, nxr, nbgp )
	882	CALL exchange_horiz_2d_int( nzb_v_inner, nys, nyn, nxl, nxr, nbgp )
	883	CALL exchange_horiz_2d_int( nzb_v_outer, nys, nyn, nxl, nxr, nbgp )
	884	CALL exchange_horiz_2d_int( nzb_w_outer, nys, nyn, nxl, nxr, nbgp )
	885	CALL exchange_horiz_2d_int( nzb_s_outer, nys, nyn, nxl, nxr, nbgp )
	886
	887	!
	888	!-- Set the individual index arrays which define the k index from which on
	889	!-- the usual finite difference form (which does not use surface fluxes) is
	890	!-- applied
	891	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	892	nzb_diff_s_inner = nzb_s_inner + 2
	893	nzb_diff_s_outer = nzb_s_outer + 2
	894	ELSE
	895	nzb_diff_s_inner = nzb_s_inner + 1
	896	nzb_diff_s_outer = nzb_s_outer + 1
	897	ENDIF
	898	!
	899	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	900	!-- coarse grid
	901	IF ( vnested ) CALL vnest_init_grid
	902
	903	END SUBROUTINE init_grid
	904
[3065]	905
[2696]	906	! Description:
	907	! -----------------------------------------------------------------------------!
[3065]	908	!> Calculation of the stretching factor through an iterative method. Ideas were
	909	!> taken from the paper "Regional stretched grid generation and its application
	910	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	911	!> system of equations has two variables (r,l) but four requirements
	912	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	913	!> results into an overdetermined system.
	914	!------------------------------------------------------------------------------!
	915	SUBROUTINE calculate_stretching_factor( number_end )
	916
	917	USE control_parameters, &
[3241]	918	ONLY: dz, dz_stretch_factor_array, &
[3065]	919	dz_stretch_level_end, dz_stretch_level_start, message_string
	920
	921	USE kinds
	922
	923	IMPLICIT NONE
	924
	925	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	926	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	927	INTEGER(iwp) :: n !< loop variable for stretching
	928
	929	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	930
	931	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	932	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	933	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	934	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	935	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	936	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	937	REAL(wp) :: numerator !< numerator of the quotient
	938	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	939	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	940
[3068]	941	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	942
[3065]	943	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06 !< interval for sampling possible stretching factors
	944	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88 !< lowest possible stretching factor
	945	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12 !< highest possible stretching factor
	946
	947
[3068]	948	l = 0
	949	DO n = 1, number_end
	950
	951	iterations = 1
	952	stretch_factor_1 = 1.0
	953	stretch_factor_2 = 1.0
	954	delta_total_old = 1.0
[3065]	955
[3068]	956	IF ( dz(n) > dz(n+1) ) THEN
	957	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	958
	959	stretch_factor_1 = 1.0 - iterations * stretch_factor_interval
	960	distance = ABS( dz_stretch_level_end(n) - &
	961	dz_stretch_level_start(n) )
	962	numerator = distance*stretch_factor_1/dz(n) + &
	963	stretch_factor_1 - distance/dz(n)
	964
	965	IF ( numerator > 0.0 ) THEN
	966	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	967	l_rounded = NINT( l )
	968	delta_l = ABS( l_rounded - l ) / l
	969	ENDIF
	970
	971	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	972
	973	delta_stretch_factor = ABS( stretch_factor_1 - &
	974	stretch_factor_2 ) / &
	975	stretch_factor_2
	976
	977	delta_total_new = delta_l + delta_stretch_factor
[3065]	978
	979	!
	980	!-- stretch_factor_1 is taken to guarantee that the stretching
	981	!-- procedure ends as close as possible to dz_stretch_level_end.
	982	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	983	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	984	IF (delta_total_new < delta_total_old) THEN
	985	dz_stretch_factor_array(n) = stretch_factor_1
	986	dz_stretch_factor_array_2(n) = stretch_factor_2
	987	delta_total_old = delta_total_new
	988	ENDIF
	989
	990	iterations = iterations + 1
	991
	992	ENDDO
	993
	994	ELSEIF ( dz(n) < dz(n+1) ) THEN
	995	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	996
	997	stretch_factor_1 = 1.0 + iterations * stretch_factor_interval
	998	distance = ABS( dz_stretch_level_end(n) - &
	999	dz_stretch_level_start(n) )
	1000	numerator = distance*stretch_factor_1/dz(n) + &
	1001	stretch_factor_1 - distance/dz(n)
	1002
	1003	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1004	l_rounded = NINT( l )
	1005	delta_l = ABS( l_rounded - l ) / l
	1006
	1007	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	1008
[3068]	1009	delta_stretch_factor = ABS( stretch_factor_1 - &
	1010	stretch_factor_2 ) / &
	1011	stretch_factor_2
	1012
	1013	delta_total_new = delta_l + delta_stretch_factor
	1014
[3065]	1015	!
	1016	!-- stretch_factor_1 is taken to guarantee that the stretching
	1017	!-- procedure ends as close as possible to dz_stretch_level_end.
	1018	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1019	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1020	IF (delta_total_new < delta_total_old) THEN
	1021	dz_stretch_factor_array(n) = stretch_factor_1
	1022	dz_stretch_factor_array_2(n) = stretch_factor_2
	1023	delta_total_old = delta_total_new
	1024	ENDIF
[3065]	1025
[3068]	1026	iterations = iterations + 1
	1027	ENDDO
	1028
	1029	ELSE
	1030	message_string= 'Two adjacent values of dz must be different'
	1031	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	1032
	1033	ENDIF
	1034
	1035	!
	1036	!-- Check if also the second stretching factor fits into the allowed
	1037	!-- interval. If not, print a warning for the user.
	1038	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	1039	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	1040	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	1041	dz_stretch_factor_array_2(n), ' which is',&
	1042	' responsible for exactly reaching& dz =',&
	1043	dz(n+1), 'after a specific amount of', &
	1044	' grid levels& exceeds the upper', &
	1045	' limit =', stretch_factor_upper_limit, &
	1046	' &or lower limit = ', &
	1047	stretch_factor_lower_limit
	1048	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	1049
	1050	ENDIF
	1051	ENDDO
[3065]	1052
	1053	END SUBROUTINE calculate_stretching_factor
	1054
	1055
	1056	! Description:
	1057	! -----------------------------------------------------------------------------!
[2696]	1058	!> Set temporary topography flags and reference buildings on top of underlying
	1059	!> orography.
	1060	!------------------------------------------------------------------------------!
	1061	SUBROUTINE process_topography( topo_3d )
	1062
	1063	USE arrays_3d, &
[2747]	1064	ONLY: zu, zw
[2696]	1065
	1066	USE control_parameters, &
[3294]	1067	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	1068
	1069	USE indices, &
	1070	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	1071	nzt
	1072
	1073	USE netcdf_data_input_mod, &
[3115]	1074	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	1075	terrain_height_f
	1076
	1077	USE kinds
	1078
	1079	USE pegrid
	1080
	1081	IMPLICIT NONE
	1082
[2867]	1083	INTEGER(iwp) :: i !< running index along x-direction
	1084	INTEGER(iwp) :: j !< running index along y-direction
	1085	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	1086	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	1087	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	1088	INTEGER(iwp) :: num_build !< counter for number of buildings
	1089	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	1090
	1091	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
	1092	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	1093	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	1094	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	1095	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	1096	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	1097
	1098	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	1099	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	1100
	1101	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	1102
	1103	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	1104	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	1105	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	1106	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	1107
	1108	!
[3103]	1109	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	1110	!-- is non-zero, all grid points of the lower vertical grid levels might be
	1111	!-- entirely below the surface, meaning a waste of computational resources.
	1112	!-- In order to avoid this, remove the lowest terrain height. Please note,
	1113	!-- in case of a nested run, the global minimum from all parent and childs
	1114	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	1115	IF ( input_pids_static ) THEN
[4159]	1116
[3200]	1117	#if defined( __parallel )
[3103]	1118	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	1119	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	1120	#else
	1121	oro_min = MINVAL( terrain_height_f%var )
	1122	#endif
[3103]	1123	terrain_height_f%var = terrain_height_f%var - oro_min
	1124	!
	1125	!-- Give an informative message that terrain height is referenced to zero
	1126	IF ( oro_min > 0.0_wp ) THEN
	1127	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	1128	'downwards by ', oro_min, 'meter(s) to save ' // &
	1129	'computational resources.'
	1130	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	1131	ENDIF
	1132	ENDIF
	1133
	1134	!
[2696]	1135	!-- In the following, buildings and orography are further preprocessed
	1136	!-- before they are mapped on the LES grid.
	1137	!-- Buildings are mapped on top of the orography by maintaining the roof
	1138	!-- shape of the building. This can be achieved by referencing building on
	1139	!-- top of the maximum terrain height within the area occupied by the
	1140	!-- respective building. As buildings and terrain height are defined PE-wise,
	1141	!-- parallelization of this referencing is required (a building can be
	1142	!-- distributed between different PEs).
	1143	!-- In a first step, determine the number of buildings with different
	1144	!-- building id on each PE. In a next step, all building ids are gathered
	1145	!-- into one array which is present to all PEs. For each building ID,
	1146	!-- the maximum terrain height occupied by the respective building is
	1147	!-- computed and distributed to each PE.
	1148	!-- Finally, for each building id and its respective reference orography,
	1149	!-- builidings are mapped on top.
	1150	!--
	1151	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1152	!-- buildings
	1153	!-- classify the respective surfaces.
	1154	topo_3d = IBSET( topo_3d, 0 )
	1155	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1156	!
[3051]	1157	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1158	!-- pre-calculate an offset value.
[3294]	1159	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1160	!
[2696]	1161	!-- Reference buildings on top of orography. This is not necessary
	1162	!-- if topography is read from ASCII file as no distinction between buildings
	1163	!-- and terrain height can be made. Moreover, this is also not necessary if
	1164	!-- urban-surface and land-surface model are used at the same time.
[2897]	1165	IF ( input_pids_static ) THEN
	1166
	1167	IF ( buildings_f%from_file ) THEN
	1168	num_buildings_l = 0
	1169	num_buildings = 0
[2696]	1170	!
[3925]	1171	!-- Allocate at least one element for building ids and give it an inital
	1172	!-- negative value that will be overwritten later. This, however, is
	1173	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1174	ALLOCATE( build_ids_l(1) )
[3925]	1175	build_ids_l = -1
[2897]	1176	DO i = nxl, nxr
	1177	DO j = nys, nyn
	1178	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1179	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1180	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1181	THEN
	1182	CYCLE
	1183	ELSE
	1184	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1185	!
	1186	!-- Resize array with different local building ids
	1187	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1188	build_ids_l_tmp = build_ids_l
	1189	DEALLOCATE( build_ids_l )
	1190	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1191	build_ids_l(1:num_buildings_l(myid)-1) = &
	1192	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1193	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1194	DEALLOCATE( build_ids_l_tmp )
	1195	ENDIF
	1196	!
[2897]	1197	!-- First occuring building id on PE
	1198	ELSE
	1199	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1200	build_ids_l(1) = building_id_f%var(j,i)
	1201	ENDIF
[2696]	1202	ENDIF
[2897]	1203	ENDDO
[2696]	1204	ENDDO
	1205	!
[2897]	1206	!-- Determine number of different building ids for the entire domain
[2696]	1207	#if defined( __parallel )
[2897]	1208	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1209	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1210	#else
[2897]	1211	num_buildings = num_buildings_l
[2696]	1212	#endif
	1213	!
[2897]	1214	!-- Gather all buildings ids on each PEs.
	1215	!-- First, allocate array encompassing all building ids in model domain.
	1216	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1217	#if defined( __parallel )
	1218	!
[2897]	1219	!-- Allocate array for displacements.
	1220	!-- As each PE may has a different number of buildings, so that
	1221	!-- the block sizes send by each PE may not be equal. Hence,
	1222	!-- information about the respective displacement is required, indicating
	1223	!-- the respective adress where each MPI-task writes into the receive
	1224	!-- buffer array
	1225	ALLOCATE( displace_dum(0:numprocs-1) )
	1226	displace_dum(0) = 0
	1227	DO i = 1, numprocs-1
	1228	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1229	ENDDO
[2696]	1230
[2897]	1231	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1232	num_buildings(myid), &
	1233	MPI_INTEGER, &
	1234	build_ids, &
	1235	num_buildings, &
	1236	displace_dum, &
	1237	MPI_INTEGER, &
	1238	comm2d, ierr )
[2696]	1239
[2897]	1240	DEALLOCATE( displace_dum )
[2696]	1241
	1242	#else
[2897]	1243	build_ids = build_ids_l
[2696]	1244	#endif
	1245
	1246	!
[2897]	1247	!-- Note, in parallel mode building ids can occure mutliple times, as
	1248	!-- each PE has send its own ids. Therefore, sort out building ids which
	1249	!-- appear more than one time.
	1250	num_build = 0
	1251	DO nr = 1, SIZE(build_ids)
[2696]	1252
[2897]	1253	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1254	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1255	CYCLE
	1256	ELSE
	1257	num_build = num_build + 1
	1258	!
	1259	!-- Resize
	1260	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1261	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1262	DEALLOCATE( build_ids_final )
	1263	ALLOCATE( build_ids_final(1:num_build) )
	1264	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1265	build_ids_final(num_build) = build_ids(nr)
	1266	DEALLOCATE( build_ids_final_tmp )
	1267	ENDIF
[2696]	1268	ELSE
	1269	num_build = num_build + 1
	1270	ALLOCATE( build_ids_final(1:num_build) )
	1271	build_ids_final(num_build) = build_ids(nr)
[2897]	1272	ENDIF
	1273	ENDDO
[2696]	1274
	1275	!
[3051]	1276	!-- Determine maximumum terrain height occupied by the respective
	1277	!-- building and temporalily store on oro_max
[2897]	1278	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1279	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1280	oro_max_l = 0.0_wp
[2696]	1281
[2897]	1282	DO nr = 1, SIZE(build_ids_final)
[4159]	1283	oro_max_l(nr) = MAXVAL( &
	1284	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1285	0.0_wp, &
	1286	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1287	build_ids_final(nr) ) )
	1288	ENDDO
[2696]	1289
	1290	#if defined( __parallel )
[2897]	1291	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1292	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1293	MPI_MAX, comm2d, ierr )
	1294	ENDIF
[2696]	1295	#else
[2897]	1296	oro_max = oro_max_l
[2696]	1297	#endif
[3051]	1298	!
	1299	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1300	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1301	!-- exceeds the scalar level the grid box is fully terrain and the
	1302	!-- maximum terrain is set to the zw level.
	1303	!-- terrain or
[3051]	1304	oro_max_l = 0.0
	1305	DO nr = 1, SIZE(build_ids_final)
	1306	DO k = nzb, nzt
	1307	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1308	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1309	ENDDO
[3142]	1310	oro_max(nr) = oro_max_l(nr)
[3051]	1311	ENDDO
[2897]	1312	ENDIF
[2696]	1313	!
[2867]	1314	!-- Map orography as well as buildings onto grid.
[2696]	1315	DO i = nxl, nxr
	1316	DO j = nys, nyn
[2867]	1317	topo_top_index = 0
[3142]	1318	!
	1319	!-- Obtain index in global building_id array
	1320	IF ( buildings_f%from_file ) THEN
	1321	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1322	!
	1323	!-- Determine index where maximum terrain height occupied by
	1324	!-- the respective building height is stored.
	1325	nr = MINLOC( ABS( build_ids_final - &
	1326	building_id_f%var(j,i) ), DIM = 1 )
	1327	ENDIF
	1328	ENDIF
[2696]	1329	DO k = nzb, nzt
	1330	!
	1331	!-- In a first step, if grid point is below or equal the given
	1332	!-- terrain height, grid point is flagged to be of type natural.
	1333	!-- Please note, in case there is also a building which is lower
	1334	!-- than the vertical grid spacing, initialization of surface
	1335	!-- attributes will not be correct as given surface information
	1336	!-- will not be in accordance to the classified grid points.
[4159]	1337	!-- Hence, in this case, also a building flag.
[2747]	1338	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1339	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1340	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1341	topo_top_index = k ! topo_top_index + 1
[2696]	1342	ENDIF
	1343	!
	1344	!-- Set building grid points. Here, only consider 2D buildings.
	1345	!-- 3D buildings require separate treatment.
[2897]	1346	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1347	!
	1348	!-- Fill-up the terrain to the level of maximum orography
	1349	!-- within the building-covered area.
	1350	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1351	!
	1352	!-- Note, oro_max is always on zw level
	1353	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1354	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1355	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1356	ELSEIF ( zu(k) - ocean_offset <= &
	1357	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1358	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1359	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1360	ENDIF
	1361	ENDIF
	1362	ENDIF
	1363	ENDDO
	1364	!
[4159]	1365	!-- Special treatment for non grid-resolved buildings. This case,
	1366	!-- the uppermost terrain grid point is flagged as building as well
	1367	!-- well, even though no building exists at all. However, the
	1368	!-- surface element will be identified as urban-surface and the
	1369	!-- input data provided by the drivers is consistent to the surface
	1370	!-- classification. Else, all non grid-resolved buildings would vanish
	1371	!-- and identified as terrain grid points, which, however, won't be
	1372	!-- consistent with the input data.
	1373	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1374	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1375	DO k = nzb, nzt
	1376	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1377	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1378	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1379	ENDIF
	1380	ENDIF
	1381	ENDDO
	1382	ENDIF
	1383	ENDIF
	1384	!
[2696]	1385	!-- Map 3D buildings onto terrain height.
[2867]	1386	!-- In case of any slopes, map building on top of maximum terrain
	1387	!-- height covered by the building. In other words, extend
	1388	!-- building down to the respective local terrain-surface height.
[2897]	1389	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1390	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1391	!
[3051]	1392	!-- Extend building down to the terrain surface, i.e. fill-up
	1393	!-- surface irregularities below a building. Note, oro_max
	1394	!-- is already a discrete height according to the all-or-nothing
	1395	!-- approach, i.e. grid box is either topography or atmosphere,
	1396	!-- terrain top is defined at upper bound of the grid box.
	1397	!-- Hence, check for zw in this case.
[3115]	1398	!-- Note, do this only for buildings which are surface mounted,
	1399	!-- i.e. building types 1-6. Below bridges, which are represented
	1400	!-- exclusively by building type 7, terrain shape should be
	1401	!-- maintained.
[3855]	1402	IF ( building_type_f%from_file ) THEN
	1403	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1404	DO k = topo_top_index + 1, nzt + 1
[4159]	1405	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1406	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1407	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1408	ENDIF
	1409	ENDDO
	1410	!
	1411	!-- After surface irregularities are smoothen, determine
	1412	!-- lower start index where building starts.
	1413	DO k = nzb, nzt
[4159]	1414	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1415	topo_top_index = k
	1416	ENDDO
	1417	ENDIF
[3115]	1418	ENDIF
[3051]	1419	!
	1420	!-- Finally, map building on top.
[2867]	1421	k2 = 0
	1422	DO k = topo_top_index, nzt + 1
[2796]	1423	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1424	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1425	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1426	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1427	ENDIF
	1428	ENDIF
	1429	k2 = k2 + 1
	1430	ENDDO
	1431	ENDIF
	1432	ENDIF
	1433	ENDDO
	1434	ENDDO
	1435	!
	1436	!-- Deallocate temporary arrays required for processing and reading data
	1437	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1438	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1439	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1440	!
	1441	!-- Topography input via ASCII format.
	1442	ELSE
[3294]	1443	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1444	!
	1445	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1446	!-- and clear all grid points at nzb, where alway a surface is defined.
	1447	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1448	!-- used for masked data output and further processing. Note, in the
	1449	!-- ASCII case no distinction is made between buildings and terrain,
	1450	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1451	topo_3d = IBSET( topo_3d, 0 )
	1452	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1453	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1454	DO i = nxl, nxr
	1455	DO j = nys, nyn
	1456	DO k = nzb, nzt
[3538]	1457	!
	1458	!-- Flag topography for all grid points which are below
	1459	!-- the local topography height.
	1460	!-- Note, each topography is flagged as building.
[2747]	1461	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1462	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1463	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1464	ENDIF
	1465	ENDDO
	1466	ENDDO
	1467	ENDDO
	1468	ENDIF
	1469
	1470	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1471
	1472	IF ( .NOT. bc_ns_cyc ) THEN
	1473	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1474	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1475	ENDIF
	1476
	1477	IF ( .NOT. bc_lr_cyc ) THEN
	1478	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1479	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1480	ENDIF
	1481
	1482	END SUBROUTINE process_topography
	1483
	1484
	1485	! Description:
	1486	! -----------------------------------------------------------------------------!
	1487	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1488	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1489	!> equation on discrete grid cannot be fulfilled in such case.
	1490	!------------------------------------------------------------------------------!
	1491	SUBROUTINE filter_topography( topo_3d )
	1492
	1493	USE control_parameters, &
	1494	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1495
	1496	USE indices, &
	1497	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1498
	1499	USE netcdf_data_input_mod, &
	1500	ONLY: building_id_f, building_type_f
	1501
	1502	USE pegrid
	1503
	1504	IMPLICIT NONE
	1505
[2893]	1506	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1507
[2696]	1508	INTEGER(iwp) :: i !< running index along x-direction
	1509	INTEGER(iwp) :: j !< running index along y-direction
	1510	INTEGER(iwp) :: k !< running index along z-direction
	1511	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1512	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1513	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1514
[2955]	1515	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1516	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1517	!
	1518	!-- Before checking for holes, set lateral boundary conditions for
	1519	!-- topography. After hole-filling, boundary conditions must be set again.
	1520	!-- Several iterations are performed, in order to fill holes which might
	1521	!-- emerge by the filling-algorithm itself.
	1522	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1523	topo_tmp = 0
	1524
	1525	num_hole = 99999
	1526	DO WHILE ( num_hole > 0 )
	1527
	1528	num_hole = 0
	1529	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1530	!
	1531	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1532	!-- variable.
	1533	IF ( building_id_f%from_file ) &
	1534	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1535	IF ( building_type_f%from_file ) &
	1536	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1537
	1538	topo_tmp = topo_3d
	1539	!
	1540	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1541	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1542	!-- boundary and some topographic structure will be filled.
	1543	IF ( .NOT. bc_ns_cyc ) THEN
	1544	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1545	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1546	ENDIF
	1547
	1548	IF ( .NOT. bc_lr_cyc ) THEN
	1549	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1550	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1551	ENDIF
	1552
	1553	num_hole_l = 0
	1554	DO i = nxl, nxr
	1555	DO j = nys, nyn
	1556	DO k = nzb+1, nzt
	1557	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1558	num_wall = 0
	1559	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1560	num_wall = num_wall + 1
	1561	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1562	num_wall = num_wall + 1
	1563	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1564	num_wall = num_wall + 1
	1565	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1566	num_wall = num_wall + 1
	1567	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1568	num_wall = num_wall + 1
	1569	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1570	num_wall = num_wall + 1
	1571
	1572	IF ( num_wall >= 4 ) THEN
	1573	num_hole_l = num_hole_l + 1
	1574	!
	1575	!-- Clear flag 0 and set special flag ( bit 3) to indicate
	1576	!-- that new topography point is a result of filtering process.
	1577	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1578	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 3 )
	1579	!
	1580	!-- If filled grid point is occupied by a building, classify
	1581	!-- it as building grid point.
	1582	IF ( building_type_f%from_file ) THEN
	1583	IF ( building_type_f%var(j,i) /= &
	1584	building_type_f%fill .OR. &
	1585	building_type_f%var(j+1,i) /= &
	1586	building_type_f%fill .OR. &
	1587	building_type_f%var(j-1,i) /= &
	1588	building_type_f%fill .OR. &
	1589	building_type_f%var(j,i+1) /= &
	1590	building_type_f%fill .OR. &
	1591	building_type_f%var(j,i-1) /= &
	1592	building_type_f%fill ) THEN
	1593	!
	1594	!-- Set flag indicating building surfaces
	1595	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1596	!
	1597	!-- Set building_type and ID at this position if not
	1598	!-- already set. This is required for proper
	1599	!-- initialization of urban-surface energy balance
	1600	!-- solver.
	1601	IF ( building_type_f%var(j,i) == &
	1602	building_type_f%fill ) THEN
	1603
	1604	IF ( building_type_f%var(j+1,i) /= &
	1605	building_type_f%fill ) THEN
	1606	building_type_f%var(j,i) = &
	1607	building_type_f%var(j+1,i)
	1608	building_id_f%var(j,i) = &
	1609	building_id_f%var(j+1,i)
	1610	ELSEIF ( building_type_f%var(j-1,i) /= &
	1611	building_type_f%fill ) THEN
	1612	building_type_f%var(j,i) = &
	1613	building_type_f%var(j-1,i)
	1614	building_id_f%var(j,i) = &
	1615	building_id_f%var(j-1,i)
	1616	ELSEIF ( building_type_f%var(j,i+1) /= &
	1617	building_type_f%fill ) THEN
	1618	building_type_f%var(j,i) = &
	1619	building_type_f%var(j,i+1)
	1620	building_id_f%var(j,i) = &
	1621	building_id_f%var(j,i+1)
	1622	ELSEIF ( building_type_f%var(j,i-1) /= &
	1623	building_type_f%fill ) THEN
	1624	building_type_f%var(j,i) = &
	1625	building_type_f%var(j,i-1)
	1626	building_id_f%var(j,i) = &
	1627	building_id_f%var(j,i-1)
	1628	ENDIF
	1629	ENDIF
	1630	ENDIF
	1631	ENDIF
	1632	!
	1633	!-- If filled grid point is already classified as building
	1634	!-- everything is fine, else classify this grid point as
	1635	!-- natural type grid point. This case, values for the
	1636	!-- surface type are already set.
	1637	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1638	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1639	ENDIF
	1640	ENDIF
	1641	ENDIF
	1642	ENDDO
	1643	ENDDO
	1644	ENDDO
	1645	!
	1646	!-- Count the total number of holes, required for informative message.
	1647	#if defined( __parallel )
	1648	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1649	comm2d, ierr )
	1650	#else
	1651	num_hole = num_hole_l
	1652	#endif
[2893]	1653	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1654
[2893]	1655	ENDDO
[2696]	1656	!
[2893]	1657	!-- Create an informative message if any holes were filled.
	1658	IF ( filled ) THEN
	1659	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1660	'resolved by only one grid point ' // &
	1661	'were filled during initialization.'
	1662	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1663	ENDIF
[2696]	1664
	1665	DEALLOCATE( topo_tmp )
	1666	!
	1667	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1668	!-- condition in case of non-cyclic lateral boundaries.
	1669	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1670
	1671	IF ( .NOT. bc_ns_cyc ) THEN
	1672	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1673	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1674	ENDIF
	1675
	1676	IF ( .NOT. bc_lr_cyc ) THEN
	1677	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1678	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1679	ENDIF
[2955]	1680	!
	1681	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1682	IF ( building_id_f%from_file ) &
	1683	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1684	IF ( building_type_f%from_file ) &
	1685	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1686
	1687	END SUBROUTINE filter_topography
	1688
	1689
	1690	! Description:
	1691	! -----------------------------------------------------------------------------!
	1692	!> Reads topography information from file or sets generic topography. Moreover,
	1693	!> all topography-relevant topography arrays are initialized, and grid flags
	1694	!> are set.
	1695	!------------------------------------------------------------------------------!
	1696	SUBROUTINE init_topo( topo )
	1697
	1698	USE arrays_3d, &
	1699	ONLY: zw
	1700
	1701	USE control_parameters, &
	1702	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1703	building_length_y, building_wall_left, building_wall_south, &
	1704	canyon_height, canyon_wall_left, canyon_wall_south, &
	1705	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1706	message_string, topography, topography_grid_convention, &
[2696]	1707	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1708	tunnel_wall_depth
	1709
	1710	USE grid_variables, &
	1711	ONLY: dx, dy
	1712
	1713	USE indices, &
	1714	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1715	nzb, nzt
	1716
	1717	USE kinds
[4189]	1718
	1719	USE netcdf_data_input_mod, &
	1720	ONLY: buildings_f, terrain_height_f
[2696]	1721
	1722	USE pegrid
	1723
	1724	IMPLICIT NONE
	1725
	1726	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1727	INTEGER(iwp) :: blx !< grid point number of building size along x
	1728	INTEGER(iwp) :: bly !< grid point number of building size along y
	1729	INTEGER(iwp) :: bxl !< index for left building wall
	1730	INTEGER(iwp) :: bxr !< index for right building wall
	1731	INTEGER(iwp) :: byn !< index for north building wall
	1732	INTEGER(iwp) :: bys !< index for south building wall
	1733	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1734	INTEGER(iwp) :: cwx !< grid point number of canyon size along x
	1735	INTEGER(iwp) :: cwy !< grid point number of canyon size along y
	1736	INTEGER(iwp) :: cxl !< index for left canyon wall
	1737	INTEGER(iwp) :: cxr !< index for right canyon wall
	1738	INTEGER(iwp) :: cyn !< index for north canyon wall
	1739	INTEGER(iwp) :: cys !< index for south canyon wall
	1740	INTEGER(iwp) :: i !< index variable along x
	1741	INTEGER(iwp) :: j !< index variable along y
	1742	INTEGER(iwp) :: k !< index variable along z
	1743	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1744	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1745	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1746	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1747	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1748	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1749	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1750	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1751	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1752	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1753	INTEGER(iwp) :: td !< tunnel wall depth
	1754	INTEGER(iwp) :: th !< height of outer tunnel wall
	1755
	1756	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1757	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1758	!
[4189]	1759	!-- Check for correct setting of the namelist parameter topography. If
	1760	!-- topography information is read from file but topography = 'flat',
	1761	!-- initialization does not properly.
	1762	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1763	TRIM( topography ) /= 'read_from_file' ) THEN
	1764	message_string = 'If topography information is provided (via ' // &
	1765	'Netcdf or ASCII input) topography = ' // &
	1766	'"read_from_file" is required.'
	1767	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1768	ENDIF
	1769	!
[1]	1770	!-- Set outer and inner index arrays for non-flat topography.
	1771	!-- Here consistency checks concerning domain size and periodicity are
	1772	!-- necessary.
	1773	!-- Within this SELECT CASE structure only nzb_local is initialized
	1774	!-- individually depending on the chosen topography type, all other index
	1775	!-- arrays are initialized further below.
	1776	SELECT CASE ( TRIM( topography ) )
	1777
	1778	CASE ( 'flat' )
[2696]	1779	!
[2232]	1780	!-- Initialilize 3D topography array, used later for initializing flags
[2696]	1781	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
[1]	1782
	1783	CASE ( 'single_building' )
	1784	!
	1785	!-- Single rectangular building, by default centered in the middle of the
	1786	!-- total domain
	1787	blx = NINT( building_length_x / dx )
	1788	bly = NINT( building_length_y / dy )
[2232]	1789	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1790	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1791	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1792	IF ( building_wall_left == 9999999.9_wp ) THEN
[1]	1793	building_wall_left = ( nx + 1 - blx ) / 2 * dx
	1794	ENDIF
	1795	bxl = NINT( building_wall_left / dx )
	1796	bxr = bxl + blx
	1797
[1322]	1798	IF ( building_wall_south == 9999999.9_wp ) THEN
[2696]	1799	building_wall_south = ( ny + 1 - bly ) / 2 * dy
[1]	1800	ENDIF
	1801	bys = NINT( building_wall_south / dy )
	1802	byn = bys + bly
	1803
	1804	!
	1805	!-- Building size has to meet some requirements
[2696]	1806	IF ( ( bxl < 1 ) .OR. ( bxr > nx-1 ) .OR. ( bxr < bxl+3 ) .OR. &
[1]	1807	( bys < 1 ) .OR. ( byn > ny-1 ) .OR. ( byn < bys+3 ) ) THEN
[274]	1808	WRITE( message_string, * ) 'inconsistent building parameters:', &
[3046]	1809	'&bxl=', bxl, 'bxr=', bxr, 'bys=', bys, &
[274]	1810	'byn=', byn, 'nx=', nx, 'ny=', ny
[254]	1811	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1812	ENDIF
	1813
[2696]	1814	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1815	nzb_local = 0
[1]	1816	!
[1968]	1817	!-- Define the building.
	1818	IF ( bxl <= nxr .AND. bxr >= nxl .AND. &
[2696]	1819	bys <= nyn .AND. byn >= nys ) &
[1968]	1820	nzb_local(MAX(nys,bys):MIN(nyn,byn),MAX(nxl,bxl):MIN(nxr,bxr)) = bh
[2232]	1821	!
[2696]	1822	!-- Set bit array on basis of nzb_local
	1823	DO i = nxl, nxr
	1824	DO j = nys, nyn
	1825	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1826	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1827	ENDDO
	1828	ENDDO
[2696]	1829
	1830	DEALLOCATE( nzb_local )
[2232]	1831
[2696]	1832	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1833	!
	1834	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1835	!-- boundary conditions for topography.
	1836	IF ( .NOT. bc_ns_cyc ) THEN
	1837	IF ( nys == 0 ) THEN
	1838	DO i = 1, nbgp
	1839	topo(:,nys-i,:) = topo(:,nys,:)
	1840	ENDDO
	1841	ENDIF
	1842	IF ( nyn == ny ) THEN
	1843	DO i = 1, nbgp
	1844	topo(:,nyn+i,:) = topo(:,nyn,:)
	1845	ENDDO
	1846	ENDIF
	1847	ENDIF
	1848	IF ( .NOT. bc_lr_cyc ) THEN
	1849	IF ( nxl == 0 ) THEN
	1850	DO i = 1, nbgp
	1851	topo(:,:,nxl-i) = topo(:,:,nxl)
	1852	ENDDO
	1853	ENDIF
	1854	IF ( nxr == nx ) THEN
	1855	DO i = 1, nbgp
	1856	topo(:,:,nxr+i) = topo(:,:,nxr)
	1857	ENDDO
	1858	ENDIF
	1859	ENDIF
[2232]	1860
[240]	1861	CASE ( 'single_street_canyon' )
	1862	!
	1863	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1864	!-- The canyon is centered in the other direction by default.
[1322]	1865	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1866	!
	1867	!-- Street canyon in y direction
	1868	cwx = NINT( canyon_width_x / dx )
[1322]	1869	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[240]	1870	canyon_wall_left = ( nx + 1 - cwx ) / 2 * dx
	1871	ENDIF
	1872	cxl = NINT( canyon_wall_left / dx )
	1873	cxr = cxl + cwx
[1322]	1874	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1875	!
	1876	!-- Street canyon in x direction
	1877	cwy = NINT( canyon_width_y / dy )
[1322]	1878	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[240]	1879	canyon_wall_south = ( ny + 1 - cwy ) / 2 * dy
	1880	ENDIF
	1881	cys = NINT( canyon_wall_south / dy )
	1882	cyn = cys + cwy
[2696]	1883
[240]	1884	ELSE
[254]	1885
	1886	message_string = 'no street canyon width given'
	1887	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1888
[240]	1889	ENDIF
	1890
[2232]	1891	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1892	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1893	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1894	dp_level_ind_b = ch
	1895	!
	1896	!-- Street canyon size has to meet some requirements
[1322]	1897	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1353]	1898	IF ( ( cxl < 1 ) .OR. ( cxr > nx-1 ) .OR. ( cwx < 3 ) .OR. &
[2696]	1899	( ch < 3 ) ) THEN
[1353]	1900	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1901	'&cxl=', cxl, ' cxr=', cxr, &
[3045]	1902	' cwx=', cwx, &
	1903	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1904	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1905	ENDIF
[1322]	1906	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1353]	1907	IF ( ( cys < 1 ) .OR. ( cyn > ny-1 ) .OR. ( cwy < 3 ) .OR. &
[2696]	1908	( ch < 3 ) ) THEN
[1353]	1909	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1910	'&cys=', cys, ' cyn=', cyn, &
[3045]	1911	' cwy=', cwy, &
	1912	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1913	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1914	ENDIF
	1915	ENDIF
[1353]	1916	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1917	canyon_width_y /= 9999999.9_wp ) THEN
	1918	message_string = 'inconsistent canyon parameters:' // &
[3046]	1919	'&street canyon can only be oriented' // &
[3045]	1920	' either in x- or in y-direction'
[254]	1921	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1922	ENDIF
	1923
[2696]	1924	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	1925	nzb_local = ch
[1322]	1926	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1968]	1927	IF ( cxl <= nxr .AND. cxr >= nxl ) &
	1928	nzb_local(:,MAX(nxl,cxl+1):MIN(nxr,cxr-1)) = 0
[1322]	1929	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1968]	1930	IF ( cys <= nyn .AND. cyn >= nys ) &
	1931	nzb_local(MAX(nys,cys+1):MIN(nyn,cyn-1),:) = 0
[240]	1932	ENDIF
[2232]	1933	!
[2696]	1934	!-- Set bit array on basis of nzb_local
	1935	DO i = nxl, nxr
	1936	DO j = nys, nyn
	1937	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1938	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1939	ENDDO
	1940	ENDDO
[2696]	1941	DEALLOCATE( nzb_local )
[1994]	1942
[2696]	1943	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1944	!
	1945	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1946	!-- boundary conditions for topography.
	1947	IF ( .NOT. bc_ns_cyc ) THEN
	1948	IF ( nys == 0 ) THEN
	1949	DO i = 1, nbgp
	1950	topo(:,nys-i,:) = topo(:,nys,:)
	1951	ENDDO
	1952	ENDIF
	1953	IF ( nyn == ny ) THEN
	1954	DO i = 1, nbgp
	1955	topo(:,nyn+i,:) = topo(:,nyn,:)
	1956	ENDDO
	1957	ENDIF
	1958	ENDIF
	1959	IF ( .NOT. bc_lr_cyc ) THEN
	1960	IF ( nxl == 0 ) THEN
	1961	DO i = 1, nbgp
	1962	topo(:,:,nxl-i) = topo(:,:,nxl)
	1963	ENDDO
	1964	ENDIF
	1965	IF ( nxr == nx ) THEN
	1966	DO i = 1, nbgp
	1967	topo(:,:,nxr+i) = topo(:,:,nxr)
	1968	ENDDO
	1969	ENDIF
	1970	ENDIF
[2232]	1971
	1972	CASE ( 'tunnel' )
	1973
	1974	!
	1975	!-- Tunnel height
	1976	IF ( tunnel_height == 9999999.9_wp ) THEN
	1977	th = zw( INT( 0.2 * nz) )
	1978	ELSE
	1979	th = tunnel_height
	1980	ENDIF
	1981	!
	1982	!-- Tunnel-wall depth
[2696]	1983	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	1984	td = MAX ( dx, dy, dz(1) )
[2232]	1985	ELSE
	1986	td = tunnel_wall_depth
	1987	ENDIF
	1988	!
	1989	!-- Check for tunnel width
	1990	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	1991	tunnel_width_y == 9999999.9_wp ) THEN
	1992	message_string = 'No tunnel width is given. '
[2274]	1993	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	1994	ENDIF
	1995	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	1996	tunnel_width_y /= 9999999.9_wp ) THEN
	1997	message_string = 'Inconsistent tunnel parameters:' // &
	1998	'tunnel can only be oriented' // &
	1999	'either in x- or in y-direction.'
[2274]	2000	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	2001	ENDIF
	2002	!
	2003	!-- Tunnel axis along y
	2004	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	2005	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
	2006	message_string = 'Tunnel width too large'
[2274]	2007	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	2008	ENDIF
	2009
	2010	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	2011	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	2012	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	2013	( tunnel_width_x * 0.5_wp - td ) )
	2014	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	2015	( tunnel_width_x * 0.5_wp - td ) )
[2232]	2016
	2017	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	2018	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	2019	tys_in = tys_out
	2020	tye_in = tye_out
	2021	ENDIF
[2696]	2022	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2023	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) &
	2024	THEN
[2232]	2025	message_string = 'Tunnel width too small'
[2274]	2026	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
[2232]	2027	ENDIF
	2028	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
[2696]	2029	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) &
	2030	THEN
[2232]	2031	message_string = 'Tunnel width too small'
[2274]	2032	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
[2232]	2033	ENDIF
	2034	!
	2035	!-- Tunnel axis along x
	2036	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	2037	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
	2038	message_string = 'Tunnel width too large'
[2274]	2039	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	2040	ENDIF
	2041
	2042	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	2043	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	2044	txs_in = txs_out
	2045	txe_in = txe_out
	2046
	2047	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	2048	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	2049	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	2050	( tunnel_width_y * 0.5_wp - td ) )
[2232]	2051	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	2052	( tunnel_width_y * 0.5_wp - td ) )
	2053	ENDIF
	2054
[2696]	2055	topo = 0
[2232]	2056	DO i = nxl, nxr
	2057	DO j = nys, nyn
	2058	!
	2059	!-- Use heaviside function to model outer tunnel surface
	2060	hv_out = th * 0.5_wp * &
	2061	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	2062	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	2063
	2064	hv_out = hv_out * 0.5_wp * &
	2065	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	2066	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	2067	!
[2232]	2068	!-- Use heaviside function to model inner tunnel surface
	2069	hv_in = ( th - td ) * 0.5_wp * &
	2070	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	2071	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	2072
	2073	hv_in = hv_in * 0.5_wp * &
	2074	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	2075	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	2076	!
	2077	!-- Set flags at x-y-positions without any tunnel surface
	2078	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	2079	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	2080	!
	2081	!-- Set flags at x-y-positions with tunnel surfaces
	2082	ELSE
	2083	DO k = nzb + 1, nzt + 1
	2084	!
	2085	!-- Inner tunnel
	2086	IF ( hv_out - hv_in == th ) THEN
	2087	IF ( zw(k) <= hv_out ) THEN
[2696]	2088	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2089	ELSE
[2696]	2090	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2091	ENDIF
	2092	ENDIF
	2093	!
	2094	!-- Lateral tunnel walls
	2095	IF ( hv_out - hv_in == td ) THEN
	2096	IF ( zw(k) <= hv_in ) THEN
[2696]	2097	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2098	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	2099	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2100	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	2101	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2102	ENDIF
	2103	ENDIF
	2104	ENDDO
	2105	ENDIF
	2106	ENDDO
	2107	ENDDO
	2108
[2696]	2109	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2110	!
	2111	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2112	!-- boundary conditions for topography.
	2113	IF ( .NOT. bc_ns_cyc ) THEN
	2114	IF ( nys == 0 ) THEN
	2115	DO i = 1, nbgp
	2116	topo(:,nys-i,:) = topo(:,nys,:)
	2117	ENDDO
	2118	ENDIF
	2119	IF ( nyn == ny ) THEN
	2120	DO i = 1, nbgp
	2121	topo(:,nyn+i,:) = topo(:,nyn,:)
	2122	ENDDO
	2123	ENDIF
	2124	ENDIF
	2125	IF ( .NOT. bc_lr_cyc ) THEN
	2126	IF ( nxl == 0 ) THEN
	2127	DO i = 1, nbgp
	2128	topo(:,:,nxl-i) = topo(:,:,nxl)
	2129	ENDDO
	2130	ENDIF
	2131	IF ( nxr == nx ) THEN
	2132	DO i = 1, nbgp
	2133	topo(:,:,nxr+i) = topo(:,:,nxr)
	2134	ENDDO
	2135	ENDIF
	2136	ENDIF
[2232]	2137
[1]	2138	CASE ( 'read_from_file' )
	2139	!
[2696]	2140	!-- Note, topography information have been already read.
	2141	!-- If required, further process topography, i.e. reference buildings on
	2142	!-- top of orography and set temporary 3D topography array, which is
	2143	!-- used later to set grid flags. Calling of this rouinte is also
	2144	!-- required in case of ASCII input, even though no distinction between
	2145	!-- terrain- and building height is made in this case.
	2146	CALL process_topography( topo )
[1968]	2147	!
[2696]	2148	!-- Filter holes resolved by only one grid-point
	2149	CALL filter_topography( topo )
[1968]	2150	!
[2696]	2151	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2152	!-- conditions.
	2153	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2154	!
[2696]	2155	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2156	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2157	IF ( nys == 0 ) THEN
[2696]	2158	DO i = 1, nbgp
	2159	topo(:,nys-i,:) = topo(:,nys,:)
	2160	ENDDO
[2550]	2161	ENDIF
[2696]	2162	IF ( nyn == ny ) THEN
	2163	DO i = 1, nbgp
	2164	topo(:,nyn+i,:) = topo(:,nyn,:)
	2165	ENDDO
	2166	ENDIF
[1942]	2167	ENDIF
[1910]	2168
[1968]	2169	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2170	IF ( nxl == 0 ) THEN
[2696]	2171	DO i = 1, nbgp
	2172	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2173	ENDDO
[2696]	2174	ENDIF
	2175	IF ( nxr == nx ) THEN
	2176	DO i = 1, nbgp
	2177	topo(:,:,nxr+i) = topo(:,:,nxr)
	2178	ENDDO
	2179	ENDIF
[2232]	2180	ENDIF
	2181
[667]	2182
[1]	2183	CASE DEFAULT
[2696]	2184	!
[1]	2185	!-- The DEFAULT case is reached either if the parameter topography
[217]	2186	!-- contains a wrong character string or if the user has defined a special
[1]	2187	!-- case in the user interface. There, the subroutine user_init_grid
	2188	!-- checks which of these two conditions applies.
[2696]	2189	CALL user_init_grid( topo )
	2190	CALL filter_topography( topo )
[1]	2191
	2192	END SELECT
	2193	!
	2194	!-- Consistency checks and index array initialization are only required for
[2696]	2195	!-- non-flat topography.
[1]	2196	IF ( TRIM( topography ) /= 'flat' ) THEN
	2197	!
[2232]	2198	!-- In case of non-flat topography, check whether the convention how to
	2199	!-- define the topography grid has been set correctly, or whether the default
	2200	!-- is applicable. If this is not possible, abort.
	2201	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
	2202	IF ( TRIM( topography ) /= 'single_building' .AND. &
	2203	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2204	TRIM( topography ) /= 'tunnel' .AND. &
	2205	TRIM( topography ) /= 'read_from_file') THEN
	2206	!-- The default value is not applicable here, because it is only valid
[3045]	2207	!-- for the four standard cases 'single_building',
	2208	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2209	!-- defined in init_grid.
	2210	WRITE( message_string, * ) &
[2696]	2211	'The value for "topography_grid_convention" ', &
[3046]	2212	'is not set. Its default value is & only valid for ', &
[3045]	2213	'"topography" = ''single_building'', ''tunnel'' ', &
[3046]	2214	'''single_street_canyon'' & or ''read_from_file''.', &
	2215	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2216	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2217	ELSE
	2218	!-- The default value is applicable here.
	2219	!-- Set convention according to topography.
	2220	IF ( TRIM( topography ) == 'single_building' .OR. &
	2221	TRIM( topography ) == 'single_street_canyon' ) THEN
	2222	topography_grid_convention = 'cell_edge'
	2223	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2224	TRIM( topography ) == 'tunnel') THEN
	2225	topography_grid_convention = 'cell_center'
	2226	ENDIF
	2227	ENDIF
	2228	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2229	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2230	WRITE( message_string, * ) &
[2696]	2231	'The value for "topography_grid_convention" is ', &
[3046]	2232	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2233	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2234	ENDIF
[1]	2235
[2169]	2236
[217]	2237	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2238	!
[217]	2239	!-- The array nzb_local as defined using the 'cell_edge' convention
	2240	!-- describes the actual total size of topography which is defined at the
	2241	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2242	!-- on the topography walls in y-direction. However, PALM uses individual
	2243	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2244	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2245	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2246	!-- to form the basis for nzb_s_inner.
	2247	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2248	!-- required at this point.
	2249	DO j = nys+1, nyn+1
	2250	DO i = nxl-1, nxr
[2232]	2251	DO k = nzb, nzt+1
[2696]	2252	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2253	BTEST( topo(k,j,i+1), 0 ) ) &
	2254	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2255	ENDDO
	2256	ENDDO
	2257	ENDDO
[2696]	2258	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2259
	2260	DO i = nxl, nxr+1
	2261	DO j = nys-1, nyn
	2262	DO k = nzb, nzt+1
[2696]	2263	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2264	BTEST( topo(k,j+1,i), 0 ) ) &
	2265	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2266	ENDDO
	2267	ENDDO
	2268	ENDDO
[2696]	2269	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2270
[217]	2271	ENDIF
[2696]	2272	ENDIF
[2232]	2273
[1]	2274
[2696]	2275	END SUBROUTINE init_topo
[1]	2276
[2696]	2277	SUBROUTINE set_topo_flags(topo)
[1]	2278
[2696]	2279	USE control_parameters, &
	2280	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, land_surface, &
[4189]	2281	scalar_advec, topography, use_surface_fluxes, use_top_fluxes, &
	2282	urban_surface
[1]	2283
[2696]	2284	USE indices, &
[3241]	2285	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4168]	2286	nzt, topo_top_ind, wall_flags_0
[1]	2287
[2696]	2288	USE kinds
[1]	2289
[2696]	2290	IMPLICIT NONE
[1804]	2291
[2696]	2292	INTEGER(iwp) :: i !< index variable along x
[4168]	2293	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2294	INTEGER(iwp) :: j !< index variable along y
	2295	INTEGER(iwp) :: k !< index variable along z
[1]	2296
[2696]	2297	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2298
[2696]	2299	ALLOCATE( wall_flags_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2300	wall_flags_0 = 0
[2232]	2301	!
[2696]	2302	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2303	!-- Further special flags will be set in following loops.
[2232]	2304	DO i = nxl, nxr
	2305	DO j = nys, nyn
	2306	DO k = nzb, nzt+1
	2307	!
	2308	!-- scalar grid
[2696]	2309	IF ( BTEST( topo(k,j,i), 0 ) ) &
[2232]	2310	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 0 )
	2311	!
[2696]	2312	!-- u grid
	2313	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2314	BTEST( topo(k,j,i-1), 0 ) ) &
	2315	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 1 )
	2316	!
[2232]	2317	!-- v grid
[2696]	2318	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2319	BTEST( topo(k,j-1,i), 0 ) ) &
	2320	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 2 )
	2321
[2232]	2322	ENDDO
[1]	2323
[2232]	2324	DO k = nzb, nzt
[1]	2325	!
[2232]	2326	!-- w grid
[2696]	2327	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2328	BTEST( topo(k+1,j,i), 0 ) ) &
[2232]	2329	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 3 )
	2330	ENDDO
	2331	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 3 )
	2332
	2333	ENDDO
	2334	ENDDO
[2696]	2335
[2867]	2336	CALL exchange_horiz_int( wall_flags_0, nys, nyn, nxl, nxr, nzt, nbgp )
[1]	2337	!
[4115]	2338	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2339	!-- basis of flag 24 futher flags will be derived which are used to control
	2340	!-- production of subgrid TKE production near walls.
[2696]	2341	DO i = nxl, nxr
	2342	DO j = nys, nyn
[2232]	2343	DO k = nzb, nzt+1
[4115]	2344	IF ( BTEST( wall_flags_0(k,j-1,i), 0 ) .AND. &
	2345	BTEST( wall_flags_0(k,j+1,i), 0 ) .AND. &
	2346	BTEST( wall_flags_0(k,j,i-1), 0 ) .AND. &
	2347	BTEST( wall_flags_0(k,j,i+1), 0 ) .AND. &
	2348	BTEST( wall_flags_0(k,j-1,i-1), 0 ) .AND. &
	2349	BTEST( wall_flags_0(k,j+1,i-1), 0 ) .AND. &
	2350	BTEST( wall_flags_0(k,j-1,i+1), 0 ) .AND. &
	2351	BTEST( wall_flags_0(k,j+1,i+1), 0 ) ) &
[2696]	2352	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 24 )
[2232]	2353	ENDDO
	2354	ENDDO
	2355	ENDDO
[1]	2356	!
[2232]	2357	!-- Set further special flags
	2358	DO i = nxl, nxr
	2359	DO j = nys, nyn
	2360	DO k = nzb, nzt+1
[1]	2361	!
[2232]	2362	!-- scalar grid, former nzb_diff_s_inner.
	2363	!-- Note, use this flag also to mask topography in diffusion_u and
	2364	!-- diffusion_v along the vertical direction. In case of
	2365	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2366	!-- gradient approach is applied. Please note, in case of u- and v-
	2367	!-- diffuison, a small error is made at edges (on the east side for u,
	2368	!-- at the north side for v), since topography on scalar grid point
	2369	!-- is used instead of topography on u/v-grid. As number of topography grid
	2370	!-- points on uv-grid is different than s-grid, different number of
	2371	!-- surface elements would be required. In order to avoid this,
	2372	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2373	!-- points are not masked within diffusion_u. Tests had shown that the
	2374	!-- effect on the flow is negligible.
	2375	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2376	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2377	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	2378	ELSE
	2379	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	2380	ENDIF
[1]	2381
[2232]	2382	ENDDO
	2383	!
	2384	!-- Special flag to control vertical diffusion at model top - former
	2385	!-- nzt_diff
	2386	wall_flags_0(:,j,i) = IBSET( wall_flags_0(:,j,i), 9 )
	2387	IF ( use_top_fluxes ) &
[2478]	2388	wall_flags_0(nzt+1,j,i) = IBCLR( wall_flags_0(nzt+1,j,i), 9 )
[1]	2389
[2696]	2390
[2232]	2391	DO k = nzb+1, nzt
	2392	!
	2393	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2394	!-- for disturb_field and initialization. Do not disturb directly at
	2395	!-- topography, as well as initialize u with zero one grid point outside
	2396	!-- of topography.
	2397	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	2398	BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	2399	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	2400	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 20 )
	2401	!
	2402	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2403	!-- for disturb_field and initialization. Do not disturb directly at
	2404	!-- topography, as well as initialize v with zero one grid point outside
	2405	!-- of topography.
	2406	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	2407	BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	2408	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	2409	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 21 )
	2410	!
	2411	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2412	!-- lpm_sgs_tke
	2413	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2414	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2415	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2416	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 25 )
	2417	!
	2418	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2419	!-- in production_e
	2420	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2421	IF ( BTEST( wall_flags_0(k,j,i), 24 ) .AND. &
	2422	BTEST( wall_flags_0(k-1,j,i), 24 ) .AND. &
	2423	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2424	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
	2425	ELSE
	2426	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2427	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
[1]	2428	ENDIF
[2232]	2429	!
	2430	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2431	!-- in production_e
	2432	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2433	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2434	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2435	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2436	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	2437	ELSE
	2438	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2439	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	2440	ENDIF
	2441	ENDDO
	2442	!
	2443	!-- Flags indicating downward facing walls
	2444	DO k = nzb+1, nzt
	2445	!
	2446	!-- Scalar grid
	2447	IF ( BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2448	.NOT. BTEST( wall_flags_0(k,j,i), 0 ) ) &
[2696]	2449	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 13 )
[2232]	2450	!
	2451	!-- Downward facing wall on u grid
	2452	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	2453	.NOT. BTEST( wall_flags_0(k,j,i), 1 ) ) &
	2454	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 15 )
	2455	!
	2456	!-- Downward facing wall on v grid
	2457	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	2458	.NOT. BTEST( wall_flags_0(k,j,i), 2 ) ) &
	2459	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 17 )
	2460	!
	2461	!-- Downward facing wall on w grid
	2462	IF ( BTEST( wall_flags_0(k-1,j,i), 3 ) .AND. &
	2463	.NOT. BTEST( wall_flags_0(k,j,i), 3 ) ) &
	2464	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 19 )
	2465	ENDDO
	2466	!
	2467	!-- Flags indicating upward facing walls
	2468	DO k = nzb, nzt
	2469	!
	2470	!-- Upward facing wall on scalar grid
	2471	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2472	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2473	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 12 )
	2474	!
	2475	!-- Upward facing wall on u grid
	2476	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	2477	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	2478	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 14 )
[1]	2479
[2696]	2480	!
[2232]	2481	!-- Upward facing wall on v grid
	2482	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	2483	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	2484	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 16 )
[2696]	2485
[2232]	2486	!
	2487	!-- Upward facing wall on w grid
	2488	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 3 ) .AND. &
	2489	BTEST( wall_flags_0(k+1,j,i), 3 ) ) &
	2490	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 18 )
	2491	!
	2492	!-- Special flag on scalar grid, former nzb_s_inner
	2493	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .OR. &
	2494	BTEST( wall_flags_0(k,j,i), 12 ) .OR. &
	2495	BTEST( wall_flags_0(k,j,i), 13 ) ) &
[2696]	2496	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 22 )
[2232]	2497	!
	2498	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2499	!-- flow_statistics
	2500	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2501	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2502	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
[2696]	2503	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
[2232]	2504	ELSE
	2505	IF ( BTEST( wall_flags_0(k,j,i), 22 ) ) &
	2506	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
[1]	2507	ENDIF
[2696]	2508
[1]	2509
[2232]	2510	ENDDO
	2511	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 22 )
	2512	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 23 )
[4109]	2513	!
	2514	!-- Set flags indicating that topography is close by in horizontal
	2515	!-- direction, i.e. flags that infold the topography. These will be used
	2516	!-- to set advection flags for passive scalars, where due to large
	2517	!-- gradients near buildings stationary numerical oscillations can produce
	2518	!-- unrealistically high concentrations. This is only necessary if
	2519	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2520	!-- only used for passive scalars such as chemical species or aerosols.
	2521	IF ( scalar_advec == 'ws-scheme' ) THEN
	2522	DO k = nzb, nzt
	2523	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. ( &
	2524	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2525	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2526	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2527	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2528	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2529	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2530	ANY( .NOT. BTEST( wall_flags_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2531	ANY( .NOT. BTEST( wall_flags_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2532	ANY( .NOT. BTEST( wall_flags_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2533	ANY( .NOT. BTEST( wall_flags_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2534	ANY( .NOT. BTEST( wall_flags_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2535	ANY( .NOT. BTEST( wall_flags_0(k,j+3,i-3:i+3), 0 ) ) &
	2536	) ) &
	2537	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 31 )
	2538
	2539	ENDDO
	2540	ENDIF
[2232]	2541	ENDDO
	2542	ENDDO
	2543	!
[2696]	2544	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2545	!-- Natural terrain grid points. Information on the type of the surface is
	2546	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2547	!-- when topography is read from file. In order to run the land-surface model
	2548	!-- also without topography information, set bit 1 explicitely in this case.
[2696]	2549	IF ( land_surface ) THEN
	2550	!
[4189]	2551	!-- If no topography is initialized, the land-surface is at k = nzb.
	2552	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
	2553	wall_flags_0(nzb,:,:) = IBSET( wall_flags_0(nzb,:,:), 5 )
	2554	ELSE
	2555	DO i = nxl, nxr
	2556	DO j = nys, nyn
	2557	DO k = nzb, nzt+1
	2558	!
	2559	!-- Natural terrain grid point
	2560	IF ( BTEST( topo(k,j,i), 1 ) ) &
	2561	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 5 )
	2562	ENDDO
[2696]	2563	ENDDO
	2564	ENDDO
[4189]	2565	ENDIF
[2696]	2566	ENDIF
	2567	!
	2568	!-- Building grid points.
	2569	IF ( urban_surface ) THEN
	2570	DO i = nxl, nxr
	2571	DO j = nys, nyn
	2572	DO k = nzb, nzt+1
	2573	IF ( BTEST( topo(k,j,i), 2 ) ) &
	2574	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 6 )
	2575	ENDDO
	2576	ENDDO
	2577	ENDDO
	2578	ENDIF
	2579	!
[2232]	2580	!-- Exchange ghost points for wall flags
[2696]	2581	CALL exchange_horiz_int( wall_flags_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2582	!
	2583	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2584	!-- boundary conditions for topography.
	2585	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2586	IF ( nys == 0 ) THEN
	2587	DO i = 1, nbgp
	2588	wall_flags_0(:,nys-i,:) = wall_flags_0(:,nys,:)
	2589	ENDDO
	2590	ENDIF
	2591	IF ( nyn == ny ) THEN
	2592	DO i = 1, nbgp
	2593	wall_flags_0(:,nyn+i,:) = wall_flags_0(:,nyn,:)
	2594	ENDDO
	2595	ENDIF
[2232]	2596	ENDIF
	2597	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2598	IF ( nxl == 0 ) THEN
	2599	DO i = 1, nbgp
	2600	wall_flags_0(:,:,nxl-i) = wall_flags_0(:,:,nxl)
	2601	ENDDO
[2232]	2602	ENDIF
[2696]	2603	IF ( nxr == nx ) THEN
	2604	DO i = 1, nbgp
	2605	wall_flags_0(:,:,nxr+i) = wall_flags_0(:,:,nxr)
[2232]	2606	ENDDO
[2696]	2607	ENDIF
[2232]	2608	ENDIF
[4168]	2609	!
	2610	!-- Pre-calculate topography top indices (former get_topography_top_index
	2611	!-- function)
	2612	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2613	!
	2614	!-- Uppermost topography index on scalar grid
	2615	ibit = 12
	2616	topo_top_ind(:,:,0) = MAXLOC( &
	2617	MERGE( 1, 0, &
	2618	BTEST( wall_flags_0(:,:,:), ibit ) &
	2619	), DIM = 1 &
	2620	) - 1
	2621	!
	2622	!-- Uppermost topography index on u grid
	2623	ibit = 14
	2624	topo_top_ind(:,:,1) = MAXLOC( &
	2625	MERGE( 1, 0, &
	2626	BTEST( wall_flags_0(:,:,:), ibit ) &
	2627	), DIM = 1 &
	2628	) - 1
	2629	!
	2630	!-- Uppermost topography index on v grid
	2631	ibit = 16
	2632	topo_top_ind(:,:,2) = MAXLOC( &
	2633	MERGE( 1, 0, &
	2634	BTEST( wall_flags_0(:,:,:), ibit ) &
	2635	), DIM = 1 &
	2636	) - 1
	2637	!
	2638	!-- Uppermost topography index on w grid
	2639	ibit = 18
	2640	topo_top_ind(:,:,3) = MAXLOC( &
	2641	MERGE( 1, 0, &
	2642	BTEST( wall_flags_0(:,:,:), ibit ) &
	2643	), DIM = 1 &
	2644	) - 1
	2645	!
	2646	!-- Uppermost topography index on scalar outer grid
	2647	ibit = 24
	2648	topo_top_ind(:,:,4) = MAXLOC( &
	2649	MERGE( 1, 0, &
	2650	BTEST( wall_flags_0(:,:,:), ibit ) &
	2651	), DIM = 1 &
	2652	) - 1
[1]	2653
[2696]	2654	END SUBROUTINE set_topo_flags
[114]	2655
	2656
	2657

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