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source: palm/trunk/SOURCE/init_grid.f90 @ 4185

Last change on this file since 4185 was 4182, checked in by scharf, 5 years ago
corrected "Former revisions" section minor formatting in "Former revisions" section added "Author" section
Property svn:keywords set to `Id`
File size: 116.4 KB

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

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