Home

Context Navigation

source: palm/trunk/SOURCE/init_grid.f90 @ 4314

Last change on this file since 4314 was 4314, checked in by suehring, 4 years ago
plant-canopy: Bugfix, plant canopy was still considered at building edges on for the u- and v-component; Relax restriction of LAD on building tops. LAD is only omitted at locations where building grid points emerged artificially by the topography filtering
Property svn:keywords set to `Id`
File size: 119.3 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 4314 2019-11-29 10:29:20Z suehring $
[4314]	27	! Set additional topography flag 4 to mark topography grid points emerged
	28	! from the filtering process.
	29	!
	30	! 4294 2019-11-13 18:34:16Z suehring
[4294]	31	! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and
	32	! building surfaces in all cases, in order to enable terrain-following output
	33	! also when no land- or urban-surface model is applied.
	34	!
	35	! 4265 2019-10-15 16:16:24Z suehring
[4265]	36	! Bugfix for last commit, exchange oro_max variable only when it is allocated
	37	! (not necessarily the case when topography is input from ASCII file).
	38	!
	39	! 4245 2019-09-30 08:40:37Z pavelkrc
[4245]	40	! Store oro_max (building z-offset) in 2D for building surfaces
	41	!
	42	! 4189 2019-08-26 16:19:38Z suehring
[4189]	43	! - Add check for proper setting of namelist parameter topography
	44	! - Set flag to indicate land surfaces in case no topography is provided
	45	!
	46	! 4182 2019-08-22 15:20:23Z scharf
[4182]	47	! Corrected "Former revisions" section
	48	!
	49	! 4168 2019-08-16 13:50:17Z suehring
[4168]	50	! Pre-calculate topography top index and store it on an array (replaces former
	51	! functions get_topography_top_index)
	52	!
	53	! 4159 2019-08-15 13:31:35Z suehring
[4159]	54	! Revision of topography processing. This was not consistent between 2D and 3D
	55	! buildings.
	56	!
	57	! 4144 2019-08-06 09:11:47Z raasch
[4144]	58	! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
	59	!
	60	! 4115 2019-07-24 12:50:49Z suehring
[4115]	61	! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
	62	!
	63	! 4110 2019-07-22 17:05:21Z suehring
[4110]	64	! - Separate initialization of advection flags for momentum and scalars.
	65	! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
	66	!
	67	! 4109 2019-07-22 17:00:34Z suehring
[3927]	68	! Fix bad commit
	69	!
	70	! 3926 2019-04-23 12:56:42Z suehring
[3925]	71	! Minor bugfix in building mapping when all building IDs in the model domain
	72	! are missing
	73	!
	74	! 3857 2019-04-03 13:00:16Z knoop
[3855]	75	! In projection of non-building 3D objects onto numerical grid remove
	76	! dependency on building_type
	77	!
	78	! 3763 2019-02-25 17:33:49Z suehring
[3763]	79	! Replace work-around for ghost point exchange of 1-byte arrays with specific
	80	! routine as already done in other routines
	81	!
	82	! 3761 2019-02-25 15:31:42Z raasch
[3761]	83	! unused variables removed
	84	!
	85	! 3661 2019-01-08 18:22:50Z suehring
[3661]	86	! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead,
	87	! order degradation of advection scheme is handeled directly in advec_ws
	88	!
	89	! 3655 2019-01-07 16:51:22Z knoop
[3538]	90	! Comment added
[2716]	91	!
[4182]	92	! Revision 1.1 1997/08/11 06:17:45 raasch
	93	! Initial revision (Testversion)
	94	!
	95	!
[1]	96	! Description:
[2696]	97	! -----------------------------------------------------------------------------!
[1682]	98	!> Creating grid depending constants
[2696]	99	!> @todo: Rearrange topo flag list
	100	!> @todo: reference 3D buildings on top of orography is not tested and may need
	101	!> further improvement for steep slopes
	102	!> @todo: Use more advanced setting of building type at filled holes
[1]	103	!------------------------------------------------------------------------------!
[1682]	104	SUBROUTINE init_grid
	105
[1942]	106	USE advec_ws, &
[4109]	107	ONLY: ws_init_flags_momentum, ws_init_flags_scalar
[1]	108
[1320]	109	USE arrays_3d, &
[3857]	110	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
[1320]	111
[1353]	112	USE control_parameters, &
[3761]	113	ONLY: bc_lr_cyc, bc_ns_cyc, &
[4109]	114	bc_dirichlet_l, &
	115	bc_dirichlet_n, &
	116	bc_dirichlet_r, &
	117	bc_dirichlet_s, &
	118	bc_radiation_l, &
	119	bc_radiation_n, &
	120	bc_radiation_r, &
	121	bc_radiation_s, &
[3241]	122	constant_flux_layer, dz, dz_max, dz_stretch_factor, &
[3065]	123	dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
	124	dz_stretch_level_end_index, dz_stretch_level_start_index, &
[3241]	125	dz_stretch_level_start, ibc_uv_b, message_string, &
[3182]	126	momentum_advec, number_stretch_level_end, &
[3294]	127	number_stretch_level_start, ocean_mode, psolver, scalar_advec, &
[3241]	128	topography, use_surface_fluxes
[2021]	129
[1320]	130	USE grid_variables, &
[2232]	131	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[1320]	132
	133	USE indices, &
[4109]	134	ONLY: advc_flags_m, &
	135	advc_flags_s, &
	136	nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
[2232]	137	nzb, nzb_diff, nzb_diff_s_inner, nzb_diff_s_outer, &
	138	nzb_max, nzb_s_inner, nzb_s_outer, nzb_u_inner, &
[1845]	139	nzb_u_outer, nzb_v_inner, nzb_v_outer, nzb_w_inner, &
[4168]	140	nzb_w_outer, nzt, topo_top_ind, topo_min_level
[1320]	141
	142	USE kinds
[2696]	143
[1]	144	USE pegrid
	145
[2696]	146	USE poismg_noopt_mod
	147
[2232]	148	USE surface_mod, &
[4168]	149	ONLY: init_bc
[2232]	150
[2365]	151	USE vertical_nesting_mod, &
	152	ONLY: vnested, vnest_init_grid
	153
[1]	154	IMPLICIT NONE
	155
[3182]	156	INTEGER(iwp) :: i !< index variable along x
	157	INTEGER(iwp) :: j !< index variable along y
	158	INTEGER(iwp) :: k !< index variable along z
	159	INTEGER(iwp) :: k_top !< topography top index on local PE
	160	INTEGER(iwp) :: n !< loop variable for stretching
	161	INTEGER(iwp) :: number_dz !< number of user-specified dz values
	162	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	163	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
[2232]	164
[3065]	165	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	166	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_tmp !< dummy to calculate topography indices on u- and v-grid
[1]	167
[2696]	168	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	169
[3065]	170	REAL(wp) :: dz_level_end !< distance between calculated height level for u/v-grid and user-specified end level for stretching
[1886]	171	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[3065]	172
	173	REAL(wp), DIMENSION(:), ALLOCATABLE :: min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
[861]	174
[1]	175
	176	!
[709]	177	!-- Calculation of horizontal array bounds including ghost layers
[667]	178	nxlg = nxl - nbgp
	179	nxrg = nxr + nbgp
	180	nysg = nys - nbgp
	181	nyng = nyn + nbgp
[709]	182
[667]	183	!
[1]	184	!-- Allocate grid arrays
[3857]	185	ALLOCATE( x(0:nx), xu(0:nx) )
	186	DO i = 0, nx
	187	xu(i) = i * dx
	188	x(i) = i * dx + 0.5_wp * dx
	189	ENDDO
	190
	191	ALLOCATE( y(0:ny), yv(0:ny) )
	192	DO j = 0, ny
	193	yv(j) = j * dy
	194	y(j) = j * dy + 0.5_wp * dy
	195	ENDDO
	196
	197	!
	198	!-- Allocate grid arrays
[1353]	199	ALLOCATE( ddzu(1:nzt+1), ddzw(1:nzt+1), dd2zu(1:nzt), dzu(1:nzt+1), &
[2696]	200	dzw(1:nzt+1), zu(nzb:nzt+1), zw(nzb:nzt+1) )
[1]	201
	202	!
	203	!-- Compute height of u-levels from constant grid length and dz stretch factors
[3065]	204	IF ( dz(1) == -1.0_wp ) THEN
[254]	205	message_string = 'missing dz'
	206	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[3065]	207	ELSEIF ( dz(1) <= 0.0_wp ) THEN
	208	WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
[254]	209	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	210	ENDIF
[94]	211
[1]	212	!
[3065]	213	!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
	214	!-- if it was set by the user
	215	IF ( dz_stretch_level /= -9999999.9_wp ) THEN
	216	dz_stretch_level_start(1) = dz_stretch_level
	217	ENDIF
	218
	219	!
	220	!-- Determine number of dz values and stretching levels specified by the
	221	!-- user to allow right controlling of the stretching mechanism and to
[3139]	222	!-- perform error checks. The additional requirement that dz /= dz_max
	223	!-- for counting number of user-specified dz values is necessary. Otherwise
	224	!-- restarts would abort if the old stretching mechanism with dz_stretch_level
	225	!-- is used (Attention: The user is not allowed to specify a dz value equal
	226	!-- to the default of dz_max = 999.0).
	227	number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
[3065]	228	number_stretch_level_start = COUNT( dz_stretch_level_start /= &
	229	-9999999.9_wp )
	230	number_stretch_level_end = COUNT( dz_stretch_level_end /= &
	231	9999999.9_wp )
	232
	233	!
	234	!-- The number of specified end levels +1 has to be the same than the number
	235	!-- of specified dz values
	236	IF ( number_dz /= number_stretch_level_end + 1 ) THEN
	237	WRITE( message_string, * ) 'The number of values for dz = ', &
	238	number_dz, 'has to be the same than& ', &
	239	'the number of values for ', &
	240	'dz_stretch_level_end + 1 = ', &
	241	number_stretch_level_end+1
	242	CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
	243	ENDIF
	244
	245	!
	246	!-- The number of specified start levels has to be the same or one less than
	247	!-- the number of specified dz values
	248	IF ( number_dz /= number_stretch_level_start + 1 .AND. &
	249	number_dz /= number_stretch_level_start ) THEN
	250	WRITE( message_string, * ) 'The number of values for dz = ', &
	251	number_dz, 'has to be the same or one ', &
	252	'more than& the number of values for ', &
	253	'dz_stretch_level_start = ', &
	254	number_stretch_level_start
	255	CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
	256	ENDIF
	257
	258	!-- The number of specified start levels has to be the same or one more than
	259	!-- the number of specified end levels
	260	IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND. &
	261	number_stretch_level_start /= number_stretch_level_end ) THEN
	262	WRITE( message_string, * ) 'The number of values for ', &
	263	'dz_stretch_level_start = ', &
	264	dz_stretch_level_start, 'has to be the ',&
	265	'same or one more than& the number of ', &
	266	'values for dz_stretch_level_end = ', &
	267	number_stretch_level_end
	268	CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
	269	ENDIF
	270
	271	!
	272	!-- Initialize dz for the free atmosphere with the value of dz_max
	273	IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND. &
	274	number_stretch_level_start /= 0 ) THEN
	275	dz(number_stretch_level_start+1) = dz_max
	276	ENDIF
	277
	278	!
	279	!-- Initialize the stretching factor if (infinitely) stretching in the free
	280	!-- atmosphere is desired (dz_stretch_level_end was not specified for the
	281	!-- free atmosphere)
	282	IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN
	283	dz_stretch_factor_array(number_stretch_level_start) = &
	284	dz_stretch_factor
	285	ENDIF
	286
	287	!
	288	!-- Allocation of arrays for stretching
	289	ALLOCATE( min_dz_stretch_level_end(number_stretch_level_start) )
[3066]	290
[3065]	291	!
[94]	292	!-- Define the vertical grid levels
[3294]	293	IF ( .NOT. ocean_mode ) THEN
[3065]	294
[94]	295	!
[3065]	296	!-- The stretching region has to be large enough to allow for a smooth
	297	!-- transition between two different grid spacings
	298	DO n = 1, number_stretch_level_start
	299	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + &
	300	4 * MAX( dz(n),dz(n+1) )
	301	ENDDO
	302
[3066]	303	IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) > &
	304	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	305	message_string= 'Eeach dz_stretch_level_end has to be larger ' // &
	306	'than its corresponding value for &' // &
	307	'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//&
	308	'to allow for smooth grid stretching'
	309	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	310	ENDIF
	311
	312	!
	313	!-- Stretching must not be applied within the prandtl_layer
	314	!-- (first two grid points). For the default case dz_stretch_level_start
	315	!-- is negative. Therefore the absolut value is checked here.
	316	IF ( ANY( ABS( dz_stretch_level_start ) < dz(1) * 1.5_wp ) ) THEN
	317	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	318	'larger than ', dz(1) * 1.5
	319	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	320	ENDIF
	321
	322	!
	323	!-- The stretching has to start and end on a grid level. Therefore
	324	!-- user-specified values have to ''interpolate'' to the next lowest level
	325	IF ( number_stretch_level_start /= 0 ) THEN
	326	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - &
	327	dz(1)/2.0) / dz(1) ) &
	328	* dz(1) + dz(1)/2.0
	329	ENDIF
	330
	331	IF ( number_stretch_level_start > 1 ) THEN
	332	DO n = 2, number_stretch_level_start
	333	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	334	dz(n) ) * dz(n)
	335	ENDDO
	336	ENDIF
	337
	338	IF ( number_stretch_level_end /= 0 ) THEN
	339	DO n = 1, number_stretch_level_end
	340	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	341	dz(n+1) ) * dz(n+1)
	342	ENDDO
	343	ENDIF
	344
	345	!
	346	!-- Determine stretching factor if necessary
	347	IF ( number_stretch_level_end >= 1 ) THEN
	348	CALL calculate_stretching_factor( number_stretch_level_end )
	349	ENDIF
	350
	351	!
[94]	352	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[3065]	353	!-- First compute the u- and v-levels. In case of dirichlet bc for u and v
	354	!-- the first u/v- and w-level (k=0) are defined at same height (z=0).
[843]	355	!-- The second u-level (k=1) corresponds to the top of the
[94]	356	!-- Prandtl-layer.
[667]	357	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 ) THEN
[1353]	358	zu(0) = 0.0_wp
[667]	359	ELSE
[3065]	360	zu(0) = - dz(1) * 0.5_wp
[667]	361	ENDIF
[3065]	362
	363	zu(1) = dz(1) * 0.5_wp
	364
	365	!
	366	!-- Determine u and v height levels considering the possibility of grid
	367	!-- stretching in several heights.
	368	n = 1
	369	dz_stretch_level_start_index = nzt+1
	370	dz_stretch_level_end_index = nzt+1
	371	dz_stretched = dz(1)
[1]	372
[3065]	373	!-- The default value of dz_stretch_level_start is negative, thus the first
	374	!-- condition is always true. Hence, the second condition is necessary.
[94]	375	DO k = 2, nzt+1
[3065]	376	IF ( dz_stretch_level_start(n) <= zu(k-1) .AND. &
	377	dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
	378	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	379
	380	IF ( dz(n) > dz(n+1) ) THEN
	381	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	382	ELSE
	383	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	384	ENDIF
	385
	386	IF ( dz_stretch_level_start_index(n) == nzt+1 ) &
	387	dz_stretch_level_start_index(n) = k-1
	388
[94]	389	ENDIF
[3065]	390
[94]	391	zu(k) = zu(k-1) + dz_stretched
[3065]	392
	393	!
	394	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	395	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	396
	397	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	398	zu(k) = dz_stretch_level_end(n)
	399	dz_stretched = dz(n+1)
	400	dz_stretch_level_end_index(n) = k
	401	n = n + 1
	402	ENDIF
[94]	403	ENDDO
[1]	404
	405	!
[94]	406	!-- Compute the w-levels. They are always staggered half-way between the
[843]	407	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	408	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
	409	!-- The top w-level is extrapolated linearly.
[1353]	410	zw(0) = 0.0_wp
[94]	411	DO k = 1, nzt
[1353]	412	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	413	ENDDO
[1353]	414	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
[1]	415
[94]	416	ELSE
[3065]	417
[1]	418	!
[3065]	419	!-- The stretching region has to be large enough to allow for a smooth
	420	!-- transition between two different grid spacings
	421	DO n = 1, number_stretch_level_start
	422	min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - &
	423	4 * MAX( dz(n),dz(n+1) )
	424	ENDDO
	425
[3066]	426	IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) < &
	427	dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
[3065]	428	message_string= 'Eeach dz_stretch_level_end has to be less ' // &
	429	'than its corresponding value for &' // &
	430	'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
	431	'to allow for smooth grid stretching'
	432	CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
	433	ENDIF
	434
	435	!
[3068]	436	!-- Stretching must not be applied close to the surface (last two grid
	437	!-- points). For the default case dz_stretch_level_start is negative.
	438	IF ( ANY( dz_stretch_level_start > - dz(1) * 1.5_wp ) ) THEN
[3065]	439	WRITE( message_string, * ) 'Eeach dz_stretch_level_start has to be ',&
	440	'less than ', dz(1) * 1.5
	441	CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
	442	ENDIF
	443
	444	!
	445	!-- The stretching has to start and end on a grid level. Therefore
	446	!-- user-specified values have to ''interpolate'' to the next highest level
	447	IF ( number_stretch_level_start /= 0 ) THEN
	448	dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + &
	449	dz(1)/2.0) / dz(1) ) &
	450	* dz(1) - dz(1)/2.0
	451	ENDIF
	452
	453	IF ( number_stretch_level_start > 1 ) THEN
	454	DO n = 2, number_stretch_level_start
	455	dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / &
	456	dz(n) ) * dz(n)
	457	ENDDO
	458	ENDIF
	459
	460	IF ( number_stretch_level_end /= 0 ) THEN
	461	DO n = 1, number_stretch_level_end
	462	dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / &
	463	dz(n+1) ) * dz(n+1)
	464	ENDDO
	465	ENDIF
	466
	467	!
	468	!-- Determine stretching factor if necessary
	469	IF ( number_stretch_level_end >= 1 ) THEN
	470	CALL calculate_stretching_factor( number_stretch_level_end )
	471	ENDIF
	472
	473	!
[843]	474	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	475	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	476	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	477	!-- w-level are defined at same height, but staggered from the second level.
	478	!-- The second u-level (k=1) corresponds to the top of the Prandtl-layer.
[3065]	479	!-- z values are negative starting from z=0 (surface)
	480	zu(nzt+1) = dz(1) * 0.5_wp
	481	zu(nzt) = - dz(1) * 0.5_wp
[94]	482
[3065]	483	!
	484	!-- Determine u and v height levels considering the possibility of grid
	485	!-- stretching in several heights.
	486	n = 1
	487	dz_stretch_level_start_index = 0
	488	dz_stretch_level_end_index = 0
	489	dz_stretched = dz(1)
	490
[94]	491	DO k = nzt-1, 0, -1
[3065]	492
	493	IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
	494	dz_stretched = dz_stretched * dz_stretch_factor_array(n)
	495
	496	IF ( dz(n) > dz(n+1) ) THEN
	497	dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
	498	ELSE
	499	dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
	500	ENDIF
	501
	502	IF ( dz_stretch_level_start_index(n) == 0 ) &
	503	dz_stretch_level_start_index(n) = k+1
	504
	505	ENDIF
	506
	507	zu(k) = zu(k+1) - dz_stretched
	508
[1418]	509	!
[3065]	510	!-- Make sure that the stretching ends exactly at dz_stretch_level_end
	511	dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
	512
	513	IF ( dz_level_end < dz(n+1)/3.0 ) THEN
	514	zu(k) = dz_stretch_level_end(n)
	515	dz_stretched = dz(n+1)
	516	dz_stretch_level_end_index(n) = k
	517	n = n + 1
[94]	518	ENDIF
	519	ENDDO
[3065]	520
[94]	521	!
	522	!-- Compute the w-levels. They are always staggered half-way between the
[843]	523	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	524	!-- at the ground. In this case the first u- and w-level are defined at
	525	!-- same height. The top w-level (nzt+1) is not used but set for
	526	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[3065]	527	zw(nzt+1) = dz(1)
[1353]	528	zw(nzt) = 0.0_wp
[94]	529	DO k = 0, nzt
[1353]	530	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	531	ENDDO
	532
[843]	533	!
	534	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	535	!-- at same height.
	536	IF ( ibc_uv_b == 0 ) THEN
	537	zu(0) = zw(0)
	538	ENDIF
	539
[94]	540	ENDIF
	541
	542	!
[1]	543	!-- Compute grid lengths.
	544	DO k = 1, nzt+1
	545	dzu(k) = zu(k) - zu(k-1)
[1353]	546	ddzu(k) = 1.0_wp / dzu(k)
[1]	547	dzw(k) = zw(k) - zw(k-1)
[1353]	548	ddzw(k) = 1.0_wp / dzw(k)
[1]	549	ENDDO
	550
	551	DO k = 1, nzt
[1353]	552	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	553	ENDDO
[667]	554
	555	!
[709]	556	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	557	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	558	!-- is only dz/2, but should be dz. Therefore, an additional array
	559	!-- containing with appropriate grid information is created for these
	560	!-- solvers.
[1575]	561	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	562	ALLOCATE( ddzu_pres(1:nzt+1) )
	563	ddzu_pres = ddzu
[864]	564	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	565	ENDIF
	566
	567	!
	568	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	569	ddx = 1.0_wp / dx
	570	ddy = 1.0_wp / dy
[1]	571	dx2 = dx * dx
	572	dy2 = dy * dy
[1353]	573	ddx2 = 1.0_wp / dx2
	574	ddy2 = 1.0_wp / dy2
[1]	575
	576	!
[2696]	577	!-- Allocate 3D array to set topography
	578	ALLOCATE( topo(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	579	topo = 0
	580	!
	581	!-- Initialize topography by generic topography or read from topography from file.
	582	CALL init_topo( topo )
	583	!
	584	!-- Set flags to mask topography on the grid.
	585	CALL set_topo_flags( topo )
	586	!
	587	!-- Calculate wall flag arrays for the multigrid method.
	588	!-- Please note, wall flags are only applied in the non-optimized version.
[4109]	589	IF ( psolver == 'multigrid_noopt' ) CALL poismg_noopt_init
[2696]	590
	591	!
	592	!-- Init flags for ws-scheme to degrade order of the numerics near walls, i.e.
[4109]	593	!-- to decrease the numerical stencil appropriately. The order of the scheme
	594	!-- is degraded near solid walls as well as near non-cyclic inflow and outflow
	595	!-- boundaries. Do this separately for momentum and scalars.
	596	IF ( momentum_advec == 'ws-scheme' ) THEN
	597	ALLOCATE( advc_flags_m(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	598	CALL ws_init_flags_momentum
	599	ENDIF
	600	IF ( scalar_advec == 'ws-scheme' ) THEN
	601	ALLOCATE( advc_flags_s(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	602	advc_flags_s = 0
	603
	604	CALL ws_init_flags_scalar( bc_dirichlet_l .OR. bc_radiation_l, &
	605	bc_dirichlet_n .OR. bc_radiation_n, &
	606	bc_dirichlet_r .OR. bc_radiation_r, &
	607	bc_dirichlet_s .OR. bc_radiation_s, &
	608	advc_flags_s )
	609	ENDIF
[2696]	610
	611	!
	612	!-- Determine the maximum level of topography. It is used for
	613	!-- steering the degradation of order of the applied advection scheme,
	614	!-- as well in the lpm.
	615	k_top = 0
	616	DO i = nxl, nxr
	617	DO j = nys, nyn
	618	DO k = nzb, nzt + 1
[4109]	619	k_top = MAX( k_top, MERGE( k, 0, .NOT. BTEST( topo(k,j,i), 0 ) ) )
[2696]	620	ENDDO
	621	ENDDO
[1]	622	ENDDO
[2696]	623	#if defined( __parallel )
	624	CALL MPI_ALLREDUCE( k_top + 1, nzb_max, 1, MPI_INTEGER, & !is +1 really necessary here?
	625	MPI_MAX, comm2d, ierr )
	626	#else
	627	nzb_max = k_top + 1
	628	#endif
	629	!
[3661]	630	!-- If topography extents up to the model top, limit nzb_max to nzt.
[3182]	631	nzb_max = MIN( nzb_max, nzt )
[1]	632	!
[2968]	633	!-- Determine minimum index of topography. Usually, this will be nzb. In case
	634	!-- there is elevated topography, however, the lowest topography will be higher.
	635	!-- This index is e.g. used to calculate mean first-grid point atmosphere
	636	!-- temperature, surface pressure and density, etc. .
	637	topo_min_level = 0
	638	#if defined( __parallel )
[4168]	639	CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[2968]	640	topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
	641	#else
[4168]	642	topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2968]	643	#endif
	644	!
[2696]	645	!-- Initialize boundary conditions via surface type
	646	CALL init_bc
[3182]	647
[2696]	648	!
	649	!-- Allocate and set topography height arrays required for data output
	650	IF ( TRIM( topography ) /= 'flat' ) THEN
	651	!
	652	!-- Allocate and set the arrays containing the topography height
	653	IF ( nxr == nx .AND. nyn /= ny ) THEN
	654	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	655	zw_w_inner(nxl:nxr+1,nys:nyn) )
	656	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	657	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	658	zw_w_inner(nxl:nxr,nys:nyn+1) )
	659	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	660	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	661	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	662	ELSE
	663	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	664	zw_w_inner(nxl:nxr,nys:nyn) )
	665	ENDIF
	666
	667	zu_s_inner = 0.0_wp
	668	zw_w_inner = 0.0_wp
	669	!
	670	!-- Determine local topography height on scalar and w-grid. Note, setting
	671	!-- lateral boundary values is not necessary, realized via wall_flags_0
	672	!-- array. Further, please note that loop bounds are different from
	673	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	674	!-- use intrinsic lbound and ubound functions to infer array bounds.
	675	DO i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
	676	DO j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
	677	!
	678	!-- Topography height on scalar grid. Therefore, determine index of
	679	!-- upward-facing surface element on scalar grid.
[4168]	680	zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
[2696]	681	!
	682	!-- Topography height on w grid. Therefore, determine index of
	683	!-- upward-facing surface element on w grid.
[4168]	684	zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
[2696]	685	ENDDO
	686	ENDDO
	687	ENDIF
	688
	689	!
	690	!-- In the following, calculate 2D index arrays. Note, these will be removed
	691	!-- soon.
[1]	692	!-- Allocate outer and inner index arrays for topography and set
[2232]	693	!-- defaults.
[2696]	694	ALLOCATE( nzb_s_inner(nysg:nyng,nxlg:nxrg), &
	695	nzb_s_outer(nysg:nyng,nxlg:nxrg), &
	696	nzb_u_inner(nysg:nyng,nxlg:nxrg), &
	697	nzb_u_outer(nysg:nyng,nxlg:nxrg), &
	698	nzb_v_inner(nysg:nyng,nxlg:nxrg), &
	699	nzb_v_outer(nysg:nyng,nxlg:nxrg), &
	700	nzb_w_inner(nysg:nyng,nxlg:nxrg), &
	701	nzb_w_outer(nysg:nyng,nxlg:nxrg), &
	702	nzb_diff_s_inner(nysg:nyng,nxlg:nxrg), &
	703	nzb_diff_s_outer(nysg:nyng,nxlg:nxrg), &
	704	nzb_local(nysg:nyng,nxlg:nxrg), &
	705	nzb_tmp(nysg:nyng,nxlg:nxrg) )
	706	!
	707	!-- Initialize 2D-index arrays. Note, these will be removed soon!
[4168]	708	nzb_local(nys:nyn,nxl:nxr) = topo_top_ind(nys:nyn,nxl:nxr,0)
[2696]	709	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2968]	710	!
	711	!-- Check topography for consistency with model domain. Therefore, use
	712	!-- maximum and minium topography-top indices. Note, minimum topography top
	713	!-- index is already calculated.
[2696]	714	IF ( TRIM( topography ) /= 'flat' ) THEN
	715	#if defined( __parallel )
[4168]	716	CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), &
[3182]	717	nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
[2696]	718	#else
[4168]	719	nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
[2696]	720	#endif
[2968]	721	nzb_local_min = topo_min_level
[2696]	722	!
	723	!-- Consistency checks
	724	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
	725	WRITE( message_string, * ) 'nzb_local values are outside the', &
[3045]	726	' model domain', &
[3046]	727	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	728	'&MAXVAL( nzb_local ) = ', nzb_local_max
[2696]	729	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
	730	ENDIF
	731	ENDIF
[1]	732
	733	nzb_s_inner = nzb; nzb_s_outer = nzb
	734	nzb_u_inner = nzb; nzb_u_outer = nzb
	735	nzb_v_inner = nzb; nzb_v_outer = nzb
	736	nzb_w_inner = nzb; nzb_w_outer = nzb
	737
	738	!
[19]	739	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	740	!-- form (which does not use surface fluxes) is applied
[1691]	741	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	742	nzb_diff = nzb + 2
	743	ELSE
	744	nzb_diff = nzb + 1
	745	ENDIF
	746
	747	nzb_diff_s_inner = nzb_diff; nzb_diff_s_outer = nzb_diff
[2696]	748	!
	749	!-- Set Neumann conditions for topography. Will be removed soon.
	750	IF ( .NOT. bc_ns_cyc ) THEN
	751	IF ( nys == 0 ) THEN
[2927]	752	DO i = 1, nbgp
	753	nzb_local(nys-i,:) = nzb_local(nys,:)
	754	ENDDO
[2696]	755	ELSEIF ( nyn == ny ) THEN
[2927]	756	DO i = 1, nbgp
	757	nzb_local(ny+i,:) = nzb_local(ny,:)
	758	ENDDO
[2696]	759	ENDIF
	760	ENDIF
[1]	761
[2696]	762	IF ( .NOT. bc_lr_cyc ) THEN
	763	IF ( nxl == 0 ) THEN
[2927]	764	DO i = 1, nbgp
	765	nzb_local(:,nxl-i) = nzb_local(:,nxl)
	766	ENDDO
[2696]	767	ELSEIF ( nxr == nx ) THEN
[2927]	768	DO i = 1, nbgp
	769	nzb_local(:,nx+i) = nzb_local(:,nx)
	770	ENDDO
[2696]	771	ENDIF
	772	ENDIF
[1]	773	!
[2696]	774	!-- Initialization of 2D index arrays, will be removed soon!
	775	!-- Initialize nzb_s_inner and nzb_w_inner
	776	nzb_s_inner = nzb_local
	777	nzb_w_inner = nzb_local
	778
	779	!
	780	!-- Initialize remaining index arrays:
	781	!-- first pre-initialize them with nzb_s_inner...
	782	nzb_u_inner = nzb_s_inner
	783	nzb_u_outer = nzb_s_inner
	784	nzb_v_inner = nzb_s_inner
	785	nzb_v_outer = nzb_s_inner
	786	nzb_w_outer = nzb_s_inner
	787	nzb_s_outer = nzb_s_inner
	788
	789	!
	790	!-- nzb_s_outer:
	791	!-- extend nzb_local east-/westwards first, then north-/southwards
	792	nzb_tmp = nzb_local
	793	DO j = nys, nyn
	794	DO i = nxl, nxr
	795	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i), &
	796	nzb_local(j,i+1) )
	797	ENDDO
	798	ENDDO
	799
	800	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	801
	802	DO i = nxl, nxr
	803	DO j = nys, nyn
	804	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	805	nzb_tmp(j+1,i) )
	806	ENDDO
	807	!
	808	!-- non-cyclic boundary conditions (overwritten by call of
	809	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	810	IF ( nys == 0 ) THEN
	811	j = -1
	812	nzb_s_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	813	ENDIF
	814	IF ( nyn == ny ) THEN
	815	j = ny + 1
	816	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	817	ENDIF
	818	ENDDO
	819	!
	820	!-- nzb_w_outer:
	821	!-- identical to nzb_s_outer
	822	nzb_w_outer = nzb_s_outer
	823	!
	824	!-- nzb_u_inner:
	825	!-- extend nzb_local rightwards only
	826	nzb_tmp = nzb_local
	827	DO j = nys, nyn
	828	DO i = nxl, nxr
	829	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i) )
	830	ENDDO
	831	ENDDO
	832
	833	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	834
	835	nzb_u_inner = nzb_tmp
	836	!
	837	!-- nzb_u_outer:
	838	!-- extend current nzb_tmp (nzb_u_inner) north-/southwards
	839	DO i = nxl, nxr
	840	DO j = nys, nyn
	841	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
	842	nzb_tmp(j+1,i) )
	843	ENDDO
	844	!
	845	!-- non-cyclic boundary conditions (overwritten by call of
	846	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	847	IF ( nys == 0 ) THEN
	848	j = -1
	849	nzb_u_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	850	ENDIF
	851	IF ( nyn == ny ) THEN
	852	j = ny + 1
	853	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	854	ENDIF
	855	ENDDO
	856
	857	!
	858	!-- nzb_v_inner:
	859	!-- extend nzb_local northwards only
	860	nzb_tmp = nzb_local
	861	DO i = nxl, nxr
	862	DO j = nys, nyn
	863	nzb_tmp(j,i) = MAX( nzb_local(j-1,i), nzb_local(j,i) )
	864	ENDDO
	865	ENDDO
	866
	867	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	868	nzb_v_inner = nzb_tmp
	869
	870	!
	871	!-- nzb_v_outer:
	872	!-- extend current nzb_tmp (nzb_v_inner) right-/leftwards
	873	DO j = nys, nyn
	874	DO i = nxl, nxr
	875	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i), &
	876	nzb_tmp(j,i+1) )
	877	ENDDO
	878	!
	879	!-- non-cyclic boundary conditions (overwritten by call of
	880	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	881	IF ( nxl == 0 ) THEN
	882	i = -1
	883	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i+1), nzb_tmp(j,i) )
	884	ENDIF
	885	IF ( nxr == nx ) THEN
	886	i = nx + 1
	887	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i) )
	888	ENDIF
	889	ENDDO
	890
	891	!
	892	!-- Exchange of lateral boundary values (parallel computers) and cyclic
	893	!-- boundary conditions, if applicable.
	894	!-- Since nzb_s_inner and nzb_w_inner are derived directly from nzb_local
	895	!-- they do not require exchange and are not included here.
	896	CALL exchange_horiz_2d_int( nzb_u_inner, nys, nyn, nxl, nxr, nbgp )
	897	CALL exchange_horiz_2d_int( nzb_u_outer, nys, nyn, nxl, nxr, nbgp )
	898	CALL exchange_horiz_2d_int( nzb_v_inner, nys, nyn, nxl, nxr, nbgp )
	899	CALL exchange_horiz_2d_int( nzb_v_outer, nys, nyn, nxl, nxr, nbgp )
	900	CALL exchange_horiz_2d_int( nzb_w_outer, nys, nyn, nxl, nxr, nbgp )
	901	CALL exchange_horiz_2d_int( nzb_s_outer, nys, nyn, nxl, nxr, nbgp )
	902
	903	!
	904	!-- Set the individual index arrays which define the k index from which on
	905	!-- the usual finite difference form (which does not use surface fluxes) is
	906	!-- applied
	907	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	908	nzb_diff_s_inner = nzb_s_inner + 2
	909	nzb_diff_s_outer = nzb_s_outer + 2
	910	ELSE
	911	nzb_diff_s_inner = nzb_s_inner + 1
	912	nzb_diff_s_outer = nzb_s_outer + 1
	913	ENDIF
	914	!
	915	!-- Vertical nesting: communicate vertical grid level arrays between fine and
	916	!-- coarse grid
	917	IF ( vnested ) CALL vnest_init_grid
	918
	919	END SUBROUTINE init_grid
	920
[3065]	921
[2696]	922	! Description:
	923	! -----------------------------------------------------------------------------!
[3065]	924	!> Calculation of the stretching factor through an iterative method. Ideas were
	925	!> taken from the paper "Regional stretched grid generation and its application
	926	!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
	927	!> system of equations has two variables (r,l) but four requirements
	928	!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
	929	!> results into an overdetermined system.
	930	!------------------------------------------------------------------------------!
	931	SUBROUTINE calculate_stretching_factor( number_end )
	932
	933	USE control_parameters, &
[3241]	934	ONLY: dz, dz_stretch_factor_array, &
[3065]	935	dz_stretch_level_end, dz_stretch_level_start, message_string
	936
	937	USE kinds
	938
	939	IMPLICIT NONE
	940
	941	INTEGER(iwp) :: iterations !< number of iterations until stretch_factor_lower/upper_limit is reached
	942	INTEGER(iwp) :: l_rounded !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
	943	INTEGER(iwp) :: n !< loop variable for stretching
	944
	945	INTEGER(iwp), INTENT(IN) :: number_end !< number of user-specified end levels for stretching
	946
	947	REAL(wp) :: delta_l !< absolute difference between l and l_rounded
	948	REAL(wp) :: delta_stretch_factor !< absolute difference between stretch_factor_1 and stretch_factor_2
	949	REAL(wp) :: delta_total_new !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible)
	950	REAL(wp) :: delta_total_old !< sum of delta_l and delta_stretch_factor for the last iteration
	951	REAL(wp) :: distance !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
	952	REAL(wp) :: l !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
	953	REAL(wp) :: numerator !< numerator of the quotient
	954	REAL(wp) :: stretch_factor_1 !< stretching factor that fulfil Eq. (5) togehter with l exactly
	955	REAL(wp) :: stretch_factor_2 !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
	956
[3068]	957	REAL(wp) :: dz_stretch_factor_array_2(9) = 1.08_wp !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1
	958
[3065]	959	REAL(wp), PARAMETER :: stretch_factor_interval = 1.0E-06 !< interval for sampling possible stretching factors
	960	REAL(wp), PARAMETER :: stretch_factor_lower_limit = 0.88 !< lowest possible stretching factor
	961	REAL(wp), PARAMETER :: stretch_factor_upper_limit = 1.12 !< highest possible stretching factor
	962
	963
[3068]	964	l = 0
	965	DO n = 1, number_end
	966
	967	iterations = 1
	968	stretch_factor_1 = 1.0
	969	stretch_factor_2 = 1.0
	970	delta_total_old = 1.0
[3065]	971
[3068]	972	IF ( dz(n) > dz(n+1) ) THEN
	973	DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
	974
	975	stretch_factor_1 = 1.0 - iterations * stretch_factor_interval
	976	distance = ABS( dz_stretch_level_end(n) - &
	977	dz_stretch_level_start(n) )
	978	numerator = distance*stretch_factor_1/dz(n) + &
	979	stretch_factor_1 - distance/dz(n)
	980
	981	IF ( numerator > 0.0 ) THEN
	982	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	983	l_rounded = NINT( l )
	984	delta_l = ABS( l_rounded - l ) / l
	985	ENDIF
	986
	987	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
	988
	989	delta_stretch_factor = ABS( stretch_factor_1 - &
	990	stretch_factor_2 ) / &
	991	stretch_factor_2
	992
	993	delta_total_new = delta_l + delta_stretch_factor
[3065]	994
	995	!
	996	!-- stretch_factor_1 is taken to guarantee that the stretching
	997	!-- procedure ends as close as possible to dz_stretch_level_end.
	998	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	999	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1000	IF (delta_total_new < delta_total_old) THEN
	1001	dz_stretch_factor_array(n) = stretch_factor_1
	1002	dz_stretch_factor_array_2(n) = stretch_factor_2
	1003	delta_total_old = delta_total_new
	1004	ENDIF
	1005
	1006	iterations = iterations + 1
	1007
	1008	ENDDO
	1009
	1010	ELSEIF ( dz(n) < dz(n+1) ) THEN
	1011	DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
	1012
	1013	stretch_factor_1 = 1.0 + iterations * stretch_factor_interval
	1014	distance = ABS( dz_stretch_level_end(n) - &
	1015	dz_stretch_level_start(n) )
	1016	numerator = distance*stretch_factor_1/dz(n) + &
	1017	stretch_factor_1 - distance/dz(n)
	1018
	1019	l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0
	1020	l_rounded = NINT( l )
	1021	delta_l = ABS( l_rounded - l ) / l
	1022
	1023	stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
[3065]	1024
[3068]	1025	delta_stretch_factor = ABS( stretch_factor_1 - &
	1026	stretch_factor_2 ) / &
	1027	stretch_factor_2
	1028
	1029	delta_total_new = delta_l + delta_stretch_factor
	1030
[3065]	1031	!
	1032	!-- stretch_factor_1 is taken to guarantee that the stretching
	1033	!-- procedure ends as close as possible to dz_stretch_level_end.
	1034	!-- stretch_factor_2 would guarantee that the stretched dz(n) is
	1035	!-- equal to dz(n+1) after l_rounded grid levels.
[3068]	1036	IF (delta_total_new < delta_total_old) THEN
	1037	dz_stretch_factor_array(n) = stretch_factor_1
	1038	dz_stretch_factor_array_2(n) = stretch_factor_2
	1039	delta_total_old = delta_total_new
	1040	ENDIF
[3065]	1041
[3068]	1042	iterations = iterations + 1
	1043	ENDDO
	1044
	1045	ELSE
	1046	message_string= 'Two adjacent values of dz must be different'
	1047	CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
	1048
	1049	ENDIF
	1050
	1051	!
	1052	!-- Check if also the second stretching factor fits into the allowed
	1053	!-- interval. If not, print a warning for the user.
	1054	IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR. &
	1055	dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
	1056	WRITE( message_string, * ) 'stretch_factor_2 = ', &
	1057	dz_stretch_factor_array_2(n), ' which is',&
	1058	' responsible for exactly reaching& dz =',&
	1059	dz(n+1), 'after a specific amount of', &
	1060	' grid levels& exceeds the upper', &
	1061	' limit =', stretch_factor_upper_limit, &
	1062	' &or lower limit = ', &
	1063	stretch_factor_lower_limit
	1064	CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
	1065
	1066	ENDIF
	1067	ENDDO
[3065]	1068
	1069	END SUBROUTINE calculate_stretching_factor
	1070
	1071
	1072	! Description:
	1073	! -----------------------------------------------------------------------------!
[2696]	1074	!> Set temporary topography flags and reference buildings on top of underlying
	1075	!> orography.
	1076	!------------------------------------------------------------------------------!
	1077	SUBROUTINE process_topography( topo_3d )
	1078
	1079	USE arrays_3d, &
[2747]	1080	ONLY: zu, zw
[2696]	1081
	1082	USE control_parameters, &
[3294]	1083	ONLY: bc_lr_cyc, bc_ns_cyc, message_string, ocean_mode
[2696]	1084
	1085	USE indices, &
	1086	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
	1087	nzt
	1088
	1089	USE netcdf_data_input_mod, &
[3115]	1090	ONLY: buildings_f, building_id_f, building_type_f, input_pids_static, &
[2696]	1091	terrain_height_f
	1092
	1093	USE kinds
	1094
	1095	USE pegrid
	1096
	1097	IMPLICIT NONE
	1098
[2867]	1099	INTEGER(iwp) :: i !< running index along x-direction
	1100	INTEGER(iwp) :: j !< running index along y-direction
	1101	INTEGER(iwp) :: k !< running index along z-direction with respect to numeric grid
	1102	INTEGER(iwp) :: k2 !< running index along z-direction with respect to netcdf grid
	1103	INTEGER(iwp) :: nr !< index variable indication maximum terrain height for respective building ID
	1104	INTEGER(iwp) :: num_build !< counter for number of buildings
	1105	INTEGER(iwp) :: topo_top_index !< orography top index, used to map 3D buildings onto terrain
[2696]	1106
	1107	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: displace_dum !< displacements of start addresses, used for MPI_ALLGATHERV
	1108	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids !< building IDs on entire model domain
	1109	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final !< building IDs on entire model domain, multiple occurences are sorted out
	1110	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_final_tmp !< temporary array used for resizing
	1111	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l !< building IDs on local subdomain
	1112	INTEGER(iwp), DIMENSION(:), ALLOCATABLE :: build_ids_l_tmp !< temporary array used to resize array of building IDs
	1113
	1114	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings !< number of buildings with different ID on entire model domain
	1115	INTEGER(iwp), DIMENSION(0:numprocs-1) :: num_buildings_l !< number of buildings with different ID on local subdomain
	1116
	1117	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	1118
	1119	REAL(wp) :: ocean_offset !< offset to consider inverse vertical coordinate at topography definition
[3103]	1120	REAL(wp) :: oro_min = 0.0_wp !< minimum terrain height in entire model domain, used to reference terrain to zero
[2696]	1121	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max !< maximum terrain height occupied by an building with certain id
	1122	REAL(wp), DIMENSION(:), ALLOCATABLE :: oro_max_l !< maximum terrain height occupied by an building with certain id, on local subdomain
	1123
	1124	!
[3103]	1125	!-- Reference lowest terrain height to zero. In case the minimum terrain height
	1126	!-- is non-zero, all grid points of the lower vertical grid levels might be
	1127	!-- entirely below the surface, meaning a waste of computational resources.
	1128	!-- In order to avoid this, remove the lowest terrain height. Please note,
	1129	!-- in case of a nested run, the global minimum from all parent and childs
	1130	!-- need to be remove to avoid steep edges at the child-domain boundaries.
	1131	IF ( input_pids_static ) THEN
[4159]	1132
[3200]	1133	#if defined( __parallel )
[3103]	1134	CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, &
	1135	MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
[3200]	1136	#else
	1137	oro_min = MINVAL( terrain_height_f%var )
	1138	#endif
[3103]	1139	terrain_height_f%var = terrain_height_f%var - oro_min
	1140	!
	1141	!-- Give an informative message that terrain height is referenced to zero
	1142	IF ( oro_min > 0.0_wp ) THEN
	1143	WRITE( message_string, * ) 'Terrain height was internally shifted '//&
	1144	'downwards by ', oro_min, 'meter(s) to save ' // &
	1145	'computational resources.'
	1146	CALL message( 'init_grid', 'PA0505', 0, 0, 0, 6, 0 )
	1147	ENDIF
	1148	ENDIF
	1149
	1150	!
[2696]	1151	!-- In the following, buildings and orography are further preprocessed
	1152	!-- before they are mapped on the LES grid.
	1153	!-- Buildings are mapped on top of the orography by maintaining the roof
	1154	!-- shape of the building. This can be achieved by referencing building on
	1155	!-- top of the maximum terrain height within the area occupied by the
	1156	!-- respective building. As buildings and terrain height are defined PE-wise,
	1157	!-- parallelization of this referencing is required (a building can be
	1158	!-- distributed between different PEs).
	1159	!-- In a first step, determine the number of buildings with different
	1160	!-- building id on each PE. In a next step, all building ids are gathered
	1161	!-- into one array which is present to all PEs. For each building ID,
	1162	!-- the maximum terrain height occupied by the respective building is
	1163	!-- computed and distributed to each PE.
	1164	!-- Finally, for each building id and its respective reference orography,
	1165	!-- builidings are mapped on top.
	1166	!--
	1167	!-- First, pre-set topography flags, bit 1 indicates orography, bit 2
	1168	!-- buildings
	1169	!-- classify the respective surfaces.
	1170	topo_3d = IBSET( topo_3d, 0 )
	1171	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
	1172	!
[3051]	1173	!-- In order to map topography on PALM grid also in case of ocean simulations,
	1174	!-- pre-calculate an offset value.
[3294]	1175	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[3051]	1176	!
[2696]	1177	!-- Reference buildings on top of orography. This is not necessary
	1178	!-- if topography is read from ASCII file as no distinction between buildings
	1179	!-- and terrain height can be made. Moreover, this is also not necessary if
	1180	!-- urban-surface and land-surface model are used at the same time.
[2897]	1181	IF ( input_pids_static ) THEN
	1182
	1183	IF ( buildings_f%from_file ) THEN
	1184	num_buildings_l = 0
	1185	num_buildings = 0
[2696]	1186	!
[3925]	1187	!-- Allocate at least one element for building ids and give it an inital
	1188	!-- negative value that will be overwritten later. This, however, is
	1189	!-- necessary in case there all IDs in the model domain are fill values.
[2897]	1190	ALLOCATE( build_ids_l(1) )
[3925]	1191	build_ids_l = -1
[2897]	1192	DO i = nxl, nxr
	1193	DO j = nys, nyn
	1194	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1195	IF ( num_buildings_l(myid) > 0 ) THEN
[4144]	1196	IF ( ANY( building_id_f%var(j,i) == build_ids_l ) ) &
[2897]	1197	THEN
	1198	CYCLE
	1199	ELSE
	1200	num_buildings_l(myid) = num_buildings_l(myid) + 1
[2696]	1201	!
	1202	!-- Resize array with different local building ids
	1203	ALLOCATE( build_ids_l_tmp(1:SIZE(build_ids_l)) )
	1204	build_ids_l_tmp = build_ids_l
	1205	DEALLOCATE( build_ids_l )
	1206	ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
	1207	build_ids_l(1:num_buildings_l(myid)-1) = &
	1208	build_ids_l_tmp(1:num_buildings_l(myid)-1)
	1209	build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
	1210	DEALLOCATE( build_ids_l_tmp )
	1211	ENDIF
	1212	!
[2897]	1213	!-- First occuring building id on PE
	1214	ELSE
	1215	num_buildings_l(myid) = num_buildings_l(myid) + 1
	1216	build_ids_l(1) = building_id_f%var(j,i)
	1217	ENDIF
[2696]	1218	ENDIF
[2897]	1219	ENDDO
[2696]	1220	ENDDO
	1221	!
[2897]	1222	!-- Determine number of different building ids for the entire domain
[2696]	1223	#if defined( __parallel )
[2897]	1224	CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, &
	1225	MPI_INTEGER, MPI_SUM, comm2d, ierr )
[2696]	1226	#else
[2897]	1227	num_buildings = num_buildings_l
[2696]	1228	#endif
	1229	!
[2897]	1230	!-- Gather all buildings ids on each PEs.
	1231	!-- First, allocate array encompassing all building ids in model domain.
	1232	ALLOCATE( build_ids(1:SUM(num_buildings)) )
[2696]	1233	#if defined( __parallel )
	1234	!
[2897]	1235	!-- Allocate array for displacements.
	1236	!-- As each PE may has a different number of buildings, so that
	1237	!-- the block sizes send by each PE may not be equal. Hence,
	1238	!-- information about the respective displacement is required, indicating
	1239	!-- the respective adress where each MPI-task writes into the receive
	1240	!-- buffer array
	1241	ALLOCATE( displace_dum(0:numprocs-1) )
	1242	displace_dum(0) = 0
	1243	DO i = 1, numprocs-1
	1244	displace_dum(i) = displace_dum(i-1) + num_buildings(i-1)
	1245	ENDDO
[2696]	1246
[2897]	1247	CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), &
	1248	num_buildings(myid), &
	1249	MPI_INTEGER, &
	1250	build_ids, &
	1251	num_buildings, &
	1252	displace_dum, &
	1253	MPI_INTEGER, &
	1254	comm2d, ierr )
[2696]	1255
[2897]	1256	DEALLOCATE( displace_dum )
[2696]	1257
	1258	#else
[2897]	1259	build_ids = build_ids_l
[2696]	1260	#endif
	1261
	1262	!
[2897]	1263	!-- Note, in parallel mode building ids can occure mutliple times, as
	1264	!-- each PE has send its own ids. Therefore, sort out building ids which
	1265	!-- appear more than one time.
	1266	num_build = 0
	1267	DO nr = 1, SIZE(build_ids)
[2696]	1268
[2897]	1269	IF ( ALLOCATED(build_ids_final) ) THEN
[4144]	1270	IF ( ANY( build_ids(nr) == build_ids_final ) ) THEN
[2897]	1271	CYCLE
	1272	ELSE
	1273	num_build = num_build + 1
	1274	!
	1275	!-- Resize
	1276	ALLOCATE( build_ids_final_tmp(1:num_build) )
	1277	build_ids_final_tmp(1:num_build-1) = build_ids_final(1:num_build-1)
	1278	DEALLOCATE( build_ids_final )
	1279	ALLOCATE( build_ids_final(1:num_build) )
	1280	build_ids_final(1:num_build-1) = build_ids_final_tmp(1:num_build-1)
	1281	build_ids_final(num_build) = build_ids(nr)
	1282	DEALLOCATE( build_ids_final_tmp )
	1283	ENDIF
[2696]	1284	ELSE
	1285	num_build = num_build + 1
	1286	ALLOCATE( build_ids_final(1:num_build) )
	1287	build_ids_final(num_build) = build_ids(nr)
[2897]	1288	ENDIF
	1289	ENDDO
[2696]	1290
	1291	!
[3051]	1292	!-- Determine maximumum terrain height occupied by the respective
	1293	!-- building and temporalily store on oro_max
[2897]	1294	ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
	1295	ALLOCATE( oro_max(1:SIZE(build_ids_final)) )
	1296	oro_max_l = 0.0_wp
[2696]	1297
[2897]	1298	DO nr = 1, SIZE(build_ids_final)
[4159]	1299	oro_max_l(nr) = MAXVAL( &
	1300	MERGE( terrain_height_f%var(nys:nyn,nxl:nxr), &
	1301	0.0_wp, &
	1302	building_id_f%var(nys:nyn,nxl:nxr) == &
[2897]	1303	build_ids_final(nr) ) )
	1304	ENDDO
[2696]	1305
	1306	#if defined( __parallel )
[2897]	1307	IF ( SIZE(build_ids_final) >= 1 ) THEN
[4159]	1308	CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
[2897]	1309	MPI_MAX, comm2d, ierr )
	1310	ENDIF
[2696]	1311	#else
[2897]	1312	oro_max = oro_max_l
[2696]	1313	#endif
[3051]	1314	!
	1315	!-- Finally, determine discrete grid height of maximum orography occupied
[4159]	1316	!-- by a building. Use all-or-nothing approach, i.e. if terrain
	1317	!-- exceeds the scalar level the grid box is fully terrain and the
	1318	!-- maximum terrain is set to the zw level.
	1319	!-- terrain or
[3051]	1320	oro_max_l = 0.0
	1321	DO nr = 1, SIZE(build_ids_final)
	1322	DO k = nzb, nzt
	1323	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3142]	1324	oro_max_l(nr) = zw(k) - ocean_offset
[3051]	1325	ENDDO
[3142]	1326	oro_max(nr) = oro_max_l(nr)
[3051]	1327	ENDDO
[2897]	1328	ENDIF
[2696]	1329	!
[4245]	1330	!-- Allocate array for storing terrain height under buildings
	1331	IF ( buildings_f%from_file ) THEN
	1332	ALLOCATE( buildings_f%oro_max(nysg:nyng,nxlg:nxrg) )
	1333	buildings_f%oro_max = buildings_f%fill1
	1334	END IF
	1335	!
[2867]	1336	!-- Map orography as well as buildings onto grid.
[2696]	1337	DO i = nxl, nxr
	1338	DO j = nys, nyn
[2867]	1339	topo_top_index = 0
[3142]	1340	!
	1341	!-- Obtain index in global building_id array
	1342	IF ( buildings_f%from_file ) THEN
	1343	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1344	!
	1345	!-- Determine index where maximum terrain height occupied by
	1346	!-- the respective building height is stored.
	1347	nr = MINLOC( ABS( build_ids_final - &
	1348	building_id_f%var(j,i) ), DIM = 1 )
[4245]	1349	!
	1350	!-- Save grid-indexed oro_max
	1351	buildings_f%oro_max(j,i) = oro_max(nr)
[3142]	1352	ENDIF
	1353	ENDIF
[2696]	1354	DO k = nzb, nzt
	1355	!
	1356	!-- In a first step, if grid point is below or equal the given
	1357	!-- terrain height, grid point is flagged to be of type natural.
	1358	!-- Please note, in case there is also a building which is lower
	1359	!-- than the vertical grid spacing, initialization of surface
	1360	!-- attributes will not be correct as given surface information
	1361	!-- will not be in accordance to the classified grid points.
[4159]	1362	!-- Hence, in this case, also a building flag.
[2747]	1363	IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) ) THEN
[4189]	1364	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1365	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1366	topo_top_index = k ! topo_top_index + 1
[2696]	1367	ENDIF
	1368	!
	1369	!-- Set building grid points. Here, only consider 2D buildings.
	1370	!-- 3D buildings require separate treatment.
[2897]	1371	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
[4159]	1372	!
	1373	!-- Fill-up the terrain to the level of maximum orography
	1374	!-- within the building-covered area.
	1375	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1376	!
	1377	!-- Note, oro_max is always on zw level
	1378	IF ( zu(k) - ocean_offset < oro_max(nr) ) THEN
[2696]	1379	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1380	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1381	ELSEIF ( zu(k) - ocean_offset <= &
	1382	oro_max(nr) + buildings_f%var_2d(j,i) ) THEN
	1383	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[2696]	1384	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1385	ENDIF
	1386	ENDIF
	1387	ENDIF
	1388	ENDDO
	1389	!
[4159]	1390	!-- Special treatment for non grid-resolved buildings. This case,
	1391	!-- the uppermost terrain grid point is flagged as building as well
	1392	!-- well, even though no building exists at all. However, the
	1393	!-- surface element will be identified as urban-surface and the
	1394	!-- input data provided by the drivers is consistent to the surface
	1395	!-- classification. Else, all non grid-resolved buildings would vanish
	1396	!-- and identified as terrain grid points, which, however, won't be
	1397	!-- consistent with the input data.
	1398	IF ( buildings_f%from_file .AND. buildings_f%lod == 1 ) THEN
	1399	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1400	DO k = nzb, nzt
	1401	IF( zw(k) - ocean_offset == oro_max(nr) ) THEN
	1402	IF ( buildings_f%var_2d(j,i) <= zu(k+1) - zw(k) ) THEN
	1403	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1404	ENDIF
	1405	ENDIF
	1406	ENDDO
	1407	ENDIF
	1408	ENDIF
	1409	!
[2696]	1410	!-- Map 3D buildings onto terrain height.
[2867]	1411	!-- In case of any slopes, map building on top of maximum terrain
	1412	!-- height covered by the building. In other words, extend
	1413	!-- building down to the respective local terrain-surface height.
[2897]	1414	IF ( buildings_f%from_file .AND. buildings_f%lod == 2 ) THEN
[2696]	1415	IF ( building_id_f%var(j,i) /= building_id_f%fill ) THEN
	1416	!
[3051]	1417	!-- Extend building down to the terrain surface, i.e. fill-up
	1418	!-- surface irregularities below a building. Note, oro_max
	1419	!-- is already a discrete height according to the all-or-nothing
	1420	!-- approach, i.e. grid box is either topography or atmosphere,
	1421	!-- terrain top is defined at upper bound of the grid box.
	1422	!-- Hence, check for zw in this case.
[3115]	1423	!-- Note, do this only for buildings which are surface mounted,
	1424	!-- i.e. building types 1-6. Below bridges, which are represented
	1425	!-- exclusively by building type 7, terrain shape should be
	1426	!-- maintained.
[3855]	1427	IF ( building_type_f%from_file ) THEN
	1428	IF ( building_type_f%var(j,i) /= 7 ) THEN
	1429	DO k = topo_top_index + 1, nzt + 1
[4159]	1430	IF ( zu(k) - ocean_offset <= oro_max(nr) ) THEN
[3855]	1431	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4159]	1432	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
[3855]	1433	ENDIF
	1434	ENDDO
	1435	!
	1436	!-- After surface irregularities are smoothen, determine
	1437	!-- lower start index where building starts.
	1438	DO k = nzb, nzt
[4159]	1439	IF ( zu(k) - ocean_offset <= oro_max(nr) ) &
[3855]	1440	topo_top_index = k
	1441	ENDDO
	1442	ENDIF
[3115]	1443	ENDIF
[3051]	1444	!
	1445	!-- Finally, map building on top.
[2867]	1446	k2 = 0
	1447	DO k = topo_top_index, nzt + 1
[2796]	1448	IF ( k2 <= buildings_f%nz-1 ) THEN
[2696]	1449	IF ( buildings_f%var_3d(k2,j,i) == 1 ) THEN
	1450	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1451	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1452	ENDIF
	1453	ENDIF
	1454	k2 = k2 + 1
	1455	ENDDO
	1456	ENDIF
	1457	ENDIF
	1458	ENDDO
	1459	ENDDO
	1460	!
[4265]	1461	!-- Horizontal exchange the oro_max array, which is required to for
	1462	!-- initialization of building-surface properties.
	1463	IF ( ALLOCATED( buildings_f%oro_max ) ) THEN
	1464	CALL exchange_horiz_2d( buildings_f%oro_max(:,:), nbgp )
	1465	ENDIF
[4245]	1466	!
[2696]	1467	!-- Deallocate temporary arrays required for processing and reading data
	1468	IF ( ALLOCATED( oro_max ) ) DEALLOCATE( oro_max )
	1469	IF ( ALLOCATED( oro_max_l ) ) DEALLOCATE( oro_max_l )
	1470	IF ( ALLOCATED( build_ids_final ) ) DEALLOCATE( build_ids_final )
	1471	!
	1472	!-- Topography input via ASCII format.
	1473	ELSE
[3294]	1474	ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
[4159]	1475	!
	1476	!-- Initialize topography bit 0 (indicates obstacle) everywhere to zero
	1477	!-- and clear all grid points at nzb, where alway a surface is defined.
	1478	!-- Further, set also bit 1 (indicates terrain) at nzb, which is further
	1479	!-- used for masked data output and further processing. Note, in the
	1480	!-- ASCII case no distinction is made between buildings and terrain,
	1481	!-- so that setting of bit 1 and 2 at the same time has no effect.
[2696]	1482	topo_3d = IBSET( topo_3d, 0 )
	1483	topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
[4159]	1484	topo_3d(nzb,:,:) = IBSET( topo_3d(nzb,:,:), 1 )
[2696]	1485	DO i = nxl, nxr
	1486	DO j = nys, nyn
	1487	DO k = nzb, nzt
[3538]	1488	!
	1489	!-- Flag topography for all grid points which are below
	1490	!-- the local topography height.
	1491	!-- Note, each topography is flagged as building.
[2747]	1492	IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) ) THEN
[4189]	1493	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	1494	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 ) !indicates building
[2696]	1495	ENDIF
	1496	ENDDO
	1497	ENDDO
	1498	ENDDO
	1499	ENDIF
	1500
	1501	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1502
	1503	IF ( .NOT. bc_ns_cyc ) THEN
	1504	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1505	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1506	ENDIF
	1507
	1508	IF ( .NOT. bc_lr_cyc ) THEN
	1509	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1510	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1511	ENDIF
	1512
	1513	END SUBROUTINE process_topography
	1514
	1515
	1516	! Description:
	1517	! -----------------------------------------------------------------------------!
	1518	!> Filter topography, i.e. fill holes resolved by only one grid point.
	1519	!> Such holes are suspected to lead to velocity blow-ups as continuity
	1520	!> equation on discrete grid cannot be fulfilled in such case.
	1521	!------------------------------------------------------------------------------!
	1522	SUBROUTINE filter_topography( topo_3d )
	1523
	1524	USE control_parameters, &
	1525	ONLY: bc_lr_cyc, bc_ns_cyc, message_string
	1526
	1527	USE indices, &
	1528	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
	1529
	1530	USE netcdf_data_input_mod, &
	1531	ONLY: building_id_f, building_type_f
	1532
	1533	USE pegrid
	1534
	1535	IMPLICIT NONE
	1536
[2893]	1537	LOGICAL :: filled = .FALSE. !< flag indicating if holes were filled
	1538
[2696]	1539	INTEGER(iwp) :: i !< running index along x-direction
	1540	INTEGER(iwp) :: j !< running index along y-direction
	1541	INTEGER(iwp) :: k !< running index along z-direction
	1542	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	1543	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	1544	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	1545
[2955]	1546	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_tmp !< temporary 3D-topography used to fill holes
	1547	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo_3d !< 3D-topography array merging buildings and orography
[2696]	1548	!
	1549	!-- Before checking for holes, set lateral boundary conditions for
	1550	!-- topography. After hole-filling, boundary conditions must be set again.
	1551	!-- Several iterations are performed, in order to fill holes which might
	1552	!-- emerge by the filling-algorithm itself.
	1553	ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1554	topo_tmp = 0
	1555
	1556	num_hole = 99999
	1557	DO WHILE ( num_hole > 0 )
	1558
	1559	num_hole = 0
	1560	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
[2955]	1561	!
	1562	!-- Exchange also building ID and type. Note, building_type is an one-byte
	1563	!-- variable.
	1564	IF ( building_id_f%from_file ) &
	1565	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1566	IF ( building_type_f%from_file ) &
	1567	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1568
	1569	topo_tmp = topo_3d
	1570	!
	1571	!-- In case of non-cyclic lateral boundaries, assume lateral boundary to be
	1572	!-- a solid wall. Thus, intermediate spaces of one grid point between
	1573	!-- boundary and some topographic structure will be filled.
	1574	IF ( .NOT. bc_ns_cyc ) THEN
	1575	IF ( nys == 0 ) topo_tmp(:,-1,:) = IBCLR( topo_tmp(:,0,:), 0 )
	1576	IF ( nyn == ny ) topo_tmp(:,ny+1,:) = IBCLR( topo_tmp(:,ny,:), 0 )
	1577	ENDIF
	1578
	1579	IF ( .NOT. bc_lr_cyc ) THEN
	1580	IF ( nxl == 0 ) topo_tmp(:,:,-1) = IBCLR( topo_tmp(:,:,0), 0 )
	1581	IF ( nxr == nx ) topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
	1582	ENDIF
	1583
	1584	num_hole_l = 0
	1585	DO i = nxl, nxr
	1586	DO j = nys, nyn
	1587	DO k = nzb+1, nzt
	1588	IF ( BTEST( topo_tmp(k,j,i), 0 ) ) THEN
	1589	num_wall = 0
	1590	IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) ) &
	1591	num_wall = num_wall + 1
	1592	IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) ) &
	1593	num_wall = num_wall + 1
	1594	IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) ) &
	1595	num_wall = num_wall + 1
	1596	IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) ) &
	1597	num_wall = num_wall + 1
	1598	IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) ) &
	1599	num_wall = num_wall + 1
	1600	IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) ) &
	1601	num_wall = num_wall + 1
	1602
	1603	IF ( num_wall >= 4 ) THEN
	1604	num_hole_l = num_hole_l + 1
	1605	!
[4314]	1606	!-- Clear flag 0 and set special flag ( bit 4) to indicate
[2696]	1607	!-- that new topography point is a result of filtering process.
	1608	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
[4314]	1609	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
[2696]	1610	!
	1611	!-- If filled grid point is occupied by a building, classify
	1612	!-- it as building grid point.
	1613	IF ( building_type_f%from_file ) THEN
	1614	IF ( building_type_f%var(j,i) /= &
	1615	building_type_f%fill .OR. &
	1616	building_type_f%var(j+1,i) /= &
	1617	building_type_f%fill .OR. &
	1618	building_type_f%var(j-1,i) /= &
	1619	building_type_f%fill .OR. &
	1620	building_type_f%var(j,i+1) /= &
	1621	building_type_f%fill .OR. &
	1622	building_type_f%var(j,i-1) /= &
	1623	building_type_f%fill ) THEN
	1624	!
	1625	!-- Set flag indicating building surfaces
	1626	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
	1627	!
	1628	!-- Set building_type and ID at this position if not
	1629	!-- already set. This is required for proper
	1630	!-- initialization of urban-surface energy balance
	1631	!-- solver.
	1632	IF ( building_type_f%var(j,i) == &
	1633	building_type_f%fill ) THEN
	1634
	1635	IF ( building_type_f%var(j+1,i) /= &
	1636	building_type_f%fill ) THEN
	1637	building_type_f%var(j,i) = &
	1638	building_type_f%var(j+1,i)
	1639	building_id_f%var(j,i) = &
	1640	building_id_f%var(j+1,i)
	1641	ELSEIF ( building_type_f%var(j-1,i) /= &
	1642	building_type_f%fill ) THEN
	1643	building_type_f%var(j,i) = &
	1644	building_type_f%var(j-1,i)
	1645	building_id_f%var(j,i) = &
	1646	building_id_f%var(j-1,i)
	1647	ELSEIF ( building_type_f%var(j,i+1) /= &
	1648	building_type_f%fill ) THEN
	1649	building_type_f%var(j,i) = &
	1650	building_type_f%var(j,i+1)
	1651	building_id_f%var(j,i) = &
	1652	building_id_f%var(j,i+1)
	1653	ELSEIF ( building_type_f%var(j,i-1) /= &
	1654	building_type_f%fill ) THEN
	1655	building_type_f%var(j,i) = &
	1656	building_type_f%var(j,i-1)
	1657	building_id_f%var(j,i) = &
	1658	building_id_f%var(j,i-1)
	1659	ENDIF
	1660	ENDIF
	1661	ENDIF
	1662	ENDIF
	1663	!
	1664	!-- If filled grid point is already classified as building
	1665	!-- everything is fine, else classify this grid point as
	1666	!-- natural type grid point. This case, values for the
	1667	!-- surface type are already set.
	1668	IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) ) THEN
	1669	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
	1670	ENDIF
	1671	ENDIF
	1672	ENDIF
	1673	ENDDO
	1674	ENDDO
	1675	ENDDO
	1676	!
	1677	!-- Count the total number of holes, required for informative message.
	1678	#if defined( __parallel )
	1679	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1680	comm2d, ierr )
	1681	#else
	1682	num_hole = num_hole_l
	1683	#endif
[2893]	1684	IF ( num_hole > 0 .AND. .NOT. filled ) filled = .TRUE.
[2696]	1685
[2893]	1686	ENDDO
[2696]	1687	!
[2893]	1688	!-- Create an informative message if any holes were filled.
	1689	IF ( filled ) THEN
	1690	WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' // &
	1691	'resolved by only one grid point ' // &
	1692	'were filled during initialization.'
	1693	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1694	ENDIF
[2696]	1695
	1696	DEALLOCATE( topo_tmp )
	1697	!
	1698	!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
	1699	!-- condition in case of non-cyclic lateral boundaries.
	1700	CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
	1701
	1702	IF ( .NOT. bc_ns_cyc ) THEN
	1703	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1704	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1705	ENDIF
	1706
	1707	IF ( .NOT. bc_lr_cyc ) THEN
	1708	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1709	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1710	ENDIF
[2955]	1711	!
	1712	!-- Exchange building ID and type. Note, building_type is an one-byte variable.
	1713	IF ( building_id_f%from_file ) &
	1714	CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
[3763]	1715	IF ( building_type_f%from_file ) &
	1716	CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
[2696]	1717
	1718	END SUBROUTINE filter_topography
	1719
	1720
	1721	! Description:
	1722	! -----------------------------------------------------------------------------!
	1723	!> Reads topography information from file or sets generic topography. Moreover,
	1724	!> all topography-relevant topography arrays are initialized, and grid flags
	1725	!> are set.
	1726	!------------------------------------------------------------------------------!
	1727	SUBROUTINE init_topo( topo )
	1728
	1729	USE arrays_3d, &
	1730	ONLY: zw
	1731
	1732	USE control_parameters, &
	1733	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
	1734	building_length_y, building_wall_left, building_wall_south, &
	1735	canyon_height, canyon_wall_left, canyon_wall_south, &
	1736	canyon_width_x, canyon_width_y, dp_level_ind_b, dz, &
[3241]	1737	message_string, topography, topography_grid_convention, &
[2696]	1738	tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y, &
	1739	tunnel_wall_depth
	1740
	1741	USE grid_variables, &
	1742	ONLY: dx, dy
	1743
	1744	USE indices, &
	1745	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, &
	1746	nzb, nzt
	1747
	1748	USE kinds
[4189]	1749
	1750	USE netcdf_data_input_mod, &
	1751	ONLY: buildings_f, terrain_height_f
[2696]	1752
	1753	USE pegrid
	1754
	1755	IMPLICIT NONE
	1756
	1757	INTEGER(iwp) :: bh !< temporary vertical index of building height
	1758	INTEGER(iwp) :: blx !< grid point number of building size along x
	1759	INTEGER(iwp) :: bly !< grid point number of building size along y
	1760	INTEGER(iwp) :: bxl !< index for left building wall
	1761	INTEGER(iwp) :: bxr !< index for right building wall
	1762	INTEGER(iwp) :: byn !< index for north building wall
	1763	INTEGER(iwp) :: bys !< index for south building wall
	1764	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	1765	INTEGER(iwp) :: cwx !< grid point number of canyon size along x
	1766	INTEGER(iwp) :: cwy !< grid point number of canyon size along y
	1767	INTEGER(iwp) :: cxl !< index for left canyon wall
	1768	INTEGER(iwp) :: cxr !< index for right canyon wall
	1769	INTEGER(iwp) :: cyn !< index for north canyon wall
	1770	INTEGER(iwp) :: cys !< index for south canyon wall
	1771	INTEGER(iwp) :: i !< index variable along x
	1772	INTEGER(iwp) :: j !< index variable along y
	1773	INTEGER(iwp) :: k !< index variable along z
	1774	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	1775	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	1776	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	1777	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	1778	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	1779	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	1780	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	1781	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	1782	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	1783	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	1784	INTEGER(iwp) :: td !< tunnel wall depth
	1785	INTEGER(iwp) :: th !< height of outer tunnel wall
	1786
	1787	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	1788	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
	1789	!
[4189]	1790	!-- Check for correct setting of the namelist parameter topography. If
	1791	!-- topography information is read from file but topography = 'flat',
	1792	!-- initialization does not properly.
	1793	IF ( ( buildings_f%from_file .OR. terrain_height_f%from_file ) .AND. &
	1794	TRIM( topography ) /= 'read_from_file' ) THEN
	1795	message_string = 'If topography information is provided (via ' // &
	1796	'Netcdf or ASCII input) topography = ' // &
	1797	'"read_from_file" is required.'
	1798	CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
	1799	ENDIF
	1800	!
[1]	1801	!-- Set outer and inner index arrays for non-flat topography.
	1802	!-- Here consistency checks concerning domain size and periodicity are
	1803	!-- necessary.
	1804	!-- Within this SELECT CASE structure only nzb_local is initialized
	1805	!-- individually depending on the chosen topography type, all other index
	1806	!-- arrays are initialized further below.
	1807	SELECT CASE ( TRIM( topography ) )
	1808
	1809	CASE ( 'flat' )
[2696]	1810	!
[2232]	1811	!-- Initialilize 3D topography array, used later for initializing flags
[2696]	1812	topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
[1]	1813
	1814	CASE ( 'single_building' )
	1815	!
	1816	!-- Single rectangular building, by default centered in the middle of the
	1817	!-- total domain
	1818	blx = NINT( building_length_x / dx )
	1819	bly = NINT( building_length_y / dy )
[2232]	1820	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	1821	IF ( ABS( zw(bh) - building_height ) == &
[1675]	1822	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1322]	1823	IF ( building_wall_left == 9999999.9_wp ) THEN
[1]	1824	building_wall_left = ( nx + 1 - blx ) / 2 * dx
	1825	ENDIF
	1826	bxl = NINT( building_wall_left / dx )
	1827	bxr = bxl + blx
	1828
[1322]	1829	IF ( building_wall_south == 9999999.9_wp ) THEN
[2696]	1830	building_wall_south = ( ny + 1 - bly ) / 2 * dy
[1]	1831	ENDIF
	1832	bys = NINT( building_wall_south / dy )
	1833	byn = bys + bly
	1834
	1835	!
	1836	!-- Building size has to meet some requirements
[2696]	1837	IF ( ( bxl < 1 ) .OR. ( bxr > nx-1 ) .OR. ( bxr < bxl+3 ) .OR. &
[1]	1838	( bys < 1 ) .OR. ( byn > ny-1 ) .OR. ( byn < bys+3 ) ) THEN
[274]	1839	WRITE( message_string, * ) 'inconsistent building parameters:', &
[3046]	1840	'&bxl=', bxl, 'bxr=', bxr, 'bys=', bys, &
[274]	1841	'byn=', byn, 'nx=', nx, 'ny=', ny
[254]	1842	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	1843	ENDIF
	1844
[2696]	1845	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[2892]	1846	nzb_local = 0
[1]	1847	!
[1968]	1848	!-- Define the building.
	1849	IF ( bxl <= nxr .AND. bxr >= nxl .AND. &
[2696]	1850	bys <= nyn .AND. byn >= nys ) &
[1968]	1851	nzb_local(MAX(nys,bys):MIN(nyn,byn),MAX(nxl,bxl):MIN(nxr,bxr)) = bh
[2232]	1852	!
[2696]	1853	!-- Set bit array on basis of nzb_local
	1854	DO i = nxl, nxr
	1855	DO j = nys, nyn
	1856	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1857	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1858	ENDDO
	1859	ENDDO
[2696]	1860
	1861	DEALLOCATE( nzb_local )
[2232]	1862
[2696]	1863	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1864	!
	1865	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1866	!-- boundary conditions for topography.
	1867	IF ( .NOT. bc_ns_cyc ) THEN
	1868	IF ( nys == 0 ) THEN
	1869	DO i = 1, nbgp
	1870	topo(:,nys-i,:) = topo(:,nys,:)
	1871	ENDDO
	1872	ENDIF
	1873	IF ( nyn == ny ) THEN
	1874	DO i = 1, nbgp
	1875	topo(:,nyn+i,:) = topo(:,nyn,:)
	1876	ENDDO
	1877	ENDIF
	1878	ENDIF
	1879	IF ( .NOT. bc_lr_cyc ) THEN
	1880	IF ( nxl == 0 ) THEN
	1881	DO i = 1, nbgp
	1882	topo(:,:,nxl-i) = topo(:,:,nxl)
	1883	ENDDO
	1884	ENDIF
	1885	IF ( nxr == nx ) THEN
	1886	DO i = 1, nbgp
	1887	topo(:,:,nxr+i) = topo(:,:,nxr)
	1888	ENDDO
	1889	ENDIF
	1890	ENDIF
[2232]	1891
[240]	1892	CASE ( 'single_street_canyon' )
	1893	!
	1894	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	1895	!-- The canyon is centered in the other direction by default.
[1322]	1896	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	1897	!
	1898	!-- Street canyon in y direction
	1899	cwx = NINT( canyon_width_x / dx )
[1322]	1900	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[240]	1901	canyon_wall_left = ( nx + 1 - cwx ) / 2 * dx
	1902	ENDIF
	1903	cxl = NINT( canyon_wall_left / dx )
	1904	cxr = cxl + cwx
[1322]	1905	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	1906	!
	1907	!-- Street canyon in x direction
	1908	cwy = NINT( canyon_width_y / dy )
[1322]	1909	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[240]	1910	canyon_wall_south = ( ny + 1 - cwy ) / 2 * dy
	1911	ENDIF
	1912	cys = NINT( canyon_wall_south / dy )
	1913	cyn = cys + cwy
[2696]	1914
[240]	1915	ELSE
[254]	1916
	1917	message_string = 'no street canyon width given'
	1918	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	1919
[240]	1920	ENDIF
	1921
[2232]	1922	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	1923	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	1924	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
[240]	1925	dp_level_ind_b = ch
	1926	!
	1927	!-- Street canyon size has to meet some requirements
[1322]	1928	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1353]	1929	IF ( ( cxl < 1 ) .OR. ( cxr > nx-1 ) .OR. ( cwx < 3 ) .OR. &
[2696]	1930	( ch < 3 ) ) THEN
[1353]	1931	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1932	'&cxl=', cxl, ' cxr=', cxr, &
[3045]	1933	' cwx=', cwx, &
	1934	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1935	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	1936	ENDIF
[1322]	1937	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1353]	1938	IF ( ( cys < 1 ) .OR. ( cyn > ny-1 ) .OR. ( cwy < 3 ) .OR. &
[2696]	1939	( ch < 3 ) ) THEN
[1353]	1940	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
[3046]	1941	'&cys=', cys, ' cyn=', cyn, &
[3045]	1942	' cwy=', cwy, &
	1943	' ch=', ch, ' nx=', nx, ' ny=', ny
[254]	1944	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	1945	ENDIF
	1946	ENDIF
[1353]	1947	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	1948	canyon_width_y /= 9999999.9_wp ) THEN
	1949	message_string = 'inconsistent canyon parameters:' // &
[3046]	1950	'&street canyon can only be oriented' // &
[3045]	1951	' either in x- or in y-direction'
[254]	1952	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	1953	ENDIF
	1954
[2696]	1955	ALLOCATE( nzb_local(nysg:nyng,nxlg:nxrg) )
[240]	1956	nzb_local = ch
[1322]	1957	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1968]	1958	IF ( cxl <= nxr .AND. cxr >= nxl ) &
	1959	nzb_local(:,MAX(nxl,cxl+1):MIN(nxr,cxr-1)) = 0
[1322]	1960	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1968]	1961	IF ( cys <= nyn .AND. cyn >= nys ) &
	1962	nzb_local(MAX(nys,cys+1):MIN(nyn,cyn-1),:) = 0
[240]	1963	ENDIF
[2232]	1964	!
[2696]	1965	!-- Set bit array on basis of nzb_local
	1966	DO i = nxl, nxr
	1967	DO j = nys, nyn
	1968	topo(nzb_local(j,i)+1:nzt+1,j,i) = &
	1969	IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
[2232]	1970	ENDDO
	1971	ENDDO
[2696]	1972	DEALLOCATE( nzb_local )
[1994]	1973
[2696]	1974	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	1975	!
	1976	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1977	!-- boundary conditions for topography.
	1978	IF ( .NOT. bc_ns_cyc ) THEN
	1979	IF ( nys == 0 ) THEN
	1980	DO i = 1, nbgp
	1981	topo(:,nys-i,:) = topo(:,nys,:)
	1982	ENDDO
	1983	ENDIF
	1984	IF ( nyn == ny ) THEN
	1985	DO i = 1, nbgp
	1986	topo(:,nyn+i,:) = topo(:,nyn,:)
	1987	ENDDO
	1988	ENDIF
	1989	ENDIF
	1990	IF ( .NOT. bc_lr_cyc ) THEN
	1991	IF ( nxl == 0 ) THEN
	1992	DO i = 1, nbgp
	1993	topo(:,:,nxl-i) = topo(:,:,nxl)
	1994	ENDDO
	1995	ENDIF
	1996	IF ( nxr == nx ) THEN
	1997	DO i = 1, nbgp
	1998	topo(:,:,nxr+i) = topo(:,:,nxr)
	1999	ENDDO
	2000	ENDIF
	2001	ENDIF
[2232]	2002
	2003	CASE ( 'tunnel' )
	2004
	2005	!
	2006	!-- Tunnel height
	2007	IF ( tunnel_height == 9999999.9_wp ) THEN
	2008	th = zw( INT( 0.2 * nz) )
	2009	ELSE
	2010	th = tunnel_height
	2011	ENDIF
	2012	!
	2013	!-- Tunnel-wall depth
[2696]	2014	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
[3065]	2015	td = MAX ( dx, dy, dz(1) )
[2232]	2016	ELSE
	2017	td = tunnel_wall_depth
	2018	ENDIF
	2019	!
	2020	!-- Check for tunnel width
	2021	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	2022	tunnel_width_y == 9999999.9_wp ) THEN
	2023	message_string = 'No tunnel width is given. '
[2274]	2024	CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
[2232]	2025	ENDIF
	2026	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2027	tunnel_width_y /= 9999999.9_wp ) THEN
	2028	message_string = 'Inconsistent tunnel parameters:' // &
	2029	'tunnel can only be oriented' // &
	2030	'either in x- or in y-direction.'
[2274]	2031	CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
[2232]	2032	ENDIF
	2033	!
	2034	!-- Tunnel axis along y
	2035	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	2036	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
	2037	message_string = 'Tunnel width too large'
[2274]	2038	CALL message( 'init_grid', 'PA0282', 1, 2, 0, 6, 0 )
[2232]	2039	ENDIF
	2040
	2041	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	2042	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	2043	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	2044	( tunnel_width_x * 0.5_wp - td ) )
	2045	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
[2696]	2046	( tunnel_width_x * 0.5_wp - td ) )
[2232]	2047
	2048	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	2049	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	2050	tys_in = tys_out
	2051	tye_in = tye_out
	2052	ENDIF
[2696]	2053	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	2054	tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx ) &
	2055	THEN
[2232]	2056	message_string = 'Tunnel width too small'
[2274]	2057	CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
[2232]	2058	ENDIF
	2059	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
[2696]	2060	tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy ) &
	2061	THEN
[2232]	2062	message_string = 'Tunnel width too small'
[2274]	2063	CALL message( 'init_grid', 'PA0455', 1, 2, 0, 6, 0 )
[2232]	2064	ENDIF
	2065	!
	2066	!-- Tunnel axis along x
	2067	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	2068	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
	2069	message_string = 'Tunnel width too large'
[2274]	2070	CALL message( 'init_grid', 'PA0456', 1, 2, 0, 6, 0 )
[2232]	2071	ENDIF
	2072
	2073	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	2074	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	2075	txs_in = txs_out
	2076	txe_in = txe_out
	2077
	2078	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	2079	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	2080	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
[2696]	2081	( tunnel_width_y * 0.5_wp - td ) )
[2232]	2082	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	2083	( tunnel_width_y * 0.5_wp - td ) )
	2084	ENDIF
	2085
[2696]	2086	topo = 0
[2232]	2087	DO i = nxl, nxr
	2088	DO j = nys, nyn
	2089	!
	2090	!-- Use heaviside function to model outer tunnel surface
	2091	hv_out = th * 0.5_wp * &
	2092	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	2093	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	2094
	2095	hv_out = hv_out * 0.5_wp * &
	2096	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	2097	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
[2696]	2098	!
[2232]	2099	!-- Use heaviside function to model inner tunnel surface
	2100	hv_in = ( th - td ) * 0.5_wp * &
	2101	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	2102	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	2103
	2104	hv_in = hv_in * 0.5_wp * &
	2105	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	2106	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	2107	!
	2108	!-- Set flags at x-y-positions without any tunnel surface
	2109	IF ( hv_out - hv_in == 0.0_wp ) THEN
[2696]	2110	topo(nzb+1:nzt+1,j,i) = IBSET( topo(nzb+1:nzt+1,j,i), 0 )
[2232]	2111	!
	2112	!-- Set flags at x-y-positions with tunnel surfaces
	2113	ELSE
	2114	DO k = nzb + 1, nzt + 1
	2115	!
	2116	!-- Inner tunnel
	2117	IF ( hv_out - hv_in == th ) THEN
	2118	IF ( zw(k) <= hv_out ) THEN
[2696]	2119	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2120	ELSE
[2696]	2121	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2122	ENDIF
	2123	ENDIF
	2124	!
	2125	!-- Lateral tunnel walls
	2126	IF ( hv_out - hv_in == td ) THEN
	2127	IF ( zw(k) <= hv_in ) THEN
[2696]	2128	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2129	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
[2696]	2130	topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
[2232]	2131	ELSEIF ( zw(k) > hv_out ) THEN
[2696]	2132	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2133	ENDIF
	2134	ENDIF
	2135	ENDDO
	2136	ENDIF
	2137	ENDDO
	2138	ENDDO
	2139
[2696]	2140	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2823]	2141	!
	2142	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2143	!-- boundary conditions for topography.
	2144	IF ( .NOT. bc_ns_cyc ) THEN
	2145	IF ( nys == 0 ) THEN
	2146	DO i = 1, nbgp
	2147	topo(:,nys-i,:) = topo(:,nys,:)
	2148	ENDDO
	2149	ENDIF
	2150	IF ( nyn == ny ) THEN
	2151	DO i = 1, nbgp
	2152	topo(:,nyn+i,:) = topo(:,nyn,:)
	2153	ENDDO
	2154	ENDIF
	2155	ENDIF
	2156	IF ( .NOT. bc_lr_cyc ) THEN
	2157	IF ( nxl == 0 ) THEN
	2158	DO i = 1, nbgp
	2159	topo(:,:,nxl-i) = topo(:,:,nxl)
	2160	ENDDO
	2161	ENDIF
	2162	IF ( nxr == nx ) THEN
	2163	DO i = 1, nbgp
	2164	topo(:,:,nxr+i) = topo(:,:,nxr)
	2165	ENDDO
	2166	ENDIF
	2167	ENDIF
[2232]	2168
[1]	2169	CASE ( 'read_from_file' )
	2170	!
[2696]	2171	!-- Note, topography information have been already read.
	2172	!-- If required, further process topography, i.e. reference buildings on
	2173	!-- top of orography and set temporary 3D topography array, which is
	2174	!-- used later to set grid flags. Calling of this rouinte is also
	2175	!-- required in case of ASCII input, even though no distinction between
	2176	!-- terrain- and building height is made in this case.
	2177	CALL process_topography( topo )
[1968]	2178	!
[2696]	2179	!-- Filter holes resolved by only one grid-point
	2180	CALL filter_topography( topo )
[1968]	2181	!
[2696]	2182	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	2183	!-- conditions.
	2184	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2185	!
[4314]	2186	!-- Set lateral boundary conditions for topography on all ghost layers
[1968]	2187	IF ( .NOT. bc_ns_cyc ) THEN
[2550]	2188	IF ( nys == 0 ) THEN
[2696]	2189	DO i = 1, nbgp
	2190	topo(:,nys-i,:) = topo(:,nys,:)
	2191	ENDDO
[2550]	2192	ENDIF
[2696]	2193	IF ( nyn == ny ) THEN
	2194	DO i = 1, nbgp
	2195	topo(:,nyn+i,:) = topo(:,nyn,:)
	2196	ENDDO
	2197	ENDIF
[1942]	2198	ENDIF
[1910]	2199
[1968]	2200	IF ( .NOT. bc_lr_cyc ) THEN
[2550]	2201	IF ( nxl == 0 ) THEN
[2696]	2202	DO i = 1, nbgp
	2203	topo(:,:,nxl-i) = topo(:,:,nxl)
[2232]	2204	ENDDO
[2696]	2205	ENDIF
	2206	IF ( nxr == nx ) THEN
	2207	DO i = 1, nbgp
	2208	topo(:,:,nxr+i) = topo(:,:,nxr)
	2209	ENDDO
	2210	ENDIF
[2232]	2211	ENDIF
	2212
[667]	2213
[1]	2214	CASE DEFAULT
[2696]	2215	!
[1]	2216	!-- The DEFAULT case is reached either if the parameter topography
[217]	2217	!-- contains a wrong character string or if the user has defined a special
[1]	2218	!-- case in the user interface. There, the subroutine user_init_grid
	2219	!-- checks which of these two conditions applies.
[2696]	2220	CALL user_init_grid( topo )
	2221	CALL filter_topography( topo )
[1]	2222
	2223	END SELECT
	2224	!
	2225	!-- Consistency checks and index array initialization are only required for
[2696]	2226	!-- non-flat topography.
[1]	2227	IF ( TRIM( topography ) /= 'flat' ) THEN
	2228	!
[2232]	2229	!-- In case of non-flat topography, check whether the convention how to
	2230	!-- define the topography grid has been set correctly, or whether the default
	2231	!-- is applicable. If this is not possible, abort.
	2232	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
	2233	IF ( TRIM( topography ) /= 'single_building' .AND. &
	2234	TRIM( topography ) /= 'single_street_canyon' .AND. &
	2235	TRIM( topography ) /= 'tunnel' .AND. &
	2236	TRIM( topography ) /= 'read_from_file') THEN
	2237	!-- The default value is not applicable here, because it is only valid
[3045]	2238	!-- for the four standard cases 'single_building',
	2239	!-- 'single_street_canyon', 'tunnel' and 'read_from_file'
[2232]	2240	!-- defined in init_grid.
	2241	WRITE( message_string, * ) &
[2696]	2242	'The value for "topography_grid_convention" ', &
[3046]	2243	'is not set. Its default value is & only valid for ', &
[3045]	2244	'"topography" = ''single_building'', ''tunnel'' ', &
[3046]	2245	'''single_street_canyon'' & or ''read_from_file''.', &
	2246	'& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2247	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	2248	ELSE
	2249	!-- The default value is applicable here.
	2250	!-- Set convention according to topography.
	2251	IF ( TRIM( topography ) == 'single_building' .OR. &
	2252	TRIM( topography ) == 'single_street_canyon' ) THEN
	2253	topography_grid_convention = 'cell_edge'
	2254	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	2255	TRIM( topography ) == 'tunnel') THEN
	2256	topography_grid_convention = 'cell_center'
	2257	ENDIF
	2258	ENDIF
	2259	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	2260	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	2261	WRITE( message_string, * ) &
[2696]	2262	'The value for "topography_grid_convention" is ', &
[3046]	2263	'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
[2232]	2264	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	2265	ENDIF
[1]	2266
[2169]	2267
[217]	2268	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	2269	!
[217]	2270	!-- The array nzb_local as defined using the 'cell_edge' convention
	2271	!-- describes the actual total size of topography which is defined at the
	2272	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	2273	!-- on the topography walls in y-direction. However, PALM uses individual
	2274	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	2275	!-- Therefore, the extent of topography in nzb_local is now reduced by
	2276	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	2277	!-- to form the basis for nzb_s_inner.
	2278	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	2279	!-- required at this point.
	2280	DO j = nys+1, nyn+1
	2281	DO i = nxl-1, nxr
[2232]	2282	DO k = nzb, nzt+1
[2696]	2283	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2284	BTEST( topo(k,j,i+1), 0 ) ) &
	2285	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2286	ENDDO
	2287	ENDDO
	2288	ENDDO
[2696]	2289	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2290
	2291	DO i = nxl, nxr+1
	2292	DO j = nys-1, nyn
	2293	DO k = nzb, nzt+1
[2696]	2294	IF ( BTEST( topo(k,j,i), 0 ) .OR. &
	2295	BTEST( topo(k,j+1,i), 0 ) ) &
	2296	topo(k,j,i) = IBSET( topo(k,j,i), 0 )
[2232]	2297	ENDDO
	2298	ENDDO
	2299	ENDDO
[2696]	2300	CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2301
[217]	2302	ENDIF
[2696]	2303	ENDIF
[2232]	2304
[1]	2305
[2696]	2306	END SUBROUTINE init_topo
[1]	2307
[2696]	2308	SUBROUTINE set_topo_flags(topo)
[1]	2309
[2696]	2310	USE control_parameters, &
[4294]	2311	ONLY: bc_lr_cyc, bc_ns_cyc, constant_flux_layer, &
	2312	scalar_advec, topography, use_surface_fluxes, use_top_fluxes
[1]	2313
[2696]	2314	USE indices, &
[3241]	2315	ONLY: nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, &
[4168]	2316	nzt, topo_top_ind, wall_flags_0
[1]	2317
[2696]	2318	USE kinds
[1]	2319
[2696]	2320	IMPLICIT NONE
[1804]	2321
[2696]	2322	INTEGER(iwp) :: i !< index variable along x
[4168]	2323	INTEGER(iwp) :: ibit !< integer bit position of topgraphy masking array
[2696]	2324	INTEGER(iwp) :: j !< index variable along y
	2325	INTEGER(iwp) :: k !< index variable along z
[1]	2326
[2696]	2327	INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) :: topo !< input array for 3D topography and dummy array for setting "outer"-flags
[2232]	2328
[2696]	2329	ALLOCATE( wall_flags_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	2330	wall_flags_0 = 0
[2232]	2331	!
[2696]	2332	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	2333	!-- Further special flags will be set in following loops.
[2232]	2334	DO i = nxl, nxr
	2335	DO j = nys, nyn
	2336	DO k = nzb, nzt+1
	2337	!
	2338	!-- scalar grid
[2696]	2339	IF ( BTEST( topo(k,j,i), 0 ) ) &
[2232]	2340	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 0 )
	2341	!
[2696]	2342	!-- u grid
	2343	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2344	BTEST( topo(k,j,i-1), 0 ) ) &
	2345	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 1 )
	2346	!
[2232]	2347	!-- v grid
[2696]	2348	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2349	BTEST( topo(k,j-1,i), 0 ) ) &
	2350	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 2 )
	2351
[2232]	2352	ENDDO
[1]	2353
[2232]	2354	DO k = nzb, nzt
[1]	2355	!
[2232]	2356	!-- w grid
[2696]	2357	IF ( BTEST( topo(k,j,i), 0 ) .AND. &
	2358	BTEST( topo(k+1,j,i), 0 ) ) &
[2232]	2359	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 3 )
	2360	ENDDO
	2361	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 3 )
	2362
	2363	ENDDO
	2364	ENDDO
[2696]	2365
[2867]	2366	CALL exchange_horiz_int( wall_flags_0, nys, nyn, nxl, nxr, nzt, nbgp )
[1]	2367	!
[4115]	2368	!-- Set outer array for scalars to mask near-surface grid points. Note, on
	2369	!-- basis of flag 24 futher flags will be derived which are used to control
	2370	!-- production of subgrid TKE production near walls.
[2696]	2371	DO i = nxl, nxr
	2372	DO j = nys, nyn
[2232]	2373	DO k = nzb, nzt+1
[4115]	2374	IF ( BTEST( wall_flags_0(k,j-1,i), 0 ) .AND. &
	2375	BTEST( wall_flags_0(k,j+1,i), 0 ) .AND. &
	2376	BTEST( wall_flags_0(k,j,i-1), 0 ) .AND. &
	2377	BTEST( wall_flags_0(k,j,i+1), 0 ) .AND. &
	2378	BTEST( wall_flags_0(k,j-1,i-1), 0 ) .AND. &
	2379	BTEST( wall_flags_0(k,j+1,i-1), 0 ) .AND. &
	2380	BTEST( wall_flags_0(k,j-1,i+1), 0 ) .AND. &
	2381	BTEST( wall_flags_0(k,j+1,i+1), 0 ) ) &
[2696]	2382	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 24 )
[2232]	2383	ENDDO
	2384	ENDDO
	2385	ENDDO
[1]	2386	!
[2232]	2387	!-- Set further special flags
	2388	DO i = nxl, nxr
	2389	DO j = nys, nyn
	2390	DO k = nzb, nzt+1
[1]	2391	!
[2232]	2392	!-- scalar grid, former nzb_diff_s_inner.
	2393	!-- Note, use this flag also to mask topography in diffusion_u and
	2394	!-- diffusion_v along the vertical direction. In case of
	2395	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	2396	!-- gradient approach is applied. Please note, in case of u- and v-
	2397	!-- diffuison, a small error is made at edges (on the east side for u,
	2398	!-- at the north side for v), since topography on scalar grid point
	2399	!-- is used instead of topography on u/v-grid. As number of topography grid
	2400	!-- points on uv-grid is different than s-grid, different number of
	2401	!-- surface elements would be required. In order to avoid this,
	2402	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	2403	!-- points are not masked within diffusion_u. Tests had shown that the
	2404	!-- effect on the flow is negligible.
	2405	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2406	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2407	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	2408	ELSE
	2409	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	2410	ENDIF
[1]	2411
[2232]	2412	ENDDO
	2413	!
	2414	!-- Special flag to control vertical diffusion at model top - former
	2415	!-- nzt_diff
	2416	wall_flags_0(:,j,i) = IBSET( wall_flags_0(:,j,i), 9 )
	2417	IF ( use_top_fluxes ) &
[2478]	2418	wall_flags_0(nzt+1,j,i) = IBCLR( wall_flags_0(nzt+1,j,i), 9 )
[1]	2419
[2696]	2420
[2232]	2421	DO k = nzb+1, nzt
	2422	!
	2423	!-- Special flag on u grid, former nzb_u_inner + 1, required
	2424	!-- for disturb_field and initialization. Do not disturb directly at
	2425	!-- topography, as well as initialize u with zero one grid point outside
	2426	!-- of topography.
	2427	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	2428	BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	2429	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	2430	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 20 )
	2431	!
	2432	!-- Special flag on v grid, former nzb_v_inner + 1, required
	2433	!-- for disturb_field and initialization. Do not disturb directly at
	2434	!-- topography, as well as initialize v with zero one grid point outside
	2435	!-- of topography.
	2436	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	2437	BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	2438	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	2439	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 21 )
	2440	!
	2441	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	2442	!-- lpm_sgs_tke
	2443	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2444	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2445	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2446	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 25 )
	2447	!
	2448	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2449	!-- in production_e
	2450	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2451	IF ( BTEST( wall_flags_0(k,j,i), 24 ) .AND. &
	2452	BTEST( wall_flags_0(k-1,j,i), 24 ) .AND. &
	2453	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2454	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
	2455	ELSE
	2456	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2457	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
[1]	2458	ENDIF
[2232]	2459	!
	2460	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	2461	!-- in production_e
	2462	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2463	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2464	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2465	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2466	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	2467	ELSE
	2468	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	2469	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	2470	ENDIF
	2471	ENDDO
	2472	!
	2473	!-- Flags indicating downward facing walls
	2474	DO k = nzb+1, nzt
	2475	!
	2476	!-- Scalar grid
	2477	IF ( BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	2478	.NOT. BTEST( wall_flags_0(k,j,i), 0 ) ) &
[2696]	2479	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 13 )
[2232]	2480	!
	2481	!-- Downward facing wall on u grid
	2482	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	2483	.NOT. BTEST( wall_flags_0(k,j,i), 1 ) ) &
	2484	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 15 )
	2485	!
	2486	!-- Downward facing wall on v grid
	2487	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	2488	.NOT. BTEST( wall_flags_0(k,j,i), 2 ) ) &
	2489	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 17 )
	2490	!
	2491	!-- Downward facing wall on w grid
	2492	IF ( BTEST( wall_flags_0(k-1,j,i), 3 ) .AND. &
	2493	.NOT. BTEST( wall_flags_0(k,j,i), 3 ) ) &
	2494	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 19 )
	2495	ENDDO
	2496	!
	2497	!-- Flags indicating upward facing walls
	2498	DO k = nzb, nzt
	2499	!
	2500	!-- Upward facing wall on scalar grid
	2501	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2502	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	2503	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 12 )
	2504	!
	2505	!-- Upward facing wall on u grid
	2506	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	2507	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	2508	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 14 )
[1]	2509
[2696]	2510	!
[2232]	2511	!-- Upward facing wall on v grid
	2512	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	2513	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	2514	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 16 )
[2696]	2515
[2232]	2516	!
	2517	!-- Upward facing wall on w grid
	2518	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 3 ) .AND. &
	2519	BTEST( wall_flags_0(k+1,j,i), 3 ) ) &
	2520	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 18 )
	2521	!
	2522	!-- Special flag on scalar grid, former nzb_s_inner
	2523	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .OR. &
	2524	BTEST( wall_flags_0(k,j,i), 12 ) .OR. &
	2525	BTEST( wall_flags_0(k,j,i), 13 ) ) &
[2696]	2526	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 22 )
[2232]	2527	!
	2528	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	2529	!-- flow_statistics
	2530	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	2531	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	2532	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
[2696]	2533	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
[2232]	2534	ELSE
	2535	IF ( BTEST( wall_flags_0(k,j,i), 22 ) ) &
	2536	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
[1]	2537	ENDIF
[2696]	2538
[1]	2539
[2232]	2540	ENDDO
	2541	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 22 )
	2542	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 23 )
[4109]	2543	!
	2544	!-- Set flags indicating that topography is close by in horizontal
	2545	!-- direction, i.e. flags that infold the topography. These will be used
	2546	!-- to set advection flags for passive scalars, where due to large
	2547	!-- gradients near buildings stationary numerical oscillations can produce
	2548	!-- unrealistically high concentrations. This is only necessary if
	2549	!-- WS-scheme is applied for scalar advection. Note, these flags will be
	2550	!-- only used for passive scalars such as chemical species or aerosols.
	2551	IF ( scalar_advec == 'ws-scheme' ) THEN
	2552	DO k = nzb, nzt
	2553	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. ( &
	2554	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-1), 0 ) ) .OR.&
	2555	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-2), 0 ) ) .OR.&
	2556	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i-3), 0 ) ) .OR.&
	2557	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+1), 0 ) ) .OR.&
	2558	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+2), 0 ) ) .OR.&
	2559	ANY( .NOT. BTEST( wall_flags_0(k,j-3:j+3,i+3), 0 ) ) .OR.&
	2560	ANY( .NOT. BTEST( wall_flags_0(k,j-1,i-3:i+3), 0 ) ) .OR.&
	2561	ANY( .NOT. BTEST( wall_flags_0(k,j-2,i-3:i+3), 0 ) ) .OR.&
	2562	ANY( .NOT. BTEST( wall_flags_0(k,j-3,i-3:i+3), 0 ) ) .OR.&
	2563	ANY( .NOT. BTEST( wall_flags_0(k,j+1,i-3:i+3), 0 ) ) .OR.&
	2564	ANY( .NOT. BTEST( wall_flags_0(k,j+2,i-3:i+3), 0 ) ) .OR.&
	2565	ANY( .NOT. BTEST( wall_flags_0(k,j+3,i-3:i+3), 0 ) ) &
	2566	) ) &
	2567	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 31 )
	2568
	2569	ENDDO
	2570	ENDIF
[2232]	2571	ENDDO
	2572	ENDDO
	2573	!
[2696]	2574	!-- Finally, set identification flags indicating natural terrain or buildings.
[4189]	2575	!-- Natural terrain grid points. Information on the type of the surface is
	2576	!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set
	2577	!-- when topography is read from file. In order to run the land-surface model
	2578	!-- also without topography information, set bit 1 explicitely in this case.
[4294]	2579	!--
	2580	!-- Natural terrain grid points
	2581	!-- If no topography is initialized, the land-surface is at k = nzb.
	2582	IF ( TRIM( topography ) /= 'read_from_file' ) THEN
	2583	wall_flags_0(nzb,:,:) = IBSET( wall_flags_0(nzb,:,:), 5 )
	2584	ELSE
	2585	DO i = nxl, nxr
	2586	DO j = nys, nyn
	2587	DO k = nzb, nzt+1
[4189]	2588	!
[4294]	2589	!-- Natural terrain grid point
	2590	IF ( BTEST( topo(k,j,i), 1 ) ) &
	2591	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 5 )
[2696]	2592	ENDDO
	2593	ENDDO
[4294]	2594	ENDDO
[2696]	2595	ENDIF
	2596	!
	2597	!-- Building grid points.
[4294]	2598	DO i = nxl, nxr
	2599	DO j = nys, nyn
	2600	DO k = nzb, nzt+1
	2601	IF ( BTEST( topo(k,j,i), 2 ) ) &
	2602	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 6 )
[2696]	2603	ENDDO
	2604	ENDDO
[4294]	2605	ENDDO
[2696]	2606	!
[4314]	2607	!-- Set flag 4, indicating new topography grid points due to filtering.
	2608	DO i = nxl, nxr
	2609	DO j = nys, nyn
	2610	DO k = nzb, nzt+1
	2611	IF ( BTEST( topo(k,j,i), 4 ) ) &
	2612	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 4 )
	2613	ENDDO
	2614	ENDDO
	2615	ENDDO
	2616	!
[2232]	2617	!-- Exchange ghost points for wall flags
[2696]	2618	CALL exchange_horiz_int( wall_flags_0, nys, nyn, nxl, nxr, nzt, nbgp )
[2232]	2619	!
	2620	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	2621	!-- boundary conditions for topography.
	2622	IF ( .NOT. bc_ns_cyc ) THEN
[2696]	2623	IF ( nys == 0 ) THEN
	2624	DO i = 1, nbgp
	2625	wall_flags_0(:,nys-i,:) = wall_flags_0(:,nys,:)
	2626	ENDDO
	2627	ENDIF
	2628	IF ( nyn == ny ) THEN
	2629	DO i = 1, nbgp
	2630	wall_flags_0(:,nyn+i,:) = wall_flags_0(:,nyn,:)
	2631	ENDDO
	2632	ENDIF
[2232]	2633	ENDIF
	2634	IF ( .NOT. bc_lr_cyc ) THEN
[2696]	2635	IF ( nxl == 0 ) THEN
	2636	DO i = 1, nbgp
	2637	wall_flags_0(:,:,nxl-i) = wall_flags_0(:,:,nxl)
	2638	ENDDO
[2232]	2639	ENDIF
[2696]	2640	IF ( nxr == nx ) THEN
	2641	DO i = 1, nbgp
	2642	wall_flags_0(:,:,nxr+i) = wall_flags_0(:,:,nxr)
[2232]	2643	ENDDO
[2696]	2644	ENDIF
[2232]	2645	ENDIF
[4168]	2646	!
	2647	!-- Pre-calculate topography top indices (former get_topography_top_index
	2648	!-- function)
	2649	ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
	2650	!
	2651	!-- Uppermost topography index on scalar grid
	2652	ibit = 12
	2653	topo_top_ind(:,:,0) = MAXLOC( &
	2654	MERGE( 1, 0, &
	2655	BTEST( wall_flags_0(:,:,:), ibit ) &
	2656	), DIM = 1 &
	2657	) - 1
	2658	!
	2659	!-- Uppermost topography index on u grid
	2660	ibit = 14
	2661	topo_top_ind(:,:,1) = MAXLOC( &
	2662	MERGE( 1, 0, &
	2663	BTEST( wall_flags_0(:,:,:), ibit ) &
	2664	), DIM = 1 &
	2665	) - 1
	2666	!
	2667	!-- Uppermost topography index on v grid
	2668	ibit = 16
	2669	topo_top_ind(:,:,2) = MAXLOC( &
	2670	MERGE( 1, 0, &
	2671	BTEST( wall_flags_0(:,:,:), ibit ) &
	2672	), DIM = 1 &
	2673	) - 1
	2674	!
	2675	!-- Uppermost topography index on w grid
	2676	ibit = 18
	2677	topo_top_ind(:,:,3) = MAXLOC( &
	2678	MERGE( 1, 0, &
	2679	BTEST( wall_flags_0(:,:,:), ibit ) &
	2680	), DIM = 1 &
	2681	) - 1
	2682	!
	2683	!-- Uppermost topography index on scalar outer grid
	2684	ibit = 24
	2685	topo_top_ind(:,:,4) = MAXLOC( &
	2686	MERGE( 1, 0, &
	2687	BTEST( wall_flags_0(:,:,:), ibit ) &
	2688	), DIM = 1 &
	2689	) - 1
[1]	2690
[2696]	2691	END SUBROUTINE set_topo_flags
[114]	2692
	2693
	2694

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

| Impressum | ©Leibniz Universität Hannover |