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source: palm/trunk/SOURCE/init_grid.f90 @ 2270

Last change on this file since 2270 was 2233, checked in by suehring, 7 years ago
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[1682]	1	!> @file init_grid.f90
[2000]	2	!------------------------------------------------------------------------------!
[1036]	3	! This file is part of PALM.
	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	!
[2101]	17	! Copyright 1997-2017 Leibniz Universitaet Hannover
[2000]	18	!------------------------------------------------------------------------------!
[1036]	19	!
[254]	20	! Current revisions:
[1]	21	! -----------------
[2233]	22	!
	23	!
	24	! Former revisions:
	25	! -----------------
	26	! $Id: init_grid.f90 2233 2017-05-30 18:08:54Z maronga $
	27	!
	28	! 2232 2017-05-30 17:47:52Z suehring
[2232]	29	! - Adjustments according to new topography representation
	30	! - Bugfix: Move determination of nzb_max behind topography modification in
	31	! cell-edge case
	32	! - Get rid off global arrays required for topography output
	33	! - Enable topography input via netcdf
	34	! - Generic tunnel set-up added
[1969]	35	!
[2201]	36	! 2200 2017-04-11 11:37:51Z suehring
	37	! monotonic_adjustment removed
	38	!
[2170]	39	! 2169 2017-03-06 18:16:35Z suehring
	40	! Bugfix, move setting for topography grid convention to init_grid, else, if no
	41	! value is set, the simulation may abort in case of restarts
	42	!
[2129]	43	! 2128 2017-01-23 15:00:03Z suehring
	44	! Bugfix in setting topography from file in case of ocean simulations
	45	!
[2089]	46	! 2088 2016-12-19 16:30:25Z suehring
	47	! Bugfix in generic topography in case of ocean simulations
	48	!
[2038]	49	! 2037 2016-10-26 11:15:40Z knoop
	50	! Anelastic approximation implemented
	51	!
[2022]	52	! 2021 2016-10-07 14:08:57Z suehring
	53	! Bugfix: setting Neumann boundary conditions for topography required for
	54	! topography flags in multigrid_noopt solver
	55	!
[2001]	56	! 2000 2016-08-20 18:09:15Z knoop
	57	! Forced header and separation lines into 80 columns
	58	!
[1995]	59	! 1994 2016-08-15 09:52:21Z suehring
	60	! Bugfix in definition of generic topography
	61	!
[1983]	62	! 1982 2016-08-01 11:04:48Z suehring
	63	! Bugfix concering consistency check for topography
	64	!
[1969]	65	! 1968 2016-07-18 12:01:49Z suehring
[1968]	66	! Changed: PE-wise reading of topography file in order to avoid global definition
	67	! of arrays nzb_local and nzb_tmp. Thereby, topography definition for single
	68	! buildings and street canyons has changed, as well as flag setting for
	69	! multigrid scheme.
	70	!
	71	! Bugfix in checking l_grid anisotropy.
	72	! Simplify initial computation of lwall and vertical_influence, i.e. remove
	73	! nzb_s_inner as it is still zero at this point.
[1932]	74	!
[1943]	75	! 1942 2016-06-14 12:18:18Z suehring
	76	! Topography filter implemented to fill holes resolved by only one grid point.
	77	! Initialization of flags for ws-scheme moved to advec_ws.
	78	!
[1932]	79	! 1931 2016-06-10 12:06:59Z suehring
	80	! Rename multigrid into multigrid_noopt and multigrid_fast into multigrid
	81	!
[1911]	82	! 1910 2016-05-26 06:49:46Z raasch
	83	! Bugfix: if topography is read from file, Neumann conditions are used for the
	84	! nzb_local array (instead of cyclic conditions) in case that non-cyclic
	85	! boundary conditions are switched on for the run
	86	!
[1903]	87	! 1902 2016-05-09 11:18:56Z suehring
[1910]	88	! Set topography flags for multigrid solver only (not for multigrid_fast)
[1903]	89	!
[1887]	90	! 1886 2016-04-21 11:20:47Z suehring
	91	! Bugfix: setting advection flags near walls
	92	! reformulated index values for nzb_v_inner
	93	! variable discriptions added in declaration block
	94	!
[1846]	95	! 1845 2016-04-08 08:29:13Z raasch
	96	! nzb_2d removed
	97	!
[1805]	98	! 1804 2016-04-05 16:30:18Z maronga
	99	! Removed code for parameter file check (__check)
	100	!
[1780]	101	! 1779 2016-03-03 08:01:28Z raasch
	102	! coupling_char is trimmed at every place it occurs, because it can have
	103	! different length now
	104	!
[1763]	105	! 1762 2016-02-25 12:31:13Z hellstea
	106	! Introduction of nested domain feature
	107	!
[1744]	108	! 1743 2016-01-13 10:23:51Z raasch
	109	! Bugfix for calculation of nzb_s_outer and nzb_u_outer at north boundary of
	110	! total domain
	111	!
[1692]	112	! 1691 2015-10-26 16:17:44Z maronga
	113	! Renamed prandtl_layer to constant_flux_layer.
	114	!
[1683]	115	! 1682 2015-10-07 23:56:08Z knoop
	116	! Code annotations made doxygen readable
	117	!
[1678]	118	! 1677 2015-10-02 13:25:23Z boeske
	119	! Bugfix: Ghost points are included in wall_flags_0 and wall_flags_00
	120	!
[1676]	121	! 1675 2015-10-02 08:28:59Z gronemeier
	122	! Bugfix: Definition of topography grid levels
	123	!
[1662]	124	! 1660 2015-09-21 08:15:16Z gronemeier
	125	! Bugfix: Definition of topography grid levels if vertical grid stretching
	126	! starts below the maximum topography height.
	127	!
[1581]	128	! 1580 2015-04-10 13:43:49Z suehring
	129	! Bugfix: setting flags for 5th order scheme near buildings
	130	!
[1576]	131	! 1575 2015-03-27 09:56:27Z raasch
	132	! adjustments for psolver-queries
	133	!
[1558]	134	! 1557 2015-03-05 16:43:04Z suehring
	135	! Adjustment for monotoinic limiter
	136	!
[1419]	137	! 1418 2014-06-06 13:05:08Z fricke
	138	! Bugfix: Change if-condition for stretched grid in the ocean, with the old
	139	! condition and a negative value for dz_stretch_level the condition
	140	! was always true for the whole model domain
	141	!
[1410]	142	! 1409 2014-05-23 12:11:32Z suehring
	143	! Bugfix: set wall_flags_0 at inflow and outflow boundary also for i <= nxlu
	144	! j <= nysv
	145	!
[1354]	146	! 1353 2014-04-08 15:21:23Z heinze
	147	! REAL constants provided with KIND-attribute
	148	!
[1323]	149	! 1322 2014-03-20 16:38:49Z raasch
	150	! REAL constants defined as wp-kind
	151	!
[1321]	152	! 1320 2014-03-20 08:40:49Z raasch
[1320]	153	! ONLY-attribute added to USE-statements,
	154	! kind-parameters added to all INTEGER and REAL declaration statements,
	155	! kinds are defined in new module kinds,
	156	! revision history before 2012 removed,
	157	! comment fields (!:) to be used for variable explanations added to
	158	! all variable declaration statements
[1321]	159	!
[1222]	160	! 1221 2013-09-10 08:59:13Z raasch
	161	! wall_flags_00 introduced to hold bits 32-63,
	162	! additional 3D-flag arrays for replacing the 2D-index array nzb_s_inner in
	163	! loops optimized for openACC (pres + flow_statistics)
	164	!
[1093]	165	! 1092 2013-02-02 11:24:22Z raasch
	166	! unused variables removed
	167	!
[1070]	168	! 1069 2012-11-28 16:18:43Z maronga
[1779]	169	! bugfix: added coupling_char to TOPOGRAPHY_DATA to allow topography in the
	170	! ocean model in case of coupled runs
[1070]	171	!
[1037]	172	! 1036 2012-10-22 13:43:42Z raasch
	173	! code put under GPL (PALM 3.9)
	174	!
[1017]	175	! 1015 2012-09-27 09:23:24Z raasch
	176	! lower index for calculating wall_flags_0 set to nzb_w_inner instead of
	177	! nzb_w_inner+1
	178	!
[997]	179	! 996 2012-09-07 10:41:47Z raasch
	180	! little reformatting
	181	!
[979]	182	! 978 2012-08-09 08:28:32Z fricke
	183	! Bugfix: nzb_max is set to nzt at non-cyclic lateral boundaries
	184	! Bugfix: Set wall_flags_0 for inflow boundary
	185	!
[928]	186	! 927 2012-06-06 19:15:04Z raasch
	187	! Wall flags are not set for multigrid method in case of masking method
	188	!
[865]	189	! 864 2012-03-27 15:10:33Z gryschka
[927]	190	! In case of ocean and Dirichlet bottom bc for u and v dzu_mg and ddzu_pres
	191	! were not correctly defined for k=1.
[865]	192	!
[863]	193	! 861 2012-03-26 14:18:34Z suehring
[861]	194	! Set wall_flags_0. The array is needed for degradation in ws-scheme near walls,
	195	! inflow and outflow boundaries as well as near the bottom and the top of the
[863]	196	! model domain.!
[861]	197	! Initialization of nzb_s_inner and nzb_w_inner.
	198	! gls has to be at least nbgp to do not exceed the array bounds of nzb_local
	199	! while setting wall_flags_0
	200	!
[844]	201	! 843 2012-02-29 15:16:21Z gryschka
	202	! In case of ocean and dirichlet bc for u and v at the bottom
	203	! the first u-level ist defined at same height as the first w-level
	204	!
[819]	205	! 818 2012-02-08 16:11:23Z maronga
	206	! Bugfix: topo_height is only required if topography is used. It is thus now
	207	! allocated in the topography branch
	208	!
[810]	209	! 809 2012-01-30 13:32:58Z maronga
	210	! Bugfix: replaced .AND. and .NOT. with && and ! in the preprocessor directives
	211	!
[808]	212	! 807 2012-01-25 11:53:51Z maronga
	213	! New cpp directive "__check" implemented which is used by check_namelist_files
	214	!
[1]	215	! Revision 1.1 1997/08/11 06:17:45 raasch
	216	! Initial revision (Testversion)
	217	!
	218	!
	219	! Description:
	220	! ------------
[1682]	221	!> Creating grid depending constants
[2232]	222	!> To Do: Setting topo flags only based on topo_3d array - flags for former
	223	!> nzb_outer arrays are still not set properly.
	224	!> To Do: Rearrange topo flag list
[1]	225	!------------------------------------------------------------------------------!
[1682]	226	SUBROUTINE init_grid
	227
[1942]	228	USE advec_ws, &
	229	ONLY: ws_init_flags
[1]	230
[1320]	231	USE arrays_3d, &
	232	ONLY: dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzu_mg, dzw, dzw_mg, f1_mg, &
	233	f2_mg, f3_mg, l_grid, l_wall, zu, zw
	234
[1353]	235	USE control_parameters, &
[1910]	236	ONLY: bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, &
[1320]	237	building_length_y, building_wall_left, building_wall_south, &
	238	canyon_height, canyon_wall_left, canyon_wall_south, &
[1691]	239	canyon_width_x, canyon_width_y, constant_flux_layer, &
	240	coupling_char, dp_level_ind_b, dz, dz_max, dz_stretch_factor, &
[1968]	241	dz_stretch_level, dz_stretch_level_index, grid_level, ibc_uv_b, &
	242	io_blocks, io_group, inflow_l, inflow_n, inflow_r, inflow_s, &
[2232]	243	lod, masking_method, maximum_grid_level, message_string, &
[2021]	244	momentum_advec, nest_domain, nest_bound_l, nest_bound_n, &
	245	nest_bound_r, nest_bound_s, ocean, outflow_l, outflow_n, &
[1762]	246	outflow_r, outflow_s, psolver, scalar_advec, topography, &
[2232]	247	topography_grid_convention, tunnel_height, tunnel_length, &
	248	tunnel_width_x, tunnel_width_y, tunnel_wall_depth, &
	249	use_surface_fluxes, use_top_fluxes, wall_adjustment_factor
[2021]	250
[1320]	251	USE grid_variables, &
[2232]	252	ONLY: ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
[1320]	253
	254	USE indices, &
[2232]	255	ONLY: advc_flags_1, advc_flags_2, flags, nbgp, nx, nxl, nxlg, nxl_mg, &
	256	nxr, nxrg, nxr_mg, ny, nyn, nyng, nyn_mg, nys, nys_mg, nysg, nz,&
	257	nzb, nzb_diff, nzb_diff_s_inner, nzb_diff_s_outer, &
	258	nzb_max, nzb_s_inner, nzb_s_outer, nzb_u_inner, &
[1845]	259	nzb_u_outer, nzb_v_inner, nzb_v_outer, nzb_w_inner, &
[2232]	260	nzb_w_outer, nzt, nzt_mg, wall_flags_0, wall_flags_1, &
[1320]	261	wall_flags_10, wall_flags_2, wall_flags_3, wall_flags_4, &
	262	wall_flags_5, wall_flags_6, wall_flags_7, wall_flags_8, &
	263	wall_flags_9
	264
	265	USE kinds
[2232]	266	#if defined ( __netcdf )
	267	USE netcdf_interface, &
	268	ONLY: netcdf_close_file, netcdf_open_read_file, netcdf_get_attribute, &
	269	netcdf_get_variable
	270	#endif
[1]	271	USE pegrid
	272
[2232]	273	USE surface_mod, &
	274	ONLY: init_bc
	275
[1]	276	IMPLICIT NONE
	277
[1968]	278	INTEGER(iwp) :: bh !< temporary vertical index of building height
	279	INTEGER(iwp) :: blx !< grid point number of building size along x
	280	INTEGER(iwp) :: bly !< grid point number of building size along y
	281	INTEGER(iwp) :: bxl !< index for left building wall
	282	INTEGER(iwp) :: bxr !< index for right building wall
	283	INTEGER(iwp) :: byn !< index for north building wall
	284	INTEGER(iwp) :: bys !< index for south building wall
	285	INTEGER(iwp) :: ch !< temporary vertical index for canyon height
	286	INTEGER(iwp) :: cwx !< grid point number of canyon size along x
	287	INTEGER(iwp) :: cwy !< grid point number of canyon size along y
	288	INTEGER(iwp) :: cxl !< index for left canyon wall
	289	INTEGER(iwp) :: cxr !< index for right canyon wall
	290	INTEGER(iwp) :: cyn !< index for north canyon wall
	291	INTEGER(iwp) :: cys !< index for south canyon wall
	292	INTEGER(iwp) :: i !< index variable along x
[2232]	293	INTEGER(iwp) :: id_topo !< NetCDF id of topograhy input file
[1968]	294	INTEGER(iwp) :: ii !< loop variable for reading topography file
	295	INTEGER(iwp) :: inc !< incremental parameter for coarsening grid level
	296	INTEGER(iwp) :: j !< index variable along y
	297	INTEGER(iwp) :: k !< index variable along z
[2232]	298	INTEGER(iwp) :: k_top !< topography top index on local PE
[1968]	299	INTEGER(iwp) :: l !< loop variable
	300	INTEGER(iwp) :: nxl_l !< index of left PE boundary for multigrid level
	301	INTEGER(iwp) :: nxr_l !< index of right PE boundary for multigrid level
	302	INTEGER(iwp) :: nyn_l !< index of north PE boundary for multigrid level
	303	INTEGER(iwp) :: nys_l !< index of south PE boundary for multigrid level
	304	INTEGER(iwp) :: nzb_local_max !< vertical grid index of maximum topography height
	305	INTEGER(iwp) :: nzb_local_min !< vertical grid index of minimum topography height
	306	INTEGER(iwp) :: nzt_l !< index of top PE boundary for multigrid level
	307	INTEGER(iwp) :: num_hole !< number of holes (in topography) resolved by only one grid point
	308	INTEGER(iwp) :: num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
	309	INTEGER(iwp) :: num_wall !< number of surrounding vertical walls for a single grid point
	310	INTEGER(iwp) :: skip_n_rows !< counting variable to skip rows while reading topography file
[2232]	311	INTEGER(iwp) :: hv_in !< heavyside function to model inner tunnel surface
	312	INTEGER(iwp) :: hv_out !< heavyside function to model outer tunnel surface
	313	INTEGER(iwp) :: txe_out !< end position of outer tunnel wall in x
	314	INTEGER(iwp) :: txs_out !< start position of outer tunnel wall in x
	315	INTEGER(iwp) :: tye_out !< end position of outer tunnel wall in y
	316	INTEGER(iwp) :: tys_out !< start position of outer tunnel wall in y
	317	INTEGER(iwp) :: txe_in !< end position of inner tunnel wall in x
	318	INTEGER(iwp) :: txs_in !< start position of inner tunnel wall in x
	319	INTEGER(iwp) :: tye_in !< end position of inner tunnel wall in y
	320	INTEGER(iwp) :: tys_in !< start position of inner tunnel wall in y
	321	INTEGER(iwp) :: td !< tunnel wall depth
	322	INTEGER(iwp) :: th !< height of outer tunnel wall
	323
[1968]	324	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_local !< index for topography top at cell-center
	325	INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE :: nzb_tmp !< dummy to calculate topography indices on u- and v-grid
[1]	326
[2232]	327	INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE :: topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
	328
	329	LOGICAL :: netcdf_extend = .FALSE. !< Flag indicating wether netcdf topography input file or not
	330
[1968]	331	REAL(wp) :: dum !< dummy variable to skip columns while reading topography file
[1886]	332	REAL(wp) :: dz_stretched !< stretched vertical grid spacing
[861]	333
[2232]	334	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: oro_height !< input variable for terrain height
[1968]	335	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: topo_height !< input variable for topography height
[1]	336
	337	!
[709]	338	!-- Calculation of horizontal array bounds including ghost layers
[667]	339	nxlg = nxl - nbgp
	340	nxrg = nxr + nbgp
	341	nysg = nys - nbgp
	342	nyng = nyn + nbgp
[709]	343
[667]	344	!
[1]	345	!-- Allocate grid arrays
[1353]	346	ALLOCATE( ddzu(1:nzt+1), ddzw(1:nzt+1), dd2zu(1:nzt), dzu(1:nzt+1), &
[667]	347	dzw(1:nzt+1), l_grid(1:nzt), zu(nzb:nzt+1), zw(nzb:nzt+1) )
[1]	348
	349	!
	350	!-- Compute height of u-levels from constant grid length and dz stretch factors
[1353]	351	IF ( dz == -1.0_wp ) THEN
[254]	352	message_string = 'missing dz'
	353	CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
[1353]	354	ELSEIF ( dz <= 0.0_wp ) THEN
[254]	355	WRITE( message_string, * ) 'dz=',dz,' <= 0.0'
	356	CALL message( 'init_grid', 'PA0201', 1, 2, 0, 6, 0 )
[1]	357	ENDIF
[94]	358
[1]	359	!
[94]	360	!-- Define the vertical grid levels
	361	IF ( .NOT. ocean ) THEN
	362	!
	363	!-- Grid for atmosphere with surface at z=0 (k=0, w-grid).
[843]	364	!-- The second u-level (k=1) corresponds to the top of the
[94]	365	!-- Prandtl-layer.
[667]	366
	367	IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 ) THEN
[1353]	368	zu(0) = 0.0_wp
	369	! zu(0) = - dz * 0.5_wp
[667]	370	ELSE
[1353]	371	zu(0) = - dz * 0.5_wp
[667]	372	ENDIF
[1353]	373	zu(1) = dz * 0.5_wp
[1]	374
[94]	375	dz_stretch_level_index = nzt+1
	376	dz_stretched = dz
	377	DO k = 2, nzt+1
	378	IF ( dz_stretch_level <= zu(k-1) .AND. dz_stretched < dz_max ) THEN
	379	dz_stretched = dz_stretched * dz_stretch_factor
	380	dz_stretched = MIN( dz_stretched, dz_max )
	381	IF ( dz_stretch_level_index == nzt+1 ) dz_stretch_level_index = k-1
	382	ENDIF
	383	zu(k) = zu(k-1) + dz_stretched
	384	ENDDO
[1]	385
	386	!
[94]	387	!-- Compute the w-levels. They are always staggered half-way between the
[843]	388	!-- corresponding u-levels. In case of dirichlet bc for u and v at the
	389	!-- ground the first u- and w-level (k=0) are defined at same height (z=0).
	390	!-- The top w-level is extrapolated linearly.
[1353]	391	zw(0) = 0.0_wp
[94]	392	DO k = 1, nzt
[1353]	393	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	394	ENDDO
[1353]	395	zw(nzt+1) = zw(nzt) + 2.0_wp * ( zu(nzt+1) - zw(nzt) )
[1]	396
[94]	397	ELSE
[1]	398	!
[843]	399	!-- Grid for ocean with free water surface is at k=nzt (w-grid).
	400	!-- In case of neumann bc at the ground the first first u-level (k=0) lies
	401	!-- below the first w-level (k=0). In case of dirichlet bc the first u- and
	402	!-- w-level are defined at same height, but staggered from the second level.
	403	!-- The second u-level (k=1) corresponds to the top of the Prandtl-layer.
[1353]	404	zu(nzt+1) = dz * 0.5_wp
	405	zu(nzt) = - dz * 0.5_wp
[94]	406
	407	dz_stretch_level_index = 0
	408	dz_stretched = dz
	409	DO k = nzt-1, 0, -1
[1418]	410	!
	411	!-- The default value of dz_stretch_level is positive, thus the first
	412	!-- condition is always true. Hence, the second condition is necessary.
	413	IF ( dz_stretch_level >= zu(k+1) .AND. dz_stretch_level <= 0.0 &
	414	.AND. dz_stretched < dz_max ) THEN
[94]	415	dz_stretched = dz_stretched * dz_stretch_factor
	416	dz_stretched = MIN( dz_stretched, dz_max )
	417	IF ( dz_stretch_level_index == 0 ) dz_stretch_level_index = k+1
	418	ENDIF
	419	zu(k) = zu(k+1) - dz_stretched
	420	ENDDO
	421
	422	!
	423	!-- Compute the w-levels. They are always staggered half-way between the
[843]	424	!-- corresponding u-levels, except in case of dirichlet bc for u and v
	425	!-- at the ground. In this case the first u- and w-level are defined at
	426	!-- same height. The top w-level (nzt+1) is not used but set for
	427	!-- consistency, since w and all scalar variables are defined up tp nzt+1.
[94]	428	zw(nzt+1) = dz
[1353]	429	zw(nzt) = 0.0_wp
[94]	430	DO k = 0, nzt
[1353]	431	zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
[94]	432	ENDDO
	433
[843]	434	!
	435	!-- In case of dirichlet bc for u and v the first u- and w-level are defined
	436	!-- at same height.
	437	IF ( ibc_uv_b == 0 ) THEN
	438	zu(0) = zw(0)
	439	ENDIF
	440
[94]	441	ENDIF
	442
	443	!
[1]	444	!-- Compute grid lengths.
	445	DO k = 1, nzt+1
	446	dzu(k) = zu(k) - zu(k-1)
[1353]	447	ddzu(k) = 1.0_wp / dzu(k)
[1]	448	dzw(k) = zw(k) - zw(k-1)
[1353]	449	ddzw(k) = 1.0_wp / dzw(k)
[1]	450	ENDDO
	451
	452	DO k = 1, nzt
[1353]	453	dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
[1]	454	ENDDO
[667]	455
	456	!
[709]	457	!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
	458	!-- everywhere. For the actual grid, the grid spacing at the lowest level
	459	!-- is only dz/2, but should be dz. Therefore, an additional array
	460	!-- containing with appropriate grid information is created for these
	461	!-- solvers.
[1575]	462	IF ( psolver(1:9) /= 'multigrid' ) THEN
[667]	463	ALLOCATE( ddzu_pres(1:nzt+1) )
	464	ddzu_pres = ddzu
[864]	465	ddzu_pres(1) = ddzu_pres(2) ! change for lowest level
[1]	466	ENDIF
	467
	468	!
	469	!-- Compute the reciprocal values of the horizontal grid lengths.
[1353]	470	ddx = 1.0_wp / dx
	471	ddy = 1.0_wp / dy
[1]	472	dx2 = dx * dx
	473	dy2 = dy * dy
[1353]	474	ddx2 = 1.0_wp / dx2
	475	ddy2 = 1.0_wp / dy2
[1]	476
	477	!
	478	!-- Compute the grid-dependent mixing length.
	479	DO k = 1, nzt
[1322]	480	l_grid(k) = ( dx * dy * dzw(k) )**0.33333333333333_wp
[1]	481	ENDDO
	482
	483	!
	484	!-- Allocate outer and inner index arrays for topography and set
[2232]	485	!-- defaults.
	486	ALLOCATE( nzb_s_inner(nysg:nyng,nxlg:nxrg), &
[667]	487	nzb_s_outer(nysg:nyng,nxlg:nxrg), &
	488	nzb_u_inner(nysg:nyng,nxlg:nxrg), &
	489	nzb_u_outer(nysg:nyng,nxlg:nxrg), &
	490	nzb_v_inner(nysg:nyng,nxlg:nxrg), &
	491	nzb_v_outer(nysg:nyng,nxlg:nxrg), &
	492	nzb_w_inner(nysg:nyng,nxlg:nxrg), &
	493	nzb_w_outer(nysg:nyng,nxlg:nxrg), &
	494	nzb_diff_s_inner(nysg:nyng,nxlg:nxrg), &
	495	nzb_diff_s_outer(nysg:nyng,nxlg:nxrg), &
[1968]	496	nzb_local(nysg:nyng,nxlg:nxrg), &
	497	nzb_tmp(nysg:nyng,nxlg:nxrg), &
[2232]	498	wall_flags_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
[1]	499
[2232]	500	ALLOCATE( topo_3d(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	501	topo_3d = 0
[1]	502
[667]	503	ALLOCATE( l_wall(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	504
[1]	505	nzb_s_inner = nzb; nzb_s_outer = nzb
	506	nzb_u_inner = nzb; nzb_u_outer = nzb
	507	nzb_v_inner = nzb; nzb_v_outer = nzb
	508	nzb_w_inner = nzb; nzb_w_outer = nzb
	509
	510	!
[19]	511	!-- Define vertical gridpoint from (or to) which on the usual finite difference
[1]	512	!-- form (which does not use surface fluxes) is applied
[1691]	513	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	514	nzb_diff = nzb + 2
	515	ELSE
	516	nzb_diff = nzb + 1
	517	ENDIF
	518
	519	nzb_diff_s_inner = nzb_diff; nzb_diff_s_outer = nzb_diff
	520
	521	!
	522	!-- Initialize near-wall mixing length l_wall only in the vertical direction
	523	!-- for the moment,
	524	!-- multiplication with wall_adjustment_factor near the end of this routine
	525	l_wall(nzb,:,:) = l_grid(1)
	526	DO k = nzb+1, nzt
	527	l_wall(k,:,:) = l_grid(k)
	528	ENDDO
	529	l_wall(nzt+1,:,:) = l_grid(nzt)
	530
	531	DO k = 1, nzt
[1353]	532	IF ( l_grid(k) > 1.5_wp * dx * wall_adjustment_factor .OR. &
	533	l_grid(k) > 1.5_wp * dy * wall_adjustment_factor ) THEN
[254]	534	WRITE( message_string, * ) 'grid anisotropy exceeds ', &
	535	'threshold given by only local', &
	536	' &horizontal reduction of near_wall ', &
	537	'mixing length l_wall', &
	538	' &starting from height level k = ', k, '.'
	539	CALL message( 'init_grid', 'PA0202', 0, 1, 0, 6, 0 )
[1]	540	EXIT
	541	ENDIF
	542	ENDDO
	543	!
	544	!-- Set outer and inner index arrays for non-flat topography.
	545	!-- Here consistency checks concerning domain size and periodicity are
	546	!-- necessary.
	547	!-- Within this SELECT CASE structure only nzb_local is initialized
	548	!-- individually depending on the chosen topography type, all other index
	549	!-- arrays are initialized further below.
	550	SELECT CASE ( TRIM( topography ) )
	551
	552	CASE ( 'flat' )
	553	!
[555]	554	!-- nzb_local is required for the multigrid solver
	555	nzb_local = 0
[2232]	556	!
	557	!-- Initialilize 3D topography array, used later for initializing flags
	558	topo_3d(nzb+1:nzt+1,:,:) = IBSET( topo_3d(nzb+1:nzt+1,:,:), 0 )
	559	!
	560	!-- level of detail is required for output routines
	561	lod = 1
[1]	562
	563	CASE ( 'single_building' )
	564	!
	565	!-- Single rectangular building, by default centered in the middle of the
	566	!-- total domain
	567	blx = NINT( building_length_x / dx )
	568	bly = NINT( building_length_y / dy )
[2232]	569	bh = MINLOC( ABS( zw - building_height ), 1 ) - 1
	570	IF ( ABS( zw(bh) - building_height ) == &
[1675]	571	ABS( zw(bh+1) - building_height ) ) bh = bh + 1
[1]	572
[1322]	573	IF ( building_wall_left == 9999999.9_wp ) THEN
[1]	574	building_wall_left = ( nx + 1 - blx ) / 2 * dx
	575	ENDIF
	576	bxl = NINT( building_wall_left / dx )
	577	bxr = bxl + blx
	578
[1322]	579	IF ( building_wall_south == 9999999.9_wp ) THEN
[1]	580	building_wall_south = ( ny + 1 - bly ) / 2 * dy
	581	ENDIF
	582	bys = NINT( building_wall_south / dy )
	583	byn = bys + bly
	584
	585	!
	586	!-- Building size has to meet some requirements
	587	IF ( ( bxl < 1 ) .OR. ( bxr > nx-1 ) .OR. ( bxr < bxl+3 ) .OR. &
	588	( bys < 1 ) .OR. ( byn > ny-1 ) .OR. ( byn < bys+3 ) ) THEN
[274]	589	WRITE( message_string, * ) 'inconsistent building parameters:', &
	590	'& bxl=', bxl, 'bxr=', bxr, 'bys=', bys, &
	591	'byn=', byn, 'nx=', nx, 'ny=', ny
[254]	592	CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
[1]	593	ENDIF
	594
	595	!
[1968]	596	!-- Define the building.
[1]	597	nzb_local = 0
[1968]	598	IF ( bxl <= nxr .AND. bxr >= nxl .AND. &
	599	bys <= nyn .AND. byn >= nys ) &
	600	nzb_local(MAX(nys,bys):MIN(nyn,byn),MAX(nxl,bxl):MIN(nxr,bxr)) = bh
[1]	601
[1994]	602	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2232]	603	!
	604	!-- Set bit array to mask topography
	605	DO i = nxlg, nxrg
	606	DO j = nysg, nyng
[1994]	607
[2232]	608	topo_3d(nzb_local(j,i)+1:nzt+1,j,i) = &
	609	IBSET( topo_3d(nzb_local(j,i)+1:nzt+1,j,i), 0 )
	610	ENDDO
	611	ENDDO
	612	!
	613	!-- level of detail is required for output routines. Here, 2D topography.
	614	lod = 1
	615
	616	CALL exchange_horiz_int( topo_3d, nbgp )
	617
[240]	618	CASE ( 'single_street_canyon' )
	619	!
	620	!-- Single quasi-2D street canyon of infinite length in x or y direction.
	621	!-- The canyon is centered in the other direction by default.
[1322]	622	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[240]	623	!
	624	!-- Street canyon in y direction
	625	cwx = NINT( canyon_width_x / dx )
[1322]	626	IF ( canyon_wall_left == 9999999.9_wp ) THEN
[240]	627	canyon_wall_left = ( nx + 1 - cwx ) / 2 * dx
	628	ENDIF
	629	cxl = NINT( canyon_wall_left / dx )
	630	cxr = cxl + cwx
	631
[1322]	632	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[240]	633	!
	634	!-- Street canyon in x direction
	635	cwy = NINT( canyon_width_y / dy )
[1322]	636	IF ( canyon_wall_south == 9999999.9_wp ) THEN
[240]	637	canyon_wall_south = ( ny + 1 - cwy ) / 2 * dy
	638	ENDIF
	639	cys = NINT( canyon_wall_south / dy )
	640	cyn = cys + cwy
	641
	642	ELSE
[254]	643
	644	message_string = 'no street canyon width given'
	645	CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
	646
[240]	647	ENDIF
	648
[2232]	649	ch = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
	650	IF ( ABS( zw(ch) - canyon_height ) == &
[1675]	651	ABS( zw(ch+1) - canyon_height ) ) ch = ch + 1
	652
[240]	653	dp_level_ind_b = ch
	654	!
	655	!-- Street canyon size has to meet some requirements
[1322]	656	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1353]	657	IF ( ( cxl < 1 ) .OR. ( cxr > nx-1 ) .OR. ( cwx < 3 ) .OR. &
[240]	658	( ch < 3 ) ) THEN
[1353]	659	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
	660	'&cxl=', cxl, 'cxr=', cxr, &
	661	'cwx=', cwx, &
[254]	662	'ch=', ch, 'nx=', nx, 'ny=', ny
	663	CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
[240]	664	ENDIF
[1322]	665	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1353]	666	IF ( ( cys < 1 ) .OR. ( cyn > ny-1 ) .OR. ( cwy < 3 ) .OR. &
[240]	667	( ch < 3 ) ) THEN
[1353]	668	WRITE( message_string, * ) 'inconsistent canyon parameters:', &
	669	'&cys=', cys, 'cyn=', cyn, &
	670	'cwy=', cwy, &
[254]	671	'ch=', ch, 'nx=', nx, 'ny=', ny
	672	CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
[240]	673	ENDIF
	674	ENDIF
[1353]	675	IF ( canyon_width_x /= 9999999.9_wp .AND. &
	676	canyon_width_y /= 9999999.9_wp ) THEN
	677	message_string = 'inconsistent canyon parameters:' // &
	678	'&street canyon can only be oriented' // &
[254]	679	'&either in x- or in y-direction'
	680	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
[240]	681	ENDIF
	682
	683	nzb_local = ch
[1322]	684	IF ( canyon_width_x /= 9999999.9_wp ) THEN
[1968]	685	IF ( cxl <= nxr .AND. cxr >= nxl ) &
	686	nzb_local(:,MAX(nxl,cxl+1):MIN(nxr,cxr-1)) = 0
[1322]	687	ELSEIF ( canyon_width_y /= 9999999.9_wp ) THEN
[1968]	688	IF ( cys <= nyn .AND. cyn >= nys ) &
	689	nzb_local(MAX(nys,cys+1):MIN(nyn,cyn-1),:) = 0
[240]	690	ENDIF
	691
[1994]	692	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2232]	693	!
	694	!-- Set bit array to mask topography
	695	DO i = nxlg, nxrg
	696	DO j = nysg, nyng
	697	topo_3d(nzb_local(j,i)+1:nzt+1,j,i) = &
	698	IBSET( topo_3d(nzb_local(j,i)+1:nzt+1,j,i), 0 )
	699	ENDDO
	700	ENDDO
	701	!
	702	!-- level of detail is required for output routines. Here, 2D topography.
	703	lod = 1
[1994]	704
[2232]	705	CALL exchange_horiz_int( topo_3d, nbgp )
	706
	707	CASE ( 'tunnel' )
	708
	709	!
	710	!-- Tunnel height
	711	IF ( tunnel_height == 9999999.9_wp ) THEN
	712	th = zw( INT( 0.2 * nz) )
	713	ELSE
	714	th = tunnel_height
	715	ENDIF
	716	!
	717	!-- Tunnel-wall depth
	718	IF ( tunnel_wall_depth == 9999999.9_wp ) THEN
	719	td = MAX ( dx, dy, dz )
	720	ELSE
	721	td = tunnel_wall_depth
	722	ENDIF
	723	!
	724	!-- Check for tunnel width
	725	IF ( tunnel_width_x == 9999999.9_wp .AND. &
	726	tunnel_width_y == 9999999.9_wp ) THEN
	727	message_string = 'No tunnel width is given. '
	728	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	729	ENDIF
	730	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	731	tunnel_width_y /= 9999999.9_wp ) THEN
	732	message_string = 'Inconsistent tunnel parameters:' // &
	733	'tunnel can only be oriented' // &
	734	'either in x- or in y-direction.'
	735	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	736	ENDIF
	737	!
	738	!-- Tunnel axis along y
	739	IF ( tunnel_width_x /= 9999999.9_wp ) THEN
	740	IF ( tunnel_width_x > ( nx + 1 ) * dx ) THEN
	741	message_string = 'Tunnel width too large'
	742	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	743	ENDIF
	744
	745	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
	746	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
	747	txs_in = INT( ( nx + 1 ) * 0.5_wp * dx - &
	748	( tunnel_width_x * 0.5_wp - td ) )
	749	txe_in = INT( ( nx + 1 ) * 0.5_wp * dx + &
	750	( tunnel_width_x * 0.5_wp - td ) )
	751
	752	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
	753	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_length * 0.5_wp )
	754	tys_in = tys_out
	755	tye_in = tye_out
	756	ENDIF
	757	IF ( tunnel_width_x /= 9999999.9_wp .AND. &
	758	tunnel_width_x - 2.0_wp * tunnel_wall_depth <= 2.0_wp * dx ) THEN
	759	message_string = 'Tunnel width too small'
	760	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	761	ENDIF
	762	IF ( tunnel_width_y /= 9999999.9_wp .AND. &
	763	tunnel_width_y - 2.0_wp * tunnel_wall_depth <= 2.0_wp * dy ) THEN
	764	message_string = 'Tunnel width too small'
	765	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	766	ENDIF
	767	!
	768	!-- Tunnel axis along x
	769	IF ( tunnel_width_y /= 9999999.9_wp ) THEN
	770	IF ( tunnel_width_y > ( ny + 1 ) * dy ) THEN
	771	message_string = 'Tunnel width too large'
	772	CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
	773	ENDIF
	774
	775	txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_length * 0.5_wp )
	776	txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_length * 0.5_wp )
	777	txs_in = txs_out
	778	txe_in = txe_out
	779
	780	tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
	781	tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
	782	tys_in = INT( ( ny + 1 ) * 0.5_wp * dy - &
	783	( tunnel_width_y * 0.5_wp - td ) )
	784	tye_in = INT( ( ny + 1 ) * 0.5_wp * dy + &
	785	( tunnel_width_y * 0.5_wp - td ) )
	786	ENDIF
	787
	788	topo_3d = 0
	789	DO i = nxl, nxr
	790	DO j = nys, nyn
	791	!
	792	!-- Use heaviside function to model outer tunnel surface
	793	hv_out = th * 0.5_wp * &
	794	( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp ) &
	795	- ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
	796
	797	hv_out = hv_out * 0.5_wp * &
	798	( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp ) &
	799	- ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
	800	!
	801	!-- Use heaviside function to model inner tunnel surface
	802	hv_in = ( th - td ) * 0.5_wp * &
	803	( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
	804	- ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
	805
	806	hv_in = hv_in * 0.5_wp * &
	807	( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
	808	- ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
	809	!
	810	!-- Set flags at x-y-positions without any tunnel surface
	811	IF ( hv_out - hv_in == 0.0_wp ) THEN
	812	topo_3d(nzb+1:nzt+1,j,i) = IBSET( topo_3d(nzb+1:nzt+1,j,i), 0 )
	813	!
	814	!-- Set flags at x-y-positions with tunnel surfaces
	815	ELSE
	816	DO k = nzb + 1, nzt + 1
	817	!
	818	!-- Inner tunnel
	819	IF ( hv_out - hv_in == th ) THEN
	820	IF ( zw(k) <= hv_out ) THEN
	821	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	822	ELSE
	823	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 0 )
	824	ENDIF
	825	ENDIF
	826	!
	827	!-- Lateral tunnel walls
	828	IF ( hv_out - hv_in == td ) THEN
	829	IF ( zw(k) <= hv_in ) THEN
	830	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 0 )
	831	ELSEIF ( zw(k) > hv_in .AND. zw(k) <= hv_out ) THEN
	832	topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
	833	ELSEIF ( zw(k) > hv_out ) THEN
	834	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 0 )
	835	ENDIF
	836	ENDIF
	837	ENDDO
	838	ENDIF
	839	ENDDO
	840	ENDDO
	841
	842	nzb_local = 0
	843	!
	844	!-- level of detail is required for output routines. Here, 3D topography.
	845	lod = 2
	846
	847	CALL exchange_horiz_int( topo_3d, nbgp )
	848
[1]	849	CASE ( 'read_from_file' )
[759]	850
[2232]	851	ALLOCATE ( oro_height(nys:nyn,nxl:nxr) )
[1968]	852	ALLOCATE ( topo_height(nys:nyn,nxl:nxr) )
[2232]	853	oro_height = 0.0_wp
	854	topo_height = 0.0_wp
[818]	855
[759]	856	DO ii = 0, io_blocks-1
	857	IF ( ii == io_group ) THEN
	858
[1]	859	!
[759]	860	!-- Arbitrary irregular topography data in PALM format (exactly
[2232]	861	!-- matching the grid size and total domain size).
	862	!-- First, check if NetCDF file for topography exist or not.
	863	!-- This case, read topography from NetCDF, else read it from
	864	!-- ASCII file.
	865	#if defined ( __netcdf )
	866	INQUIRE( FILE='TOPOGRAPHY_DATA_NC'//TRIM( coupling_char ), &
	867	EXIST=netcdf_extend )
[1968]	868	!
[2232]	869	!-- NetCDF branch
	870	IF ( netcdf_extend ) THEN
[1968]	871	!
[2232]	872	!-- Open file in read-only mode
	873	CALL netcdf_open_read_file( 'TOPOGRAPHY_DATA_NC', &
	874	id_topo, 20 ) !Error number still need to be set properly
	875
	876	!
	877	!-- Read terrain height. Reading is done PE-wise, i.e. each
	878	!-- processor reads its own domain. Reading is realized
	879	!-- via looping over x-dimension, i.e. calling
	880	!-- netcdf_get_variable reads topography along y for given x.
	881	!-- Orography is 2D.
	882	DO i = nxl, nxr
	883	CALL netcdf_get_variable( id_topo, 'orography_0', &
	884	i, oro_height(:,i), 20 ) !Error number still need to be set properly
	885	ENDDO
	886	!
	887	!-- Read attribute lod (level of detail), required for variable
	888	!-- buildings_0
	889	CALL netcdf_get_attribute( id_topo, "lod", lod, .FALSE., &
	890	20, 'buildings_0' ) !Error number still need to be set properly
	891	!
	892	!-- Read building height
	893	!-- 2D for lod = 1, 3D for lod = 2
	894	IF ( lod == 1 ) THEN
	895	DO i = nxl, nxr
	896	CALL netcdf_get_variable( id_topo, 'buildings_0', &
	897	i, topo_height(:,i), 20 ) !Error number still need to be set properly
	898	ENDDO
	899
	900	ELSEIF ( lod == 2 ) THEN
	901	!
	902	!-- Read data PE-wise. Read yz-slices.
	903	DO i = nxl, nxr
	904	DO j = nys, nyn
	905	CALL netcdf_get_variable( id_topo, 'buildings_0', &
	906	i, j, topo_3d(:,j,i), 20 ) !Error number still need to be set properly
	907	ENDDO
	908	ENDDO
	909	ELSE
	910	message_string = 'NetCDF attribute lod ' // &
	911	'(level of detail) is not set properly.'
	912	CALL message( 'init_grid', 'PA0208', 1, 2, 0, 6, 0 ) !Error number still need to be set properly
	913	ENDIF
	914	!
	915	!-- Close topography input file
	916	CALL netcdf_close_file( id_topo, 20 )
	917	#endif
	918
	919	!
	920	!-- ASCII branch. Please note, reading of 3D topography is not
	921	!-- supported in ASCII format. Further, no distinction is made
	922	!-- between orography and buildings
	923	ELSE
	924
	925	OPEN( 90, FILE='TOPOGRAPHY_DATA'//TRIM( coupling_char ), &
	926	STATUS='OLD', FORM='FORMATTED', ERR=10 )
	927	!
	928	!-- Read topography PE-wise. Rows are read from nyn to nys, columns
	929	!-- are read from nxl to nxr. At first, ny-nyn rows need to be skipped.
	930	skip_n_rows = 0
	931	DO WHILE ( skip_n_rows < ny - nyn )
	932	READ( 90, * )
	933	skip_n_rows = skip_n_rows + 1
	934	ENDDO
	935	!
	936	!-- Read data from nyn to nys and nxl to nxr. Therefore, skip
	937	!-- column until nxl-1 is reached
	938	DO j = nyn, nys, -1
	939	READ( 90, *, ERR=11, END=11 ) &
[1968]	940	( dum, i = 0, nxl-1 ), &
	941	( topo_height(j,i), i = nxl, nxr )
[2232]	942	ENDDO
[759]	943
[2232]	944	GOTO 12
[759]	945
[2232]	946	10 message_string = 'file TOPOGRAPHY'//TRIM( coupling_char )// &
	947	' does not exist'
	948	CALL message( 'init_grid', 'PA0208', 1, 2, 0, 6, 0 )
[759]	949
[2232]	950	11 message_string = 'errors in file TOPOGRAPHY_DATA'// &
	951	TRIM( coupling_char )
	952	CALL message( 'init_grid', 'PA0209', 1, 2, 0, 6, 0 )
[759]	953
[2232]	954	12 CLOSE( 90 )
[759]	955
[2232]	956	ENDIF
	957
[759]	958	ENDIF
[1804]	959	#if defined( __parallel )
[759]	960	CALL MPI_BARRIER( comm2d, ierr )
	961	#endif
[559]	962	ENDDO
[759]	963
[1]	964	!
	965	!-- Calculate the index height of the topography
[1968]	966	nzb_local = 0
	967	DO i = nxl, nxr
	968	DO j = nys, nyn
[2128]	969	IF ( .NOT. ocean ) THEN
[2232]	970	nzb_local(j,i) = MINLOC( ABS( zw - topo_height(j,i) &
	971	- oro_height(j,i) ), 1 ) - 1
	972	IF ( ABS( zw(nzb_local(j,i) ) - topo_height(j,i) &
	973	- oro_height(j,i) ) == &
	974	ABS( zw(nzb_local(j,i)+1) - topo_height(j,i) &
	975	- oro_height(j,i) ) ) &
[2128]	976	nzb_local(j,i) = nzb_local(j,i) + 1
	977	ELSE
	978	nzb_local(j,i) = MINLOC( ABS( zw - zw(0) &
[2232]	979	- topo_height(j,i) &
	980	- oro_height(j,i) ), 1 ) - 1
[2128]	981	IF ( ABS( zw(nzb_local(j,i) ) - zw(0) &
[2232]	982	- topo_height(j,i) &
	983	- oro_height(j,i) ) == &
[2128]	984	ABS( zw(nzb_local(j,i)+1) - zw(0) &
[2232]	985	- topo_height(j,i) &
	986	- oro_height(j,i) ) ) &
[2128]	987	nzb_local(j,i) = nzb_local(j,i) + 1
	988	ENDIF
	989
[1]	990	ENDDO
	991	ENDDO
[818]	992
[2232]	993	DEALLOCATE ( oro_height )
[818]	994	DEALLOCATE ( topo_height )
[1942]	995	!
	996	!-- Filter topography, i.e. fill holes resolved by only one grid point.
	997	!-- Such holes are suspected to lead to velocity blow-ups as continuity
	998	!-- equation on discrete grid cannot be fulfilled in such case.
	999	!-- For now, check only for holes and fill them to the lowest height level
	1000	!-- of the directly adjoining grid points along x- and y- direction.
	1001	!-- Before checking for holes, set lateral boundary conditions for
	1002	!-- topography. After hole-filling, boundary conditions must be set again!
[1968]	1003	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
	1004
	1005	IF ( .NOT. bc_ns_cyc ) THEN
	1006	IF ( nys == 0 ) nzb_local(-1,:) = nzb_local(0,:)
	1007	IF ( nyn == ny ) nzb_local(ny+1,:) = nzb_local(ny,:)
[1942]	1008	ENDIF
[1910]	1009
[1968]	1010	IF ( .NOT. bc_lr_cyc ) THEN
	1011	IF ( nxl == 0 ) nzb_local(:,-1) = nzb_local(:,0)
	1012	IF ( nxr == nx ) nzb_local(:,nx+1) = nzb_local(:,nx)
[1942]	1013	ENDIF
	1014
[1968]	1015	num_hole_l = 0
	1016	DO i = nxl, nxr
	1017	DO j = nys, nyn
[1942]	1018
	1019	num_wall = 0
	1020
	1021	IF ( nzb_local(j-1,i) > nzb_local(j,i) ) &
	1022	num_wall = num_wall + 1
	1023	IF ( nzb_local(j+1,i) > nzb_local(j,i) ) &
	1024	num_wall = num_wall + 1
	1025	IF ( nzb_local(j,i-1) > nzb_local(j,i) ) &
	1026	num_wall = num_wall + 1
	1027	IF ( nzb_local(j,i+1) > nzb_local(j,i) ) &
	1028	num_wall = num_wall + 1
	1029
	1030	IF ( num_wall == 4 ) THEN
	1031	nzb_local(j,i) = MIN( nzb_local(j-1,i), nzb_local(j+1,i), &
	1032	nzb_local(j,i-1), nzb_local(j,i+1) )
[1968]	1033	num_hole_l = num_hole_l + 1
[1942]	1034	ENDIF
	1035	ENDDO
	1036	ENDDO
[114]	1037	!
[1968]	1038	!-- Count the total number of holes, required for informative message.
	1039	#if defined( __parallel )
	1040	CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, &
	1041	comm2d, ierr )
	1042	#else
	1043	num_hole = num_hole_l
	1044	#endif
	1045	!
[1942]	1046	!-- Create an informative message if any hole was removed.
[1968]	1047	IF ( num_hole > 0 ) THEN
[1942]	1048	WRITE( message_string, * ) num_hole, 'hole(s) resolved by only '//&
	1049	'one grid point were filled'
	1050	CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
	1051	ENDIF
[2232]	1052
[1942]	1053	!
[2232]	1054	!-- Set bit array to mask topography. Only required for lod = 1
	1055	IF ( lod == 1 ) THEN
	1056	DO i = nxlg, nxrg
	1057	DO j = nysg, nyng
	1058	topo_3d(nzb_local(j,i)+1:nzt+1,j,i) = &
	1059	IBSET( topo_3d(nzb_local(j,i)+1:nzt+1,j,i), 0 )
	1060	ENDDO
	1061	ENDDO
	1062	ENDIF
	1063	!
[1968]	1064	!-- Exchange ghost-points, as well as add cyclic or Neumann boundary
	1065	!-- conditions.
[2232]	1066	CALL exchange_horiz_int( topo_3d, nbgp )
[1968]	1067	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
	1068
	1069	IF ( .NOT. bc_ns_cyc ) THEN
[2232]	1070	IF ( nys == 0 ) topo_3d(:,-1,:) = topo_3d(:,0,:)
	1071	IF ( nyn == ny ) topo_3d(:,ny+1,:) = topo_3d(:,ny,:)
	1072
[1968]	1073	IF ( nys == 0 ) nzb_local(-1,:) = nzb_local(0,:)
	1074	IF ( nyn == ny ) nzb_local(ny+1,:) = nzb_local(ny,:)
[1910]	1075	ENDIF
[667]	1076
[1968]	1077	IF ( .NOT. bc_lr_cyc ) THEN
[2232]	1078	IF ( nxl == 0 ) topo_3d(:,:,-1) = topo_3d(:,:,0)
	1079	IF ( nxr == nx ) topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
	1080
[1968]	1081	IF ( nxl == 0 ) nzb_local(:,-1) = nzb_local(:,0)
	1082	IF ( nxr == nx ) nzb_local(:,nx+1) = nzb_local(:,nx)
[1910]	1083	ENDIF
	1084
[2232]	1085
[1]	1086	CASE DEFAULT
	1087	!
	1088	!-- The DEFAULT case is reached either if the parameter topography
[217]	1089	!-- contains a wrong character string or if the user has defined a special
[1]	1090	!-- case in the user interface. There, the subroutine user_init_grid
	1091	!-- checks which of these two conditions applies.
[2232]	1092	CALL user_init_grid( topo_3d )
[1]	1093
	1094	END SELECT
	1095	!
	1096	!-- Consistency checks and index array initialization are only required for
[217]	1097	!-- non-flat topography, also the initialization of topography height arrays
[49]	1098	!-- zu_s_inner and zw_w_inner
[1]	1099	IF ( TRIM( topography ) /= 'flat' ) THEN
[1968]	1100	#if defined( __parallel )
	1101	CALL MPI_ALLREDUCE( MAXVAL( nzb_local ), nzb_local_max, 1, MPI_INTEGER, &
	1102	MPI_MAX, comm2d, ierr )
[1982]	1103	CALL MPI_ALLREDUCE( MINVAL( nzb_local ), nzb_local_min, 1, MPI_INTEGER, &
[1968]	1104	MPI_MIN, comm2d, ierr )
	1105	#else
	1106	nzb_local_max = MAXVAL( nzb_local )
	1107	nzb_local_min = MINVAL( nzb_local )
	1108	#endif
[1982]	1109
[1]	1110	!
	1111	!-- Consistency checks
[1968]	1112	IF ( nzb_local_min < 0 .OR. nzb_local_max > nz + 1 ) THEN
[1353]	1113	WRITE( message_string, * ) 'nzb_local values are outside the', &
	1114	'model domain', &
[1968]	1115	'&MINVAL( nzb_local ) = ', nzb_local_min, &
	1116	'&MAXVAL( nzb_local ) = ', nzb_local_max
[254]	1117	CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
[1]	1118	ENDIF
[2232]	1119	!
	1120	!-- In case of non-flat topography, check whether the convention how to
	1121	!-- define the topography grid has been set correctly, or whether the default
	1122	!-- is applicable. If this is not possible, abort.
	1123	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
	1124	IF ( TRIM( topography ) /= 'single_building' .AND. &
	1125	TRIM( topography ) /= 'single_street_canyon' .AND. &
	1126	TRIM( topography ) /= 'tunnel' .AND. &
	1127	TRIM( topography ) /= 'read_from_file') THEN
	1128	!-- The default value is not applicable here, because it is only valid
	1129	!-- for the two standard cases 'single_building' and 'read_from_file'
	1130	!-- defined in init_grid.
	1131	WRITE( message_string, * ) &
	1132	'The value for "topography_grid_convention" ', &
	1133	'is not set. Its default value is & only valid for ', &
	1134	'"topography" = ''single_building'', ', &
	1135	'''single_street_canyon'' & or ''read_from_file''.', &
	1136	' & Choose ''cell_edge'' or ''cell_center''.'
	1137	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	1138	ELSE
	1139	!-- The default value is applicable here.
	1140	!-- Set convention according to topography.
	1141	IF ( TRIM( topography ) == 'single_building' .OR. &
	1142	TRIM( topography ) == 'single_street_canyon' ) THEN
	1143	topography_grid_convention = 'cell_edge'
	1144	ELSEIF ( TRIM( topography ) == 'read_from_file' .OR. &
	1145	TRIM( topography ) == 'tunnel') THEN
	1146	topography_grid_convention = 'cell_center'
	1147	ENDIF
	1148	ENDIF
	1149	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	1150	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	1151	WRITE( message_string, * ) &
	1152	'The value for "topography_grid_convention" is ', &
	1153	'not recognized. & Choose ''cell_edge'' or ''cell_center''.'
	1154	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	1155	ENDIF
[1]	1156
[2169]	1157	!
	1158	!-- In case of non-flat topography, check whether the convention how to
	1159	!-- define the topography grid has been set correctly, or whether the default
	1160	!-- is applicable. If this is not possible, abort.
	1161	IF ( TRIM( topography_grid_convention ) == ' ' ) THEN
	1162	IF ( TRIM( topography ) /= 'single_building' .AND. &
	1163	TRIM( topography ) /= 'single_street_canyon' .AND. &
	1164	TRIM( topography ) /= 'read_from_file' ) THEN
	1165	!-- The default value is not applicable here, because it is only valid
	1166	!-- for the two standard cases 'single_building' and 'read_from_file'
	1167	!-- defined in init_grid.
	1168	WRITE( message_string, * ) &
	1169	'The value for "topography_grid_convention" ', &
	1170	'is not set. Its default value is & only valid for ', &
	1171	'"topography" = ''single_building'', ', &
	1172	'''single_street_canyon'' & or ''read_from_file''.', &
	1173	' & Choose ''cell_edge'' or ''cell_center''.'
	1174	CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
	1175	ELSE
	1176	!-- The default value is applicable here.
	1177	!-- Set convention according to topography.
	1178	IF ( TRIM( topography ) == 'single_building' .OR. &
	1179	TRIM( topography ) == 'single_street_canyon' ) THEN
	1180	topography_grid_convention = 'cell_edge'
	1181	ELSEIF ( TRIM( topography ) == 'read_from_file' ) THEN
	1182	topography_grid_convention = 'cell_center'
	1183	ENDIF
	1184	ENDIF
	1185	ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND. &
	1186	TRIM( topography_grid_convention ) /= 'cell_center' ) THEN
	1187	WRITE( message_string, * ) &
	1188	'The value for "topography_grid_convention" is ', &
	1189	'not recognized. & Choose ''cell_edge'' or ''cell_center''.'
	1190	CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
	1191	ENDIF
	1192
[217]	1193	IF ( topography_grid_convention == 'cell_edge' ) THEN
[134]	1194	!
[217]	1195	!-- The array nzb_local as defined using the 'cell_edge' convention
	1196	!-- describes the actual total size of topography which is defined at the
	1197	!-- cell edges where u=0 on the topography walls in x-direction and v=0
	1198	!-- on the topography walls in y-direction. However, PALM uses individual
	1199	!-- arrays nzb_u\|v\|w\|s_inner\|outer that are based on nzb_s_inner.
	1200	!-- Therefore, the extent of topography in nzb_local is now reduced by
	1201	!-- 1dx at the E topography walls and by 1dy at the N topography walls
[1968]	1202	!-- to form the basis for nzb_s_inner.
	1203	!-- Note, the reverse memory access (i-j instead of j-i) is absolutely
	1204	!-- required at this point.
	1205	DO j = nys+1, nyn+1
	1206	DO i = nxl-1, nxr
[217]	1207	nzb_local(j,i) = MIN( nzb_local(j,i), nzb_local(j,i+1) )
	1208	ENDDO
[134]	1209	ENDDO
[1968]	1210	!
	1211	!-- Exchange ghost points
	1212	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
	1213
	1214	DO i = nxl, nxr+1
	1215	DO j = nys-1, nyn
[217]	1216	nzb_local(j,i) = MIN( nzb_local(j,i), nzb_local(j+1,i) )
	1217	ENDDO
[2232]	1218	ENDDO
[1968]	1219	!
	1220	!-- Exchange ghost points
	1221	CALL exchange_horiz_2d_int( nzb_local, nys, nyn, nxl, nxr, nbgp )
[2232]	1222	!
	1223	!-- Apply cell-edge convention also for 3D topo array. The former setting
	1224	!-- of nzb_local will be removed later.
	1225	DO j = nys+1, nyn+1
	1226	DO i = nxl-1, nxr
	1227	DO k = nzb, nzt+1
	1228	IF ( BTEST( topo_3d(k,j,i), 0 ) .OR. &
	1229	BTEST( topo_3d(k,j,i+1), 0 ) ) &
	1230	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 0 )
	1231	ENDDO
	1232	ENDDO
	1233	ENDDO
	1234	CALL exchange_horiz_int( topo_3d, nbgp )
	1235
	1236	DO i = nxl, nxr+1
	1237	DO j = nys-1, nyn
	1238	DO k = nzb, nzt+1
	1239	IF ( BTEST( topo_3d(k,j,i), 0 ) .OR. &
	1240	BTEST( topo_3d(k,j+1,i), 0 ) ) &
	1241	topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 0 )
	1242	ENDDO
	1243	ENDDO
	1244	ENDDO
	1245	CALL exchange_horiz_int( topo_3d, nbgp )
	1246
[217]	1247	ENDIF
[2232]	1248
[1]	1249	!
	1250	!-- Initialize index arrays nzb_s_inner and nzb_w_inner
[2232]	1251
[1968]	1252	nzb_s_inner = nzb_local
	1253	nzb_w_inner = nzb_local
[1]	1254
	1255	!
	1256	!-- Initialize remaining index arrays:
	1257	!-- first pre-initialize them with nzb_s_inner...
	1258	nzb_u_inner = nzb_s_inner
	1259	nzb_u_outer = nzb_s_inner
	1260	nzb_v_inner = nzb_s_inner
	1261	nzb_v_outer = nzb_s_inner
	1262	nzb_w_outer = nzb_s_inner
	1263	nzb_s_outer = nzb_s_inner
	1264
	1265	!
	1266	!-- ...then extend pre-initialized arrays in their according directions
	1267	!-- based on nzb_local using nzb_tmp as a temporary global index array
	1268
	1269	!
	1270	!-- nzb_s_outer:
	1271	!-- extend nzb_local east-/westwards first, then north-/southwards
[1968]	1272	nzb_tmp = nzb_local
	1273	DO j = nys, nyn
	1274	DO i = nxl, nxr
[1353]	1275	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i), &
[1]	1276	nzb_local(j,i+1) )
	1277	ENDDO
	1278	ENDDO
[1968]	1279
	1280	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	1281
[1]	1282	DO i = nxl, nxr
	1283	DO j = nys, nyn
[1353]	1284	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
[1]	1285	nzb_tmp(j+1,i) )
	1286	ENDDO
	1287	!
	1288	!-- non-cyclic boundary conditions (overwritten by call of
	1289	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	1290	IF ( nys == 0 ) THEN
	1291	j = -1
	1292	nzb_s_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	1293	ENDIF
[1743]	1294	IF ( nyn == ny ) THEN
[1]	1295	j = ny + 1
	1296	nzb_s_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	1297	ENDIF
	1298	ENDDO
	1299	!
	1300	!-- nzb_w_outer:
	1301	!-- identical to nzb_s_outer
	1302	nzb_w_outer = nzb_s_outer
	1303
	1304	!
	1305	!-- nzb_u_inner:
	1306	!-- extend nzb_local rightwards only
[1968]	1307	nzb_tmp = nzb_local
	1308	DO j = nys, nyn
	1309	DO i = nxl, nxr
[1]	1310	nzb_tmp(j,i) = MAX( nzb_local(j,i-1), nzb_local(j,i) )
	1311	ENDDO
	1312	ENDDO
[1968]	1313
	1314	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	1315
	1316	nzb_u_inner = nzb_tmp
[1]	1317	!
	1318	!-- nzb_u_outer:
	1319	!-- extend current nzb_tmp (nzb_u_inner) north-/southwards
	1320	DO i = nxl, nxr
	1321	DO j = nys, nyn
[1353]	1322	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i), &
[1]	1323	nzb_tmp(j+1,i) )
	1324	ENDDO
	1325	!
	1326	!-- non-cyclic boundary conditions (overwritten by call of
	1327	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	1328	IF ( nys == 0 ) THEN
	1329	j = -1
	1330	nzb_u_outer(j,i) = MAX( nzb_tmp(j+1,i), nzb_tmp(j,i) )
	1331	ENDIF
[1743]	1332	IF ( nyn == ny ) THEN
[1]	1333	j = ny + 1
	1334	nzb_u_outer(j,i) = MAX( nzb_tmp(j-1,i), nzb_tmp(j,i) )
	1335	ENDIF
	1336	ENDDO
	1337
	1338	!
	1339	!-- nzb_v_inner:
	1340	!-- extend nzb_local northwards only
[1968]	1341	nzb_tmp = nzb_local
	1342	DO i = nxl, nxr
	1343	DO j = nys, nyn
[1]	1344	nzb_tmp(j,i) = MAX( nzb_local(j-1,i), nzb_local(j,i) )
	1345	ENDDO
	1346	ENDDO
[1968]	1347
	1348	CALL exchange_horiz_2d_int( nzb_tmp, nys, nyn, nxl, nxr, nbgp )
	1349	nzb_v_inner = nzb_tmp
[1]	1350
	1351	!
	1352	!-- nzb_v_outer:
	1353	!-- extend current nzb_tmp (nzb_v_inner) right-/leftwards
	1354	DO j = nys, nyn
	1355	DO i = nxl, nxr
[1353]	1356	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i), &
[1]	1357	nzb_tmp(j,i+1) )
	1358	ENDDO
	1359	!
	1360	!-- non-cyclic boundary conditions (overwritten by call of
	1361	!-- exchange_horiz_2d_int below in case of cyclic boundary conditions)
	1362	IF ( nxl == 0 ) THEN
	1363	i = -1
	1364	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i+1), nzb_tmp(j,i) )
	1365	ENDIF
	1366	IF ( nxr == nx ) THEN
	1367	i = nx + 1
	1368	nzb_v_outer(j,i) = MAX( nzb_tmp(j,i-1), nzb_tmp(j,i) )
	1369	ENDIF
	1370	ENDDO
[1804]	1371
[1]	1372	!
	1373	!-- Exchange of lateral boundary values (parallel computers) and cyclic
	1374	!-- boundary conditions, if applicable.
	1375	!-- Since nzb_s_inner and nzb_w_inner are derived directly from nzb_local
	1376	!-- they do not require exchange and are not included here.
[1968]	1377	CALL exchange_horiz_2d_int( nzb_u_inner, nys, nyn, nxl, nxr, nbgp )
	1378	CALL exchange_horiz_2d_int( nzb_u_outer, nys, nyn, nxl, nxr, nbgp )
	1379	CALL exchange_horiz_2d_int( nzb_v_inner, nys, nyn, nxl, nxr, nbgp )
	1380	CALL exchange_horiz_2d_int( nzb_v_outer, nys, nyn, nxl, nxr, nbgp )
	1381	CALL exchange_horiz_2d_int( nzb_w_outer, nys, nyn, nxl, nxr, nbgp )
	1382	CALL exchange_horiz_2d_int( nzb_s_outer, nys, nyn, nxl, nxr, nbgp )
[1]	1383
[2232]	1384	ENDIF
[49]	1385	!
[2232]	1386	!-- Deallocate temporary array, as it might be reused for different
	1387	!-- grid-levels further below.
	1388	DEALLOCATE( nzb_tmp )
	1389
	1390	!
	1391	!-- Determine the maximum level of topography. It is used for
	1392	!-- steering the degradation of order of the applied advection scheme.
	1393	!-- In case of non-cyclic lateral boundaries, the order of the advection
	1394	!-- scheme has to be reduced up to nzt (required at the lateral boundaries).
	1395	k_top = 0
	1396	DO i = nxl, nxr
	1397	DO j = nys, nyn
	1398	DO k = nzb, nzt + 1
	1399	k_top = MAX( k_top, MERGE( k, 0, &
	1400	.NOT. BTEST( topo_3d(k,j,i), 0 ) ) )
[1968]	1401	ENDDO
	1402	ENDDO
[2232]	1403	ENDDO
[1968]	1404	#if defined( __parallel )
[2232]	1405	CALL MPI_ALLREDUCE( k_top + 1, nzb_max, 1, MPI_INTEGER, & !is +1 really necessary here?
	1406	MPI_MAX, comm2d, ierr )
[1968]	1407	#else
[2232]	1408	nzb_max = k_top + 1
[1968]	1409	#endif
[2232]	1410	IF ( inflow_l .OR. outflow_l .OR. inflow_r .OR. outflow_r .OR. &
	1411	inflow_n .OR. outflow_n .OR. inflow_s .OR. outflow_s .OR. &
	1412	nest_domain ) &
	1413	THEN
	1414	nzb_max = nzt
[1]	1415	ENDIF
[1968]	1416	!
[2232]	1417	!-- Finally, if topography extents up to the model top, limit nzb_max to nzt.
	1418	nzb_max = MIN( nzb_max, nzt )
[1]	1419
	1420	!
	1421	!-- Set the individual index arrays which define the k index from which on
	1422	!-- the usual finite difference form (which does not use surface fluxes) is
	1423	!-- applied
[1691]	1424	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
[1]	1425	nzb_diff_s_inner = nzb_s_inner + 2
	1426	nzb_diff_s_outer = nzb_s_outer + 2
	1427	ELSE
	1428	nzb_diff_s_inner = nzb_s_inner + 1
	1429	nzb_diff_s_outer = nzb_s_outer + 1
	1430	ENDIF
	1431
	1432	!
[2232]	1433	!-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
	1434	!-- Further special flags will be set in following loops.
	1435	wall_flags_0 = 0
	1436	DO j = nys, nyn
	1437	DO i = nxl, nxr
	1438	DO k = nzb, nzt+1
	1439	!
	1440	!-- scalar grid
	1441	IF ( BTEST( topo_3d(k,j,i), 0 ) ) &
	1442	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 0 )
	1443	!
	1444	!-- v grid
	1445	IF ( BTEST( topo_3d(k,j,i), 0 ) .AND. &
	1446	BTEST( topo_3d(k,j-1,i), 0 ) ) &
	1447	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 2 )
	1448	!
	1449	!-- To do: set outer arrays on basis of topo_3d array, adjust for downward-facing walls
	1450	!-- s grid outer array
	1451	IF ( k >= nzb_s_outer(j,i) ) &
	1452	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 24 )
	1453	!
	1454	!-- s grid outer array
	1455	IF ( k >= nzb_u_outer(j,i) ) &
	1456	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 26 )
	1457	!
	1458	!-- s grid outer array
	1459	IF ( k >= nzb_v_outer(j,i) ) &
	1460	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 27 )
	1461	!
	1462	!-- w grid outer array
	1463	IF ( k >= nzb_w_outer(j,i) ) &
	1464	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 28 )
	1465	ENDDO
[1]	1466
[2232]	1467	DO k = nzb, nzt
[1]	1468	!
[2232]	1469	!-- w grid
	1470	IF ( BTEST( topo_3d(k,j,i), 0 ) .AND. &
	1471	BTEST( topo_3d(k+1,j,i), 0 ) ) &
	1472	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 3 )
	1473	ENDDO
	1474	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 3 )
	1475
	1476	ENDDO
	1477	ENDDO
[1]	1478	!
[2232]	1479	!-- u grid. Note, reverse
	1480	!-- memory access is required for setting flag on u-grid
	1481	DO j = nys, nyn
	1482	DO i = nxl, nxr
	1483	DO k = nzb, nzt+1
	1484	IF ( BTEST( topo_3d(k,j,i), 0 ) .AND. &
	1485	BTEST( topo_3d(k,j,i-1), 0 ) ) &
	1486	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 1 )
	1487	ENDDO
	1488	ENDDO
	1489	ENDDO
[1]	1490	!
[2232]	1491	!-- Set further special flags
	1492	DO i = nxl, nxr
	1493	DO j = nys, nyn
	1494	DO k = nzb, nzt+1
[1]	1495	!
[2232]	1496	!-- scalar grid, former nzb_diff_s_inner.
	1497	!-- Note, use this flag also to mask topography in diffusion_u and
	1498	!-- diffusion_v along the vertical direction. In case of
	1499	!-- use_surface_fluxes, fluxes are calculated via MOST, else, simple
	1500	!-- gradient approach is applied. Please note, in case of u- and v-
	1501	!-- diffuison, a small error is made at edges (on the east side for u,
	1502	!-- at the north side for v), since topography on scalar grid point
	1503	!-- is used instead of topography on u/v-grid. As number of topography grid
	1504	!-- points on uv-grid is different than s-grid, different number of
	1505	!-- surface elements would be required. In order to avoid this,
	1506	!-- treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
	1507	!-- points are not masked within diffusion_u. Tests had shown that the
	1508	!-- effect on the flow is negligible.
	1509	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	1510	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	1511	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	1512	ELSE
	1513	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 8 )
	1514	ENDIF
[1]	1515
[2232]	1516	ENDDO
	1517	!
	1518	!-- Special flag to control vertical diffusion at model top - former
	1519	!-- nzt_diff
	1520	wall_flags_0(:,j,i) = IBSET( wall_flags_0(:,j,i), 9 )
	1521	IF ( use_top_fluxes ) &
	1522	wall_flags_0(nzt:nzt+1,j,i) = IBCLR( wall_flags_0(nzt:nzt+1,j,i), 9 )
[1]	1523
[2232]	1524	DO k = nzb+1, nzt
	1525	!
	1526	!-- Special flag on u grid, former nzb_u_inner + 1, required
	1527	!-- for disturb_field and initialization. Do not disturb directly at
	1528	!-- topography, as well as initialize u with zero one grid point outside
	1529	!-- of topography.
	1530	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	1531	BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	1532	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	1533	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 20 )
	1534	!
	1535	!-- Special flag on v grid, former nzb_v_inner + 1, required
	1536	!-- for disturb_field and initialization. Do not disturb directly at
	1537	!-- topography, as well as initialize v with zero one grid point outside
	1538	!-- of topography.
	1539	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	1540	BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	1541	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	1542	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 21 )
	1543	!
	1544	!-- Special flag on scalar grid, former nzb_s_inner+1. Used for
	1545	!-- lpm_sgs_tke
	1546	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	1547	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	1548	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1549	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 25 )
	1550	!
	1551	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	1552	!-- in production_e
	1553	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	1554	IF ( BTEST( wall_flags_0(k,j,i), 24 ) .AND. &
	1555	BTEST( wall_flags_0(k-1,j,i), 24 ) .AND. &
	1556	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1557	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
	1558	ELSE
	1559	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	1560	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 29 )
[1]	1561	ENDIF
[2232]	1562	!
	1563	!-- Special flag on scalar grid, nzb_diff_s_outer - 1, required in
	1564	!-- in production_e
	1565	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	1566	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	1567	BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	1568	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1569	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	1570	ELSE
	1571	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) &
	1572	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 30 )
	1573	ENDIF
	1574	ENDDO
	1575	!
	1576	!-- Flags indicating downward facing walls
	1577	DO k = nzb+1, nzt
	1578	!
	1579	!-- Scalar grid
	1580	IF ( BTEST( wall_flags_0(k-1,j,i), 0 ) .AND. &
	1581	.NOT. BTEST( wall_flags_0(k,j,i), 0 ) ) &
	1582	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 13 )
	1583	!
	1584	!-- Downward facing wall on u grid
	1585	IF ( BTEST( wall_flags_0(k-1,j,i), 1 ) .AND. &
	1586	.NOT. BTEST( wall_flags_0(k,j,i), 1 ) ) &
	1587	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 15 )
	1588	!
	1589	!-- Downward facing wall on v grid
	1590	IF ( BTEST( wall_flags_0(k-1,j,i), 2 ) .AND. &
	1591	.NOT. BTEST( wall_flags_0(k,j,i), 2 ) ) &
	1592	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 17 )
	1593	!
	1594	!-- Downward facing wall on w grid
	1595	IF ( BTEST( wall_flags_0(k-1,j,i), 3 ) .AND. &
	1596	.NOT. BTEST( wall_flags_0(k,j,i), 3 ) ) &
	1597	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 19 )
	1598	ENDDO
	1599	!
	1600	!-- Flags indicating upward facing walls
	1601	DO k = nzb, nzt
	1602	!
	1603	!-- Upward facing wall on scalar grid
	1604	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	1605	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1606	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 12 )
	1607	!
	1608	!-- Upward facing wall on u grid
	1609	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 1 ) .AND. &
	1610	BTEST( wall_flags_0(k+1,j,i), 1 ) ) &
	1611	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 14 )
[1]	1612
[2232]	1613	!
	1614	!-- Upward facing wall on v grid
	1615	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 2 ) .AND. &
	1616	BTEST( wall_flags_0(k+1,j,i), 2 ) ) &
	1617	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 16 )
	1618
	1619	!
	1620	!-- Upward facing wall on w grid
	1621	IF ( .NOT. BTEST( wall_flags_0(k,j,i), 3 ) .AND. &
	1622	BTEST( wall_flags_0(k+1,j,i), 3 ) ) &
	1623	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 18 )
	1624	!
	1625	!-- Special flag on scalar grid, former nzb_s_inner
	1626	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .OR. &
	1627	BTEST( wall_flags_0(k,j,i), 12 ) .OR. &
	1628	BTEST( wall_flags_0(k,j,i), 13 ) ) &
	1629	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 22 )
	1630	!
	1631	!-- Special flag on scalar grid, nzb_diff_s_inner - 1, required for
	1632	!-- flow_statistics
	1633	IF ( constant_flux_layer .OR. use_surface_fluxes ) THEN
	1634	IF ( BTEST( wall_flags_0(k,j,i), 0 ) .AND. &
	1635	BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1636	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
	1637	ELSE
	1638	IF ( BTEST( wall_flags_0(k,j,i), 22 ) ) &
	1639	wall_flags_0(k,j,i) = IBSET( wall_flags_0(k,j,i), 23 )
[1]	1640	ENDIF
	1641
	1642
[2232]	1643	ENDDO
	1644	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 22 )
	1645	wall_flags_0(nzt+1,j,i) = IBSET( wall_flags_0(nzt+1,j,i), 23 )
	1646	ENDDO
	1647	ENDDO
	1648	!
	1649	!-- Exchange ghost points for wall flags
	1650	CALL exchange_horiz_int( wall_flags_0, nbgp )
	1651	!
	1652	!-- Set boundary conditions also for flags. Can be interpreted as Neumann
	1653	!-- boundary conditions for topography.
	1654	IF ( .NOT. bc_ns_cyc ) THEN
	1655	IF ( nys == 0 ) wall_flags_0(:,-1,:) = wall_flags_0(:,0,:)
	1656	IF ( nyn == ny ) wall_flags_0(:,ny+1,:) = wall_flags_0(:,ny,:)
	1657	ENDIF
	1658	IF ( .NOT. bc_lr_cyc ) THEN
	1659	IF ( nxl == 0 ) wall_flags_0(:,:,-1) = wall_flags_0(:,:,0)
	1660	IF ( nxr == nx ) wall_flags_0(:,:,nx+1) = wall_flags_0(:,:,nx)
	1661	ENDIF
[1]	1662
[2232]	1663	!
	1664	!-- Initialize boundary conditions via surface type
	1665	CALL init_bc
	1666	!
	1667	!-- Allocate and set topography height arrays required for data output
	1668	IF ( TRIM( topography ) /= 'flat' ) THEN
	1669	!
	1670	!-- Allocate and set the arrays containing the topography height
[1]	1671
[2232]	1672	IF ( nxr == nx .AND. nyn /= ny ) THEN
	1673	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), &
	1674	zw_w_inner(nxl:nxr+1,nys:nyn) )
	1675	ELSEIF ( nxr /= nx .AND. nyn == ny ) THEN
	1676	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), &
	1677	zw_w_inner(nxl:nxr,nys:nyn+1) )
	1678	ELSEIF ( nxr == nx .AND. nyn == ny ) THEN
	1679	ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), &
	1680	zw_w_inner(nxl:nxr+1,nys:nyn+1) )
	1681	ELSE
	1682	ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), &
	1683	zw_w_inner(nxl:nxr,nys:nyn) )
	1684	ENDIF
[1]	1685
[2232]	1686	zu_s_inner = 0.0_wp
	1687	zw_w_inner = 0.0_wp
	1688	!
	1689	!-- Determine local topography height on scalar and w-grid. Note, setting
	1690	!-- lateral boundary values is not necessary, realized via wall_flags_0
	1691	!-- array. Further, please note that loop bounds are different from
	1692	!-- nxl to nxr and nys to nyn on south and right model boundary, hence,
	1693	!-- use intrinsic lbound and ubound functions to infer array bounds.
	1694	DO i = lbound(zu_s_inner, 1), ubound(zu_s_inner, 1)
	1695	DO j = lbound(zu_s_inner, 2), ubound(zu_s_inner, 2)
	1696	!
	1697	!-- Topography height on scalar grid. Therefore, determine index of
	1698	!-- upward-facing surface element on scalar grid (bit 12).
	1699	zu_s_inner(i,j) = zu( MAXLOC( MERGE( &
	1700	1, 0, BTEST( wall_flags_0(:,j,i), 12 )&
	1701	), DIM = 1 &
	1702	) - 1 &
	1703	)
	1704	!
	1705	!-- Topography height on w grid. Therefore, determine index of
	1706	!-- upward-facing surface element on w grid (bit 18).
	1707	zw_w_inner(i,j) = zw( MAXLOC( MERGE( &
	1708	1, 0, BTEST( wall_flags_0(:,j,i), 18 )&
	1709	), DIM = 1 &
	1710	) - 1 &
	1711	)
	1712	ENDDO
	1713	ENDDO
[1]	1714
	1715
[2232]	1716	ENDIF
[1]	1717
	1718	!
[1931]	1719	!-- Calculate wall flag arrays for the multigrid method.
	1720	!-- Please note, wall flags are only applied in the not cache-optimized
	1721	!-- version.
	1722	IF ( psolver == 'multigrid_noopt' ) THEN
[1968]	1723
[114]	1724	!
[1968]	1725	!-- Gridpoint increment of the current level.
[114]	1726	inc = 1
	1727	DO l = maximum_grid_level, 1 , -1
[1968]	1728	!
	1729	!-- Set grid_level as it is required for exchange_horiz_2d_int
	1730	grid_level = l
[114]	1731
	1732	nxl_l = nxl_mg(l)
	1733	nxr_l = nxr_mg(l)
	1734	nys_l = nys_mg(l)
	1735	nyn_l = nyn_mg(l)
	1736	nzt_l = nzt_mg(l)
	1737	!
	1738	!-- Assign the flag level to be calculated
	1739	SELECT CASE ( l )
	1740	CASE ( 1 )
	1741	flags => wall_flags_1
	1742	CASE ( 2 )
	1743	flags => wall_flags_2
	1744	CASE ( 3 )
	1745	flags => wall_flags_3
	1746	CASE ( 4 )
	1747	flags => wall_flags_4
	1748	CASE ( 5 )
	1749	flags => wall_flags_5
	1750	CASE ( 6 )
	1751	flags => wall_flags_6
	1752	CASE ( 7 )
	1753	flags => wall_flags_7
	1754	CASE ( 8 )
	1755	flags => wall_flags_8
	1756	CASE ( 9 )
	1757	flags => wall_flags_9
	1758	CASE ( 10 )
	1759	flags => wall_flags_10
	1760	END SELECT
	1761
	1762	!
	1763	!-- Depending on the grid level, set the respective bits in case of
	1764	!-- neighbouring walls
	1765	!-- Bit 0: wall to the bottom
	1766	!-- Bit 1: wall to the top (not realized in remaining PALM code so far)
	1767	!-- Bit 2: wall to the south
	1768	!-- Bit 3: wall to the north
	1769	!-- Bit 4: wall to the left
	1770	!-- Bit 5: wall to the right
[116]	1771	!-- Bit 6: inside building
[114]	1772
	1773	flags = 0
	1774
[927]	1775	!
	1776	!-- In case of masking method, flags are not set and multigrid method
	1777	!-- works like FFT-solver
[1931]	1778	IF ( .NOT. masking_method ) THEN
[927]	1779
[1968]	1780	!
	1781	!-- Allocate temporary array for topography heights on coarser grid
	1782	!-- level. Please note, 2 ghoist points are required, in order to
	1783	!-- calculate flags() on the interior ghost point.
	1784	ALLOCATE( nzb_tmp(nys_l-2:nyn_l+2,nxl_l-2:nxr_l+2) )
	1785	nzb_tmp = 0
	1786
	1787	DO i = nxl_l, nxr_l
	1788	DO j = nys_l, nyn_l
	1789	nzb_tmp(j,i) = nzb_local(jinc,iinc)
	1790	ENDDO
	1791	ENDDO
	1792	!
	1793	!-- Exchange ghost points on respective multigrid level. 2 ghost points
	1794	!-- are required, in order to calculate flags on
	1795	!-- nys_l-1 / nyn_l+1 / nxl_l-1 / nxr_l+1. The alternative would be to
	1796	!-- exchange 3D-INTEGER array flags on the respective multigrid level.
	1797	CALL exchange_horiz_2d_int( nzb_tmp, nys_l, nyn_l, nxl_l, nxr_l, 2 )
	1798	!
	1799	!-- Set non-cyclic boundary conditions on respective multigrid level
	1800	IF ( .NOT. bc_ns_cyc ) THEN
[2021]	1801	IF ( inflow_s .OR. outflow_s .OR. nest_bound_s ) THEN
[1968]	1802	nzb_tmp(-2,:) = nzb_tmp(0,:)
	1803	nzb_tmp(-1,:) = nzb_tmp(0,:)
	1804	ENDIF
[2021]	1805	IF ( inflow_n .OR. outflow_n .OR. nest_bound_n ) THEN
	1806	nzb_tmp(nyn_l+2,:) = nzb_tmp(nyn_l,:)
	1807	nzb_tmp(nyn_l+1,:) = nzb_tmp(nyn_l,:)
[1968]	1808	ENDIF
	1809	ENDIF
	1810	IF ( .NOT. bc_lr_cyc ) THEN
[2021]	1811	IF ( inflow_l .OR. outflow_l .OR. nest_bound_l ) THEN
[1968]	1812	nzb_tmp(:,-2) = nzb_tmp(:,0)
	1813	nzb_tmp(:,-1) = nzb_tmp(:,0)
	1814	ENDIF
[2021]	1815	IF ( inflow_r .OR. outflow_r .OR. nest_bound_r ) THEN
	1816	nzb_tmp(:,nxr_l+1) = nzb_tmp(:,nxr_l)
	1817	nzb_tmp(:,nxr_l+2) = nzb_tmp(:,nxr_l)
[1968]	1818	ENDIF
	1819	ENDIF
	1820
[927]	1821	DO i = nxl_l-1, nxr_l+1
	1822	DO j = nys_l-1, nyn_l+1
[1968]	1823	DO k = nzb, nzt_l+1
[114]	1824	!
[927]	1825	!-- Inside/outside building (inside building does not need
	1826	!-- further tests for walls)
[1968]	1827	IF ( k*inc <= nzb_tmp(j,i) ) THEN
[114]	1828
[927]	1829	flags(k,j,i) = IBSET( flags(k,j,i), 6 )
[114]	1830
[927]	1831	ELSE
[114]	1832	!
[927]	1833	!-- Bottom wall
[1968]	1834	IF ( (k-1)*inc <= nzb_tmp(j,i) ) THEN
[927]	1835	flags(k,j,i) = IBSET( flags(k,j,i), 0 )
	1836	ENDIF
[114]	1837	!
[927]	1838	!-- South wall
[1968]	1839	IF ( k*inc <= nzb_tmp(j-1,i) ) THEN
[927]	1840	flags(k,j,i) = IBSET( flags(k,j,i), 2 )
	1841	ENDIF
[114]	1842	!
[927]	1843	!-- North wall
[1968]	1844	IF ( k*inc <= nzb_tmp(j+1,i) ) THEN
[927]	1845	flags(k,j,i) = IBSET( flags(k,j,i), 3 )
	1846	ENDIF
[114]	1847	!
[927]	1848	!-- Left wall
[1968]	1849	IF ( k*inc <= nzb_tmp(j,i-1) ) THEN
[927]	1850	flags(k,j,i) = IBSET( flags(k,j,i), 4 )
	1851	ENDIF
[114]	1852	!
[927]	1853	!-- Right wall
[1968]	1854	IF ( k*inc <= nzb_tmp(j,i+1) ) THEN
[927]	1855	flags(k,j,i) = IBSET( flags(k,j,i), 5 )
	1856	ENDIF
	1857
[114]	1858	ENDIF
	1859
[927]	1860	ENDDO
[114]	1861	ENDDO
	1862	ENDDO
	1863
[1968]	1864	DEALLOCATE( nzb_tmp )
	1865
[927]	1866	ENDIF
	1867
[114]	1868	inc = inc * 2
	1869
	1870	ENDDO
[1968]	1871	!
	1872	!-- Reset grid_level to "normal" grid
	1873	grid_level = 0
	1874
[114]	1875	ENDIF
[861]	1876	!
[1942]	1877	!-- Allocate flags needed for masking walls. Even though these flags are only
[2021]	1878	!-- required in the ws-scheme, the arrays need to be allocated here as they are
[1942]	1879	!-- used in OpenACC directives.
[2232]	1880	ALLOCATE( advc_flags_1(nzb:nzt+1,nysg:nyng,nxlg:nxrg), &
	1881	advc_flags_2(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
	1882	advc_flags_1 = 0
	1883	advc_flags_2 = 0
[114]	1884	!
[2021]	1885	!-- Init flags for ws-scheme to degrade order of the numerics near walls, i.e.
	1886	!-- to decrease the numerical stencil appropriately.
[2200]	1887	IF ( momentum_advec == 'ws-scheme' .OR. scalar_advec == 'ws-scheme' &
	1888	) THEN
[1942]	1889	CALL ws_init_flags
[861]	1890	ENDIF
	1891
	1892	!
[1]	1893	!-- In case of topography: limit near-wall mixing length l_wall further:
	1894	!-- Go through all points of the subdomain one by one and look for the closest
	1895	!-- surface
[2232]	1896	DO i = nxl, nxr
	1897	DO j = nys, nyn
	1898	DO k = nzb+1, nzt
[1]	1899	!
[2232]	1900	!-- Check if current gridpoint belongs to the atmosphere
	1901	IF ( BTEST( wall_flags_0(k,j,i), 0 ) ) THEN
[1]	1902	!
[2232]	1903	!-- Check for neighbouring grid-points.
	1904	!-- Vertical distance, down
	1905	IF ( .NOT. BTEST( wall_flags_0(k-1,j,i), 0 ) ) &
	1906	l_wall(k,j,i) = MIN( l_grid(k), zu(k) - zw(k-1) )
[1]	1907	!
[2232]	1908	!-- Vertical distance, up
	1909	IF ( .NOT. BTEST( wall_flags_0(k+1,j,i), 0 ) ) &
	1910	l_wall(k,j,i) = MIN( l_grid(k), zw(k) - zu(k) )
[1]	1911	!
[2232]	1912	!-- y-distance
	1913	IF ( .NOT. BTEST( wall_flags_0(k,j-1,i), 0 ) .OR. &
	1914	.NOT. BTEST( wall_flags_0(k,j+1,i), 0 ) ) &
	1915	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), 0.5_wp * dy )
[1]	1916	!
[2232]	1917	!-- x-distance
	1918	IF ( .NOT. BTEST( wall_flags_0(k,j,i-1), 0 ) .OR. &
	1919	.NOT. BTEST( wall_flags_0(k,j,i+1), 0 ) ) &
	1920	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), 0.5_wp * dx )
[1]	1921	!
[2232]	1922	!-- yz-distance (vertical edges, down)
	1923	IF ( .NOT. BTEST( wall_flags_0(k-1,j-1,i), 0 ) .OR. &
	1924	.NOT. BTEST( wall_flags_0(k-1,j+1,i), 0 ) ) &
	1925	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1926	SQRT( 0.25_wp * dy**2 + &
	1927	( zu(k) - zw(k-1) )**2 ) )
[1]	1928	!
[2232]	1929	!-- yz-distance (vertical edges, up)
	1930	IF ( .NOT. BTEST( wall_flags_0(k+1,j-1,i), 0 ) .OR. &
	1931	.NOT. BTEST( wall_flags_0(k+1,j+1,i), 0 ) ) &
	1932	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1933	SQRT( 0.25_wp * dy**2 + &
	1934	( zw(k) - zu(k) )**2 ) )
[1]	1935	!
[2232]	1936	!-- xz-distance (vertical edges, down)
	1937	IF ( .NOT. BTEST( wall_flags_0(k-1,j,i-1), 0 ) .OR. &
	1938	.NOT. BTEST( wall_flags_0(k-1,j,i+1), 0 ) ) &
	1939	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1940	SQRT( 0.25_wp * dx**2 + &
	1941	( zu(k) - zw(k-1) )**2 ) )
[1]	1942	!
[2232]	1943	!-- xz-distance (vertical edges, up)
	1944	IF ( .NOT. BTEST( wall_flags_0(k+1,j,i-1), 0 ) .OR. &
	1945	.NOT. BTEST( wall_flags_0(k+1,j,i+1), 0 ) ) &
	1946	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1947	SQRT( 0.25_wp * dx**2 + &
	1948	( zw(k) - zu(k) )**2 ) )
[1]	1949	!
[2232]	1950	!-- xy-distance (horizontal edges)
	1951	IF ( .NOT. BTEST( wall_flags_0(k,j-1,i-1), 0 ) .OR. &
	1952	.NOT. BTEST( wall_flags_0(k,j+1,i-1), 0 ) .OR. &
	1953	.NOT. BTEST( wall_flags_0(k,j-1,i+1), 0 ) .OR. &
	1954	.NOT. BTEST( wall_flags_0(k,j+1,i+1), 0 ) ) &
	1955	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1956	SQRT( 0.25_wp * ( dx2 + dy2 ) ) )
[1]	1957	!
[2232]	1958	!-- xyz distance (vertical and horizontal edges, down)
	1959	IF ( .NOT. BTEST( wall_flags_0(k-1,j-1,i-1), 0 ) .OR. &
	1960	.NOT. BTEST( wall_flags_0(k-1,j+1,i-1), 0 ) .OR. &
	1961	.NOT. BTEST( wall_flags_0(k-1,j-1,i+1), 0 ) .OR. &
	1962	.NOT. BTEST( wall_flags_0(k-1,j+1,i+1), 0 ) ) &
	1963	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1964	SQRT( 0.25_wp * ( dx2 + dy2 ) &
	1965	+ ( zu(k) - zw(k-1) )**2 ) )
[1]	1966	!
[2232]	1967	!-- xyz distance (vertical and horizontal edges, up)
	1968	IF ( .NOT. BTEST( wall_flags_0(k+1,j-1,i-1), 0 ) .OR. &
	1969	.NOT. BTEST( wall_flags_0(k+1,j+1,i-1), 0 ) .OR. &
	1970	.NOT. BTEST( wall_flags_0(k+1,j-1,i+1), 0 ) .OR. &
	1971	.NOT. BTEST( wall_flags_0(k+1,j+1,i+1), 0 ) ) &
	1972	l_wall(k,j,i) = MIN( l_wall(k,j,i), l_grid(k), &
	1973	SQRT( 0.25_wp * ( dx2 + dy2 ) &
	1974	+ ( zw(k) - zu(k) )**2 ) )
	1975
[1]	1976	ENDIF
	1977	ENDDO
	1978	ENDDO
[2232]	1979	ENDDO
[1]	1980	!
[709]	1981	!-- Set lateral boundary conditions for l_wall
[2232]	1982	CALL exchange_horiz( l_wall, nbgp )
[667]	1983
[1]	1984
	1985	END SUBROUTINE init_grid

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