Changeset 4648 for palm/trunk/SOURCE/init_grid.f90

Timestamp:

Aug 25, 2020 7:52:08 AM (4 years ago)

Author:

raasch

Message:

files re-formatted to follow the PALM coding standard

File:

• palm/trunk/SOURCE/init_grid.f90 (modified) (108 diffs)

palm/trunk/SOURCE/init_grid.f90

@@ -1 +1 @@
 !> @file init_grid.f90
-!------------------------------------------------------------------------------!
+!--------------------------------------------------------------------------------------------------!
 ! This file is part of the PALM model system.
 !
-! PALM is free software: you can redistribute it and/or modify it under the
-! terms of the GNU General Public License as published by the Free Software
-! Foundation, either version 3 of the License, or (at your option) any later
-! version.
-!
-! PALM is distributed in the hope that it will be useful, but WITHOUT ANY
-! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-! A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
-!
-! You should have received a copy of the GNU General Public License along with
-! PALM. If not, see <http://www.gnu.org/licenses/>.
+! PALM is free software: you can redistribute it and/or modify it under the terms of the GNU General
+! Public License as published by the Free Software Foundation, either version 3 of the License, or
+! (at your option) any later version.
+!
+! PALM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
+! implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+! Public License for more details.
+!
+! You should have received a copy of the GNU General Public License along with PALM. If not, see
+! <http://www.gnu.org/licenses/>.
 !
 ! Copyright 1997-2020 Leibniz Universitaet Hannover
-!------------------------------------------------------------------------------!
+!--------------------------------------------------------------------------------------------------!
 !
 ! Current revisions:
@@ -25 +24 @@
 ! -----------------
 ! $Id$
+! file re-formatted to follow the PALM coding standard
+!
+! 4630 2020-07-30 14:54:34Z suehring
 ! In case of ASCII topography input flag grid points as terrain and building.
 !
 ! 4601 2020-07-14 12:06:09Z suehring
 ! Minor formatting adjustments
-! 
+!
 ! 4564 2020-06-12 14:03:36Z raasch
 ! Vertical nesting method of Huq et al. (2019) removed
-! 
+!
 ! 4543 2020-05-20 14:12:22Z gronemeier
 ! Remove non-required check for canyon height
-! 
+!
 ! 4507 2020-04-22 18:21:45Z gronemeier
 ! update origin_z with shifting height of orography (oro_min)
-! 
+!
 ! 4457 2020-03-11 14:20:43Z raasch
 ! use statement for exchange horiz added,
 ! bugfix for call of exchange horiz 2d
-! 
+!
 ! 4444 2020-03-05 15:59:50Z raasch
 ! bugfix: cpp-directives for serial mode added
-! 
+!
 ! 4414 2020-02-19 20:16:04Z suehring
 ! - Remove deprecated topography arrays nzb_s_inner, nzb_u_inner, etc.
-! - Move initialization of boundary conditions and multigrid into an extra
-!   module interface.
-! 
+! - Move initialization of boundary conditions and multigrid into an extra module interface.
+!
 ! 4386 2020-01-27 15:07:30Z Giersch
-! Allocation statements, comments, naming of variables revised and _wp added to 
-! real type values
-! 
+! Allocation statements, comments, naming of variables revised and _wp added to real type values
+!
 ! 4360 2020-01-07 11:25:50Z suehring
 ! Revise error messages for generic tunnel setup.
-! 
+!
 ! 4346 2019-12-18 11:55:56Z motisi
-! Introduction of wall_flags_total_0, which currently sets bits based on static
-! topography information used in wall_flags_static_0
-! 
+! Introduction of wall_flags_total_0, which currently sets bits based on static topography
+! information used in wall_flags_static_0
+!
 ! 4340 2019-12-16 08:17:03Z Giersch
 ! Topography closed channel flow with symmetric boundaries implemented
-! 
+!
 ! 4329 2019-12-10 15:46:36Z motisi
 ! Renamed wall_flags_0 to wall_flags_static_0
-! 
+!
 ! 4328 2019-12-09 18:53:04Z suehring
 ! Minor change in nzb_max computation. Commentation added.
-! 
+!
 ! 4314 2019-11-29 10:29:20Z suehring
-! Set additional topography flag 4 to mark topography grid points emerged
-! from the filtering process.
-! 
+! Set additional topography flag 4 to mark topography grid points emerged from the filtering process.
+!
 ! 4294 2019-11-13 18:34:16Z suehring
-! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and 
-! building surfaces in all  cases, in order to enable terrain-following output 
-! also when no land- or urban-surface model is applied. 
-! 
+! Bugfix, always set bit 5 and 6 of wall_flags, indicating terrain- and building surfaces in all
+! cases, in order to enable terrain-following output also when no land- or urban-surface model is
+! applied.
+!
 ! 4265 2019-10-15 16:16:24Z suehring
-! Bugfix for last commit, exchange oro_max variable only when it is allocated 
-! (not necessarily the case when topography is input from ASCII file).
-! 
+! Bugfix for last commit, exchange oro_max variable only when it is allocated (not necessarily the
+! case when topography is input from ASCII file).
+!
 ! 4245 2019-09-30 08:40:37Z pavelkrc
 ! Store oro_max (building z-offset) in 2D for building surfaces
-! 
+!
 ! 4189 2019-08-26 16:19:38Z suehring
 ! - Add check for proper setting of namelist parameter topography
 ! - Set flag to indicate land surfaces in case no topography is provided
-! 
+!
 ! 4182 2019-08-22 15:20:23Z scharf
 ! Corrected "Former revisions" section
-! 
+!
 ! 4168 2019-08-16 13:50:17Z suehring
-! Pre-calculate topography top index and store it on an array (replaces former
-! functions get_topography_top_index)
-! 
+! Pre-calculate topography top index and store it on an array (replaces former functions
+! get_topography_top_index)
+!
 ! 4159 2019-08-15 13:31:35Z suehring
-! Revision of topography processing. This was not consistent between 2D and 3D
-! buildings. 
-! 
+! Revision of topography processing. This was not consistent between 2D and 3D buildings.
+!
 ! 4144 2019-08-06 09:11:47Z raasch
 ! relational operators .EQ., .NE., etc. replaced by ==, /=, etc.
-! 
+!
 ! 4115 2019-07-24 12:50:49Z suehring
-! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points 
-! 
+! Bugfix in setting near-surface flag 24, inidicating wall-bounded grid points
+!
 ! 4110 2019-07-22 17:05:21Z suehring
 ! - Separate initialization of advection flags for momentum and scalars.
 ! - Change subroutine interface for ws_init_flags_scalar to pass boundary flags
-! 
+!
 ! 4109 2019-07-22 17:00:34Z suehring
 ! Fix bad commit
-! 
+!
 ! 3926 2019-04-23 12:56:42Z suehring
-! Minor bugfix in building mapping when all building IDs in the model domain
-! are missing
-! 
+! Minor bugfix in building mapping when all building IDs in the model domain are missing
+!
 ! 3857 2019-04-03 13:00:16Z knoop
-! In projection of non-building 3D objects onto numerical grid remove 
-! dependency on building_type
-! 
+! In projection of non-building 3D objects onto numerical grid remove dependency on building_type
+!
 ! 3763 2019-02-25 17:33:49Z suehring
-! Replace work-around for ghost point exchange of 1-byte arrays with specific 
-! routine as already done in other routines
-! 
+! Replace work-around for ghost point exchange of 1-byte arrays with specific routine as already
+! done in other routines
+!
 ! 3761 2019-02-25 15:31:42Z raasch
 ! unused variables removed
-! 
+!
 ! 3661 2019-01-08 18:22:50Z suehring
-! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead, 
-! order degradation of advection scheme is handeled directly in advec_ws
-! 
+! Remove setting of nzb_max to nzt at non-cyclic boundary PEs, instead, order degradation of
+! advection scheme is handeled directly in advec_ws
+!
 ! 3655 2019-01-07 16:51:22Z knoop
 ! Comment added
@@ -142 +138 @@
 !
 ! Description:
-! -----------------------------------------------------------------------------!
+! -------------------------------------------------------------------------------------------------!
 !> Creating grid depending constants
 !> @todo: Rearrange topo flag list
-!> @todo: reference 3D buildings on top of orography is not tested and may need
-!>        further improvement for steep slopes
-!> @todo: Use more advanced setting of building type at filled holes 
-!------------------------------------------------------------------------------!
+!> @todo: reference 3D buildings on top of orography is not tested and may need further improvement
+!>        for steep slopes
+!> @todo: Use more advanced setting of building type at filled holes
+!--------------------------------------------------------------------------------------------------!
  SUBROUTINE init_grid
 
-    USE arrays_3d,                                                             &
+    USE arrays_3d,                                                                                 &
         ONLY:  dd2zu, ddzu, ddzu_pres, ddzw, dzu, dzw, x, xu, y, yv, zu, zw
 
-    USE control_parameters,                                                    &
-        ONLY:  constant_flux_layer, dz, dz_max, dz_stretch_factor,             &
-               dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,&
-               dz_stretch_level_end_index, dz_stretch_level_start_index,       &
-               dz_stretch_level_start, ibc_uv_b, message_string,               &
-               number_stretch_level_end,                                       &
-               number_stretch_level_start,                                     &
-               ocean_mode,                                                     &
-               psolver,                                                        &
-               symmetry_flag,                                                  &
-               topography,                                                     &
+    USE control_parameters,                                                                        &
+        ONLY:  constant_flux_layer, dz, dz_max, dz_stretch_factor,                                 &
+               dz_stretch_factor_array, dz_stretch_level, dz_stretch_level_end,                    &
+               dz_stretch_level_end_index, dz_stretch_level_start_index,                           &
+               dz_stretch_level_start, ibc_uv_b, message_string,                                   &
+               number_stretch_level_end,                                                           &
+               number_stretch_level_start,                                                         &
+               ocean_mode,                                                                         &
+               psolver,                                                                            &
+               symmetry_flag,                                                                      &
+               topography,                                                                         &
                use_surface_fluxes
 
-    USE grid_variables,                                                        &
+    USE grid_variables,                                                                            &
         ONLY:  ddx, ddx2, ddy, ddy2, dx, dx2, dy, dy2, zu_s_inner, zw_w_inner
 
-    USE indices,                                                               &
-        ONLY:  nbgp,                                                           &
-               nx,                                                             &
-               nxl,                                                            &
-               nxlg,                                                           &
-               nxr,                                                            &
-               nxrg,                                                           &
-               ny,                                                             &
-               nyn,                                                            &
-               nyng,                                                           &
-               nys,                                                            &
-               nysg,                                                           &
-               nz,                                                             &
-               nzb,                                                            &
-               nzb_diff,                                                       &
-               nzb_max,                                                        &
-               nzt,                                                            &
-               topo_top_ind,                                                   &
+    USE indices,                                                                                   &
+        ONLY:  nbgp,                                                                               &
+               nx,                                                                                 &
+               nxl,                                                                                &
+               nxlg,                                                                               &
+               nxr,                                                                                &
+               nxrg,                                                                               &
+               ny,                                                                                 &
+               nyn,                                                                                &
+               nyng,                                                                               &
+               nys,                                                                                &
+               nysg,                                                                               &
+               nz,                                                                                 &
+               nzb,                                                                                &
+               nzb_diff,                                                                           &
+               nzb_max,                                                                            &
+               nzt,                                                                                &
+               topo_top_ind,                                                                       &
                topo_min_level
 
@@ -196 +192 @@
     IMPLICIT NONE
 
-    INTEGER(iwp) ::  i             !< index variable along x 
+    INTEGER(iwp) ::  i             !< index variable along x
     INTEGER(iwp) ::  j             !< index variable along y
     INTEGER(iwp) ::  k             !< index variable along z
     INTEGER(iwp) ::  k_top         !< topography top index on local PE
     INTEGER(iwp) ::  n             !< loop variable for stretching
-    INTEGER(iwp) ::  number_dz     !< number of user-specified dz values       
+    INTEGER(iwp) ::  number_dz     !< number of user-specified dz values
     INTEGER(iwp) ::  nzb_local_max !< vertical grid index of maximum topography height
     INTEGER(iwp) ::  nzb_local_min !< vertical grid index of minimum topography height
@@ -209 +205 @@
     REAL(wp) ::  dz_level_end  !< distance between calculated height level for u/v-grid and user-specified end level for stretching
     REAL(wp) ::  dz_stretched  !< stretched vertical grid spacing
-    
-    REAL(wp), DIMENSION(:), ALLOCATABLE ::  min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching can end
+
+    REAL(wp), DIMENSION(:), ALLOCATABLE ::  min_dz_stretch_level_end !< Array that contains all minimum heights where the stretching
+                                                                     !< can end
 
 
@@ -224 +221 @@
     ALLOCATE( x(0:nx) )
     ALLOCATE( xu(0:nx) )
-    
+
     DO i = 0, nx
        xu(i) = i * dx
@@ -232 +229 @@
     ALLOCATE( y(0:ny) )
     ALLOCATE( yv(0:ny) )
-    
+
     DO j = 0, ny
        yv(j) = j * dy
@@ -247 +244 @@
 
 !
-!-- For constructing an appropriate grid, the vertical grid spacing dz has to
-!-- be specified with a non-negative value in the parameter file
+!-- For constructing an appropriate grid, the vertical grid spacing dz has to be specified with a
+!-- non-negative value in the parameter file.
     IF ( dz(1) == -1.0_wp )  THEN
        message_string = 'missing dz'
-       CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 ) 
+       CALL message( 'init_grid', 'PA0200', 1, 2, 0, 6, 0 )
     ELSEIF ( dz(1) <= 0.0_wp )  THEN
        WRITE( message_string, * ) 'dz=',dz(1),' <= 0.0'
@@ -258 +255 @@
 
 !
-!-- Initialize dz_stretch_level_start with the value of dz_stretch_level
-!-- if it was set by the user
+!-- Initialize dz_stretch_level_start with the value of dz_stretch_level if it was set by the user.
     IF ( dz_stretch_level /= -9999999.9_wp ) THEN
        dz_stretch_level_start(1) = dz_stretch_level
     ENDIF
-       
-!
-!-- Determine number of dz values and stretching levels specified by the
-!-- user to allow right controlling of the stretching mechanism and to
-!-- perform error checks. The additional requirement that dz /= dz_max
-!-- for counting number of user-specified dz values is necessary. Otherwise 
-!-- restarts would abort if the old stretching mechanism with dz_stretch_level
-!-- is used (Attention: The user is not allowed to specify a dz value equal
-!-- to the default of dz_max = 999.0). 
-    number_dz = COUNT( dz /= -1.0_wp .AND. dz /= dz_max)
-    number_stretch_level_start = COUNT( dz_stretch_level_start /=              &
-                                       -9999999.9_wp )
-    number_stretch_level_end = COUNT( dz_stretch_level_end /=                  &
-                                      9999999.9_wp )
-
-!
-!-- The number of specified end levels +1 has to be the same as the number 
+
+!
+!-- Determine number of dz values and stretching levels specified by the user to allow right
+!-- controlling of the stretching mechanism and to perform error checks. The additional requirement
+!-- that dz /= dz_max for counting number of user-specified dz values is necessary. Otherwise
+!-- restarts would abort if the old stretching mechanism with dz_stretch_level is used (Attention:
+!-- The user is not allowed to specify a dz value equal to the default of dz_max = 999.0).
+    number_dz = COUNT( dz /= -1.0_wp  .AND.  dz /= dz_max)
+    number_stretch_level_start = COUNT( dz_stretch_level_start /= -9999999.9_wp )
+    number_stretch_level_end = COUNT( dz_stretch_level_end /= 9999999.9_wp )
+
+!
+!-- The number of specified end levels +1 has to be the same as the number
 !-- of specified dz values
     IF ( number_dz /= number_stretch_level_end + 1 ) THEN
-       WRITE( message_string, * ) 'The number of values for dz = ',            &
-                                   number_dz, 'has to be the same as& ',       &
-                                   'the number of values for ',                &
-                                   'dz_stretch_level_end + 1 = ',              &
-                                   number_stretch_level_end+1
+       WRITE( message_string, * )  'The number of values for dz = ', number_dz,                    &
+                                   'has to be the same as& ', 'the number of values for ',         &
+                                   'dz_stretch_level_end + 1 = ', number_stretch_level_end+1
        CALL message( 'init_grid', 'PA0156', 1, 2, 0, 6, 0 )
     ENDIF
-    
-!
-!-- The number of specified start levels has to be the same or one less than 
-!-- the number of specified dz values
-    IF ( number_dz /= number_stretch_level_start + 1 .AND.                     &
-         number_dz /= number_stretch_level_start ) THEN
-       WRITE( message_string, * ) 'The number of values for dz = ',            &
-                                   number_dz, 'has to be the same as or one ', &
-                                   'more than& the number of values for ',     &
-                                   'dz_stretch_level_start = ',                &
-                                   number_stretch_level_start
+
+!
+!-- The number of specified start levels has to be the same or one less than the number of specified
+!-- dz values
+    IF ( number_dz /= number_stretch_level_start + 1  .AND.                                        &
+         number_dz /= number_stretch_level_start )  THEN
+       WRITE( message_string, * )  'The number of values for dz = ', number_dz,                    &
+                                   'has to be the same as or one ',                                &
+                                   'more than& the number of values for ',                         &
+                                   'dz_stretch_level_start = ', number_stretch_level_start
        CALL message( 'init_grid', 'PA0211', 1, 2, 0, 6, 0 )
     ENDIF
-    
-!-- The number of specified start levels has to be the same or one more than 
-!-- the number of specified end levels
-    IF ( number_stretch_level_start /= number_stretch_level_end + 1 .AND.      &
+
+!-- The number of specified start levels has to be the same or one more than the number of specified
+!-- end levels
+    IF ( number_stretch_level_start /= number_stretch_level_end + 1  .AND.                         &
          number_stretch_level_start /= number_stretch_level_end ) THEN
-       WRITE( message_string, * ) 'The number of values for ',                 &
-                                  'dz_stretch_level_start = ',                 &
-                                   dz_stretch_level_start, 'has to be the ',   &
-                                   'same or one more than& the number of ',    &
-                                   'values for dz_stretch_level_end = ',       &
-                                   number_stretch_level_end
+       WRITE( message_string, * )  'The number of values for ',                                    &
+                                   'dz_stretch_level_start = ', dz_stretch_level_start,            &
+                                   'has to be the ', 'same or one more than& the number of ',      &
+                                   'values for dz_stretch_level_end = ', number_stretch_level_end
        CALL message( 'init_grid', 'PA0216', 1, 2, 0, 6, 0 )
     ENDIF
@@ -318 +305 @@
 !
 !-- Initialize dz for the free atmosphere with the value of dz_max
-    IF ( dz(number_stretch_level_start+1) == -1.0_wp .AND.                     &
-         number_stretch_level_start /= 0 ) THEN 
+    IF ( dz(number_stretch_level_start+1) == -1.0_wp  .AND.  number_stretch_level_start /= 0 ) THEN
        dz(number_stretch_level_start+1) = dz_max
     ENDIF
-       
-!
-!-- Initialize the stretching factor if (infinitely) stretching in the free 
-!-- atmosphere is desired (dz_stretch_level_end was not specified for the 
-!-- free atmosphere)
-    IF ( number_stretch_level_start == number_stretch_level_end + 1 ) THEN 
-       dz_stretch_factor_array(number_stretch_level_start) =                   &
-       dz_stretch_factor
+
+!
+!-- Initialize the stretching factor if (infinitely) stretching in the free atmosphere is desired
+!-- (dz_stretch_level_end was not specified for the free atmosphere)
+    IF ( number_stretch_level_start == number_stretch_level_end + 1 )  THEN
+       dz_stretch_factor_array(number_stretch_level_start) = dz_stretch_factor
     ENDIF
-    
+
 !
 !-- Allocation of arrays for stretching
@@ -339 +323 @@
 !-- Define the vertical grid levels. Start with atmosphere branch
     IF ( .NOT. ocean_mode )  THEN
-    
-!
-!--    The stretching region has to be large enough to allow for a smooth
-!--    transition between two different grid spacings. The number 4 is an
-!--    empirical value
+
+!
+!--    The stretching region has to be large enough to allow for a smooth transition between two
+!--    different grid spacings. The number 4 is an empirical value.
        DO n = 1, number_stretch_level_start
-          min_dz_stretch_level_end(n) = dz_stretch_level_start(n) +            &
-                                        4 * MAX( dz(n),dz(n+1) )
+          min_dz_stretch_level_end(n) = dz_stretch_level_start(n) + 4 * MAX( dz(n),dz(n+1) )
        ENDDO
 
-       IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) >      &
-                 dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
-          message_string= 'Each dz_stretch_level_end has to be larger ' //     &
-                          'than its corresponding value for &' //              &
-                          'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//   &
+       IF ( ANY( min_dz_stretch_level_end(1:number_stretch_level_start) >                          &
+                 dz_stretch_level_end(1:number_stretch_level_start) ) )  THEN
+          message_string= 'Each dz_stretch_level_end has to be larger ' //                         &
+                          'than its corresponding value for &' //                                  &
+                          'dz_stretch_level_start + 4*MAX(dz(n),dz(n+1)) '//                       &
                           'to allow for smooth grid stretching'
           CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
        ENDIF
-       
-!
-!--    Stretching must not be applied within the surface layer 
-!--    (first two grid points). For the default case dz_stretch_level_start 
-!--    is negative. Therefore the absolut value is checked here.
+
+!
+!--    Stretching must not be applied within the surface layer (first two grid points). For the
+!--    default case dz_stretch_level_start is negative. Therefore the absolut value is checked here.
        IF ( ANY( ABS( dz_stretch_level_start ) <= dz(1) * 1.5_wp ) ) THEN
-          WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
-                                     'larger than ', dz(1) * 1.5
+          WRITE( message_string, * )  'Each dz_stretch_level_start has to be ',                    &
+                                      'larger than ', dz(1) * 1.5
           CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
        ENDIF
 
 !
-!--    The stretching has to start and end on a grid level. Therefore 
-!--    user-specified values are mapped to the next lowest level. The  
-!--    calculation of the first level is realized differently just because of 
-!--    historical reasons (the advanced/new stretching mechanism was realized  
-!--    in a way that results don't change if the old parameters 
-!--    dz_stretch_level, dz_stretch_factor and dz_max are used)
-       IF ( number_stretch_level_start /= 0 ) THEN
-          dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) -        &
-                                            dz(1)/2.0) / dz(1) )               &
+!--    The stretching has to start and end on a grid level. Therefore user-specified values are
+!--    mapped to the next lowest level. The calculation of the first level is realized differently
+!--    just because of historical reasons (the advanced/new stretching mechanism was realized in a
+!--    way that results don't change if the old parameters dz_stretch_level, dz_stretch_factor and
+!--    dz_max are used).
+       IF ( number_stretch_level_start /= 0 )  THEN
+          dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) - dz(1)/2.0) / dz(1) )       &
                                       * dz(1) + dz(1)/2.0
        ENDIF
-       
+
        IF ( number_stretch_level_start > 1 ) THEN
           DO n = 2, number_stretch_level_start
-             dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) /      &
-                                              dz(n) ) * dz(n)
-          ENDDO
-       ENDIF
-       
+             dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / dz(n) ) * dz(n)
+          ENDDO
+       ENDIF
+
        IF ( number_stretch_level_end /= 0 ) THEN
           DO n = 1, number_stretch_level_end
-             dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) /          &
-                                            dz(n+1) ) * dz(n+1)
+             dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / dz(n+1) ) * dz(n+1)
           ENDDO
        ENDIF
@@ -397 +374 @@
 !
 !--    Determine stretching factor if necessary
-       IF ( number_stretch_level_end >= 1 ) THEN 
+       IF ( number_stretch_level_end >= 1 ) THEN
           CALL calculate_stretching_factor( number_stretch_level_end )
        ENDIF
@@ -403 +380 @@
 !
 !--    Grid for atmosphere with surface at z=0 (k=0, w-grid).
-!--    First compute the u- and v-levels. In case of dirichlet bc for u and v
-!--    the first u/v- and w-level (k=0) are defined at same height (z=0). 
-!--    The second u-level (k=1) corresponds to the top of the 
-!--    surface layer. In case of symmetric boundaries (closed channel flow), 
-!--    the first grid point is always at z=0.
-       IF ( ibc_uv_b == 0 .OR. ibc_uv_b == 2 .OR.                              & 
-            topography == 'closed_channel' ) THEN
+!--    First compute the u- and v-levels. In case of dirichlet bc for u and v the first u/v- and
+!--    w-level (k=0) are defined at same height (z=0).
+!--    The second u-level (k=1) corresponds to the top of the surface layer. In case of symmetric
+!--    boundaries (closed channel flow), the first grid point is always at z=0.
+       IF ( ibc_uv_b == 0  .OR.  ibc_uv_b == 2  .OR.  topography == 'closed_channel' )  THEN
           zu(0) = 0.0_wp
        ELSE
           zu(0) = - dz(1) * 0.5_wp
        ENDIF
-          
+
        zu(1) =   dz(1) * 0.5_wp
-       
-!
-!--    Determine u and v height levels considering the possibility of grid
-!--    stretching in several heights.
+
+!
+!--    Determine u and v height levels considering the possibility of grid stretching in several
+!--    heights.
        n = 1
        dz_stretch_level_start_index = nzt+1
@@ -425 +400 @@
        dz_stretched = dz(1)
 
-!--    The default value of dz_stretch_level_start is negative, thus the first
-!--    condition is true even if no stretching shall be applied. Hence, the 
-!--    second condition is also necessary.
+!--    The default value of dz_stretch_level_start is negative, thus the first condition is true
+!--    even if no stretching shall be applied. Hence, the second condition is also necessary.
        DO  k = 2, nzt+1-symmetry_flag
-          IF ( dz_stretch_level_start(n) <= zu(k-1) .AND.                      &
-               dz_stretch_level_start(n) /= -9999999.9_wp ) THEN
+          IF ( dz_stretch_level_start(n) <= zu(k-1)  .AND.                                         &
+               dz_stretch_level_start(n) /= -9999999.9_wp )  THEN
              dz_stretched = dz_stretched * dz_stretch_factor_array(n)
-             
-             IF ( dz(n) > dz(n+1) ) THEN
+
+             IF ( dz(n) > dz(n+1) )  THEN
                 dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
              ELSE
                 dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
              ENDIF
-             
-             IF ( dz_stretch_level_start_index(n) == nzt+1 )                         &
-             dz_stretch_level_start_index(n) = k-1
-             
-          ENDIF
-          
+
+             IF ( dz_stretch_level_start_index(n) == nzt+1 )  dz_stretch_level_start_index(n) = k-1
+
+          ENDIF
+
           zu(k) = zu(k-1) + dz_stretched
-          
-!
-!--       Make sure that the stretching ends exactly at dz_stretch_level_end 
-          dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) ) 
-          
-          IF ( dz_level_end  < dz(n+1)/3.0 ) THEN
+
+!
+!--       Make sure that the stretching ends exactly at dz_stretch_level_end
+          dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
+
+          IF ( dz_level_end  < dz(n+1)/3.0 )  THEN
              zu(k) = dz_stretch_level_end(n)
              dz_stretched = dz(n+1)
              dz_stretch_level_end_index(n) = k
-             n = n + 1             
+             n = n + 1
           ENDIF
        ENDDO
-       
-!
-!--    If a closed channel flow is simulated, make sure that grid structure is  
-!--    the same for both bottom and top boundary. (Hint: Using a different dz 
-!--    at the bottom and at the top makes no sense due to symmetric boundaries
-!--    where dz should be equal. Therefore, different dz at the bottom and top  
-!--    causes an abort (see check_parameters).)
-       IF ( topography == 'closed_channel' ) THEN
+
+!
+!--    If a closed channel flow is simulated, make sure that grid structure is the same for both
+!--    bottom and top boundary. (Hint: Using a different dz at the bottom and at the top makes no
+!--    sense due to symmetric boundaries where dz should be equal. Therefore, different dz at the
+!--    bottom and top causes an abort (see check_parameters).)
+       IF ( topography == 'closed_channel' )  THEN
           zu(nzt+1) = zu(nzt) + dz(1) * 0.5_wp
        ENDIF
 
 !
-!--    Compute the w-levels. They are always staggered half-way between the 
-!--    corresponding u-levels. In case of dirichlet bc for u and v at the 
-!--    ground the first u- and w-level (k=0) are defined at same height (z=0). 
-!--    Per default, the top w-level is extrapolated linearly. In case of 
-!--    a closed channel flow, zu(nzt+1) and zw(nzt) must be set explicitely.
-!--    (Hint: Using a different dz at the bottom and at the top makes no sense
-!--    due to symmetric boundaries where dz should be equal. Therefore, 
-!--    different dz at the bottom and top causes an abort (see 
-!--    check_parameters).)
+!--    Compute the w-levels. They are always staggered half-way between the corresponding u-levels.
+!--    In case of dirichlet bc for u and v at the ground the first u- and w-level (k=0) are defined
+!--    at same height (z=0).
+!--    Per default, the top w-level is extrapolated linearly. In case of a closed channel flow,
+!--    zu(nzt+1) and zw(nzt) must be set explicitely.
+!--    (Hint: Using a different dz at the bottom and at the top makes no sense due to symmetric
+!--    boundaries where dz should be equal. Therefore, different dz at the bottom and top causes an
+!--    abort (see check_parameters).)
        zw(0) = 0.0_wp
        DO  k = 1, nzt-symmetry_flag
           zw(k) = ( zu(k) + zu(k+1) ) * 0.5_wp
        ENDDO
-       IF ( topography == 'closed_channel' ) THEN
+       IF ( topography == 'closed_channel' )  THEN
           zw(nzt)   = zw(nzt-1) + dz(1)
           zw(nzt+1) = zw(nzt) + dz(1)
@@ -492 +463 @@
 
 !
-!--    The stretching region has to be large enough to allow for a smooth
-!--    transition between two different grid spacings. The number 4 is an
-!--    empirical value
+!--    The stretching region has to be large enough to allow for a smooth transition between two
+!--    different grid spacings. The number 4 is an empirical value
        DO n = 1, number_stretch_level_start
-          min_dz_stretch_level_end(n) = dz_stretch_level_start(n) -            &
-                                        4 * MAX( dz(n),dz(n+1) )
+          min_dz_stretch_level_end(n) = dz_stretch_level_start(n) - 4 * MAX( dz(n),dz(n+1) )
        ENDDO
-       
-       IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) <     &
-                 dz_stretch_level_end(1:number_stretch_level_start) ) ) THEN
-             message_string= 'Each dz_stretch_level_end has to be less ' //   &
-                             'than its corresponding value for &' //           &
-                             'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//&
+
+       IF ( ANY( min_dz_stretch_level_end (1:number_stretch_level_start) <                         &
+                 dz_stretch_level_end(1:number_stretch_level_start) ) )  THEN
+             message_string= 'Each dz_stretch_level_end has to be less ' //                        &
+                             'than its corresponding value for &' //                               &
+                             'dz_stretch_level_start - 4*MAX(dz(n),dz(n+1)) '//                    &
                              'to allow for smooth grid stretching'
              CALL message( 'init_grid', 'PA0224', 1, 2, 0, 6, 0 )
        ENDIF
-       
-!
-!--    Stretching must not be applied close to the surface (last two grid 
-!--    points). For the default case dz_stretch_level_start is negative. 
-       IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) ) THEN
-          WRITE( message_string, * ) 'Each dz_stretch_level_start has to be ',&
-                                     'less than ', -dz(1) * 1.5
+
+!
+!--    Stretching must not be applied close to the surface (last two grid points). For the default
+!--    case dz_stretch_level_start is negative.
+       IF ( ANY( dz_stretch_level_start >= - dz(1) * 1.5_wp ) )  THEN
+          WRITE( message_string, * )  'Each dz_stretch_level_start has to be ',                    &
+                                      'less than ', -dz(1) * 1.5
              CALL message( 'init_grid', 'PA0226', 1, 2, 0, 6, 0 )
        ENDIF
 
 !
-!--    The stretching has to start and end on a grid level. Therefore 
-!--    user-specified values are mapped to the next highest level. The  
-!--    calculation of the first level is realized differently just because of 
-!--    historical reasons (the advanced/new stretching mechanism was realized  
-!--    in a way that results don't change if the old parameters 
-!--    dz_stretch_level, dz_stretch_factor and dz_max are used)
-       IF ( number_stretch_level_start /= 0 ) THEN
-          dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) +        &
-                                            dz(1)/2.0) / dz(1) )               &
+!--    The stretching has to start and end on a grid level. Therefore user-specified values are
+!--    mapped to the next highest level. The calculation of the first level is realized differently
+!--    just because of historical reasons (the advanced/new stretching mechanism was realized in a
+!--    way that results don't change if the old parameters dz_stretch_level, dz_stretch_factor and
+!--    dz_max are used)
+       IF ( number_stretch_level_start /= 0 )  THEN
+          dz_stretch_level_start(1) = INT( (dz_stretch_level_start(1) + dz(1)/2.0) / dz(1) )       &
                                       * dz(1) - dz(1)/2.0
        ENDIF
-       
-       IF ( number_stretch_level_start > 1 ) THEN
+
+       IF ( number_stretch_level_start > 1 )  THEN
           DO n = 2, number_stretch_level_start
-             dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) /      &
-                                              dz(n) ) * dz(n)
-          ENDDO
-       ENDIF
-       
-       IF ( number_stretch_level_end /= 0 ) THEN
+             dz_stretch_level_start(n) = INT( dz_stretch_level_start(n) / dz(n) ) * dz(n)
+          ENDDO
+       ENDIF
+
+       IF ( number_stretch_level_end /= 0 )  THEN
           DO n = 1, number_stretch_level_end
-             dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) /          &
-                                            dz(n+1) ) * dz(n+1)
-          ENDDO
-       ENDIF
-       
+             dz_stretch_level_end(n) = INT( dz_stretch_level_end(n) / dz(n+1) ) * dz(n+1)
+          ENDDO
+       ENDIF
+
 !
 !--    Determine stretching factor if necessary
-       IF ( number_stretch_level_end >= 1 ) THEN 
+       IF ( number_stretch_level_end >= 1 ) THEN
           CALL calculate_stretching_factor( number_stretch_level_end )
        ENDIF
@@ -553 +518 @@
 !
 !--    Grid for ocean with free water surface is at k=nzt (w-grid).
-!--    In case of neumann bc at the ground the first first u-level (k=0) lies
-!--    below the first w-level (k=0). In case of dirichlet bc the first u- and
-!--    w-level are defined at same height, but staggered from the second level.
+!--    In case of neumann bc at the ground the first first u-level (k=0) lies below the first
+!--    w-level (k=0). In case of dirichlet bc the first u- and w-level are defined at same height,
+!--    but staggered from the second level.
 !--    The second u-level (k=1) corresponds to the top of the surface layer.
 !--    z values are negative starting from z=0 (surface)
@@ -562 +527 @@
 
 !
-!--    Determine u and v height levels considering the possibility of grid
-!--    stretching in several heights.
+!--    Determine u and v height levels considering the possibility of grid stretching in several
+!--    heights.
        n = 1
        dz_stretch_level_start_index = 0
@@ -570 +535 @@
 
        DO  k = nzt-1, 0, -1
-          
-          IF ( dz_stretch_level_start(n) >= zu(k+1) ) THEN
+
+          IF ( dz_stretch_level_start(n) >= zu(k+1) )  THEN
              dz_stretched = dz_stretched * dz_stretch_factor_array(n)
 
-             IF ( dz(n) > dz(n+1) ) THEN
+             IF ( dz(n) > dz(n+1) )  THEN
                 dz_stretched = MAX( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (higher) dz
              ELSE
                 dz_stretched = MIN( dz_stretched, dz(n+1) ) !Restrict dz_stretched to the user-specified (lower) dz
              ENDIF
-             
-             IF ( dz_stretch_level_start_index(n) == 0 )                             &
-             dz_stretch_level_start_index(n) = k+1
-             
-          ENDIF
-          
+
+             IF ( dz_stretch_level_start_index(n) == 0 )  dz_stretch_level_start_index(n) = k+1
+
+          ENDIF
+
           zu(k) = zu(k+1) - dz_stretched
-          
-!
-!--       Make sure that the stretching ends exactly at dz_stretch_level_end 
-          dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) ) 
-          
-          IF ( dz_level_end  < dz(n+1)/3.0 ) THEN
+
+!
+!--       Make sure that the stretching ends exactly at dz_stretch_level_end
+          dz_level_end = ABS( zu(k) - dz_stretch_level_end(n) )
+
+          IF ( dz_level_end  < dz(n+1)/3.0 )  THEN
              zu(k) = dz_stretch_level_end(n)
              dz_stretched = dz(n+1)
              dz_stretch_level_end_index(n) = k
-             n = n + 1             
+             n = n + 1
           ENDIF
        ENDDO
-       
-!
-!--    Compute the w-levels. They are always staggered half-way between the 
-!--    corresponding u-levels, except in case of dirichlet bc for u and v
-!--    at the ground. In this case the first u- and w-level are defined at 
-!--    same height. The top w-level (nzt+1) is not used but set for 
+
+!
+!--    Compute the w-levels. They are always staggered half-way between the corresponding u-levels,
+!--    except in case of dirichlet bc for u and v at the ground. In this case the first u- and
+!--    w-level are defined at same height. The top w-level (nzt+1) is not used but set for
 !--    consistency, since w and all scalar variables are defined up tp nzt+1.
        zw(nzt+1) = dz(1)
@@ -612 +575 @@
 
 !
-!--    In case of dirichlet bc for u and v the first u- and w-level are defined
-!--    at same height.
+!--    In case of dirichlet bc for u and v the first u- and w-level are defined at same height.
        IF ( ibc_uv_b == 0 ) THEN
           zu(0) = zw(0)
@@ -632 +594 @@
        dd2zu(k) = 1.0_wp / ( dzu(k) + dzu(k+1) )
     ENDDO
-    
-!    
-!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid
-!-- everywhere. For the actual grid, the grid spacing at the lowest level
-!-- is only dz/2, but should be dz. Therefore, an additional array
-!-- containing with appropriate grid information is created for these
-!-- solvers.
+
+!
+!-- The FFT- SOR-pressure solvers assume grid spacings of a staggered grid everywhere. For the
+!-- actual grid, the grid spacing at the lowest level is only dz/2, but should be dz. Therefore, an
+!-- additional array containing with appropriate grid information is created for these solvers.
     IF ( psolver(1:9) /= 'multigrid' )  THEN
        ALLOCATE( ddzu_pres(1:nzt+1) )
@@ -659 +619 @@
     topo = 0
 !
-!-- Initialize topography by generic topography or read topography from file.  
+!-- Initialize topography by generic topography or read topography from file.
     CALL init_topo( topo )
 !
-!-- Set flags to mask topography on the grid. 
+!-- Set flags to mask topography on the grid.
     CALL set_topo_flags( topo )
 
 !
-!-- Determine the maximum level of topography. It is used for
-!-- steering the degradation of order of the applied advection scheme, 
-!-- as well in the lpm.
+!-- Determine the maximum level of topography. It is used for steering the degradation of order of
+!-- the applied advection scheme, as well in the lpm.
     k_top = 0
     DO  i = nxl, nxr
@@ -678 +637 @@
     ENDDO
 #if defined( __parallel )
-    CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER,                        &
-                        MPI_MAX, comm2d, ierr )
+    CALL MPI_ALLREDUCE( k_top, nzb_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )
 #else
     nzb_max = k_top
@@ -686 +644 @@
 !-- Increment nzb_max by 1 in order to allow for proper diverengence correction.
 !-- Further, in case topography extents up to the model top, limit to nzt.
-    nzb_max = MIN( nzb_max+1, nzt ) 
-!
-!-- Determine minimum index of topography. Usually, this will be nzb. In case
-!-- there is elevated topography, however, the lowest topography will be higher. 
-!-- This index is e.g. used to calculate mean first-grid point atmosphere 
-!-- temperature, surface pressure and density, etc. .
+    nzb_max = MIN( nzb_max+1, nzt )
+!
+!-- Determine minimum index of topography. Usually, this will be nzb. In case there is elevated
+!-- topography, however, the lowest topography will be higher.
+!-- This index is e.g. used to calculate mean first-grid point atmosphere temperature, surface
+!-- pressure and density, etc. .
     topo_min_level   = 0
 #if defined( __parallel )
-    CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ),             &
-                        topo_min_level, 1, MPI_INTEGER, MPI_MIN, comm2d, ierr )
+    CALL MPI_ALLREDUCE( MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), topo_min_level, 1, MPI_INTEGER, &
+                        MPI_MIN, comm2d, ierr )
 #else
     topo_min_level = MINVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
@@ -701 +659 @@
 
 !
-!-- Check topography for consistency with model domain. Therefore, use
-!-- maximum and minium topography-top indices. Note, minimum topography top
-!-- index is already calculated.  
+!-- Check topography for consistency with model domain. Therefore, use maximum and minium
+!-- topography-top indices. Note, minimum topography top index is already calculated.
     IF ( TRIM( topography ) /= 'flat' )  THEN
 #if defined( __parallel )
-       CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ),          &
-                           nzb_local_max, 1, MPI_INTEGER, MPI_MAX, comm2d, ierr )               
+       CALL MPI_ALLREDUCE( MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) ), nzb_local_max, 1,            &
+                           MPI_INTEGER, MPI_MAX, comm2d, ierr )
 #else
        nzb_local_max = MAXVAL( topo_top_ind(nys:nyn,nxl:nxr,0) )
@@ -715 +672 @@
 !--    Consistency checks
        IF ( nzb_local_min < 0  .OR.  nzb_local_max  > nz + 1 )  THEN
-          WRITE( message_string, * ) 'nzb_local values are outside the',       &
-                                ' model domain',                               &
-                                '&MINVAL( nzb_local ) = ', nzb_local_min,      &
-                                '&MAXVAL( nzb_local ) = ', nzb_local_max
+          WRITE( message_string, * ) 'nzb_local values are outside the model domain',              &
+                                     '&MINVAL( nzb_local ) = ', nzb_local_min,                     &
+                                     '&MAXVAL( nzb_local ) = ', nzb_local_max
           CALL message( 'init_grid', 'PA0210', 1, 2, 0, 6, 0 )
        ENDIF
     ENDIF
 !
-!-- Define vertical gridpoint from (or to) which on the usual finite difference
-!-- form (which does not use surface fluxes) is applied 
+!-- Define vertical gridpoint from (or to) which on the usual finite difference form (which does not
+!-- use surface fluxes) is applied.
     IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
        nzb_diff = nzb + 2
@@ -733 +689 @@
     IF ( TRIM( topography ) /= 'flat' )  THEN
 !
-!--    Allocate and set the arrays containing the topography height (for output
-!--    reasons only).
+!--    Allocate and set the arrays containing the topography height (for output reasons only).
        IF ( nxr == nx  .AND.  nyn /= ny )  THEN
-          ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn),                             &
-                    zw_w_inner(nxl:nxr+1,nys:nyn) )
+          ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn), zw_w_inner(nxl:nxr+1,nys:nyn) )
        ELSEIF ( nxr /= nx  .AND.  nyn == ny )  THEN
-          ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1),                             &
-                    zw_w_inner(nxl:nxr,nys:nyn+1) )
+          ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn+1), zw_w_inner(nxl:nxr,nys:nyn+1) )
        ELSEIF ( nxr == nx  .AND.  nyn == ny )  THEN
-          ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1),                           &
-                    zw_w_inner(nxl:nxr+1,nys:nyn+1) )
+          ALLOCATE( zu_s_inner(nxl:nxr+1,nys:nyn+1), zw_w_inner(nxl:nxr+1,nys:nyn+1) )
        ELSE
-          ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn),                               &
-                    zw_w_inner(nxl:nxr,nys:nyn) )
+          ALLOCATE( zu_s_inner(nxl:nxr,nys:nyn), zw_w_inner(nxl:nxr,nys:nyn) )
        ENDIF
 
@@ -752 +703 @@
        zw_w_inner   = 0.0_wp
 !
-!--    Determine local topography height on scalar and w-grid. Note, setting
-!--    lateral boundary values is not necessary, realized via wall_flags_static_0
-!--    array. Further, please note that loop bounds are different from
-!--    nxl to nxr and nys to nyn on south and right model boundary, hence,
+!--    Determine local topography height on scalar and w-grid. Note, setting lateral boundary values
+!--    is not necessary, realized via wall_flags_static_0 array. Further, please note that loop
+!--    bounds are different from nxl to nxr and nys to nyn on south and right model boundary, hence,
 !--    use intrinsic lbound and ubound functions to infer array bounds.
        DO  i = LBOUND(zu_s_inner, 1), UBOUND(zu_s_inner, 1)
           DO  j = LBOUND(zu_s_inner, 2), UBOUND(zu_s_inner, 2)
 !
-!--          Topography height on scalar grid. Therefore, determine index of
-!--          upward-facing surface element on scalar grid.
+!--          Topography height on scalar grid. Therefore, determine index of upward-facing surface
+!--          element on scalar grid.
              zu_s_inner(i,j) = zu(topo_top_ind(j,i,0))
 !
-!--          Topography height on w grid. Therefore, determine index of
-!--          upward-facing surface element on w grid.
+!--          Topography height on w grid. Therefore, determine index of upward-facing surface
+!--          element on w grid.
              zw_w_inner(i,j) = zw(topo_top_ind(j,i,3))
           ENDDO
@@ -775 +725 @@
 
 ! Description:
-! -----------------------------------------------------------------------------!
-!> Calculation of the stretching factor through an iterative method. Ideas were 
-!> taken from the paper "Regional stretched grid generation and its application
-!> to the NCAR RegCM (1999)". Normally, no analytic solution exists because the
-!> system of equations has two variables (r,l) but four requirements 
-!> (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which
-!> results into an overdetermined system. 
-!------------------------------------------------------------------------------!
+! -------------------------------------------------------------------------------------------------!
+!> Calculation of the stretching factor through an iterative method. Ideas were taken from the paper
+!> "Regional stretched grid generation and its application to the NCAR RegCM (1999)". Normally, no
+!> analytic solution exists because the system of equations has two variables (r,l) but four
+!> requirements  (l=integer, r=[0,88;1,2], Eq(6), Eq(5) starting from index j=1) which results into
+!> an overdetermined system.
+!--------------------------------------------------------------------------------------------------!
  SUBROUTINE calculate_stretching_factor( number_end )
- 
-    USE control_parameters,                                                    &
-        ONLY:  dz, dz_stretch_factor_array,                 &
-               dz_stretch_level_end, dz_stretch_level_start, message_string
-  
+
+    USE control_parameters,                                                                        &
+        ONLY:  dz, dz_stretch_factor_array, dz_stretch_level_end, dz_stretch_level_start,          &
+               message_string
+
     USE kinds
-    
+
     IMPLICIT NONE
-    
-    INTEGER(iwp) ::  iterations  !< number of iterations until stretch_factor_lower/upper_limit is reached  
-    INTEGER(iwp) ::  l_rounded   !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2 
+
+    REAL(wp), PARAMETER ::  stretch_factor_interval = 1.0E-06_wp  !< interval for sampling possible stretching factors
+    REAL(wp), PARAMETER ::  stretch_factor_lower_limit = 0.88_wp  !< lowest possible stretching factor
+    REAL(wp), PARAMETER ::  stretch_factor_upper_limit = 1.12_wp  !< highest possible stretching factor
+
+    INTEGER(iwp) ::  iterations  !< number of iterations until stretch_factor_lower/upper_limit is reached
+    INTEGER(iwp) ::  l_rounded   !< after l_rounded grid levels dz(n) is strechted to dz(n+1) with stretch_factor_2
     INTEGER(iwp) ::  n           !< loop variable for stretching
-    
+
     INTEGER(iwp), INTENT(IN) ::  number_end !< number of user-specified end levels for stretching
-        
+
     REAL(wp) ::  delta_l               !< absolute difference between l and l_rounded
     REAL(wp) ::  delta_stretch_factor  !< absolute difference between stretch_factor_1 and stretch_factor_2
-    REAL(wp) ::  delta_total_new       !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as possible) 
-    REAL(wp) ::  delta_total_old       !< sum of delta_l and delta_stretch_factor for the last iteration 
+    REAL(wp) ::  delta_total_new       !< sum of delta_l and delta_stretch_factor for the next iteration (should be as small as
+                                       !< possible)
+    REAL(wp) ::  delta_total_old       !< sum of delta_l and delta_stretch_factor for the last iteration
     REAL(wp) ::  distance              !< distance between dz_stretch_level_start and dz_stretch_level_end (stretching region)
-    REAL(wp) ::  l                     !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1 exactly
+    REAL(wp) ::  l                     !< value that fulfil Eq. (5) in the paper mentioned above together with stretch_factor_1
+                                       !< exactly
     REAL(wp) ::  numerator             !< numerator of the quotient
     REAL(wp) ::  stretch_factor_1      !< stretching factor that fulfil Eq. (5) togehter with l exactly
     REAL(wp) ::  stretch_factor_2      !< stretching factor that fulfil Eq. (6) togehter with l_rounded exactly
-    
-    REAL(wp) ::  dz_stretch_factor_array_2(9) = 1.08_wp  !< Array that contains all stretch_factor_2 that belongs to stretch_factor_1 
-    
-    REAL(wp), PARAMETER ::  stretch_factor_interval = 1.0E-06_wp  !< interval for sampling possible stretching factors
-    REAL(wp), PARAMETER ::  stretch_factor_lower_limit = 0.88_wp  !< lowest possible stretching factor
-    REAL(wp), PARAMETER ::  stretch_factor_upper_limit = 1.12_wp  !< highest possible stretching factor
- 
- 
+
+    REAL(wp) ::  dz_stretch_factor_array_2(9) = 1.08_wp  !< Array that contains all stretch_factor_2 that belongs to
+                                                         !< stretch_factor_1
+
+
     l = 0
     DO  n = 1, number_end
-    
+
        iterations = 1
-       stretch_factor_1 = 1.0_wp 
+       stretch_factor_1 = 1.0_wp
        stretch_factor_2 = 1.0_wp
        delta_total_old = 1.0_wp
-       
+
 !
 !--    First branch for stretching from rough to fine
-       IF ( dz(n) > dz(n+1) ) THEN
-          DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit ) 
-             
+       IF ( dz(n) > dz(n+1) )  THEN
+          DO WHILE ( stretch_factor_1 >= stretch_factor_lower_limit )
+
              stretch_factor_1 = 1.0_wp - iterations * stretch_factor_interval
-             distance = ABS( dz_stretch_level_end(n) -                         &
-                        dz_stretch_level_start(n) )   
-             numerator = distance*stretch_factor_1/dz(n) +                     &
-                         stretch_factor_1 - distance/dz(n)
-             
-             IF ( numerator > 0.0_wp ) THEN
+             distance = ABS( dz_stretch_level_end(n) - dz_stretch_level_start(n) )
+             numerator = distance * stretch_factor_1 / dz(n) + stretch_factor_1 - distance / dz(n)
+
+             IF ( numerator > 0.0_wp )  THEN
                 l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
                 l_rounded = NINT( l )
                 delta_l = ABS( l_rounded - l ) / l
              ENDIF
-             
+
              stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
-             
-             delta_stretch_factor = ABS( stretch_factor_1 -                    &
-                                         stretch_factor_2 ) /                  &
-                                    stretch_factor_2
-             
+
+             delta_stretch_factor = ABS( stretch_factor_1 - stretch_factor_2 ) / stretch_factor_2
+
              delta_total_new = delta_l + delta_stretch_factor
 
 !
-!--          stretch_factor_1 is taken to guarantee that the stretching
-!--          procedure ends as close as possible to dz_stretch_level_end.
-!--          stretch_factor_2 would guarantee that the stretched dz(n) is
-!--          equal to dz(n+1) after l_rounded grid levels.
-             IF (delta_total_new < delta_total_old) THEN
+!--          stretch_factor_1 is taken to guarantee that the stretching procedure ends as close as
+!--          possible to dz_stretch_level_end.
+!--          stretch_factor_2 would guarantee that the stretched dz(n) is equal to dz(n+1) after
+!--          l_rounded grid levels.
+             IF (delta_total_new < delta_total_old)  THEN
                 dz_stretch_factor_array(n) = stretch_factor_1
                 dz_stretch_factor_array_2(n) = stretch_factor_2
                 delta_total_old = delta_total_new
              ENDIF
-             
+
              iterations = iterations + 1
-            
+
           ENDDO
 
 !
 !--    Second branch for stretching from fine to rough
-       ELSEIF ( dz(n) < dz(n+1) ) THEN 
+       ELSEIF ( dz(n) < dz(n+1) )  THEN
           DO WHILE ( stretch_factor_1 <= stretch_factor_upper_limit )
-                     
+
              stretch_factor_1 = 1.0_wp + iterations * stretch_factor_interval
-             distance = ABS( dz_stretch_level_end(n) -                         &
-                        dz_stretch_level_start(n) ) 
-             numerator = distance*stretch_factor_1/dz(n) +                     &
-                         stretch_factor_1 - distance/dz(n)
-             
+             distance = ABS( dz_stretch_level_end(n) - dz_stretch_level_start(n) )
+             numerator = distance * stretch_factor_1 / dz(n) + stretch_factor_1 - distance / dz(n)
+
              l = LOG( numerator ) / LOG( stretch_factor_1 ) - 1.0_wp
              l_rounded = NINT( l )
              delta_l = ABS( l_rounded - l ) / l
-             
+
              stretch_factor_2 = EXP( LOG( dz(n+1)/dz(n) ) / (l_rounded) )
 
-             delta_stretch_factor = ABS( stretch_factor_1 -                    &
-                                        stretch_factor_2 ) /                   &
-                                        stretch_factor_2
-             
+             delta_stretch_factor = ABS( stretch_factor_1 - stretch_factor_2 ) / stretch_factor_2
+
              delta_total_new = delta_l + delta_stretch_factor
-             
-!
-!--          stretch_factor_1 is taken to guarantee that the stretching
-!--          procedure ends as close as possible to dz_stretch_level_end.
-!--          stretch_factor_2 would guarantee that the stretched dz(n) is
-!--          equal to dz(n+1) after l_rounded grid levels.
-             IF (delta_total_new < delta_total_old) THEN
+
+!
+!--          stretch_factor_1 is taken to guarantee that the stretching procedure ends as close as
+!--          possible to dz_stretch_level_end.
+!--          stretch_factor_2 would guarantee that the stretched dz(n) is equal to dz(n+1) after
+!--          l_rounded grid levels.
+             IF (delta_total_new < delta_total_old)  THEN
                 dz_stretch_factor_array(n) = stretch_factor_1
                 dz_stretch_factor_array_2(n) = stretch_factor_2
                 delta_total_old = delta_total_new
              ENDIF
-             
+
              iterations = iterations + 1
           ENDDO
-          
+
        ELSE
           message_string= 'Two adjacent values of dz must be different'
           CALL message( 'init_grid', 'PA0228', 1, 2, 0, 6, 0 )
-          
-       ENDIF
-
-!
-!--    Check if also the second stretching factor fits into the allowed
-!--    interval. If not, print a warning for the user.
-       IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit .OR.     & 
-            dz_stretch_factor_array_2(n) > stretch_factor_upper_limit ) THEN
-          WRITE( message_string, * ) 'stretch_factor_2 = ',                    &
-                                     dz_stretch_factor_array_2(n), ' which is',&
-                                     ' responsible for exactly reaching& dz =',&
-                                      dz(n+1), 'after a specific amount of',   & 
-                                     ' grid levels& exceeds the upper',        &
-                                     ' limit =', stretch_factor_upper_limit,   &
-                                     ' &or lower limit = ',                    &
-                                     stretch_factor_lower_limit
+
+       ENDIF
+
+!
+!--    Check if also the second stretching factor fits into the allowed interval. If not, print a
+!--    warning for the user.
+       IF ( dz_stretch_factor_array_2(n) < stretch_factor_lower_limit  .OR.                        &
+            dz_stretch_factor_array_2(n) > stretch_factor_upper_limit )  THEN
+          WRITE( message_string, * ) 'stretch_factor_2 = ', dz_stretch_factor_array_2(n),          &
+                                     ' which is', ' responsible for exactly reaching& dz =',       &
+                                      dz(n+1), 'after a specific amount of',                       &
+                                     ' grid levels& exceeds the upper',                            &
+                                     ' limit =', stretch_factor_upper_limit,                       &
+                                     ' &or lower limit = ', stretch_factor_lower_limit
           CALL message( 'init_grid', 'PA0499', 0, 1, 0, 6, 0 )
-            
+
        ENDIF
     ENDDO
-        
+
  END SUBROUTINE calculate_stretching_factor
- 
- 
+
+
 ! Description:
-! -----------------------------------------------------------------------------!
-!> Set temporary topography flags and reference buildings on top of underlying
-!> orography. 
-!------------------------------------------------------------------------------!
+! -------------------------------------------------------------------------------------------------!
+!> Set temporary topography flags and reference buildings on top of underlying orography.
+!--------------------------------------------------------------------------------------------------!
  SUBROUTINE process_topography( topo_3d )
 
-    USE arrays_3d,                                                             &
+    USE arrays_3d,                                                                                 &
         ONLY:  zu, zw
 
-    USE control_parameters,                                                    &
+    USE control_parameters,                                                                        &
         ONLY:  bc_lr_cyc, bc_ns_cyc, ocean_mode
 
-    USE exchange_horiz_mod,                                                    &
-        ONLY:  exchange_horiz_int, exchange_horiz_2d
-
-    USE indices,                                                               &
-        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb,  &
-               nzt
-
-    USE netcdf_data_input_mod,                                                 &
-        ONLY:  buildings_f, building_id_f, building_type_f,                    &
-               init_model,                                                     &
-               input_pids_static,                                              &
+    USE exchange_horiz_mod,                                                                        &
+        ONLY:  exchange_horiz_2d, exchange_horiz_int
+
+    USE indices,                                                                                   &
+        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
+
+    USE netcdf_data_input_mod,                                                                     &
+        ONLY:  buildings_f, building_id_f, building_type_f,                                        &
+               init_model,                                                                         &
+               input_pids_static,                                                                  &
                terrain_height_f
 
@@ -972 +912 @@
 #endif
     INTEGER(iwp), DIMENSION(:), ALLOCATABLE ::  build_ids           !< building IDs on entire model domain
-    INTEGER(iwp), DIMENSION(:), ALLOCATABLE ::  build_ids_final     !< building IDs on entire model domain, multiple occurences are sorted out 
+    INTEGER(iwp), DIMENSION(:), ALLOCATABLE ::  build_ids_final     !< building IDs on entire model domain, multiple occurences are
+                                                                    !< sorted out
     INTEGER(iwp), DIMENSION(:), ALLOCATABLE ::  build_ids_final_tmp !< temporary array used for resizing
     INTEGER(iwp), DIMENSION(:), ALLOCATABLE ::  build_ids_l         !< building IDs on local subdomain
@@ -980 +921 @@
     INTEGER(iwp), DIMENSION(0:numprocs-1) ::  num_buildings_l   !< number of buildings with different ID on local subdomain
 
-    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo_3d !< input array for 3D topography and dummy array for setting "outer"-flags
-
-    REAL(wp)                            ::  ocean_offset        !< offset to consider inverse vertical coordinate at topography definition
-    REAL(wp)                            ::  oro_min = 0.0_wp    !< minimum terrain height in entire model domain, used to reference terrain to zero
+    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo_3d !< input array for 3D topography and dummy array for setting
+                                                                       !< "outer"-flags
+
+    REAL(wp)                            ::  ocean_offset        !< offset to consider inverse vertical coordinate at topography
+                                                                !< definition
+    REAL(wp)                            ::  oro_min = 0.0_wp    !< minimum terrain height in entire model domain, used to reference
+                                                                !< terrain to zero
     REAL(wp), DIMENSION(:), ALLOCATABLE ::  oro_max             !< maximum terrain height occupied by an building with certain id
-    REAL(wp), DIMENSION(:), ALLOCATABLE ::  oro_max_l           !< maximum terrain height occupied by an building with certain id, on local subdomain
-
-!
-!-- Reference lowest terrain height to zero. This ensures that first, 
-!-- non-required gird levels (those which lie entirely below the minimum 
-!-- orography) are avoided, and second, that also negative orography can be used
-!-- within the input file.
-!-- Please note, in case of a nested run, the global minimum from all parent and 
-!-- childs need to be remove to avoid steep edges at the child-domain boundaries.
+    REAL(wp), DIMENSION(:), ALLOCATABLE ::  oro_max_l           !< maximum terrain height occupied by an building with certain id,
+                                                                !< on local subdomain
+
+!
+!-- Reference lowest terrain height to zero. This ensures that first, non-required gird levels
+!-- (those which lie entirely below the minimum orography) are avoided, and second, that also
+!-- negative orography can be used within the input file.
+!-- Please note, in case of a nested run, the global minimum from all parent and childs needs to be
+!-- removed to avoid steep edges at the child-domain boundaries.
     IF ( input_pids_static )  THEN
-    
-#if defined( __parallel ) 
-       CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1,         &
-                           MPI_REAL, MPI_MIN, MPI_COMM_WORLD, ierr )
+
+#if defined( __parallel )
+       CALL MPI_ALLREDUCE( MINVAL( terrain_height_f%var ), oro_min, 1, MPI_REAL, MPI_MIN,          &
+                           MPI_COMM_WORLD, ierr )
 #else
        oro_min = MINVAL( terrain_height_f%var )
@@ -1007 +951 @@
        init_model%origin_z = init_model%origin_z + oro_min
 
-    ENDIF    
-    
-!
-!-- In the following, buildings and orography are further preprocessed 
-!-- before they are mapped on the LES grid.
-!-- Buildings are mapped on top of the orography by maintaining the roof 
-!-- shape of the building. This can be achieved by referencing building on 
-!-- top of the maximum terrain height within the area occupied by the 
-!-- respective building. As buildings and terrain height are defined PE-wise,
-!-- parallelization of this referencing is required (a building can be 
-!-- distributed between different PEs).  
-!-- In a first step, determine the number of buildings with different 
-!-- building id on each PE. In a next step, all building ids are gathered
-!-- into one array which is present to all PEs. For each building ID, 
-!-- the maximum terrain height occupied by the respective building is 
-!-- computed and distributed to each PE.  
-!-- Finally, for each building id and its respective reference orography, 
-!-- builidings are mapped on top.   
-!-- 
-!-- First, pre-set topography flags, bit 1 indicates orography, bit 2 
-!-- buildings 
-!-- classify the respective surfaces.
+    ENDIF
+
+!
+!-- In the following, buildings and orography are further preprocessed before they are mapped on the
+!-- LES grid.
+!-- Buildings are mapped on top of the orography by maintaining the roof shape of the building. This
+!-- can be achieved by referencing building on top of the maximum terrain height within the area
+!-- occupied by the respective building. As buildings and terrain height are defined PE-wise,
+!-- parallelization of this referencing is required (a building can be distributed between different
+!-- PEs).
+!-- In a first step, determine the number of buildings with different building id on each PE. In a
+!-- next step, all building ids are gathered into one array which is present to all PEs. For each
+!-- building ID, the maximum terrain height occupied by the respective building is computed and
+!-- distributed to each PE.
+!-- Finally, for each building id and its respective reference orography, builidings are mapped on
+!-- top.
+!--
+!-- First, pre-set topography flags, bit 1 indicates orography, bit 2 buildings classify the
+!-- respective surfaces.
     topo_3d          = IBSET( topo_3d, 0 )
     topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
 !
-!-- In order to map topography on PALM grid also in case of ocean simulations,
-!-- pre-calculate an offset value.
+!-- In order to map topography on PALM grid also in case of ocean simulations, pre-calculate an
+!-- offset value.
     ocean_offset = MERGE( zw(0), 0.0_wp, ocean_mode )
 !
-!-- Reference buildings on top of orography. This is not necessary
-!-- if topography is read from ASCII file as no distinction between buildings
-!-- and terrain height can be made. Moreover, this is also not necessary if
-!-- urban-surface and land-surface model are used at the same time. 
+!-- Reference buildings on top of orography. This is not necessary if topography is read from ASCII
+!-- file as no distinction between buildings and terrain height can be made. Moreover, this is also
+!-- not necessary if urban-surface and land-surface model are used at the same time.
     IF ( input_pids_static )  THEN
 
-       IF ( buildings_f%from_file )  THEN 
+       IF ( buildings_f%from_file )  THEN
           num_buildings_l = 0
           num_buildings   = 0
 !
-!--       Allocate at least one element for building ids and give it an inital
-!--       negative value that will be overwritten later. This, however, is 
-!--       necessary in case there all IDs in the model domain are fill values. 
+!--       Allocate at least one element for building ids and give it an inital negative value that
+!--       will be overwritten later. This, however, is necessary in case there all IDs in the model
+!--       domain are fill values.
           ALLOCATE( build_ids_l(1) )
-          build_ids_l = -1 
+          build_ids_l = -1
           DO  i = nxl, nxr
              DO  j = nys, nyn
                 IF ( building_id_f%var(j,i) /= building_id_f%fill )  THEN
                    IF ( num_buildings_l(myid) > 0 )  THEN
-                      IF ( ANY( building_id_f%var(j,i) ==  build_ids_l ) )   &
-                      THEN
+                      IF ( ANY( building_id_f%var(j,i) ==  build_ids_l ) )  THEN
                          CYCLE
                       ELSE
@@ -1066 +1005 @@
                       DEALLOCATE( build_ids_l )
                       ALLOCATE( build_ids_l(1:num_buildings_l(myid)) )
-                      build_ids_l(1:num_buildings_l(myid)-1) =                 &
-                                  build_ids_l_tmp(1:num_buildings_l(myid)-1)
+                      build_ids_l(1:num_buildings_l(myid)-1) =                                     &
+                                                          build_ids_l_tmp(1:num_buildings_l(myid)-1)
                       build_ids_l(num_buildings_l(myid)) = building_id_f%var(j,i)
                       DEALLOCATE( build_ids_l_tmp )
                    ENDIF
 !
-!--                First occuring building id on PE 
-                   ELSE 
+!--                First occuring building id on PE
+                   ELSE
                       num_buildings_l(myid) = num_buildings_l(myid) + 1
                       build_ids_l(1) = building_id_f%var(j,i)
@@ -1081 +1020 @@
           ENDDO
 !
-!--       Determine number of different building ids for the entire domain 
-#if defined( __parallel ) 
-          CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs,              &
-                              MPI_INTEGER, MPI_SUM, comm2d, ierr ) 
+!--       Determine number of different building ids for the entire domain
+#if defined( __parallel )
+          CALL MPI_ALLREDUCE( num_buildings_l, num_buildings, numprocs, MPI_INTEGER, MPI_SUM,      &
+                              comm2d, ierr )
 #else
           num_buildings = num_buildings_l
 #endif
 !
-!--       Gather all buildings ids on each PEs. 
-!--       First, allocate array encompassing all building ids in model domain.  
+!--       Gather all buildings ids on each PEs.
+!--       First, allocate array encompassing all building ids in model domain.
           ALLOCATE( build_ids(1:SUM(num_buildings)) )
-#if defined( __parallel ) 
-!
-!--       Allocate array for displacements. 
-!--       As each PE may has a different number of buildings, so that
-!--       the block sizes send by each PE may not be equal. Hence, 
-!--       information about the respective displacement is required, indicating 
-!--       the respective adress where each MPI-task writes into the receive 
-!--       buffer array  
+#if defined( __parallel )
+!
+!--       Allocate array for displacements.
+!--       As each PE may has a different number of buildings, so that the block sizes send by each
+!--       PE may not be equal. Hence,  information about the respective displacement is required,
+!--       indicating the respective adress where each MPI-task writes into the receive buffer array.
           ALLOCATE( displace_dum(0:numprocs-1) )
           displace_dum(0) = 0
@@ -1106 +1043 @@
           ENDDO
 
-          CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)),                 &
-                               num_buildings(myid),                                  &
-                               MPI_INTEGER,                                          &
-                               build_ids,                                            &
-                               num_buildings,                                        &
-                               displace_dum,                                         & 
-                               MPI_INTEGER,                                          &
-                               comm2d, ierr )   
+          CALL MPI_ALLGATHERV( build_ids_l(1:num_buildings_l(myid)), num_buildings(myid),          &
+                               MPI_INTEGER, build_ids, num_buildings, displace_dum, MPI_INTEGER,   &
+                               comm2d, ierr )
 
           DEALLOCATE( displace_dum )
@@ -1122 +1054 @@
 
 !
-!--       Note, in parallel mode building ids can occure mutliple times, as 
-!--       each PE has send its own ids. Therefore, sort out building ids which 
-!--       appear more than one time. 
+!--       Note, in parallel mode building ids can occure mutliple times, as each PE has send its own
+!--       ids. Therefore, sort out building ids which appear more than one time.
           num_build = 0
           DO  nr = 1, SIZE(build_ids)
@@ -1142 +1073 @@
                    build_ids_final(num_build) = build_ids(nr)
                    DEALLOCATE( build_ids_final_tmp )
-                ENDIF             
+                ENDIF
              ELSE
                 num_build = num_build + 1
@@ -1151 +1082 @@
 
 !
-!--       Determine maximumum terrain height occupied by the respective 
-!--       building and temporalily store on oro_max 
+!--       Determine maximumum terrain height occupied by the respective building and temporalily
+!--       store on oro_max.
           ALLOCATE( oro_max_l(1:SIZE(build_ids_final)) )
           ALLOCATE( oro_max(1:SIZE(build_ids_final))   )
@@ -1158 +1089 @@
 
           DO  nr = 1, SIZE(build_ids_final)
-             oro_max_l(nr) = MAXVAL(                                           &
-                              MERGE( terrain_height_f%var(nys:nyn,nxl:nxr),    &
-                                     0.0_wp,                                   &
-                                     building_id_f%var(nys:nyn,nxl:nxr) ==     &
-                                     build_ids_final(nr) ) )
-          ENDDO
-   
-#if defined( __parallel )    
-          IF ( SIZE(build_ids_final) >= 1 ) THEN
-             CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL,&
-                                 MPI_MAX, comm2d, ierr ) 
+             oro_max_l(nr) = MAXVAL( MERGE( terrain_height_f%var(nys:nyn,nxl:nxr),                 &
+                                              0.0_wp,                                              &
+                                              building_id_f%var(nys:nyn,nxl:nxr) ==                &
+                                              build_ids_final(nr) ) )
+          ENDDO
+
+#if defined( __parallel )
+          IF ( SIZE(build_ids_final) >= 1 )  THEN
+             CALL MPI_ALLREDUCE( oro_max_l, oro_max, SIZE( oro_max ), MPI_REAL, MPI_MAX, comm2d,   &
+                                 ierr )
           ENDIF
 #else
@@ -1174 +1104 @@
 #endif
 !
-!--       Finally, determine discrete grid height of maximum orography occupied
-!--       by a building. Use all-or-nothing approach, i.e. if terrain
-!--       exceeds the scalar level the grid box is fully terrain and the 
-!--       maximum terrain is set to the zw level. 
-!--       terrain or 
+!--       Finally, determine discrete grid height of maximum orography occupied by a building. Use
+!--       all-or-nothing approach, i.e. if terrain exceeds the scalar level the grid box is fully
+!--       terrain and the maximum terrain is set to the zw level.
+!--       terrain or
           oro_max_l = 0.0
           DO  nr = 1, SIZE(build_ids_final)
              DO  k = nzb, nzt
-                IF ( zu(k) - ocean_offset <= oro_max(nr) )                     &
-                   oro_max_l(nr) = zw(k) - ocean_offset
+                IF ( zu(k) - ocean_offset <= oro_max(nr) )  oro_max_l(nr) = zw(k) - ocean_offset
              ENDDO
              oro_max(nr) = oro_max_l(nr)
@@ -1195 +1123 @@
        END IF
 !
-!--    Map orography as well as buildings onto grid. 
+!--    Map orography as well as buildings onto grid.
        DO  i = nxl, nxr
           DO  j = nys, nyn
@@ -1204 +1132 @@
                 IF ( building_id_f%var(j,i) /= building_id_f%fill )  THEN
 !
-!--                Determine index where maximum terrain height occupied by 
-!--                the respective building height is stored.
-                   nr = MINLOC( ABS( build_ids_final -                         &
-                                     building_id_f%var(j,i) ), DIM = 1 )
+!--                Determine index where maximum terrain height occupied by the respective building
+!--                height is stored.
+                   nr = MINLOC( ABS( build_ids_final - building_id_f%var(j,i) ), DIM=1 )
 !
 !--                Save grid-indexed oro_max
@@ -1215 +1142 @@
              DO  k = nzb, nzt
 !
-!--             In a first step, if grid point is below or equal the given 
-!--             terrain height, grid point is flagged to be of type natural. 
-!--             Please note, in case there is also a building which is lower
-!--             than the vertical grid spacing, initialization of surface
-!--             attributes will not be correct as given surface information
-!--             will not be in accordance to the classified grid points. 
+!--             In a first step, if grid point is below or equal the given terrain height, grid
+!--             point is flagged to be of type natural.
+!--             Please note, in case there is also a building which is lower than the vertical grid
+!--             spacing, initialization of surface attributes will not be correct as given surface
+!--             information will not be in accordance to the classified grid points.
 !--             Hence, in this case, also a building flag.
                 IF ( zu(k) - ocean_offset <= terrain_height_f%var(j,i) )  THEN
@@ -1228 +1154 @@
                 ENDIF
 !
-!--             Set building grid points. Here, only consider 2D buildings. 
-!--             3D buildings require separate treatment. 
+!--             Set building grid points. Here, only consider 2D buildings.
+!--             3D buildings require separate treatment.
                 IF ( buildings_f%from_file  .AND.  buildings_f%lod == 1 )  THEN
 !
-!--                Fill-up the terrain to the level of maximum orography
-!--                within the building-covered area.
+!--                Fill-up the terrain to the level of maximum orography within the building-covered
+!--                area.
                    IF ( building_id_f%var(j,i) /= building_id_f%fill )  THEN
 !
-!--                   Note, oro_max is always on zw level                   
+!--                   Note, oro_max is always on zw level
                       IF ( zu(k) - ocean_offset < oro_max(nr) )  THEN
                          topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
                          topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
-                      ELSEIF ( zu(k) - ocean_offset <=                         &
-                               oro_max(nr) + buildings_f%var_2d(j,i) )  THEN
+                      ELSEIF ( zu(k) - ocean_offset <= oro_max(nr) + buildings_f%var_2d(j,i) )  THEN
                          topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
                          topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
@@ -1249 +1174 @@
              ENDDO
 !
-!--          Special treatment for non grid-resolved buildings. This case,
-!--          the uppermost terrain grid point is flagged as building as well
-!--          well, even though no building exists at all. However, the 
-!--          surface element will be identified as urban-surface and the 
-!--          input data provided by the drivers is consistent to the surface
-!--          classification. Else, all non grid-resolved buildings would vanish
-!--          and identified as terrain grid points, which, however, won't be
-!--          consistent with the input data. 
+!--          Special treatment for non grid-resolved buildings. This case, the uppermost terrain
+!--          grid point is flagged as building as well, even though no building exists at all.
+!--          However, the surface element will be identified as urban-surface and the input data
+!--          provided by the drivers is consistent to the surface classification. Else, all non
+!--          grid-resolved buildings would vanish and identified as terrain grid points, which,
+!--          however, won't be consistent with the input data.
              IF ( buildings_f%from_file  .AND.  buildings_f%lod == 1 )  THEN
                 IF ( building_id_f%var(j,i) /= building_id_f%fill )  THEN
@@ -1269 +1192 @@
              ENDIF
 !
-!--          Map 3D buildings onto terrain height.  
-!--          In case of any slopes, map building on top of maximum terrain 
-!--          height covered by the building. In other words, extend 
-!--          building down to the respective local terrain-surface height. 
+!--          Map 3D buildings onto terrain height.
+!--          In case of any slopes, map building on top of maximum terrain height covered by the
+!--          building. In other words, extend building down to the respective local terrain-surface
+!--          height.
              IF ( buildings_f%from_file  .AND.  buildings_f%lod == 2 )  THEN
                 IF ( building_id_f%var(j,i) /= building_id_f%fill )  THEN
 !
-!--                Extend building down to the terrain surface, i.e. fill-up
-!--                surface irregularities below a building. Note, oro_max
-!--                is already a discrete height according to the all-or-nothing
-!--                approach, i.e. grid box is either topography or atmosphere, 
+!--                Extend building down to the terrain surface, i.e. fill-up surface irregularities
+!--                below a building. Note, oro_max is already a discrete height according to the
+!--                all-or-nothing approach, i.e. grid box is either topography or atmosphere,
 !--                terrain top is defined at upper bound of the grid box.
-!--                Hence, check for zw in this case. 
-!--                Note, do this only for buildings which are surface mounted, 
-!--                i.e. building types 1-6. Below bridges, which are represented
-!--                exclusively by building type 7, terrain shape should be
-!--                maintained. 
+!--                Hence, check for zw in this case.
+!--                Note, do this only for buildings which are surface mounted, i.e. building types
+!--                1-6. Below bridges, which are represented exclusively by building type 7, terrain
+!--                shape should be maintained.
                    IF ( building_type_f%from_file )  THEN
                       IF ( building_type_f%var(j,i) /= 7 )  THEN
-                         DO k = topo_top_index + 1, nzt + 1      
+                         DO k = topo_top_index + 1, nzt + 1
                             IF ( zu(k) - ocean_offset <= oro_max(nr) )  THEN
                                topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
                                topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
                             ENDIF
-                         ENDDO        
-!                     
-!--                      After surface irregularities are smoothen, determine 
-!--                      lower start index where building starts. 
+                         ENDDO
+!
+!--                      After surface irregularities are smoothen, determine lower start index
+!--                      where building starts.
                          DO  k = nzb, nzt
-                            IF ( zu(k) - ocean_offset <= oro_max(nr) )         &
-                               topo_top_index = k
+                            IF ( zu(k) - ocean_offset <= oro_max(nr) )  topo_top_index = k
                          ENDDO
                       ENDIF
@@ -1320 +1240 @@
        ENDDO
 !
-!--    Horizontal exchange the oro_max array, which is required to for
-!--    initialization of building-surface properties.
+!--    Horizontal exchange the oro_max array, which is required to for initialization of
+!--    building-surface properties.
        IF ( ALLOCATED( buildings_f%oro_max ) )  THEN
           CALL exchange_horiz_2d( buildings_f%oro_max(:,:) )
@@ -1331 +1251 @@
        IF ( ALLOCATED( build_ids_final ) )  DEALLOCATE( build_ids_final )
 !
-!-- Topography input via ASCII format. 
+!-- Topography input via ASCII format.
     ELSE
        ocean_offset     = MERGE( zw(0), 0.0_wp, ocean_mode )
 !
-!--    Initialize topography bit 0 (indicates obstacle) everywhere to zero
-!--    and clear all grid points at nzb, where alway a surface is defined.
-!--    Further, set also bit 1 (indicates terrain) at nzb, which is further
-!--    used for masked data output and further processing. Note, in the 
-!--    ASCII case no distinction is made between buildings and terrain, 
-!--    so that setting of bit 1 and 2 at the same time has no effect. 
+!--    Initialize topography bit 0 (indicates obstacle) everywhere to zero and clear all grid points
+!--    at nzb, where alway a surface is defined.
+!--    Further, set also bit 1 (indicates terrain) at nzb, which is further used for masked data
+!--    output and further processing. Note, in the ASCII case no distinction is made between
+!--    buildings and terrain,  so that setting of bit 1 and 2 at the same time has no effect.
        topo_3d          = IBSET( topo_3d, 0 )
        topo_3d(nzb,:,:) = IBCLR( topo_3d(nzb,:,:), 0 )
@@ -1348 +1267 @@
              DO  k = nzb, nzt
 !
-!--             Flag topography for all grid points which are below
-!--             the local topography height. 
-!--             Note, each topography is flagged as building (bit 2) as well as 
-!--             terrain (bit 1) in order to employ urban-surface as well as 
-!--             land-surface model.
+!--             Flag topography for all grid points which are below the local topography height.
+!--             Note, each topography is flagged as building (bit 2) as well as terrain (bit 1) in
+!--             order to employ urban-surface as well as land-surface model.
                 IF ( zu(k) - ocean_offset <= buildings_f%var_2d(j,i) )  THEN
                    topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
@@ -1372 +1289 @@
     IF ( .NOT. bc_lr_cyc )  THEN
        IF ( nxl == 0  )  topo_3d(:,:,-1)   = topo_3d(:,:,0)
-       IF ( nxr == nx )  topo_3d(:,:,nx+1) = topo_3d(:,:,nx)          
+       IF ( nxr == nx )  topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
     ENDIF
 
@@ -1379 +1296 @@
 
 ! Description:
-! -----------------------------------------------------------------------------!
-!> Filter topography, i.e. fill holes resolved by only one grid point.  
-!> Such holes are suspected to lead to velocity blow-ups as continuity 
-!> equation on discrete grid cannot be fulfilled in such case.
-!------------------------------------------------------------------------------!
+! -------------------------------------------------------------------------------------------------!
+!> Filter topography, i.e. fill holes resolved by only one grid point.
+!> Such holes are suspected to lead to velocity blow-ups as continuity equation on discrete grid
+!> cannot be fulfilled in such case.
+!--------------------------------------------------------------------------------------------------!
  SUBROUTINE filter_topography( topo_3d )
 
-    USE control_parameters,                                                    &
+    USE control_parameters,                                                                        &
         ONLY:  bc_lr_cyc, bc_ns_cyc, message_string
 
-    USE exchange_horiz_mod,                                                    &
+    USE exchange_horiz_mod,                                                                        &
         ONLY:  exchange_horiz_int, exchange_horiz_2d_byte, exchange_horiz_2d_int
 
-    USE indices,                                                               &
+    USE indices,                                                                                   &
         ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt
 
-    USE netcdf_data_input_mod,                                                 &
-        ONLY:  building_id_f, building_type_f 
+    USE netcdf_data_input_mod,                                                                     &
+        ONLY:  building_id_f, building_type_f
 
     USE  pegrid
 
     IMPLICIT NONE
-
-    LOGICAL      ::  filled = .FALSE. !< flag indicating if holes were filled
 
     INTEGER(iwp) ::  i          !< running index along x-direction
     INTEGER(iwp) ::  j          !< running index along y-direction
     INTEGER(iwp) ::  k          !< running index along z-direction
-    INTEGER(iwp) ::  num_hole   !< number of holes (in topography) resolved by only one grid point 
-    INTEGER(iwp) ::  num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE     
+    INTEGER(iwp) ::  num_hole   !< number of holes (in topography) resolved by only one grid point
+    INTEGER(iwp) ::  num_hole_l !< number of holes (in topography) resolved by only one grid point on local PE
     INTEGER(iwp) ::  num_wall   !< number of surrounding vertical walls for a single grid point
 
     INTEGER(iwp), DIMENSION(:,:,:), ALLOCATABLE            ::  topo_tmp          !< temporary 3D-topography used to fill holes
-    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo_3d           !< 3D-topography array merging buildings and orography
-!
-!-- Before checking for holes, set lateral boundary conditions for 
+    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo_3d           !< 3D-topography array merging buildings and
+                                                                                 !< orography
+
+    LOGICAL      ::  filled = .FALSE. !< flag indicating if holes were filled
+
+!
+!-- Before checking for holes, set lateral boundary conditions for
 !-- topography. After hole-filling, boundary conditions must be set again.
-!-- Several iterations are performed, in order to fill holes which might 
+!-- Several iterations are performed, in order to fill holes which might
 !-- emerge by the filling-algorithm itself.
     ALLOCATE( topo_tmp(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
@@ -1422 +1341 @@
 
     num_hole = 99999
-    DO WHILE ( num_hole > 0 )       
-
-       num_hole = 0    
+    DO WHILE ( num_hole > 0 )
+
+       num_hole = 0
        CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
 !
-!--    Exchange also building ID and type. Note, building_type is an one-byte 
-!--    variable.
-       IF ( building_id_f%from_file )                                          &
+!--    Exchange also building ID and type. Note, building_type is an one-byte variable.
+       IF ( building_id_f%from_file )                                                              &
           CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
-       IF ( building_type_f%from_file )                                        &
+       IF ( building_type_f%from_file )                                                            &
           CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
 
        topo_tmp = topo_3d
 !
-!--    In case of non-cyclic lateral boundaries, assume lateral boundary to be 
-!--    a solid wall. Thus, intermediate spaces of one grid point between 
-!--    boundary and some topographic structure will be filled.           
+!--    In case of non-cyclic lateral boundaries, assume lateral boundary to be a solid wall. Thus,
+!--    intermediate spaces of one grid point between boundary and some topographic structure will be
+!--    filled.
        IF ( .NOT. bc_ns_cyc )  THEN
           IF ( nys == 0  )  topo_tmp(:,-1,:)   = IBCLR( topo_tmp(:,0,:),  0 )
@@ -1446 +1364 @@
        IF ( .NOT. bc_lr_cyc )  THEN
           IF ( nxl == 0  )  topo_tmp(:,:,-1)   = IBCLR( topo_tmp(:,:,0),  0 )
-          IF ( nxr == nx )  topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )          
+          IF ( nxr == nx )  topo_tmp(:,:,nx+1) = IBCLR( topo_tmp(:,:,nx), 0 )
        ENDIF
 
@@ -1455 +1373 @@
                 IF ( BTEST( topo_tmp(k,j,i), 0 ) )  THEN
                    num_wall = 0
-                   IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) )                  &
-                      num_wall = num_wall + 1
-                   IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) )                  &
-                      num_wall = num_wall + 1
-                   IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) )                  &
-                      num_wall = num_wall + 1
-                   IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) )                  &
-                      num_wall = num_wall + 1
-                   IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) )                  &
-                      num_wall = num_wall + 1   
-                   IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) )                  &
-                      num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k,j-1,i), 0 ) )  num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k,j+1,i), 0 ) )  num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k,j,i-1), 0 ) )  num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k,j,i+1), 0 ) )  num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k-1,j,i), 0 ) )  num_wall = num_wall + 1
+                   IF ( .NOT. BTEST( topo_tmp(k+1,j,i), 0 ) )  num_wall = num_wall + 1
 
                    IF ( num_wall >= 4 )  THEN
                       num_hole_l     = num_hole_l + 1
 !
-!--                   Clear flag 0 and set special flag ( bit 4) to indicate 
-!--                   that new topography point is a result of filtering process.
+!--                   Clear flag 0 and set special flag ( bit 4) to indicate that new topography
+!--                   point is a result of filtering process.
                       topo_3d(k,j,i) = IBCLR( topo_3d(k,j,i), 0 )
                       topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 4 )
 !
-!--                   If filled grid point is occupied by a building, classify
-!--                   it as building grid point.
+!--                   If filled grid point is occupied by a building, classify it as building grid
+!--                   point.
                       IF ( building_type_f%from_file )  THEN
-                         IF ( building_type_f%var(j,i)   /=                    &  
-                              building_type_f%fill            .OR.             &       
-                              building_type_f%var(j+1,i) /=                    &  
-                              building_type_f%fill            .OR.             &                
-                              building_type_f%var(j-1,i) /=                    &                
-                              building_type_f%fill            .OR.             &                
-                              building_type_f%var(j,i+1) /=                    &                
-                              building_type_f%fill            .OR.             &                
-                              building_type_f%var(j,i-1) /=                    &                
-                              building_type_f%fill )  THEN
+                         IF ( building_type_f%var(j,i)   /=  building_type_f%fill  .OR.            &
+                              building_type_f%var(j+1,i) /=  building_type_f%fill  .OR.            &
+                              building_type_f%var(j-1,i) /=  building_type_f%fill  .OR.            &
+                              building_type_f%var(j,i+1) /=  building_type_f%fill  .OR.            &
+                              building_type_f%var(j,i-1) /=  building_type_f%fill )  THEN
 !
 !--                         Set flag indicating building surfaces
                             topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 2 )
 !
-!--                         Set building_type and ID at this position if not 
-!--                         already set. This is required for proper 
-!--                         initialization of urban-surface energy balance 
+!--                         Set building_type and ID at this position if not already set. This is
+!--                         required for proper initialization of urban-surface energy balance
 !--                         solver.
-                            IF ( building_type_f%var(j,i) ==                   &
-                                 building_type_f%fill )  THEN
-
-                               IF ( building_type_f%var(j+1,i) /=              &
-                                    building_type_f%fill )  THEN
-                                  building_type_f%var(j,i) =                   &
-                                                    building_type_f%var(j+1,i)
-                                  building_id_f%var(j,i) =                     &
-                                                    building_id_f%var(j+1,i)
-                               ELSEIF ( building_type_f%var(j-1,i) /=          &
-                                        building_type_f%fill )  THEN
-                                  building_type_f%var(j,i) =                   &
-                                                    building_type_f%var(j-1,i)
-                                  building_id_f%var(j,i) =                     &
-                                                    building_id_f%var(j-1,i)
-                               ELSEIF ( building_type_f%var(j,i+1) /=          &
-                                        building_type_f%fill )  THEN
-                                  building_type_f%var(j,i) =                   &
-                                                    building_type_f%var(j,i+1)
-                                  building_id_f%var(j,i) =                     &
-                                                    building_id_f%var(j,i+1)
-                               ELSEIF ( building_type_f%var(j,i-1) /=          &
-                                        building_type_f%fill )  THEN
-                                  building_type_f%var(j,i) =                   &
-                                                    building_type_f%var(j,i-1)
-                                  building_id_f%var(j,i) =                     &
-                                                    building_id_f%var(j,i-1)
+                            IF ( building_type_f%var(j,i) == building_type_f%fill )  THEN
+
+                               IF ( building_type_f%var(j+1,i) /= building_type_f%fill )  THEN
+                                  building_type_f%var(j,i) = building_type_f%var(j+1,i)
+                                  building_id_f%var(j,i)   = building_id_f%var(j+1,i)
+                               ELSEIF ( building_type_f%var(j-1,i) /= building_type_f%fill )  THEN
+                                  building_type_f%var(j,i) = building_type_f%var(j-1,i)
+                                  building_id_f%var(j,i)   = building_id_f%var(j-1,i)
+                               ELSEIF ( building_type_f%var(j,i+1) /= building_type_f%fill )  THEN
+                                  building_type_f%var(j,i) = building_type_f%var(j,i+1)
+                                  building_id_f%var(j,i)   = building_id_f%var(j,i+1)
+                               ELSEIF ( building_type_f%var(j,i-1) /= building_type_f%fill )  THEN
+                                  building_type_f%var(j,i) = building_type_f%var(j,i-1)
+                                  building_id_f%var(j,i)   = building_id_f%var(j,i-1)
                                ENDIF
                             ENDIF
@@ -1529 +1422 @@
                       ENDIF
 !
-!--                   If filled grid point is already classified as building
-!--                   everything is fine, else classify this grid point as
-!--                   natural type grid point. This case, values for the 
-!--                   surface type are already set.
+!--                   If filled grid point is already classified as building everything is fine,
+!--                   else classify this grid point as natural type grid point. This case, values
+!--                   for the surface type are already set.
                       IF ( .NOT. BTEST( topo_3d(k,j,i), 2 ) )  THEN
                          topo_3d(k,j,i) = IBSET( topo_3d(k,j,i), 1 )
@@ -1544 +1436 @@
 !--    Count the total number of holes, required for informative message.
 #if defined( __parallel )
-       CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM,      &
-                           comm2d, ierr )
+       CALL MPI_ALLREDUCE( num_hole_l, num_hole, 1, MPI_INTEGER, MPI_SUM, comm2d, ierr )
 #else
        num_hole = num_hole_l
-#endif    
+#endif
        IF ( num_hole > 0  .AND.  .NOT. filled )  filled = .TRUE.
 
@@ -1555 +1446 @@
 !-- Create an informative message if any holes were filled.
     IF ( filled )  THEN
-       WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' //    &
-                                  'resolved by only one grid point '     //    &
+       WRITE( message_string, * ) 'Topography was filtered, i.e. holes ' //                        &
+                                  'resolved by only one grid point '     //                        &
                                   'were filled during initialization.'
        CALL message( 'init_grid', 'PA0430', 0, 0, 0, 6, 0 )
@@ -1563 +1454 @@
     DEALLOCATE( topo_tmp )
 !
-!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary
-!-- condition in case of non-cyclic lateral boundaries. 
+!-- Finally, exchange topo_3d array again and if necessary set Neumann boundary condition in case of
+!-- non-cyclic lateral boundaries.
     CALL exchange_horiz_int( topo_3d, nys, nyn, nxl, nxr, nzt, nbgp )
 
@@ -1574 +1465 @@
     IF ( .NOT. bc_lr_cyc )  THEN
        IF ( nxl == 0  )  topo_3d(:,:,-1)   = topo_3d(:,:,0)
-       IF ( nxr == nx )  topo_3d(:,:,nx+1) = topo_3d(:,:,nx)          
+       IF ( nxr == nx )  topo_3d(:,:,nx+1) = topo_3d(:,:,nx)
     ENDIF
 !
 !-- Exchange building ID and type. Note, building_type is an one-byte variable.
-    IF ( building_id_f%from_file )                                             &
+    IF ( building_id_f%from_file )                                                                 &
        CALL exchange_horiz_2d_int( building_id_f%var, nys, nyn, nxl, nxr, nbgp )
-    IF ( building_type_f%from_file )                                           &
+    IF ( building_type_f%from_file )                                                               &
        CALL exchange_horiz_2d_byte( building_type_f%var, nys, nyn, nxl, nxr, nbgp )
 
@@ -1587 +1478 @@
 
 ! Description:
-! -----------------------------------------------------------------------------!
-!> Reads topography information from file or sets generic topography. Moreover, 
-!> all topography-relevant topography arrays are initialized, and grid flags
-!> are set.  
-!------------------------------------------------------------------------------!
+! -------------------------------------------------------------------------------------------------!
+!> Reads topography information from file or sets generic topography. Moreover, all
+!> topography-relevant topography arrays are initialized, and grid flags are set.
+!--------------------------------------------------------------------------------------------------!
  SUBROUTINE init_topo( topo )
 
-    USE arrays_3d,                                                             &
+    USE arrays_3d,                                                                                 &
         ONLY:  zw
-        
-    USE control_parameters,                                                    &
-        ONLY:  bc_lr_cyc, bc_ns_cyc, building_height, building_length_x,       &
-               building_length_y, building_wall_left, building_wall_south,     &
-               canyon_height, canyon_wall_left, canyon_wall_south,             &
-               canyon_width_x, canyon_width_y, dp_level_ind_b, dz,             &
-               message_string, topography, topography_grid_convention,         &
-               tunnel_height, tunnel_length, tunnel_width_x, tunnel_width_y,   &
-               tunnel_wall_depth
-         
-    USE exchange_horiz_mod,                                                    &
+
+    USE control_parameters,                                                                        &
+        ONLY:  bc_lr_cyc, bc_ns_cyc, building_height, building_length_x, building_length_y,        &
+               building_wall_left, building_wall_south, canyon_height, canyon_wall_left,           &
+               canyon_wall_south, canyon_width_x, canyon_width_y, dp_level_ind_b, dz,              &
+               message_string, topography, topography_grid_convention, tunnel_height,              &
+               tunnel_length, tunnel_width_x, tunnel_width_y, tunnel_wall_depth
+
+    USE exchange_horiz_mod,                                                                        &
         ONLY:  exchange_horiz_int
 
-    USE grid_variables,                                                        &
+    USE grid_variables,                                                                            &
         ONLY:  dx, dy
-        
-    USE indices,                                                               &
-        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz,   &
-               nzb, nzt
-    
+
+    USE indices,                                                                                   &
+        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nz, nzb, nzt
+
     USE kinds
-    
-    USE netcdf_data_input_mod,                                                 &
-        ONLY:  buildings_f, terrain_height_f 
+
+    USE netcdf_data_input_mod,                                                                     &
+        ONLY:  buildings_f, terrain_height_f
 
     USE pegrid
@@ -1626 +1513 @@
 
     INTEGER(iwp) ::  bh                !< temporary vertical index of building height
+    INTEGER(iwp) ::  ch                !< temporary vertical index for canyon height
+    INTEGER(iwp) ::  hv_in             !< heavyside function to model inner tunnel surface
+    INTEGER(iwp) ::  i                 !< index variable along x
+    INTEGER(iwp) ::  index_left_bwall  !< index for left building wall
+    INTEGER(iwp) ::  index_north_bwall !< index for north building wall
+    INTEGER(iwp) ::  index_right_bwall !< index for right building wall
+    INTEGER(iwp) ::  index_south_bwall !< index for south building wall
+    INTEGER(iwp) ::  index_left_cwall  !< index for left canyon wall
+    INTEGER(iwp) ::  index_north_cwall !< index for north canyon wall
+    INTEGER(iwp) ::  index_right_cwall !< index for right canyon wall
+    INTEGER(iwp) ::  index_south_cwall !< index for south canyon wall
+    INTEGER(iwp) ::  j                 !< index variable along y
+    INTEGER(iwp) ::  k                 !< index variable along z
     INTEGER(iwp) ::  ngp_bx            !< grid point number of building size along x
     INTEGER(iwp) ::  ngp_by            !< grid point number of building size along y
-    INTEGER(iwp) ::  index_left_bwall  !< index for left building wall
-    INTEGER(iwp) ::  index_right_bwall !< index for right building wall
-    INTEGER(iwp) ::  index_north_bwall !< index for north building wall
-    INTEGER(iwp) ::  index_south_bwall !< index for south building wall
-    INTEGER(iwp) ::  ch                !< temporary vertical index for canyon height
     INTEGER(iwp) ::  ngp_cx            !< grid point number of canyon size along x
     INTEGER(iwp) ::  ngp_cy            !< grid point number of canyon size along y
-    INTEGER(iwp) ::  index_left_cwall  !< index for left canyon wall
-    INTEGER(iwp) ::  index_right_cwall !< index for right canyon wall
-    INTEGER(iwp) ::  index_north_cwall !< index for north canyon wall
-    INTEGER(iwp) ::  index_south_cwall !< index for south canyon wall
-    INTEGER(iwp) ::  i                 !< index variable along x
-    INTEGER(iwp) ::  j                 !< index variable along y
-    INTEGER(iwp) ::  k                 !< index variable along z
-    INTEGER(iwp) ::  hv_in             !< heavyside function to model inner tunnel surface 
-    INTEGER(iwp) ::  hv_out            !< heavyside function to model outer tunnel surface 
-    INTEGER(iwp) ::  txe_out           !< end position of outer tunnel wall in x
-    INTEGER(iwp) ::  txs_out           !< start position of outer tunnel wall in x
-    INTEGER(iwp) ::  tye_out           !< end position of outer tunnel wall in y
-    INTEGER(iwp) ::  tys_out           !< start position of outer tunnel wall in y
-    INTEGER(iwp) ::  txe_in            !< end position of inner tunnel wall in x
-    INTEGER(iwp) ::  txs_in            !< start position of inner tunnel wall in x
-    INTEGER(iwp) ::  tye_in            !< end position of inner tunnel wall in y
-    INTEGER(iwp) ::  tys_in            !< start position of inner tunnel wall in y
+    INTEGER(iwp) ::  hv_out            !< heavyside function to model outer tunnel surface
     INTEGER(iwp) ::  td                !< tunnel wall depth
     INTEGER(iwp) ::  th                !< height of outer tunnel wall
+    INTEGER(iwp) ::  txe_in            !< end position of inner tunnel wall in x
+    INTEGER(iwp) ::  txe_out           !< end position of outer tunnel wall in x
+    INTEGER(iwp) ::  txs_in            !< start position of inner tunnel wall in x
+    INTEGER(iwp) ::  txs_out           !< start position of outer tunnel wall in x
+    INTEGER(iwp) ::  tye_in            !< end position of inner tunnel wall in y
+    INTEGER(iwp) ::  tye_out           !< end position of outer tunnel wall in y
+    INTEGER(iwp) ::  tys_in            !< start position of inner tunnel wall in y
+    INTEGER(iwp) ::  tys_out           !< start position of outer tunnel wall in y
 
     INTEGER(iwp), DIMENSION(:,:), ALLOCATABLE ::  nzb_local         !< index for topography top at cell-center
-    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo !< input array for 3D topography and dummy array for setting "outer"-flags
-!
-!-- Check for correct setting of the namelist parameter topography. If 
-!-- topography information is read from file but topography = 'flat', 
-!-- initialization does not work properly.
-    IF ( ( buildings_f%from_file  .OR.  terrain_height_f%from_file )  .AND.    &
+    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo !< input array for 3D topography and dummy array for setting
+                                                                    !< "outer"-flags
+!
+!-- Check for correct setting of the namelist parameter topography. If topography information is
+!-- read from file but topography = 'flat', initialization does not work properly.
+    IF ( ( buildings_f%from_file  .OR.  terrain_height_f%from_file )  .AND.                        &
            TRIM( topography ) /= 'read_from_file' )  THEN
-       message_string =  'If topography information is provided (via ' //      &
-                         'Netcdf or ASCII input) topography = '        //      &
+       message_string =  'If topography information is provided (via ' //                          &
+                         'Netcdf or ASCII input) topography = '        //                          &
                          '"read_from_file" is required.'
-       CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )      
+       CALL message( 'init_grid', 'PA0437', 1, 2, 0, 6, 0 )
     ENDIF
 !
 !-- Set outer and inner index arrays for non-flat topography.
-!-- Here consistency checks concerning domain size and periodicity are
-!-- necessary.
-!-- Within this SELECT CASE structure only nzb_local is initialized
-!-- individually depending on the chosen topography type, all other index 
-!-- arrays are initialized further below.
+!-- Here consistency checks concerning domain size and periodicity are necessary.
+!-- Within this SELECT CASE structure only nzb_local is initialized individually depending on the
+!-- chosen topography type, all other index arrays are initialized further below.
     SELECT CASE ( TRIM( topography ) )
 
        CASE ( 'flat' )
-!   
+!
 !--       Initialilize 3D topography array, used later for initializing flags
           topo(nzb+1:nzt+1,:,:) = IBSET( topo(nzb+1:nzt+1,:,:), 0 )
-          
+
        CASE ( 'closed_channel' )
-!   
+!
 !--       Initialilize 3D topography array, used later for initializing flags
-          topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 ) 
+          topo(nzb+1:nzt,:,:) = IBSET( topo(nzb+1:nzt,:,:), 0 )
 
        CASE ( 'single_building' )
@@ -1694 +1579 @@
           ngp_by = NINT( building_length_y / dy )
           bh  = MINLOC( ABS( zw - building_height ), 1 ) - 1
-          IF ( ABS( zw(bh)   - building_height ) == &
-               ABS( zw(bh+1) - building_height )    )  bh = bh + 1
+          IF ( ABS( zw(bh) - building_height ) ==  ABS( zw(bh+1) - building_height ) )  bh = bh + 1
           IF ( building_wall_left == 9999999.9_wp )  THEN
              building_wall_left = ( nx + 1 - ngp_bx ) / 2 * dx
@@ -1710 +1594 @@
 !
 !--       Building size has to meet some requirements
-          IF ( ( index_left_bwall < 1 ) .OR. ( index_right_bwall > nx-1 ) .OR. &
-               ( index_right_bwall < index_left_bwall+3 ) .OR.                 &
-               ( index_south_bwall < 1 ) .OR. ( index_north_bwall > ny-1 ) .OR.&
+          IF ( ( index_left_bwall  < 1 )  .OR.  ( index_right_bwall > nx-1 )  .OR.                 &
+               ( index_right_bwall < index_left_bwall+3 )  .OR.                                    &
+               ( index_south_bwall < 1 )  .OR.  ( index_north_bwall > ny-1 )  .OR.                 &
                ( index_north_bwall < index_south_bwall+3 ) )  THEN
-             WRITE( message_string, * ) 'inconsistent building parameters:',   &
-                                      '&index_left_bwall=', index_left_bwall,  &
-                                      'index_right_bwall=', index_right_bwall, &
-                                      'index_south_bwall=', index_south_bwall, &
-                                      'index_north_bwall=', index_north_bwall, &
+             WRITE( message_string, * ) 'inconsistent building parameters:',                       &
+                                      '&index_left_bwall=', index_left_bwall,                      &
+                                      'index_right_bwall=', index_right_bwall,                     &
+                                      'index_south_bwall=', index_south_bwall,                     &
+                                      'index_north_bwall=', index_north_bwall,                     &
                                       'nx=', nx, 'ny=', ny
              CALL message( 'init_grid', 'PA0203', 1, 2, 0, 6, 0 )
@@ -1726 +1610 @@
           nzb_local = 0
 !
-!--       Define the building. 
-          IF ( index_left_bwall <= nxr  .AND.  index_right_bwall >= nxl  .AND. &
-               index_south_bwall <= nyn  .AND.  index_north_bwall >= nys )     & 
-             nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall),  &
+!--       Define the building.
+          IF ( index_left_bwall <= nxr  .AND.  index_right_bwall >= nxl  .AND.                     &
+               index_south_bwall <= nyn  .AND.  index_north_bwall >= nys )                         &
+             nzb_local(MAX(nys,index_south_bwall):MIN(nyn,index_north_bwall),                      &
                        MAX(nxl,index_left_bwall):MIN(nxr,index_right_bwall)) = bh
 !
@@ -1735 +1619 @@
           DO  i = nxl, nxr
              DO  j = nys, nyn
-                topo(nzb_local(j,i)+1:nzt+1,j,i) =                             &
-                                 IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 ) 
+                topo(nzb_local(j,i)+1:nzt+1,j,i) = IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
              ENDDO
           ENDDO
-        
+
           DEALLOCATE( nzb_local )
 
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
 !
-!--       Set boundary conditions also for flags. Can be interpreted as Neumann
-!--       boundary conditions for topography. 
+!--       Set boundary conditions also for flags. Can be interpreted as Neumannb oundary conditions
+!--       for topography.
           IF ( .NOT. bc_ns_cyc )  THEN
              IF ( nys == 0  )  THEN
-                DO  i = 1, nbgp     
+                DO  i = 1, nbgp
                    topo(:,nys-i,:)   = topo(:,nys,:)
                 ENDDO
              ENDIF
              IF ( nyn == ny )  THEN
-                DO  i = 1, nbgp  
+                DO  i = 1, nbgp
                    topo(:,nyn+i,:) = topo(:,nyn,:)
                 ENDDO
@@ -1760 +1643 @@
           IF ( .NOT. bc_lr_cyc )  THEN
              IF ( nxl == 0  )  THEN
-                DO  i = 1, nbgp   
+                DO  i = 1, nbgp
                    topo(:,:,nxl-i)   = topo(:,:,nxl)
                 ENDDO
              ENDIF
-             IF ( nxr == nx )  THEN 
-                DO  i = 1, nbgp   
-                   topo(:,:,nxr+i) = topo(:,:,nxr)     
+             IF ( nxr == nx )  THEN
+                DO  i = 1, nbgp
+                   topo(:,:,nxr+i) = topo(:,:,nxr)
                 ENDDO
-             ENDIF      
+             ENDIF
           ENDIF
 
@@ -1793 +1676 @@
              index_south_cwall = NINT( canyon_wall_south / dy )
              index_north_cwall = index_south_cwall + ngp_cy
-      
+
           ELSE
-             
+
              message_string = 'no street canyon width given'
              CALL message( 'init_grid', 'PA0204', 1, 2, 0, 6, 0 )
-  
+
           ENDIF
 
           ch  = MINLOC( ABS( zw - canyon_height ), 1 ) - 1
-          IF ( ABS( zw(ch)   - canyon_height ) == &
-               ABS( zw(ch+1) - canyon_height )    )  ch = ch + 1
+          IF ( ABS( zw(ch) - canyon_height ) == ABS( zw(ch+1) - canyon_height ) )  ch = ch + 1
           dp_level_ind_b = ch
 !
 !--       Street canyon size has to meet some requirements
           IF ( canyon_width_x /= 9999999.9_wp )  THEN
-             IF ( ( index_left_cwall< 1 ) .OR. ( index_right_cwall> nx-1 ) .OR.&
+             IF ( ( index_left_cwall< 1 )  .OR.  ( index_right_cwall> nx-1 )  .OR.                 &
                   ( ngp_cx < 3 ) )  THEN
-                WRITE( message_string, * ) 'inconsistent canyon parameters:',  &
-                                           '&index_left_cwall=', index_left_cwall, &
-                                           ' index_right_cwall=', index_right_cwall, &
-                                           ' ngp_cx=', ngp_cx,                 &
-                                           ' ch=', ch, ' nx=', nx, ' ny=', ny
-                CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 ) 
+                WRITE( message_string, * ) 'inconsistent canyon parameters:',                      &
+                                           '&index_left_cwall=', index_left_cwall,                 &
+                                           ' index_right_cwall=', index_right_cwall,               &
+                                           ' ngp_cx=', ngp_cx, ' ch=', ch, ' nx=', nx, ' ny=', ny
+                CALL message( 'init_grid', 'PA0205', 1, 2, 0, 6, 0 )
              ENDIF
           ELSEIF ( canyon_width_y /= 9999999.9_wp )  THEN
-             IF ( ( index_south_cwall < 1 ) .OR.                               &
-                  ( index_north_cwall > ny-1 ) .OR. ( ngp_cy < 3 ) )  THEN
-                WRITE( message_string, * ) 'inconsistent canyon parameters:',  &
-                                           '&index_south_cwall=', index_south_cwall, & 
-                                           ' index_north_cwall=', index_north_cwall, &
-                                           ' ngp_cy=', ngp_cy,                 &
-                                           ' ch=', ch, ' nx=', nx, ' ny=', ny
-                CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 ) 
-             ENDIF
-          ENDIF
-          IF ( canyon_width_x /= 9999999.9_wp .AND.                            &                 
-               canyon_width_y /= 9999999.9_wp )  THEN
-             message_string = 'inconsistent canyon parameters:' //             &   
-                              '&street canyon can only be oriented' //         &
+             IF ( ( index_south_cwall < 1 )  .OR.                                                  &
+                  ( index_north_cwall > ny-1 )  .OR.  ( ngp_cy < 3 ) )  THEN
+                WRITE( message_string, * ) 'inconsistent canyon parameters:',                      &
+                                           '&index_south_cwall=', index_south_cwall,               &
+                                           ' index_north_cwall=', index_north_cwall,               &
+                                           ' ngp_cy=', ngp_cy, ' ch=', ch, ' nx=', nx, ' ny=', ny
+                CALL message( 'init_grid', 'PA0206', 1, 2, 0, 6, 0 )
+             ENDIF
+          ENDIF
+          IF ( canyon_width_x /= 9999999.9_wp  .AND.  canyon_width_y /= 9999999.9_wp )  THEN
+             message_string = 'inconsistent canyon parameters:' //                                 &
+                              '&street canyon can only be oriented' //                             &
                               ' either in x- or in y-direction'
              CALL message( 'init_grid', 'PA0207', 1, 2, 0, 6, 0 )
@@ -1839 +1718 @@
           nzb_local = ch
           IF ( canyon_width_x /= 9999999.9_wp )  THEN
-             IF ( index_left_cwall<= nxr  .AND.  index_right_cwall>= nxl )     &
+             IF ( index_left_cwall<= nxr  .AND.  index_right_cwall>= nxl )                         &
                 nzb_local(:,MAX(nxl,index_left_cwall+1):MIN(nxr,index_right_cwall-1)) = 0
           ELSEIF ( canyon_width_y /= 9999999.9_wp )  THEN
-             IF ( index_south_cwall <= nyn  .AND.  index_north_cwall >= nys )  &          
+             IF ( index_south_cwall <= nyn  .AND.  index_north_cwall >= nys )                      &
                 nzb_local(MAX(nys,index_south_cwall+1):MIN(nyn,index_north_cwall-1),:) = 0
           ENDIF
@@ -1849 +1728 @@
           DO  i = nxl, nxr
              DO  j = nys, nyn
-                topo(nzb_local(j,i)+1:nzt+1,j,i) =                             &
-                                 IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 ) 
+                topo(nzb_local(j,i)+1:nzt+1,j,i) = IBSET( topo(nzb_local(j,i)+1:nzt+1,j,i), 0 )
              ENDDO
           ENDDO
@@ -1857 +1735 @@
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
 !
-!--       Set boundary conditions also for flags. Can be interpreted as Neumann
-!--       boundary conditions for topography. 
+!--       Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions
+!--       for topography.
           IF ( .NOT. bc_ns_cyc )  THEN
              IF ( nys == 0  )  THEN
-                DO  i = 1, nbgp     
-                   topo(:,nys-i,:)   = topo(:,nys,:)
+                DO  i = 1, nbgp
+                   topo(:,nys-i,:) = topo(:,nys,:)
                 ENDDO
              ENDIF
              IF ( nyn == ny )  THEN
-                DO  i = 1, nbgp  
+                DO  i = 1, nbgp
                    topo(:,nyn+i,:) = topo(:,nyn,:)
                 ENDDO
@@ -1873 +1751 @@
           IF ( .NOT. bc_lr_cyc )  THEN
              IF ( nxl == 0  )  THEN
-                DO  i = 1, nbgp   
-                   topo(:,:,nxl-i)   = topo(:,:,nxl)
+                DO  i = 1, nbgp
+                   topo(:,:,nxl-i) = topo(:,:,nxl)
                 ENDDO
              ENDIF
-             IF ( nxr == nx )  THEN 
-                DO  i = 1, nbgp   
-                   topo(:,:,nxr+i) = topo(:,:,nxr)     
+             IF ( nxr == nx )  THEN
+                DO  i = 1, nbgp
+                   topo(:,:,nxr+i) = topo(:,:,nxr)
                 ENDDO
-             ENDIF      
+             ENDIF
           ENDIF
 
@@ -1895 +1773 @@
 !
 !--       Tunnel-wall depth
-          IF ( tunnel_wall_depth == 9999999.9_wp )  THEN  
+          IF ( tunnel_wall_depth == 9999999.9_wp )  THEN
              td = MAX ( dx, dy, dz(1) )
           ELSE
@@ -1902 +1780 @@
 !
 !--       Check for tunnel width
-          IF ( tunnel_width_x == 9999999.9_wp  .AND.                           &
-               tunnel_width_y == 9999999.9_wp  )  THEN
+          IF ( tunnel_width_x == 9999999.9_wp  .AND.  tunnel_width_y == 9999999.9_wp  )  THEN
              message_string = 'No tunnel width is given. '
              CALL message( 'init_grid', 'PA0280', 1, 2, 0, 6, 0 )
           ENDIF
-          IF ( tunnel_width_x /= 9999999.9_wp  .AND.                           &
-               tunnel_width_y /= 9999999.9_wp  )  THEN
-             message_string = 'Inconsistent tunnel parameters:' //             &   
-                              'tunnel can only be oriented' //                 &
+          IF ( tunnel_width_x /= 9999999.9_wp  .AND.  tunnel_width_y /= 9999999.9_wp  )  THEN
+             message_string = 'Inconsistent tunnel parameters:' //                                 &
+                              'tunnel can only be oriented' //                                     &
                               'either in x- or in y-direction.'
              CALL message( 'init_grid', 'PA0281', 1, 2, 0, 6, 0 )
@@ -1916 +1792 @@
 !
 !--       Check for too small tunnel width in x- and y-direction
-          IF ( tunnel_width_x /= 9999999.9_wp  .AND.                           &   
+          IF ( tunnel_width_x /= 9999999.9_wp  .AND.                                               &
                tunnel_width_x - 2.0_wp * td <= 2.0_wp * dx )  THEN
              message_string = 'tunnel_width_x too small'
              CALL message( 'init_grid', 'PA0175', 1, 2, 0, 6, 0 )
           ENDIF
-          IF ( tunnel_width_y /= 9999999.9_wp  .AND.                           &
+          IF ( tunnel_width_y /= 9999999.9_wp  .AND.                                               &
                tunnel_width_y - 2.0_wp * td <= 2.0_wp * dy )  THEN
              message_string = 'tunnel_width_y too small'
@@ -1927 +1803 @@
           ENDIF
 !
-!--       Check for too large tunnel width. 
+!--       Check for too large tunnel width.
 !--       Tunnel axis along y.
           IF ( tunnel_width_x /= 9999999.9_wp )  THEN
@@ -1937 +1813 @@
              txs_out = INT( ( nx + 1 ) * 0.5_wp * dx - tunnel_width_x * 0.5_wp )
              txe_out = INT( ( nx + 1 ) * 0.5_wp * dx + tunnel_width_x * 0.5_wp )
-             txs_in  = INT( ( nx + 1 ) * 0.5_wp * dx -                         &
-                                      ( tunnel_width_x * 0.5_wp - td ) )
-             txe_in  = INT( ( nx + 1 ) * 0.5_wp * dx +                         &
-                                   ( tunnel_width_x * 0.5_wp - td ) )
+             txs_in  = INT( ( nx + 1 ) * 0.5_wp * dx - ( tunnel_width_x * 0.5_wp - td ) )
+             txe_in  = INT( ( nx + 1 ) * 0.5_wp * dx + ( tunnel_width_x * 0.5_wp - td ) )
 
              tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_length * 0.5_wp )
@@ -1962 +1836 @@
              tys_out = INT( ( ny + 1 ) * 0.5_wp * dy - tunnel_width_y * 0.5_wp )
              tye_out = INT( ( ny + 1 ) * 0.5_wp * dy + tunnel_width_y * 0.5_wp )
-             tys_in  = INT( ( ny + 1 ) * 0.5_wp * dy -                         &
-                                        ( tunnel_width_y * 0.5_wp - td ) )
-             tye_in  = INT( ( ny + 1 ) * 0.5_wp * dy +                         &
-                                     ( tunnel_width_y * 0.5_wp - td ) )
+             tys_in  = INT( ( ny + 1 ) * 0.5_wp * dy - ( tunnel_width_y * 0.5_wp - td ) )
+             tye_in  = INT( ( ny + 1 ) * 0.5_wp * dy + ( tunnel_width_y * 0.5_wp - td ) )
           ENDIF
 
@@ -1973 +1845 @@
 !
 !--             Use heaviside function to model outer tunnel surface
-                hv_out = th * 0.5_wp *                                         &
-                              ( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp )  &
-                              - ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
-
-                hv_out = hv_out * 0.5_wp *                                     &
-                            ( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp )    &
-                            - ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
-!    
+                hv_out = th * 0.5_wp * ( ( SIGN( 1.0_wp, i * dx - txs_out ) + 1.0_wp )             &
+                                       - ( SIGN( 1.0_wp, i * dx - txe_out ) + 1.0_wp ) )
+
+                hv_out = hv_out * 0.5_wp * ( ( SIGN( 1.0_wp, j * dy - tys_out ) + 1.0_wp )         &
+                                           - ( SIGN( 1.0_wp, j * dy - tye_out ) + 1.0_wp ) )
+!
 !--             Use heaviside function to model inner tunnel surface
-                hv_in  = ( th - td ) * 0.5_wp *                                &
-                                ( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp ) &
-                                - ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
-
-                hv_in = hv_in * 0.5_wp *                                       &
-                                ( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp ) &
-                                - ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
+                hv_in  = ( th - td ) * 0.5_wp * ( ( SIGN( 1.0_wp, i * dx - txs_in ) + 1.0_wp )     &
+                                                - ( SIGN( 1.0_wp, i * dx - txe_in ) + 1.0_wp ) )
+
+                hv_in = hv_in * 0.5_wp * ( ( SIGN( 1.0_wp, j * dy - tys_in ) + 1.0_wp )            &
+                                         - ( SIGN( 1.0_wp, j * dy - tye_in ) + 1.0_wp ) )
 !
 !--             Set flags at x-y-positions without any tunnel surface
@@ -2009 +1877 @@
 !--                   Lateral tunnel walls
                       IF ( hv_out - hv_in == td )  THEN
-                         IF ( zw(k) <= hv_in )  THEN 
+                         IF ( zw(k) <= hv_in )  THEN
                             topo(k,j,i) = IBSET( topo(k,j,i), 0 )
-                         ELSEIF ( zw(k) > hv_in  .AND.  zw(k) <= hv_out )  THEN 
+                         ELSEIF ( zw(k) > hv_in  .AND.  zw(k) <= hv_out )  THEN
                             topo(k,j,i) = IBCLR( topo(k,j,i), 0 )
-                         ELSEIF ( zw(k) > hv_out )  THEN 
+                         ELSEIF ( zw(k) > hv_out )  THEN
                             topo(k,j,i) = IBSET( topo(k,j,i), 0 )
                          ENDIF
@@ -2024 +1892 @@
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
 !
-!--       Set boundary conditions also for flags. Can be interpreted as Neumann
-!--       boundary conditions for topography. 
+!--       Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions
+!--       for topography.
           IF ( .NOT. bc_ns_cyc )  THEN
              IF ( nys == 0  )  THEN
-                DO  i = 1, nbgp     
-                   topo(:,nys-i,:)   = topo(:,nys,:)
+                DO  i = 1, nbgp
+                   topo(:,nys-i,:) = topo(:,nys,:)
                 ENDDO
              ENDIF
              IF ( nyn == ny )  THEN
-                DO  i = 1, nbgp  
+                DO  i = 1, nbgp
                    topo(:,nyn+i,:) = topo(:,nyn,:)
                 ENDDO
@@ -2040 +1908 @@
           IF ( .NOT. bc_lr_cyc )  THEN
              IF ( nxl == 0  )  THEN
-                DO  i = 1, nbgp   
-                   topo(:,:,nxl-i)   = topo(:,:,nxl)
+                DO  i = 1, nbgp
+                   topo(:,:,nxl-i) = topo(:,:,nxl)
                 ENDDO
              ENDIF
-             IF ( nxr == nx )  THEN 
-                DO  i = 1, nbgp   
-                   topo(:,:,nxr+i) = topo(:,:,nxr)     
+             IF ( nxr == nx )  THEN
+                DO  i = 1, nbgp
+                   topo(:,:,nxr+i) = topo(:,:,nxr)
                 ENDDO
-             ENDIF      
+             ENDIF
           ENDIF
 
        CASE ( 'read_from_file' )
 !
-!--       Note, topography information have been already read.  
-!--       If required, further process topography, i.e. reference buildings on
-!--       top of orography and set temporary 3D topography array, which is 
-!--       used later to set grid flags. Calling of this rouinte is also 
-!--       required in case of ASCII input, even though no distinction between 
-!--       terrain- and building height is made in this case.  
+!--       Note, topography information have been already read.
+!--       If required, further process topography, i.e. reference buildings on top of orography and
+!--       set temporary 3D topography array, which is used later to set grid flags. Calling of this
+!--       rouinte is also required in case of ASCII input, even though no distinction between
+!--       terrain- and building height is made in this case.
           CALL process_topography( topo )
 !
@@ -2064 +1931 @@
           CALL filter_topography( topo )
 !
-!--       Exchange ghost-points, as well as add cyclic or Neumann boundary 
-!--       conditions.
+!--       Exchange ghost-points, as well as add cyclic or Neumann boundary conditions.
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
 !
@@ -2071 +1937 @@
           IF ( .NOT. bc_ns_cyc )  THEN
              IF ( nys == 0  )  THEN
-                DO  i = 1, nbgp         
+                DO  i = 1, nbgp
                    topo(:,nys-i,:) = topo(:,nys,:)
                 ENDDO
              ENDIF
              IF ( nyn == ny )  THEN
-                DO  i = 1, nbgp         
+                DO  i = 1, nbgp
                    topo(:,nyn+i,:) = topo(:,nyn,:)
                 ENDDO
@@ -2084 +1950 @@
           IF ( .NOT. bc_lr_cyc )  THEN
              IF ( nxl == 0  )  THEN
-                DO  i = 1, nbgp 
+                DO  i = 1, nbgp
                    topo(:,:,nxl-i) = topo(:,:,nxl)
                 ENDDO
              ENDIF
              IF ( nxr == nx )  THEN
-                DO  i = 1, nbgp 
+                DO  i = 1, nbgp
                    topo(:,:,nxr+i) = topo(:,:,nxr)
                 ENDDO
@@ -2097 +1963 @@
 
        CASE DEFAULT
-!   
-!--       The DEFAULT case is reached either if the parameter topography
-!--       contains a wrong character string or if the user has defined a special
-!--       case in the user interface. There, the subroutine user_init_grid 
-!--       checks which of these two conditions applies.
+!
+!--       The DEFAULT case is reached either if the parameter topography contains a wrong character
+!--       string or if the user has defined a special case in the user interface. There, the
+!--       subroutine user_init_grid checks which of these two conditions applies.
           CALL user_init_grid( topo )
           CALL filter_topography( topo )
@@ -2107 +1972 @@
     END SELECT
 !
-!-- Consistency checks and index array initialization are only required for
-!-- non-flat topography.
+!-- Consistency checks and index array initialization are only required for non-flat topography.
     IF ( TRIM( topography ) /= 'flat' )  THEN
 !
-!--    In case of non-flat topography, check whether the convention how to 
-!--    define the topography grid has been set correctly, or whether the default
-!--    is applicable. If this is not possible, abort.
+!--    In case of non-flat topography, check whether the convention how to define the topography
+!--    grid has been set correctly, or whether the default is applicable. If this is not possible,
+!--    abort.
        IF ( TRIM( topography_grid_convention ) == ' ' )  THEN
-          IF ( TRIM( topography ) /= 'closed_channel' .AND.                    &
-               TRIM( topography ) /= 'single_building' .AND.                   &
-               TRIM( topography ) /= 'single_street_canyon' .AND.              &
-               TRIM( topography ) /= 'tunnel'  .AND.                           &
+          IF ( TRIM( topography ) /= 'closed_channel'        .AND.                                 &
+               TRIM( topography ) /= 'single_building'       .AND.                                 &
+               TRIM( topography ) /= 'single_street_canyon'  .AND.                                 &
+               TRIM( topography ) /= 'tunnel'                .AND.                                 &
                TRIM( topography ) /= 'read_from_file')  THEN
-!--          The default value is not applicable here, because it is only valid
-!--          for the four standard cases 'single_building', 
-!--          'single_street_canyon', 'tunnel' and 'read_from_file'
+!--          The default value is not applicable here, because it is only valid for the four
+!--          standard cases 'single_building', 'single_street_canyon', 'tunnel' and 'read_from_file'
 !--          defined in init_grid.
-             WRITE( message_string, * )                                        &
-               'The value for "topography_grid_convention" ',                  &
-               'is not set. Its default value is & only valid for ',           &
-               '"topography" = ''single_building'', ''tunnel'' ',              &
-               '''single_street_canyon'', ''closed_channel'' & or ',           &
-               '''read_from_file''.',                                          &
-               '& Choose ''cell_edge'' or ''cell_center''.'
+             WRITE( message_string, * ) 'The value for "topography_grid_convention" ',             &
+                                        'is not set. Its default value is & only valid for ',      &
+                                        '"topography" = ''single_building'', ''tunnel'' ',         &
+                                        '''single_street_canyon'', ''closed_channel'' & or ',      &
+                                        '''read_from_file''.',                                     &
+                                        '& Choose ''cell_edge'' or ''cell_center''.'
              CALL message( 'init_grid', 'PA0239', 1, 2, 0, 6, 0 )
           ELSE
 !--          The default value is applicable here.
 !--          Set convention according to topography.
-             IF ( TRIM( topography ) == 'single_building' .OR.                 &
+             IF ( TRIM( topography ) == 'single_building'  .OR.                                    &
                   TRIM( topography ) == 'single_street_canyon' )  THEN
                 topography_grid_convention = 'cell_edge'
-             ELSEIF ( TRIM( topography ) == 'read_from_file'  .OR.             &
+             ELSEIF ( TRIM( topography ) == 'read_from_file'  .OR.                                 &
                       TRIM( topography ) == 'tunnel')  THEN
                 topography_grid_convention = 'cell_center'
              ENDIF
           ENDIF
-       ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge' .AND.        &
+       ELSEIF ( TRIM( topography_grid_convention ) /= 'cell_edge'  .AND.                           &
                 TRIM( topography_grid_convention ) /= 'cell_center' )  THEN
-          WRITE( message_string, * )                                           &
-            'The value for "topography_grid_convention" is ',                  &
-            'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
+          WRITE( message_string, * )  'The value for "topography_grid_convention" is ',            &
+                                      'not recognized.& Choose ''cell_edge'' or ''cell_center''.'
           CALL message( 'init_grid', 'PA0240', 1, 2, 0, 6, 0 )
        ENDIF
@@ -2153 +2014 @@
 
        IF ( topography_grid_convention == 'cell_edge' )  THEN
-! 
-!--       The array nzb_local as defined using the 'cell_edge' convention 
-!--       describes the actual total size of topography which is defined at the 
-!--       cell edges where u=0 on the topography walls in x-direction and v=0 
+!
+!--       The array nzb_local as defined using the 'cell_edge' convention
+!--       describes the actual total size of topography which is defined at the
+!--       cell edges where u=0 on the topography walls in x-direction and v=0
 !--       on the topography walls in y-direction. However, PALM uses individual
 !--       arrays nzb_u|v|w|s_inner|outer that are based on nzb_s_inner.
-!--       Therefore, the extent of topography in nzb_local is now reduced by 
-!--       1dx at the E topography walls and by 1dy at the N topography walls 
-!--       to form the basis for nzb_s_inner. 
+!--       Therefore, the extent of topography in nzb_local is now reduced by
+!--       1dx at the E topography walls and by 1dy at the N topography walls
+!--       to form the basis for nzb_s_inner.
 !--       Note, the reverse memory access (i-j instead of j-i) is absolutely
 !--       required at this point.
@@ -2167 +2028 @@
              DO  i = nxl-1, nxr
                 DO  k = nzb, nzt+1
-                   IF ( BTEST( topo(k,j,i), 0 )  .OR.                          &
-                        BTEST( topo(k,j,i+1), 0 ) )                            &
+                   IF ( BTEST( topo(k,j,i), 0 )  .OR.  BTEST( topo(k,j,i+1), 0 ) )                 &
                        topo(k,j,i) = IBSET( topo(k,j,i), 0 )
                 ENDDO
              ENDDO
-          ENDDO      
+          ENDDO
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
 
@@ -2178 +2038 @@
              DO  j = nys-1, nyn
                 DO  k = nzb, nzt+1
-                   IF ( BTEST( topo(k,j,i), 0 )  .OR.                          &
-                        BTEST( topo(k,j+1,i), 0 ) )                            &
+                   IF ( BTEST( topo(k,j,i), 0 )  .OR.  BTEST( topo(k,j+1,i), 0 ) )                 &
                       topo(k,j,i) = IBSET( topo(k,j,i), 0 )
                 ENDDO
              ENDDO
-          ENDDO  
+          ENDDO
           CALL exchange_horiz_int( topo, nys, nyn, nxl, nxr, nzt, nbgp )
-   
+
        ENDIF
     ENDIF
@@ -2194 +2053 @@
  SUBROUTINE set_topo_flags(topo)
 
-    USE control_parameters,                                                    &
-        ONLY:  bc_lr_cyc, bc_ns_cyc, constant_flux_layer,                      &
-               scalar_advec, topography, use_surface_fluxes, use_top_fluxes
-
-    USE exchange_horiz_mod,                                                    &
+    USE control_parameters,                                                                        &
+        ONLY:  bc_lr_cyc, bc_ns_cyc, constant_flux_layer, scalar_advec, topography,                &
+               use_surface_fluxes, use_top_fluxes
+
+    USE exchange_horiz_mod,                                                                        &
         ONLY:  exchange_horiz_int
 
-    USE indices,                                                               &
-        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb,  &
-               nzt, topo_top_ind, wall_flags_static_0, wall_flags_total_0
+    USE indices,                                                                                   &
+        ONLY:  nbgp, nx, nxl, nxlg, nxr, nxrg, ny, nyn, nyng, nys, nysg, nzb, nzt, topo_top_ind,   &
+               wall_flags_static_0, wall_flags_total_0
 
     USE kinds
@@ -2214 +2073 @@
     INTEGER(iwp) ::  k             !< index variable along z
 
-    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo !< input array for 3D topography and dummy array for setting "outer"-flags
+    INTEGER(iwp), DIMENSION(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ::  topo !< input array for 3D topography and dummy array for setting
+                                                                    !< "outer"-flags
 
     ALLOCATE( wall_flags_static_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
@@ -2220 +2080 @@
 !
 !-- Set-up topography flags. First, set flags only for s, u, v and w-grid.
-!-- Further special flags will be set in following loops. 
+!-- Further special flags will be set in following loops.
     DO  i = nxl, nxr
        DO  j = nys, nyn
@@ -2226 +2086 @@
 !
 !--          scalar grid
-             IF ( BTEST( topo(k,j,i), 0 ) )                                    &
+             IF ( BTEST( topo(k,j,i), 0 ) )                                                        &
                 wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 0 )
 !
 !--          u grid
-             IF ( BTEST( topo(k,j,i),   0 )  .AND.                             &
-                  BTEST( topo(k,j,i-1), 0 ) )                                  &
+             IF ( BTEST( topo(k,j,i), 0 )  .AND.  BTEST( topo(k,j,i-1), 0 ) )                      &
                 wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 1 )
 !
 !--          v grid
-             IF ( BTEST( topo(k,j,i),   0 )  .AND.                             &
-                  BTEST( topo(k,j-1,i), 0 ) )                                  &
+             IF ( BTEST( topo(k,j,i), 0 )  .AND.  BTEST( topo(k,j-1,i), 0 ) )                      &
                  wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 2 )
 
@@ -2244 +2102 @@
 !
 !--          w grid
-             IF ( BTEST( topo(k,j,i),   0 )  .AND.                             &
-                  BTEST( topo(k+1,j,i), 0 ) )                                  &
+             IF ( BTEST( topo(k,j,i), 0 )  .AND.  BTEST( topo(k+1,j,i), 0 ) )                      &
                 wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 3 )
           ENDDO
-          
-          IF ( topography /= 'closed_channel' ) THEN
+
+          IF ( topography /= 'closed_channel' )  THEN
              wall_flags_static_0(nzt+1,j,i) = IBSET( wall_flags_static_0(nzt+1,j,i), 3 )
           ENDIF
@@ -2259 +2116 @@
 
 !
-!-- Set outer array for scalars to mask near-surface grid points. Note, on 
-!-- basis of flag 24 futher flags will be derived which are used to control
-!-- production of subgrid TKE production near walls. 
-    
+!-- Set outer array for scalars to mask near-surface grid points. Note, on basis of flag 24 futher
+!-- flags will be derived which are used to control production of subgrid TKE production near walls.
+
     ALLOCATE( wall_flags_total_0(nzb:nzt+1,nysg:nyng,nxlg:nxrg) )
     wall_flags_total_0 = 0
-                                    
+
     DO i = nxl, nxr
        DO j = nys, nyn
@@ -2273 +2129 @@
        ENDDO
     ENDDO
-    
+
     CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
-    
+
     DO i = nxl, nxr
        DO j = nys, nyn
           DO k = nzb, nzt+1
-             IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 )    .AND.                   &
-                  BTEST( wall_flags_total_0(k,j+1,i), 0 )    .AND.                   &
-                  BTEST( wall_flags_total_0(k,j,i-1), 0 )    .AND.                   &
-                  BTEST( wall_flags_total_0(k,j,i+1), 0 )    .AND.                   &
-                  BTEST( wall_flags_total_0(k,j-1,i-1), 0 )  .AND.                   &
-                  BTEST( wall_flags_total_0(k,j+1,i-1), 0 )  .AND.                   &
-                  BTEST( wall_flags_total_0(k,j-1,i+1), 0 )  .AND.                   &
-                  BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) )                        &
+             IF ( BTEST( wall_flags_total_0(k,j-1,i), 0 )    .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j+1,i), 0 )    .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j,i-1), 0 )    .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j,i+1), 0 )    .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j-1,i-1), 0 )  .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j+1,i-1), 0 )  .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j-1,i+1), 0 )  .AND.                                 &
+                  BTEST( wall_flags_total_0(k,j+1,i+1), 0 ) )                                      &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 24 )
           ENDDO
@@ -2298 +2154 @@
 !
 !--          scalar grid, former nzb_diff_s_inner.
-!--          Note, use this flag also to mask topography in diffusion_u and 
-!--          diffusion_v along the vertical direction. In case of 
-!--          use_surface_fluxes, fluxes are calculated via MOST, else, simple
-!--          gradient approach is applied. Please note, in case of u- and v-
-!--          diffuison, a small error is made at edges (on the east side for u,
-!--          at the north side for v), since topography on scalar grid point
-!--          is used instead of topography on u/v-grid. As number of topography grid
-!--          points on uv-grid is different than s-grid, different number of 
-!--          surface elements would be required. In order to avoid this, 
-!--          treat edges (u(k,j,i+1)) simply by a gradient approach, i.e. these
-!--          points are not masked within diffusion_u. Tests had shown that the
-!--          effect on the flow is negligible. 
+!--          Note, use this flag also to mask topography in diffusion_u and diffusion_v along the
+!--          vertical direction. In case of use_surface_fluxes, fluxes are calculated via MOST,
+!--          else, simple gradient approach is applied. Please note, in case of u- and v-diffuison,
+!--          a small error is made at edges (on the east side for u, at the north side for v), since
+!--          topography on scalar grid point is used instead of topography on u/v-grid. As number of
+!--          topography grid points on uv-grid is different than s-grid, different number of surface
+!--          elements would be required. In order to avoid this, treat edges (u(k,j,i+1)) simply by
+!--          a gradient approach, i.e. these points are not masked within diffusion_u. Tests had
+!--          shown that the effect on the flow is negligible.
              IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
-                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                         &
+                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                                       &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 8 )
              ELSE
@@ -2319 +2172 @@
           ENDDO
 !
-!--       Special flag to control vertical diffusion at model top - former 
-!--       nzt_diff
+!--       Special flag to control vertical diffusion at model top - former nzt_diff
           wall_flags_total_0(:,j,i) = IBSET( wall_flags_total_0(:,j,i), 9 )
           IF ( use_top_fluxes )                                                &
@@ -2328 +2180 @@
           DO k = nzb+1, nzt
 !
-!--          Special flag on u grid, former nzb_u_inner + 1, required   
-!--          for disturb_field and initialization. Do not disturb directly at
-!--          topography, as well as initialize u with zero one grid point outside
-!--          of topography.
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k,j,i),   1 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k+1,j,i), 1 ) )                          &
+!--          Special flag on u grid, former nzb_u_inner + 1, required for disturb_field and
+!--          initialization. Do not disturb directly at topography, as well as initialize u with
+!--          zero one grid point outside of topography.
+             IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k,j,i),   1 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k+1,j,i), 1 ) )                                        &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 20 )
 !
-!--          Special flag on v grid, former nzb_v_inner + 1, required   
-!--          for disturb_field and initialization. Do not disturb directly at
-!--          topography, as well as initialize v with zero one grid point outside
-!--          of topography.
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k,j,i),   2 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k+1,j,i), 2 ) )                          &
+!--          Special flag on v grid, former nzb_v_inner + 1, required for disturb_field and
+!--          initialization. Do not disturb directly at topography, as well as initialize v with
+!--          zero one grid point outside of topography.
+             IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k,j,i),   2 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k+1,j,i), 2 ) )                                        &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 21 )
 !
-!--          Special flag on scalar grid, former nzb_s_inner+1. Used for 
-!--          lpm_sgs_tke
-             IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                     &
-                  BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                          &
+!--          Special flag on scalar grid, former nzb_s_inner+1. Used for lpm_sgs_tke
+             IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                                   &
+                  BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                                        &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 25 )
 !
-!--          Special flag on scalar grid, nzb_diff_s_outer - 1, required in 
+!--          Special flag on scalar grid, nzb_diff_s_outer - 1, required in in production_e
+             IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
+                IF ( BTEST( wall_flags_total_0(k,j,i),   24 )  .AND.                               &
+                     BTEST( wall_flags_total_0(k-1,j,i), 24 )  .AND.                               &
+                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                                     &
+                   wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
+             ELSE
+                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                                       &
+                   wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
+             ENDIF
+!
+!--          Special flag on scalar grid, nzb_diff_s_outer - 1, required in
 !--          in production_e
              IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
-                IF ( BTEST( wall_flags_total_0(k,j,i),   24 )  .AND.                 &
-                     BTEST( wall_flags_total_0(k-1,j,i), 24 )  .AND.                 &
-                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                       &
-                   wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
-             ELSE
-                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                         &
-                   wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 29 )
-             ENDIF
-!
-!--          Special flag on scalar grid, nzb_diff_s_outer - 1, required in 
-!--          in production_e
-             IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
-                IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                  &
-                     BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                  &
-                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                       &
+                IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                                &
+                     BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                                &
+                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                                     &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
              ELSE
-                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                         &
+                IF ( BTEST( wall_flags_total_0(k,j,i), 0 ) )                                       &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 30 )
              ENDIF
@@ -2382 +2230 @@
 !
 !--          Scalar grid
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                     &
-            .NOT. BTEST( wall_flags_total_0(k,j,i), 0   ) )                          & 
-                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 ) 
+             IF (       BTEST( wall_flags_total_0(k-1,j,i), 0 )  .AND.                             &
+                  .NOT. BTEST( wall_flags_total_0(k,j,i), 0   ) )                                  &
+                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 13 )
 !
 !--          Downward facing wall on u grid
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 1 )  .AND.                     &
-            .NOT. BTEST( wall_flags_total_0(k,j,i), 1   ) )                          & 
+             IF (       BTEST( wall_flags_total_0(k-1,j,i), 1 )  .AND.                             &
+                  .NOT. BTEST( wall_flags_total_0(k,j,i), 1   ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 15 )
 !
 !--          Downward facing wall on v grid
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 2 )  .AND.                     &
-            .NOT. BTEST( wall_flags_total_0(k,j,i), 2   ) )                          & 
+             IF (       BTEST( wall_flags_total_0(k-1,j,i), 2 )  .AND.                             &
+                  .NOT. BTEST( wall_flags_total_0(k,j,i), 2   ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 17 )
 !
 !--          Downward facing wall on w grid
-             IF ( BTEST( wall_flags_total_0(k-1,j,i), 3 )  .AND.                     &
-            .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) )                            & 
+             IF (       BTEST( wall_flags_total_0(k-1,j,i), 3 )  .AND.                             &
+                  .NOT. BTEST( wall_flags_total_0(k,j,i), 3 ) )                                    &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 19 )
           ENDDO
@@ -2406 +2254 @@
 !
 !--          Upward facing wall on scalar grid
-             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.               &
-                        BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                    & 
+             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                             &
+                        BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 12 )
 !
 !--          Upward facing wall on u grid
-             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   1 )  .AND.               &
-                        BTEST( wall_flags_total_0(k+1,j,i), 1 ) )                    & 
+             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   1 )  .AND.                             &
+                        BTEST( wall_flags_total_0(k+1,j,i), 1 ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 14 )
 
-!   
+!
 !--          Upward facing wall on v grid
-             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   2 )  .AND.               &
-                        BTEST( wall_flags_total_0(k+1,j,i), 2 ) )                    & 
+             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   2 )  .AND.                             &
+                        BTEST( wall_flags_total_0(k+1,j,i), 2 ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 16 )
-   
+
 !
 !--          Upward facing wall on w grid
-             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   3 )  .AND.               &
-                        BTEST( wall_flags_total_0(k+1,j,i), 3 ) )                    & 
+             IF ( .NOT. BTEST( wall_flags_total_0(k,j,i),   3 )  .AND.                             &
+                        BTEST( wall_flags_total_0(k+1,j,i), 3 ) )                                  &
                 wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 18 )
 !
 !--          Special flag on scalar grid, former nzb_s_inner
-             IF ( BTEST( wall_flags_total_0(k,j,i), 0 )  .OR.                        &
-                  BTEST( wall_flags_total_0(k,j,i), 12 ) .OR.                        &
-                  BTEST( wall_flags_total_0(k,j,i), 13 ) )                           &
+             IF ( BTEST( wall_flags_total_0(k,j,i), 0 )  .OR.                                      &
+                  BTEST( wall_flags_total_0(k,j,i), 12 ) .OR.                                      &
+                  BTEST( wall_flags_total_0(k,j,i), 13 ) )                                         &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 22 )
 !
-!--          Special flag on scalar grid, nzb_diff_s_inner - 1, required for 
+!--          Special flag on scalar grid, nzb_diff_s_inner - 1, required for
 !--          flow_statistics
              IF ( constant_flux_layer  .OR.  use_surface_fluxes )  THEN
-                IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                  &
-                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                       &
+                IF ( BTEST( wall_flags_total_0(k,j,i),   0 )  .AND.                                &
+                     BTEST( wall_flags_total_0(k+1,j,i), 0 ) )                                     &
                   wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
              ELSE
-                IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) )                        &
+                IF ( BTEST( wall_flags_total_0(k,j,i), 22 ) )                                      &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 23 )
              ENDIF
-   
+
 
           ENDDO
@@ -2449 +2297 @@
           wall_flags_total_0(nzt+1,j,i) = IBSET( wall_flags_total_0(nzt+1,j,i), 23 )
 !
-!--       Set flags indicating that topography is close by in horizontal 
-!--       direction, i.e. flags that infold the topography. These will be used
-!--       to set advection flags for passive scalars, where due to large 
-!--       gradients near buildings stationary numerical oscillations can produce 
-!--       unrealistically high concentrations. This is only necessary if 
-!--       WS-scheme is applied for scalar advection. Note, these flags will be 
-!--       only used for passive scalars such as chemical species or aerosols.
+!--       Set flags indicating that topography is close by in horizontal direction, i.e. flags that
+!--       infold the topography. These will be used to set advection flags for passive scalars,
+!--       where due to large gradients near buildings stationary numerical oscillations can produce
+!--       unrealistically high concentrations. This is only necessary if WS-scheme is applied for
+!--       scalar advection. Note, these flags will be only used for passive scalars such as chemical
+!--       species or aerosols.
           IF ( scalar_advec == 'ws-scheme' )  THEN
              DO k = nzb, nzt
-                IF ( BTEST( wall_flags_total_0(k,j,i), 0 )  .AND. (                  &
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) )  .OR.&
-                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) )      &
-                                                            ) )                      &
+                IF ( BTEST( wall_flags_total_0(k,j,i), 0 )  .AND. (                                &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-1), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-2), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i-3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+1), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+2), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3:j+3,i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-1,i-3:i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-2,i-3:i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j-3,i-3:i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+1,i-3:i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+2,i-3:i+3), 0 ) )  .OR.              &
+                     ANY( .NOT. BTEST( wall_flags_total_0(k,j+3,i-3:i+3), 0 ) )                    &
+                                                                  )                                &
+                   )                                                                               &
                    wall_flags_total_0(k,j,i) = IBSET( wall_flags_total_0(k,j,i), 31 )
-                     
              ENDDO
           ENDIF
@@ -2480 +2327 @@
 !
 !-- Finally, set identification flags indicating natural terrain or buildings.
-!-- Natural terrain grid points. Information on the type of the surface is 
-!-- stored in bit 1 of 3D Integer array topo. However, this bit is only set 
-!-- when topography is read from file. In order to run the land-surface model
-!-- also without topography information, set bit 1 explicitely in this case.
-!-- 
+!-- Natural terrain grid points. Information on the type of the surface is stored in bit 1 of
+!-- 3D Integer array topo. However, this bit is only set when topography is read from file. In order
+!-- to run the land-surface model also without topography information, set bit 1 explicitely in this
+!-- case.
+!--
 !-- Natural terrain grid points
 !-- If no topography is initialized, the land-surface is at k = nzb.
@@ -2493 +2340 @@
           DO j = nys, nyn
              DO k = nzb, nzt+1
-!         
+!
 !--             Natural terrain grid point
-                IF ( BTEST( topo(k,j,i), 1 ) )                                 &
+                IF ( BTEST( topo(k,j,i), 1 ) )                                                     &
                    wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 5 )
              ENDDO
@@ -2506 +2353 @@
        DO j = nys, nyn
           DO k = nzb, nzt+1
-             IF ( BTEST( topo(k,j,i), 2 ) )                                    &
+             IF ( BTEST( topo(k,j,i), 2 ) )                                                        &
                 wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 6 )
           ENDDO
@@ -2516 +2363 @@
        DO j = nys, nyn
           DO k = nzb, nzt+1
-             IF ( BTEST( topo(k,j,i), 4 ) )                                    &
+             IF ( BTEST( topo(k,j,i), 4 ) )                                                        &
                 wall_flags_static_0(k,j,i) = IBSET( wall_flags_static_0(k,j,i), 4 )
           ENDDO
        ENDDO
     ENDDO
-    
+
     CALL exchange_horiz_int( wall_flags_static_0, nys, nyn, nxl, nxr, nzt, nbgp )
-    
+
     DO i = nxl, nxr
        DO j = nys, nyn
@@ -2535 +2382 @@
     CALL exchange_horiz_int( wall_flags_total_0, nys, nyn, nxl, nxr, nzt, nbgp )
 !
-!-- Set boundary conditions also for flags. Can be interpreted as Neumann
-!-- boundary conditions for topography. 
+!-- Set boundary conditions also for flags. Can be interpreted as Neumann boundary conditions for
+!-- topography.
     IF ( .NOT. bc_ns_cyc )  THEN
        IF ( nys == 0  )  THEN
-          DO  i = 1, nbgp     
+          DO  i = 1, nbgp
              wall_flags_total_0(:,nys-i,:)   = wall_flags_total_0(:,nys,:)
           ENDDO
        ENDIF
        IF ( nyn == ny )  THEN
-          DO  i = 1, nbgp  
+          DO  i = 1, nbgp
              wall_flags_total_0(:,nyn+i,:) = wall_flags_total_0(:,nyn,:)
           ENDDO
@@ -2551 +2398 @@
     IF ( .NOT. bc_lr_cyc )  THEN
        IF ( nxl == 0  )  THEN
-          DO  i = 1, nbgp   
+          DO  i = 1, nbgp
              wall_flags_total_0(:,:,nxl-i)   = wall_flags_total_0(:,:,nxl)
           ENDDO
        ENDIF
-       IF ( nxr == nx )  THEN 
-          DO  i = 1, nbgp   
-             wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)     
-          ENDDO
-       ENDIF      
+       IF ( nxr == nx )  THEN
+          DO  i = 1, nbgp
+             wall_flags_total_0(:,:,nxr+i) = wall_flags_total_0(:,:,nxr)
+          ENDDO
+       ENDIF
     ENDIF
 !
-!-- Pre-calculate topography top indices (former get_topography_top_index 
+!-- Pre-calculate topography top indices (former get_topography_top_index
 !-- function)
     ALLOCATE( topo_top_ind(nysg:nyng,nxlg:nxrg,0:4) )
@@ -2568 +2415 @@
 !-- Uppermost topography index on scalar grid
     ibit = 12
-    topo_top_ind(:,:,0) = MAXLOC(                                              &
-                                  MERGE( 1, 0,                                 &
-                                    BTEST( wall_flags_total_0(:,:,:), ibit )   &
-                                       ), DIM = 1                              &
-                                ) - 1 
-!
-!-- Uppermost topography index on u grid 
+    topo_top_ind(:,:,0) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
+                          - 1
+!
+!-- Uppermost topography index on u grid
     ibit = 14
-    topo_top_ind(:,:,1) = MAXLOC(                                              &
-                                  MERGE( 1, 0,                                 &
-                                    BTEST( wall_flags_total_0(:,:,:), ibit )   &
-                                       ), DIM = 1                              &
-                                ) - 1 
-!
-!-- Uppermost topography index on v grid 
+    topo_top_ind(:,:,1) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
+                          - 1
+!
+!-- Uppermost topography index on v grid
     ibit = 16
-    topo_top_ind(:,:,2) = MAXLOC(                                              &
-                                  MERGE( 1, 0,                                 &
-                                    BTEST( wall_flags_total_0(:,:,:), ibit )   &
-                                       ), DIM = 1                              &
-                                ) - 1 
+    topo_top_ind(:,:,2) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
+                          - 1
 !
 !-- Uppermost topography index on w grid
     ibit = 18
-    topo_top_ind(:,:,3) = MAXLOC(                                              &
-                                  MERGE( 1, 0,                                 &
-                                    BTEST( wall_flags_total_0(:,:,:), ibit )   &
-                                       ), DIM = 1                              &
-                                ) - 1 
+    topo_top_ind(:,:,3) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
+                          - 1
 !
 !-- Uppermost topography index on scalar outer grid
     ibit = 24
-    topo_top_ind(:,:,4) = MAXLOC(                                              &
-                                  MERGE( 1, 0,                                 &
-                                    BTEST( wall_flags_total_0(:,:,:), ibit )   &
-                                       ), DIM = 1                              &
-                                ) - 1
+    topo_top_ind(:,:,4) = MAXLOC( MERGE( 1, 0, BTEST( wall_flags_total_0(:,:,:), ibit ) ), DIM=1 ) &
+                          - 1
 
  END SUBROUTINE set_topo_flags