SUBROUTINE disturb_field( nzb_uv_inner, dist1, field ) !--------------------------------------------------------------------------------! ! This file is part of PALM. ! ! 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 . ! ! Copyright 1997-2014 Leibniz Universitaet Hannover !--------------------------------------------------------------------------------! ! ! Current revisions: ! ------------------ ! ! ! Former revisions: ! ----------------- ! $Id: disturb_field.f90 1323 2014-03-20 17:09:54Z maronga $ ! ! 1322 2014-03-20 16:38:49Z raasch ! REAL constants defined as wp-kind ! ! 1320 2014-03-20 08:40:49Z raasch ! ONLY-attribute added to USE-statements, ! kind-parameters added to all INTEGER and REAL declaration statements, ! kinds are defined in new module kinds, ! revision history before 2012 removed, ! comment fields (!:) to be used for variable explanations added to ! all variable declaration statements ! ! 1036 2012-10-22 13:43:42Z raasch ! code put under GPL (PALM 3.9) ! ! Revision 1.1 1998/02/04 15:40:45 raasch ! Initial revision ! ! ! Description: ! ------------ ! Imposing a random perturbation on a 3D-array. ! On parallel computers, the random number generator is as well called for all ! gridpoints of the total domain to ensure, regardless of the number of PEs ! used, that the elements of the array have the same values in the same ! order in every case. The perturbation range is steered by dist_range. !------------------------------------------------------------------------------! USE control_parameters, & ONLY: dist_nxl, dist_nxr, dist_nyn, dist_nys, dist_range, & disturbance_amplitude, disturbance_created, & disturbance_level_ind_b, disturbance_level_ind_t, iran, & random_generator, topography USE cpulog, & ONLY: cpu_log, log_point USE indices, & ONLY: nbgp, nxl, nxlg, nxr, nxrg, nyn, nyng, nys, nysg, nzb, nzt USE kinds USE random_function_mod, & ONLY: random_function IMPLICIT NONE INTEGER(iwp) :: i !: INTEGER(iwp) :: j !: INTEGER(iwp) :: k !: INTEGER(iwp) :: nzb_uv_inner(nysg:nyng,nxlg:nxrg) !: REAL(wp) :: randomnumber !: REAL(wp) :: dist1(nzb:nzt+1,nysg:nyng,nxlg:nxrg) !: REAL(wp) :: field(nzb:nzt+1,nysg:nyng,nxlg:nxrg) !: REAL(wp), DIMENSION(:,:,:), ALLOCATABLE :: dist2 !: CALL cpu_log( log_point(20), 'disturb_field', 'start' ) ! !-- Create an additional temporary array and initialize the arrays needed !-- to store the disturbance ALLOCATE( dist2(nzb:nzt+1,nysg:nyng,nxlg:nxrg) ) dist1 = 0.0 dist2 = 0.0 ! !-- Create the random perturbation and store it on temporary array IF ( random_generator == 'numerical-recipes' ) THEN DO i = dist_nxl(dist_range), dist_nxr(dist_range) DO j = dist_nys(dist_range), dist_nyn(dist_range) DO k = disturbance_level_ind_b, disturbance_level_ind_t randomnumber = 3.0_wp * disturbance_amplitude * & ( random_function( iran ) - 0.5_wp ) IF ( nxl <= i .AND. nxr >= i .AND. nys <= j .AND. & nyn >= j ) & THEN dist1(k,j,i) = randomnumber ENDIF ENDDO ENDDO ENDDO ELSEIF ( random_generator == 'system-specific' ) THEN DO i = dist_nxl(dist_range), dist_nxr(dist_range) DO j = dist_nys(dist_range), dist_nyn(dist_range) DO k = disturbance_level_ind_b, disturbance_level_ind_t #if defined( __nec ) randomnumber = 3.0_wp * disturbance_amplitude * & ( RANDOM( 0 ) - 0.5_wp ) #else CALL RANDOM_NUMBER( randomnumber ) randomnumber = 3.0_wp * disturbance_amplitude * & ( randomnumber - 0.5_wp ) #endif IF ( nxl <= i .AND. nxr >= i .AND. nys <= j .AND. nyn >= j ) & THEN dist1(k,j,i) = randomnumber ENDIF ENDDO ENDDO ENDDO ENDIF ! !-- Exchange of ghost points for the random perturbation CALL exchange_horiz( dist1, nbgp ) ! !-- Applying the Shuman filter in order to smooth the perturbations. !-- Neighboured grid points in all three directions are used for the !-- filter operation. !-- Loop has been splitted to make runs reproducible on HLRN systems using !-- compiler option -O3 DO i = nxl, nxr DO j = nys, nyn DO k = disturbance_level_ind_b-1, disturbance_level_ind_t+1 dist2(k,j,i) = ( dist1(k,j,i-1) + dist1(k,j,i+1) & + dist1(k,j+1,i) + dist1(k+1,j,i) & ) / 12.0_wp ENDDO DO k = disturbance_level_ind_b-1, disturbance_level_ind_t+1 dist2(k,j,i) = dist2(k,j,i) + ( dist1(k,j-1,i) + dist1(k-1,j,i) & + 6.0_wp * dist1(k,j,i) & ) / 12.0_wp ENDDO ENDDO ENDDO ! !-- Exchange of ghost points for the filtered perturbation. !-- Afterwards, filter operation and exchange of ghost points are repeated. CALL exchange_horiz( dist2, nbgp ) DO i = nxl, nxr DO j = nys, nyn DO k = disturbance_level_ind_b-2, disturbance_level_ind_t+2 dist1(k,j,i) = ( dist2(k,j,i-1) + dist2(k,j,i+1) + dist2(k,j-1,i) & + dist2(k,j+1,i) + dist2(k+1,j,i) + dist2(k-1,j,i) & + 6.0_wp * dist2(k,j,i) & ) / 12.0_wp ENDDO ENDDO ENDDO CALL exchange_horiz( dist1, nbgp ) ! !-- Remove perturbations below topography (including one gridpoint above it !-- in order to allow for larger timesteps at the beginning of the simulation !-- (diffusion criterion)) IF ( TRIM( topography ) /= 'flat' ) THEN DO i = nxlg, nxrg DO j = nysg, nyng dist1(nzb:nzb_uv_inner(j,i)+1,j,i) = 0.0 ENDDO ENDDO ENDIF ! !-- Random perturbation is added to the array to be disturbed. DO i = nxlg, nxrg DO j = nysg, nyng DO k = disturbance_level_ind_b-2, disturbance_level_ind_t+2 field(k,j,i) = field(k,j,i) + dist1(k,j,i) ENDDO ENDDO ENDDO ! !-- Deallocate the temporary array DEALLOCATE( dist2 ) ! !-- Set a flag, which indicates that a random perturbation is imposed disturbance_created = .TRUE. CALL cpu_log( log_point(20), 'disturb_field', 'stop' ) END SUBROUTINE disturb_field