| 1 | !> @file diffusion_u.f90 |
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| 2 | !------------------------------------------------------------------------------! |
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| 3 | ! This file is part of PALM. |
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| 4 | ! |
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| 5 | ! PALM is free software: you can redistribute it and/or modify it under the |
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| 6 | ! terms of the GNU General Public License as published by the Free Software |
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| 7 | ! Foundation, either version 3 of the License, or (at your option) any later |
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| 8 | ! version. |
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| 9 | ! |
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| 10 | ! PALM is distributed in the hope that it will be useful, but WITHOUT ANY |
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| 11 | ! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR |
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| 12 | ! A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
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| 13 | ! |
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| 14 | ! You should have received a copy of the GNU General Public License along with |
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| 15 | ! PALM. If not, see <http://www.gnu.org/licenses/>. |
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| 16 | ! |
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| 17 | ! Copyright 1997-2017 Leibniz Universitaet Hannover |
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| 18 | !------------------------------------------------------------------------------! |
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| 19 | ! |
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| 20 | ! Current revisions: |
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| 21 | ! ----------------- |
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| 22 | ! |
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| 23 | ! |
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| 24 | ! Former revisions: |
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| 25 | ! ----------------- |
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| 26 | ! $Id: diffusion_u.f90 2119 2017-01-17 16:51:50Z raasch $ |
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| 27 | ! |
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| 28 | ! 2118 2017-01-17 16:38:49Z raasch |
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| 29 | ! OpenACC version of subroutine removed |
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| 30 | ! |
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| 31 | ! 2037 2016-10-26 11:15:40Z knoop |
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| 32 | ! Anelastic approximation implemented |
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| 33 | ! |
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| 34 | ! 2000 2016-08-20 18:09:15Z knoop |
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| 35 | ! Forced header and separation lines into 80 columns |
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| 36 | ! |
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| 37 | ! 1873 2016-04-18 14:50:06Z maronga |
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| 38 | ! Module renamed (removed _mod) |
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| 39 | ! |
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| 40 | ! 1850 2016-04-08 13:29:27Z maronga |
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| 41 | ! Module renamed |
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| 42 | ! |
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| 43 | ! 1740 2016-01-13 08:19:40Z raasch |
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| 44 | ! unnecessary calculations of kmzm and kmzp in wall bounded parts removed |
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| 45 | ! |
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| 46 | ! 1691 2015-10-26 16:17:44Z maronga |
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| 47 | ! Formatting corrections. |
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| 48 | ! |
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| 49 | ! 1682 2015-10-07 23:56:08Z knoop |
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| 50 | ! Code annotations made doxygen readable |
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| 51 | ! |
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| 52 | ! 1340 2014-03-25 19:45:13Z kanani |
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| 53 | ! REAL constants defined as wp-kind |
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| 54 | ! |
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| 55 | ! 1320 2014-03-20 08:40:49Z raasch |
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| 56 | ! ONLY-attribute added to USE-statements, |
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| 57 | ! kind-parameters added to all INTEGER and REAL declaration statements, |
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| 58 | ! kinds are defined in new module kinds, |
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| 59 | ! revision history before 2012 removed, |
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| 60 | ! comment fields (!:) to be used for variable explanations added to |
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| 61 | ! all variable declaration statements |
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| 62 | ! |
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| 63 | ! 1257 2013-11-08 15:18:40Z raasch |
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| 64 | ! openacc loop and loop vector clauses removed, declare create moved after |
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| 65 | ! the FORTRAN declaration statement |
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| 66 | ! |
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| 67 | ! 1128 2013-04-12 06:19:32Z raasch |
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| 68 | ! loop index bounds in accelerator version replaced by i_left, i_right, j_south, |
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| 69 | ! j_north |
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| 70 | ! |
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| 71 | ! 1036 2012-10-22 13:43:42Z raasch |
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| 72 | ! code put under GPL (PALM 3.9) |
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| 73 | ! |
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| 74 | ! 1015 2012-09-27 09:23:24Z raasch |
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| 75 | ! accelerator version (*_acc) added |
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| 76 | ! |
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| 77 | ! 1001 2012-09-13 14:08:46Z raasch |
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| 78 | ! arrays comunicated by module instead of parameter list |
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| 79 | ! |
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| 80 | ! 978 2012-08-09 08:28:32Z fricke |
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| 81 | ! outflow damping layer removed |
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| 82 | ! kmym_x/_y and kmyp_x/_y change to kmym and kmyp |
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| 83 | ! |
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| 84 | ! Revision 1.1 1997/09/12 06:23:51 raasch |
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| 85 | ! Initial revision |
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| 86 | ! |
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| 87 | ! |
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| 88 | ! Description: |
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| 89 | ! ------------ |
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| 90 | !> Diffusion term of the u-component |
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| 91 | !> @todo additional damping (needed for non-cyclic bc) causes bad vectorization |
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| 92 | !> and slows down the speed on NEC about 5-10% |
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| 93 | !------------------------------------------------------------------------------! |
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| 94 | MODULE diffusion_u_mod |
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| 95 | |
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| 96 | |
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| 97 | USE wall_fluxes_mod |
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| 98 | |
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| 99 | PRIVATE |
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| 100 | PUBLIC diffusion_u |
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| 101 | |
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| 102 | INTERFACE diffusion_u |
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| 103 | MODULE PROCEDURE diffusion_u |
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| 104 | MODULE PROCEDURE diffusion_u_ij |
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| 105 | END INTERFACE diffusion_u |
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| 106 | |
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| 107 | CONTAINS |
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| 108 | |
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| 109 | |
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| 110 | !------------------------------------------------------------------------------! |
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| 111 | ! Description: |
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| 112 | ! ------------ |
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| 113 | !> Call for all grid points |
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| 114 | !------------------------------------------------------------------------------! |
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| 115 | SUBROUTINE diffusion_u |
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| 116 | |
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| 117 | USE arrays_3d, & |
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| 118 | ONLY: ddzu, ddzw, km, tend, u, usws, uswst, v, w, & |
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| 119 | drho_air, rho_air_zw |
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| 120 | |
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| 121 | USE control_parameters, & |
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| 122 | ONLY: constant_top_momentumflux, topography, use_surface_fluxes, & |
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| 123 | use_top_fluxes |
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| 124 | |
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| 125 | USE grid_variables, & |
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| 126 | ONLY: ddx, ddx2, ddy, fym, fyp, wall_u |
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| 127 | |
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| 128 | USE indices, & |
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| 129 | ONLY: nxl, nxlu, nxr, nyn, nys, nzb, nzb_diff_u, nzb_u_inner, & |
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| 130 | nzb_u_outer, nzt, nzt_diff |
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| 131 | |
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| 132 | USE kinds |
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| 133 | |
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| 134 | IMPLICIT NONE |
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| 135 | |
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| 136 | INTEGER(iwp) :: i !< |
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| 137 | INTEGER(iwp) :: j !< |
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| 138 | INTEGER(iwp) :: k !< |
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| 139 | REAL(wp) :: kmym !< |
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| 140 | REAL(wp) :: kmyp !< |
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| 141 | REAL(wp) :: kmzm !< |
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| 142 | REAL(wp) :: kmzp !< |
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| 143 | |
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| 144 | REAL(wp), DIMENSION(nzb:nzt+1,nys:nyn,nxl:nxr) :: usvs !< |
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| 145 | |
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| 146 | ! |
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| 147 | !-- First calculate horizontal momentum flux u'v' at vertical walls, |
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| 148 | !-- if neccessary |
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| 149 | IF ( topography /= 'flat' ) THEN |
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| 150 | CALL wall_fluxes( usvs, 1.0_wp, 0.0_wp, 0.0_wp, 0.0_wp, nzb_u_inner, & |
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| 151 | nzb_u_outer, wall_u ) |
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| 152 | ENDIF |
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| 153 | |
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| 154 | DO i = nxlu, nxr |
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| 155 | DO j = nys, nyn |
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| 156 | ! |
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| 157 | !-- Compute horizontal diffusion |
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| 158 | DO k = nzb_u_outer(j,i)+1, nzt |
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| 159 | ! |
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| 160 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 161 | kmyp = 0.25_wp * & |
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| 162 | ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
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| 163 | kmym = 0.25_wp * & |
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| 164 | ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
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| 165 | |
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| 166 | tend(k,j,i) = tend(k,j,i) & |
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| 167 | & + 2.0_wp * ( & |
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| 168 | & km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
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| 169 | & - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
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| 170 | & ) * ddx2 & |
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| 171 | & + ( kmyp * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
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| 172 | & + kmyp * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
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| 173 | & - kmym * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
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| 174 | & - kmym * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
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| 175 | & ) * ddy |
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| 176 | ENDDO |
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| 177 | |
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| 178 | ! |
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| 179 | !-- Wall functions at the north and south walls, respectively |
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| 180 | IF ( wall_u(j,i) /= 0.0_wp ) THEN |
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| 181 | |
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| 182 | DO k = nzb_u_inner(j,i)+1, nzb_u_outer(j,i) |
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| 183 | kmyp = 0.25_wp * & |
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| 184 | ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
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| 185 | kmym = 0.25_wp * & |
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| 186 | ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
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| 187 | |
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| 188 | tend(k,j,i) = tend(k,j,i) & |
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| 189 | + 2.0_wp * ( & |
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| 190 | km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
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| 191 | - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
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| 192 | ) * ddx2 & |
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| 193 | + ( fyp(j,i) * ( & |
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| 194 | kmyp * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
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| 195 | + kmyp * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
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| 196 | ) & |
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| 197 | - fym(j,i) * ( & |
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| 198 | kmym * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
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| 199 | + kmym * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
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| 200 | ) & |
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| 201 | + wall_u(j,i) * usvs(k,j,i) & |
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| 202 | ) * ddy |
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| 203 | ENDDO |
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| 204 | ENDIF |
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| 205 | |
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| 206 | ! |
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| 207 | !-- Compute vertical diffusion. In case of simulating a Prandtl layer, |
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| 208 | !-- index k starts at nzb_u_inner+2. |
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| 209 | DO k = nzb_diff_u(j,i), nzt_diff |
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| 210 | ! |
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| 211 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 212 | kmzp = 0.25_wp * & |
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| 213 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
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| 214 | kmzm = 0.25_wp * & |
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| 215 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
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| 216 | |
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| 217 | tend(k,j,i) = tend(k,j,i) & |
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| 218 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
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| 219 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
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| 220 | & ) * rho_air_zw(k) & |
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| 221 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
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| 222 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
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| 223 | & ) * rho_air_zw(k-1) & |
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| 224 | & ) * ddzw(k) * drho_air(k) |
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| 225 | ENDDO |
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| 226 | |
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| 227 | ! |
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| 228 | !-- Vertical diffusion at the first grid point above the surface, |
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| 229 | !-- if the momentum flux at the bottom is given by the Prandtl law or |
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| 230 | !-- if it is prescribed by the user. |
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| 231 | !-- Difference quotient of the momentum flux is not formed over half |
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| 232 | !-- of the grid spacing (2.0*ddzw(k)) any more, since the comparison |
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| 233 | !-- with other (LES) models showed that the values of the momentum |
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| 234 | !-- flux becomes too large in this case. |
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| 235 | !-- The term containing w(k-1,..) (see above equation) is removed here |
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| 236 | !-- because the vertical velocity is assumed to be zero at the surface. |
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| 237 | IF ( use_surface_fluxes ) THEN |
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| 238 | k = nzb_u_inner(j,i)+1 |
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| 239 | ! |
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| 240 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 241 | kmzp = 0.25_wp * & |
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| 242 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
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| 243 | |
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| 244 | tend(k,j,i) = tend(k,j,i) & |
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| 245 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
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| 246 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
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| 247 | & ) * rho_air_zw(k) & |
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| 248 | & - ( -usws(j,i) ) & |
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| 249 | & ) * ddzw(k) * drho_air(k) |
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| 250 | ENDIF |
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| 251 | |
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| 252 | ! |
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| 253 | !-- Vertical diffusion at the first gridpoint below the top boundary, |
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| 254 | !-- if the momentum flux at the top is prescribed by the user |
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| 255 | IF ( use_top_fluxes .AND. constant_top_momentumflux ) THEN |
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| 256 | k = nzt |
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| 257 | ! |
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| 258 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 259 | kmzm = 0.25_wp * & |
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| 260 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
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| 261 | |
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| 262 | tend(k,j,i) = tend(k,j,i) & |
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| 263 | & + ( ( -uswst(j,i) ) & |
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| 264 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
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| 265 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
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| 266 | & ) * rho_air_zw(k-1) & |
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| 267 | & ) * ddzw(k) * drho_air(k) |
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| 268 | ENDIF |
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| 269 | |
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| 270 | ENDDO |
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| 271 | ENDDO |
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| 272 | |
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| 273 | END SUBROUTINE diffusion_u |
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| 274 | |
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| 275 | |
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| 276 | !------------------------------------------------------------------------------! |
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| 277 | ! Description: |
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| 278 | ! ------------ |
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| 279 | !> Call for grid point i,j |
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| 280 | !------------------------------------------------------------------------------! |
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| 281 | SUBROUTINE diffusion_u_ij( i, j ) |
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| 282 | |
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| 283 | USE arrays_3d, & |
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| 284 | ONLY: ddzu, ddzw, km, tend, u, usws, uswst, v, w, & |
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| 285 | drho_air, rho_air_zw |
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| 286 | |
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| 287 | USE control_parameters, & |
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| 288 | ONLY: constant_top_momentumflux, use_surface_fluxes, use_top_fluxes |
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| 289 | |
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| 290 | USE grid_variables, & |
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| 291 | ONLY: ddx, ddx2, ddy, fym, fyp, wall_u |
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| 292 | |
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| 293 | USE indices, & |
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| 294 | ONLY: nzb, nzb_diff_u, nzb_u_inner, nzb_u_outer, nzt, nzt_diff |
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| 295 | |
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| 296 | USE kinds |
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| 297 | |
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| 298 | IMPLICIT NONE |
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| 299 | |
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| 300 | INTEGER(iwp) :: i !< |
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| 301 | INTEGER(iwp) :: j !< |
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| 302 | INTEGER(iwp) :: k !< |
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| 303 | REAL(wp) :: kmym !< |
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| 304 | REAL(wp) :: kmyp !< |
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| 305 | REAL(wp) :: kmzm !< |
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| 306 | REAL(wp) :: kmzp !< |
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| 307 | |
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| 308 | REAL(wp), DIMENSION(nzb:nzt+1) :: usvs !< |
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| 309 | |
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| 310 | ! |
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| 311 | !-- Compute horizontal diffusion |
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| 312 | DO k = nzb_u_outer(j,i)+1, nzt |
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| 313 | ! |
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| 314 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 315 | kmyp = 0.25_wp * ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
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| 316 | kmym = 0.25_wp * ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
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| 317 | |
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| 318 | tend(k,j,i) = tend(k,j,i) & |
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| 319 | & + 2.0_wp * ( & |
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| 320 | & km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
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| 321 | & - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
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| 322 | & ) * ddx2 & |
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| 323 | & + ( kmyp * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
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| 324 | & + kmyp * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
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| 325 | & - kmym * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
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| 326 | & - kmym * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
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| 327 | & ) * ddy |
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| 328 | ENDDO |
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| 329 | |
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| 330 | ! |
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| 331 | !-- Wall functions at the north and south walls, respectively |
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| 332 | IF ( wall_u(j,i) /= 0.0_wp ) THEN |
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| 333 | |
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| 334 | ! |
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| 335 | !-- Calculate the horizontal momentum flux u'v' |
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| 336 | CALL wall_fluxes( i, j, nzb_u_inner(j,i)+1, nzb_u_outer(j,i), & |
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| 337 | usvs, 1.0_wp, 0.0_wp, 0.0_wp, 0.0_wp ) |
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| 338 | |
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| 339 | DO k = nzb_u_inner(j,i)+1, nzb_u_outer(j,i) |
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| 340 | kmyp = 0.25_wp * ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
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| 341 | kmym = 0.25_wp * ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
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| 342 | |
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| 343 | tend(k,j,i) = tend(k,j,i) & |
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| 344 | + 2.0_wp * ( & |
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| 345 | km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
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| 346 | - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
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| 347 | ) * ddx2 & |
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| 348 | + ( fyp(j,i) * ( & |
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| 349 | kmyp * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
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| 350 | + kmyp * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
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| 351 | ) & |
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| 352 | - fym(j,i) * ( & |
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| 353 | kmym * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
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| 354 | + kmym * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
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| 355 | ) & |
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| 356 | + wall_u(j,i) * usvs(k) & |
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| 357 | ) * ddy |
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| 358 | ENDDO |
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| 359 | ENDIF |
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| 360 | |
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| 361 | ! |
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| 362 | !-- Compute vertical diffusion. In case of simulating a Prandtl layer, |
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| 363 | !-- index k starts at nzb_u_inner+2. |
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| 364 | DO k = nzb_diff_u(j,i), nzt_diff |
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| 365 | ! |
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| 366 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 367 | kmzp = 0.25_wp * ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
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| 368 | kmzm = 0.25_wp * ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
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| 369 | |
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| 370 | tend(k,j,i) = tend(k,j,i) & |
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| 371 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
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| 372 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
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| 373 | & ) * rho_air_zw(k) & |
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| 374 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
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| 375 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
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| 376 | & ) * rho_air_zw(k-1) & |
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| 377 | & ) * ddzw(k) * drho_air(k) |
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| 378 | ENDDO |
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| 379 | |
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| 380 | ! |
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| 381 | !-- Vertical diffusion at the first grid point above the surface, if the |
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| 382 | !-- momentum flux at the bottom is given by the Prandtl law or if it is |
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| 383 | !-- prescribed by the user. |
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| 384 | !-- Difference quotient of the momentum flux is not formed over half of |
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| 385 | !-- the grid spacing (2.0*ddzw(k)) any more, since the comparison with |
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| 386 | !-- other (LES) models showed that the values of the momentum flux becomes |
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| 387 | !-- too large in this case. |
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| 388 | !-- The term containing w(k-1,..) (see above equation) is removed here |
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| 389 | !-- because the vertical velocity is assumed to be zero at the surface. |
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| 390 | IF ( use_surface_fluxes ) THEN |
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| 391 | k = nzb_u_inner(j,i)+1 |
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| 392 | ! |
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| 393 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 394 | kmzp = 0.25_wp * ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
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| 395 | |
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| 396 | tend(k,j,i) = tend(k,j,i) & |
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| 397 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
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| 398 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
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| 399 | & ) * rho_air_zw(k) & |
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| 400 | & - ( -usws(j,i) ) & |
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| 401 | & ) * ddzw(k) * drho_air(k) |
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| 402 | ENDIF |
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| 403 | |
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| 404 | ! |
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| 405 | !-- Vertical diffusion at the first gridpoint below the top boundary, |
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| 406 | !-- if the momentum flux at the top is prescribed by the user |
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| 407 | IF ( use_top_fluxes .AND. constant_top_momentumflux ) THEN |
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| 408 | k = nzt |
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| 409 | ! |
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| 410 | !-- Interpolate eddy diffusivities on staggered gridpoints |
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| 411 | kmzm = 0.25_wp * ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
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| 412 | |
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| 413 | tend(k,j,i) = tend(k,j,i) & |
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| 414 | & + ( ( -uswst(j,i) ) & |
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| 415 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
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| 416 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
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| 417 | & ) * rho_air_zw(k-1) & |
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| 418 | & ) * ddzw(k) * drho_air(k) |
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| 419 | ENDIF |
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| 420 | |
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| 421 | END SUBROUTINE diffusion_u_ij |
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| 422 | |
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| 423 | END MODULE diffusion_u_mod |
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