| 1 | MODULE diffusion_u_mod |
|---|
| 2 | |
|---|
| 3 | !------------------------------------------------------------------------------! |
|---|
| 4 | ! Current revisions: |
|---|
| 5 | ! ----------------- |
|---|
| 6 | ! |
|---|
| 7 | ! |
|---|
| 8 | ! Former revisions: |
|---|
| 9 | ! ----------------- |
|---|
| 10 | ! $Id: diffusion_u.f90 484 2010-02-05 07:36:54Z weinreis $ |
|---|
| 11 | ! |
|---|
| 12 | ! 366 2009-08-25 08:06:27Z raasch |
|---|
| 13 | ! bc_ns replaced by bc_ns_cyc |
|---|
| 14 | ! |
|---|
| 15 | ! 106 2007-08-16 14:30:26Z raasch |
|---|
| 16 | ! Momentumflux at top (uswst) included as boundary condition, |
|---|
| 17 | ! i loop is starting from nxlu (needed for non-cyclic boundary conditions) |
|---|
| 18 | ! |
|---|
| 19 | ! 75 2007-03-22 09:54:05Z raasch |
|---|
| 20 | ! Wall functions now include diabatic conditions, call of routine wall_fluxes, |
|---|
| 21 | ! z0 removed from argument list, uxrp eliminated |
|---|
| 22 | ! |
|---|
| 23 | ! 20 2007-02-26 00:12:32Z raasch |
|---|
| 24 | ! Bugfix: ddzw dimensioned 1:nzt"+1" |
|---|
| 25 | ! |
|---|
| 26 | ! RCS Log replace by Id keyword, revision history cleaned up |
|---|
| 27 | ! |
|---|
| 28 | ! Revision 1.15 2006/02/23 10:35:35 raasch |
|---|
| 29 | ! nzb_2d replaced by nzb_u_outer in horizontal diffusion and by nzb_u_inner |
|---|
| 30 | ! or nzb_diff_u, respectively, in vertical diffusion, |
|---|
| 31 | ! wall functions added for north and south walls, +z0 in argument list, |
|---|
| 32 | ! terms containing w(k-1,..) are removed from the Prandtl-layer equation |
|---|
| 33 | ! because they cause errors at the edges of topography |
|---|
| 34 | ! WARNING: loops containing the MAX function are still not properly vectorized! |
|---|
| 35 | ! |
|---|
| 36 | ! Revision 1.1 1997/09/12 06:23:51 raasch |
|---|
| 37 | ! Initial revision |
|---|
| 38 | ! |
|---|
| 39 | ! |
|---|
| 40 | ! Description: |
|---|
| 41 | ! ------------ |
|---|
| 42 | ! Diffusion term of the u-component |
|---|
| 43 | ! To do: additional damping (needed for non-cyclic bc) causes bad vectorization |
|---|
| 44 | ! and slows down the speed on NEC about 5-10% |
|---|
| 45 | !------------------------------------------------------------------------------! |
|---|
| 46 | |
|---|
| 47 | USE wall_fluxes_mod |
|---|
| 48 | |
|---|
| 49 | PRIVATE |
|---|
| 50 | PUBLIC diffusion_u |
|---|
| 51 | |
|---|
| 52 | INTERFACE diffusion_u |
|---|
| 53 | MODULE PROCEDURE diffusion_u |
|---|
| 54 | MODULE PROCEDURE diffusion_u_ij |
|---|
| 55 | END INTERFACE diffusion_u |
|---|
| 56 | |
|---|
| 57 | CONTAINS |
|---|
| 58 | |
|---|
| 59 | |
|---|
| 60 | !------------------------------------------------------------------------------! |
|---|
| 61 | ! Call for all grid points |
|---|
| 62 | !------------------------------------------------------------------------------! |
|---|
| 63 | SUBROUTINE diffusion_u( ddzu, ddzw, km, km_damp_y, tend, u, usws, uswst, & |
|---|
| 64 | v, w ) |
|---|
| 65 | |
|---|
| 66 | USE control_parameters |
|---|
| 67 | USE grid_variables |
|---|
| 68 | USE indices |
|---|
| 69 | |
|---|
| 70 | IMPLICIT NONE |
|---|
| 71 | |
|---|
| 72 | INTEGER :: i, j, k |
|---|
| 73 | REAL :: kmym_x, kmym_y, kmyp_x, kmyp_y, kmzm, kmzp |
|---|
| 74 | REAL :: ddzu(1:nzt+1), ddzw(1:nzt+1), km_damp_y(nys-1:nyn+1) |
|---|
| 75 | REAL :: tend(nzb:nzt+1,nys-1:nyn+1,nxl-1:nxr+1) |
|---|
| 76 | REAL, DIMENSION(:,:), POINTER :: usws, uswst |
|---|
| 77 | REAL, DIMENSION(:,:,:), POINTER :: km, u, v, w |
|---|
| 78 | REAL, DIMENSION(nzb:nzt+1,nys:nyn,nxl:nxr) :: usvs |
|---|
| 79 | |
|---|
| 80 | ! |
|---|
| 81 | !-- First calculate horizontal momentum flux u'v' at vertical walls, |
|---|
| 82 | !-- if neccessary |
|---|
| 83 | IF ( topography /= 'flat' ) THEN |
|---|
| 84 | CALL wall_fluxes( usvs, 1.0, 0.0, 0.0, 0.0, nzb_u_inner, & |
|---|
| 85 | nzb_u_outer, wall_u ) |
|---|
| 86 | ENDIF |
|---|
| 87 | |
|---|
| 88 | DO i = nxlu, nxr |
|---|
| 89 | DO j = nys,nyn |
|---|
| 90 | ! |
|---|
| 91 | !-- Compute horizontal diffusion |
|---|
| 92 | DO k = nzb_u_outer(j,i)+1, nzt |
|---|
| 93 | ! |
|---|
| 94 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 95 | kmyp_x = 0.25 * & |
|---|
| 96 | ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
|---|
| 97 | kmym_x = 0.25 * & |
|---|
| 98 | ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
|---|
| 99 | kmyp_y = kmyp_x |
|---|
| 100 | kmym_y = kmym_x |
|---|
| 101 | ! |
|---|
| 102 | !-- Increase diffusion at the outflow boundary in case of |
|---|
| 103 | !-- non-cyclic lateral boundaries. Damping is only needed for |
|---|
| 104 | !-- velocity components parallel to the outflow boundary in |
|---|
| 105 | !-- the direction normal to the outflow boundary. |
|---|
| 106 | IF ( .NOT. bc_ns_cyc ) THEN |
|---|
| 107 | kmyp_y = MAX( kmyp_y, km_damp_y(j) ) |
|---|
| 108 | kmym_y = MAX( kmym_y, km_damp_y(j) ) |
|---|
| 109 | ENDIF |
|---|
| 110 | |
|---|
| 111 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 112 | & + 2.0 * ( & |
|---|
| 113 | & km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
|---|
| 114 | & - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
|---|
| 115 | & ) * ddx2 & |
|---|
| 116 | & + ( kmyp_y * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
|---|
| 117 | & + kmyp_x * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
|---|
| 118 | & - kmym_y * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
|---|
| 119 | & - kmym_x * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
|---|
| 120 | & ) * ddy |
|---|
| 121 | ENDDO |
|---|
| 122 | |
|---|
| 123 | ! |
|---|
| 124 | !-- Wall functions at the north and south walls, respectively |
|---|
| 125 | IF ( wall_u(j,i) /= 0.0 ) THEN |
|---|
| 126 | |
|---|
| 127 | DO k = nzb_u_inner(j,i)+1, nzb_u_outer(j,i) |
|---|
| 128 | kmyp_x = 0.25 * & |
|---|
| 129 | ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
|---|
| 130 | kmym_x = 0.25 * & |
|---|
| 131 | ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
|---|
| 132 | kmyp_y = kmyp_x |
|---|
| 133 | kmym_y = kmym_x |
|---|
| 134 | ! |
|---|
| 135 | !-- Increase diffusion at the outflow boundary in case of |
|---|
| 136 | !-- non-cyclic lateral boundaries. Damping is only needed for |
|---|
| 137 | !-- velocity components parallel to the outflow boundary in |
|---|
| 138 | !-- the direction normal to the outflow boundary. |
|---|
| 139 | IF ( .NOT. bc_ns_cyc ) THEN |
|---|
| 140 | kmyp_y = MAX( kmyp_y, km_damp_y(j) ) |
|---|
| 141 | kmym_y = MAX( kmym_y, km_damp_y(j) ) |
|---|
| 142 | ENDIF |
|---|
| 143 | |
|---|
| 144 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 145 | + 2.0 * ( & |
|---|
| 146 | km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
|---|
| 147 | - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
|---|
| 148 | ) * ddx2 & |
|---|
| 149 | + ( fyp(j,i) * ( & |
|---|
| 150 | kmyp_y * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
|---|
| 151 | + kmyp_x * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
|---|
| 152 | ) & |
|---|
| 153 | - fym(j,i) * ( & |
|---|
| 154 | kmym_y * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
|---|
| 155 | + kmym_x * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
|---|
| 156 | ) & |
|---|
| 157 | + wall_u(j,i) * usvs(k,j,i) & |
|---|
| 158 | ) * ddy |
|---|
| 159 | ENDDO |
|---|
| 160 | ENDIF |
|---|
| 161 | |
|---|
| 162 | ! |
|---|
| 163 | !-- Compute vertical diffusion. In case of simulating a Prandtl layer, |
|---|
| 164 | !-- index k starts at nzb_u_inner+2. |
|---|
| 165 | DO k = nzb_diff_u(j,i), nzt_diff |
|---|
| 166 | ! |
|---|
| 167 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 168 | kmzp = 0.25 * & |
|---|
| 169 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 170 | kmzm = 0.25 * & |
|---|
| 171 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 172 | |
|---|
| 173 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 174 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
|---|
| 175 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
|---|
| 176 | & ) & |
|---|
| 177 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
|---|
| 178 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
|---|
| 179 | & ) & |
|---|
| 180 | & ) * ddzw(k) |
|---|
| 181 | ENDDO |
|---|
| 182 | |
|---|
| 183 | ! |
|---|
| 184 | !-- Vertical diffusion at the first grid point above the surface, |
|---|
| 185 | !-- if the momentum flux at the bottom is given by the Prandtl law or |
|---|
| 186 | !-- if it is prescribed by the user. |
|---|
| 187 | !-- Difference quotient of the momentum flux is not formed over half |
|---|
| 188 | !-- of the grid spacing (2.0*ddzw(k)) any more, since the comparison |
|---|
| 189 | !-- with other (LES) modell showed that the values of the momentum |
|---|
| 190 | !-- flux becomes too large in this case. |
|---|
| 191 | !-- The term containing w(k-1,..) (see above equation) is removed here |
|---|
| 192 | !-- because the vertical velocity is assumed to be zero at the surface. |
|---|
| 193 | IF ( use_surface_fluxes ) THEN |
|---|
| 194 | k = nzb_u_inner(j,i)+1 |
|---|
| 195 | ! |
|---|
| 196 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 197 | kmzp = 0.25 * & |
|---|
| 198 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 199 | kmzm = 0.25 * & |
|---|
| 200 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 201 | |
|---|
| 202 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 203 | & + ( kmzp * ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
|---|
| 204 | & ) * ddzw(k) & |
|---|
| 205 | & + ( kmzp * ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
|---|
| 206 | & + usws(j,i) & |
|---|
| 207 | & ) * ddzw(k) |
|---|
| 208 | ENDIF |
|---|
| 209 | |
|---|
| 210 | ! |
|---|
| 211 | !-- Vertical diffusion at the first gridpoint below the top boundary, |
|---|
| 212 | !-- if the momentum flux at the top is prescribed by the user |
|---|
| 213 | IF ( use_top_fluxes .AND. constant_top_momentumflux ) THEN |
|---|
| 214 | k = nzt |
|---|
| 215 | ! |
|---|
| 216 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 217 | kmzp = 0.25 * & |
|---|
| 218 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 219 | kmzm = 0.25 * & |
|---|
| 220 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 221 | |
|---|
| 222 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 223 | & - ( kmzm * ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
|---|
| 224 | & ) * ddzw(k) & |
|---|
| 225 | & + ( -uswst(j,i) & |
|---|
| 226 | & - kmzm * ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
|---|
| 227 | & ) * ddzw(k) |
|---|
| 228 | ENDIF |
|---|
| 229 | |
|---|
| 230 | ENDDO |
|---|
| 231 | ENDDO |
|---|
| 232 | |
|---|
| 233 | END SUBROUTINE diffusion_u |
|---|
| 234 | |
|---|
| 235 | |
|---|
| 236 | !------------------------------------------------------------------------------! |
|---|
| 237 | ! Call for grid point i,j |
|---|
| 238 | !------------------------------------------------------------------------------! |
|---|
| 239 | SUBROUTINE diffusion_u_ij( i, j, ddzu, ddzw, km, km_damp_y, tend, u, usws, & |
|---|
| 240 | uswst, v, w ) |
|---|
| 241 | |
|---|
| 242 | USE control_parameters |
|---|
| 243 | USE grid_variables |
|---|
| 244 | USE indices |
|---|
| 245 | |
|---|
| 246 | IMPLICIT NONE |
|---|
| 247 | |
|---|
| 248 | INTEGER :: i, j, k |
|---|
| 249 | REAL :: kmym_x, kmym_y, kmyp_x, kmyp_y, kmzm, kmzp |
|---|
| 250 | REAL :: ddzu(1:nzt+1), ddzw(1:nzt+1), km_damp_y(nys-1:nyn+1) |
|---|
| 251 | REAL :: tend(nzb:nzt+1,nys-1:nyn+1,nxl-1:nxr+1) |
|---|
| 252 | REAL, DIMENSION(nzb:nzt+1) :: usvs |
|---|
| 253 | REAL, DIMENSION(:,:), POINTER :: usws, uswst |
|---|
| 254 | REAL, DIMENSION(:,:,:), POINTER :: km, u, v, w |
|---|
| 255 | |
|---|
| 256 | ! |
|---|
| 257 | !-- Compute horizontal diffusion |
|---|
| 258 | DO k = nzb_u_outer(j,i)+1, nzt |
|---|
| 259 | ! |
|---|
| 260 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 261 | kmyp_x = 0.25 * ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
|---|
| 262 | kmym_x = 0.25 * ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
|---|
| 263 | kmyp_y = kmyp_x |
|---|
| 264 | kmym_y = kmym_x |
|---|
| 265 | |
|---|
| 266 | ! |
|---|
| 267 | !-- Increase diffusion at the outflow boundary in case of non-cyclic |
|---|
| 268 | !-- lateral boundaries. Damping is only needed for velocity components |
|---|
| 269 | !-- parallel to the outflow boundary in the direction normal to the |
|---|
| 270 | !-- outflow boundary. |
|---|
| 271 | IF ( .NOT. bc_ns_cyc ) THEN |
|---|
| 272 | kmyp_y = MAX( kmyp_y, km_damp_y(j) ) |
|---|
| 273 | kmym_y = MAX( kmym_y, km_damp_y(j) ) |
|---|
| 274 | ENDIF |
|---|
| 275 | |
|---|
| 276 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 277 | & + 2.0 * ( & |
|---|
| 278 | & km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
|---|
| 279 | & - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
|---|
| 280 | & ) * ddx2 & |
|---|
| 281 | & + ( kmyp_y * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
|---|
| 282 | & + kmyp_x * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
|---|
| 283 | & - kmym_y * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
|---|
| 284 | & - kmym_x * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
|---|
| 285 | & ) * ddy |
|---|
| 286 | ENDDO |
|---|
| 287 | |
|---|
| 288 | ! |
|---|
| 289 | !-- Wall functions at the north and south walls, respectively |
|---|
| 290 | IF ( wall_u(j,i) .NE. 0.0 ) THEN |
|---|
| 291 | |
|---|
| 292 | ! |
|---|
| 293 | !-- Calculate the horizontal momentum flux u'v' |
|---|
| 294 | CALL wall_fluxes( i, j, nzb_u_inner(j,i)+1, nzb_u_outer(j,i), & |
|---|
| 295 | usvs, 1.0, 0.0, 0.0, 0.0 ) |
|---|
| 296 | |
|---|
| 297 | DO k = nzb_u_inner(j,i)+1, nzb_u_outer(j,i) |
|---|
| 298 | kmyp_x = 0.25 * ( km(k,j,i)+km(k,j+1,i)+km(k,j,i-1)+km(k,j+1,i-1) ) |
|---|
| 299 | kmym_x = 0.25 * ( km(k,j,i)+km(k,j-1,i)+km(k,j,i-1)+km(k,j-1,i-1) ) |
|---|
| 300 | kmyp_y = kmyp_x |
|---|
| 301 | kmym_y = kmym_x |
|---|
| 302 | ! |
|---|
| 303 | !-- Increase diffusion at the outflow boundary in case of |
|---|
| 304 | !-- non-cyclic lateral boundaries. Damping is only needed for |
|---|
| 305 | !-- velocity components parallel to the outflow boundary in |
|---|
| 306 | !-- the direction normal to the outflow boundary. |
|---|
| 307 | IF ( .NOT. bc_ns_cyc ) THEN |
|---|
| 308 | kmyp_y = MAX( kmyp_y, km_damp_y(j) ) |
|---|
| 309 | kmym_y = MAX( kmym_y, km_damp_y(j) ) |
|---|
| 310 | ENDIF |
|---|
| 311 | |
|---|
| 312 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 313 | + 2.0 * ( & |
|---|
| 314 | km(k,j,i) * ( u(k,j,i+1) - u(k,j,i) ) & |
|---|
| 315 | - km(k,j,i-1) * ( u(k,j,i) - u(k,j,i-1) ) & |
|---|
| 316 | ) * ddx2 & |
|---|
| 317 | + ( fyp(j,i) * ( & |
|---|
| 318 | kmyp_y * ( u(k,j+1,i) - u(k,j,i) ) * ddy & |
|---|
| 319 | + kmyp_x * ( v(k,j+1,i) - v(k,j+1,i-1) ) * ddx & |
|---|
| 320 | ) & |
|---|
| 321 | - fym(j,i) * ( & |
|---|
| 322 | kmym_y * ( u(k,j,i) - u(k,j-1,i) ) * ddy & |
|---|
| 323 | + kmym_x * ( v(k,j,i) - v(k,j,i-1) ) * ddx & |
|---|
| 324 | ) & |
|---|
| 325 | + wall_u(j,i) * usvs(k) & |
|---|
| 326 | ) * ddy |
|---|
| 327 | ENDDO |
|---|
| 328 | ENDIF |
|---|
| 329 | |
|---|
| 330 | ! |
|---|
| 331 | !-- Compute vertical diffusion. In case of simulating a Prandtl layer, |
|---|
| 332 | !-- index k starts at nzb_u_inner+2. |
|---|
| 333 | DO k = nzb_diff_u(j,i), nzt_diff |
|---|
| 334 | ! |
|---|
| 335 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 336 | kmzp = 0.25 * ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 337 | kmzm = 0.25 * ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 338 | |
|---|
| 339 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 340 | & + ( kmzp * ( ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
|---|
| 341 | & + ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
|---|
| 342 | & ) & |
|---|
| 343 | & - kmzm * ( ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
|---|
| 344 | & + ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
|---|
| 345 | & ) & |
|---|
| 346 | & ) * ddzw(k) |
|---|
| 347 | ENDDO |
|---|
| 348 | |
|---|
| 349 | ! |
|---|
| 350 | !-- Vertical diffusion at the first grid point above the surface, if the |
|---|
| 351 | !-- momentum flux at the bottom is given by the Prandtl law or if it is |
|---|
| 352 | !-- prescribed by the user. |
|---|
| 353 | !-- Difference quotient of the momentum flux is not formed over half of |
|---|
| 354 | !-- the grid spacing (2.0*ddzw(k)) any more, since the comparison with |
|---|
| 355 | !-- other (LES) modell showed that the values of the momentum flux becomes |
|---|
| 356 | !-- too large in this case. |
|---|
| 357 | !-- The term containing w(k-1,..) (see above equation) is removed here |
|---|
| 358 | !-- because the vertical velocity is assumed to be zero at the surface. |
|---|
| 359 | IF ( use_surface_fluxes ) THEN |
|---|
| 360 | k = nzb_u_inner(j,i)+1 |
|---|
| 361 | ! |
|---|
| 362 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 363 | kmzp = 0.25 * ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 364 | kmzm = 0.25 * ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 365 | |
|---|
| 366 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 367 | & + ( kmzp * ( w(k,j,i) - w(k,j,i-1) ) * ddx & |
|---|
| 368 | & ) * ddzw(k) & |
|---|
| 369 | & + ( kmzp * ( u(k+1,j,i) - u(k,j,i) ) * ddzu(k+1) & |
|---|
| 370 | & + usws(j,i) & |
|---|
| 371 | & ) * ddzw(k) |
|---|
| 372 | ENDIF |
|---|
| 373 | |
|---|
| 374 | ! |
|---|
| 375 | !-- Vertical diffusion at the first gridpoint below the top boundary, |
|---|
| 376 | !-- if the momentum flux at the top is prescribed by the user |
|---|
| 377 | IF ( use_top_fluxes .AND. constant_top_momentumflux ) THEN |
|---|
| 378 | k = nzt |
|---|
| 379 | ! |
|---|
| 380 | !-- Interpolate eddy diffusivities on staggered gridpoints |
|---|
| 381 | kmzp = 0.25 * & |
|---|
| 382 | ( km(k,j,i)+km(k+1,j,i)+km(k,j,i-1)+km(k+1,j,i-1) ) |
|---|
| 383 | kmzm = 0.25 * & |
|---|
| 384 | ( km(k,j,i)+km(k-1,j,i)+km(k,j,i-1)+km(k-1,j,i-1) ) |
|---|
| 385 | |
|---|
| 386 | tend(k,j,i) = tend(k,j,i) & |
|---|
| 387 | & - ( kmzm * ( w(k-1,j,i) - w(k-1,j,i-1) ) * ddx & |
|---|
| 388 | & ) * ddzw(k) & |
|---|
| 389 | & + ( -uswst(j,i) & |
|---|
| 390 | & - kmzm * ( u(k,j,i) - u(k-1,j,i) ) * ddzu(k) & |
|---|
| 391 | & ) * ddzw(k) |
|---|
| 392 | ENDIF |
|---|
| 393 | |
|---|
| 394 | END SUBROUTINE diffusion_u_ij |
|---|
| 395 | |
|---|
| 396 | END MODULE diffusion_u_mod |
|---|
