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C $Header: /u/gcmpack/MITgcm/pkg/exf/exf_wind.F,v 1.8 2007/04/16 23:27:21 jmc Exp $ |
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C $Name: $ |
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|
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#include "EXF_OPTIONS.h" |
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|
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SUBROUTINE EXF_WIND( myTime, myIter, myThid ) |
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|
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C ================================================================== |
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C SUBROUTINE exf_wind |
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C ================================================================== |
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C |
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C o Prepare wind speed and stress fields |
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C |
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C ================================================================== |
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C SUBROUTINE exf_wind |
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C ================================================================== |
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|
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IMPLICIT NONE |
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|
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C == global variables == |
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|
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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|
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#include "EXF_PARAM.h" |
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#include "EXF_FIELDS.h" |
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#include "EXF_CONSTANTS.h" |
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|
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#ifdef ALLOW_AUTODIFF_TAMC |
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#include "tamc.h" |
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#endif |
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|
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C == routine arguments == |
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|
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_RL myTime |
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INTEGER myIter |
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INTEGER myThid |
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|
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C == external functions == |
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|
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C == local variables == |
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|
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INTEGER bi,bj |
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INTEGER i,j |
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_RL wsLoc(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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#ifdef ALLOW_ATM_WIND |
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_RL wsSq |
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#else |
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_RL usSq, recip_sqrtRhoA, ustar |
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_RL tmp1, tmp2, tmp3, tmp4 |
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_RL oneThirdRL |
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PARAMETER ( oneThirdRL = 1.d0 / 3.d0 ) |
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#endif |
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|
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C == end of interface == |
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|
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C-- Use atmospheric state to compute surface fluxes. |
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|
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C Loop over tiles. |
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DO bj = myByLo(myThid),myByHi(myThid) |
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DO bi = myBxLo(myThid),myBxHi(myThid) |
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|
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C-- Initialise |
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DO j = 1,sNy |
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DO i = 1,sNx |
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wsLoc(i,j) = 0. _d 0 |
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cw(i,j,bi,bj) = 0. _d 0 |
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sw(i,j,bi,bj) = 0. _d 0 |
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sh(i,j,bi,bj) = 0. _d 0 |
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wStress(i,j,bi,bj) = 0. _d 0 |
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ENDDO |
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ENDDO |
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|
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#ifdef ALLOW_ATM_WIND |
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|
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C-- Wind speed and direction. |
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DO j = 1,sNy |
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DO i = 1,sNx |
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wsSq = uwind(i,j,bi,bj)*uwind(i,j,bi,bj) |
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& + vwind(i,j,bi,bj)*vwind(i,j,bi,bj) |
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IF ( wsSq .NE. 0. _d 0 ) THEN |
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wsLoc(i,j) = SQRT(wsSq) |
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cw(i,j,bi,bj) = uwind(i,j,bi,bj)/wsLoc(i,j) |
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sw(i,j,bi,bj) = vwind(i,j,bi,bj)/wsLoc(i,j) |
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ELSE |
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wsLoc(i,j) = 0. _d 0 |
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cw(i,j,bi,bj) = 0. _d 0 |
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sw(i,j,bi,bj) = 0. _d 0 |
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ENDIF |
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ENDDO |
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ENDDO |
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IF ( wspeedfile .EQ. ' ' ) THEN |
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C- wind-speed is not loaded from file: save local array into common block |
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DO j = 1,sNy |
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DO i = 1,sNx |
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wspeed(i,j,bi,bj) = wsLoc(i,j) |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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#else /* ifndef ALLOW_ATM_WIND */ |
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|
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C-- Wind stress and direction. |
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DO j = 1,sNy |
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DO i = 1,sNx |
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IF ( stressIsOnCgrid ) THEN |
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usSq = ( ustress(i, j,bi,bj)*ustress(i ,j,bi,bj) |
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& +ustress(i+1,j,bi,bj)*ustress(i+1,j,bi,bj) |
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& +vstress(i,j, bi,bj)*vstress(i,j ,bi,bj) |
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& +vstress(i,j+1,bi,bj)*vstress(i,j+1,bi,bj) |
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& )*0.5 _d 0 |
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ELSE |
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usSq = ustress(i,j,bi,bj)*ustress(i,j,bi,bj) |
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& +vstress(i,j,bi,bj)*vstress(i,j,bi,bj) |
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ENDIF |
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IF ( usSq .NE. 0. _d 0 ) THEN |
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wStress(i,j,bi,bj) = SQRT(usSq) |
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c ustar = SQRT(usSq/atmrho) |
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cw(i,j,bi,bj) = ustress(i,j,bi,bj)/wStress(i,j,bi,bj) |
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sw(i,j,bi,bj) = vstress(i,j,bi,bj)/wStress(i,j,bi,bj) |
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ELSE |
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wStress(i,j,bi,bj) = 0. _d 0 |
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cw(i,j,bi,bj) = 0. _d 0 |
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sw(i,j,bi,bj) = 0. _d 0 |
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ENDIF |
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ENDDO |
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ENDDO |
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|
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IF ( wspeedfile .EQ. ' ' ) THEN |
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C-- wspeed is not loaded ; devive wind-speed by inversion of |
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C wind-stress=fct(wind-speed) relation: |
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C The variables us, sh and rdn have to be computed from |
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C given wind stresses inverting relationship for neutral |
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C drag coeff. cdn. |
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C The inversion is based on linear and quadratic form of |
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C cdn(umps); ustar can be directly computed from stress; |
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recip_sqrtRhoA = 1. _d 0 / SQRT(atmrho) |
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DO j = 1,sNy |
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DO i = 1,sNx |
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ustar = wStress(i,j,bi,bj)*recip_sqrtRhoA |
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IF ( ustar .EQ. 0. _d 0 ) THEN |
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wsLoc(i,j) = 0. _d 0 |
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ELSE IF ( ustar .LT. ustofu11 ) THEN |
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tmp1 = -cquadrag_2/cquadrag_1*exf_half |
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tmp2 = SQRT(tmp1*tmp1 + ustar*ustar/cquadrag_1) |
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wsLoc(i,j) = SQRT(tmp1 + tmp2) |
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ELSE |
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tmp1 = clindrag_2/clindrag_1*oneThirdRL |
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tmp2 = ustar*ustar/clindrag_1*exf_half |
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& - tmp1*tmp1*tmp1 |
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tmp3 = SQRT( ustar*ustar/clindrag_1* |
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& (ustar*ustar/clindrag_1*0.25 _d 0 - tmp1*tmp1*tmp1 ) |
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& ) |
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tmp4 = (tmp2 + tmp3)**oneThirdRL |
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wsLoc(i,j) = tmp4 + tmp1*tmp1 / tmp4 - tmp1 |
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c wsLoc(i,j) = (tmp2 + tmp3)**oneThirdRL + |
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c & tmp1*tmp1 * (tmp2 + tmp3)**(-oneThirdRL) - tmp1 |
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ENDIF |
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ENDDO |
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ENDDO |
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C- save local array wind-speed to common block |
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DO j = 1,sNy |
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DO i = 1,sNx |
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wspeed(i,j,bi,bj) = wsLoc(i,j) |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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C-- infer wind field from wind-speed & wind-stress direction |
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DO j = 1,sNy |
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DO i = 1,sNx |
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uwind(i,j,bi,bj) = wspeed(i,j,bi,bj)*cw(i,j,bi,bj) |
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vwind(i,j,bi,bj) = wspeed(i,j,bi,bj)*sw(i,j,bi,bj) |
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ENDDO |
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ENDDO |
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#endif /* ifndef ALLOW_ATM_WIND */ |
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|
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C-- set wind-speed lower limit |
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DO j = 1,sNy |
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DO i = 1,sNx |
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sh(i,j,bi,bj) = MAX(wspeed(i,j,bi,bj),uMin) |
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ENDDO |
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ENDDO |
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|
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C-- end bi,bj loops |
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ENDDO |
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ENDDO |
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|
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RETURN |
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END |