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C $Header: /u/gcmpack/models/MITgcmUV/model/src/calc_gt.F,v 1.10 1998/06/08 21:43:00 cnh Exp $ |
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|
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#include "CPP_EEOPTIONS.h" |
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|
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CStartOfInterFace |
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SUBROUTINE CALC_GS( |
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I bi,bj,iMin,iMax,jMin,jMax,k,kM1,kUp,kDown, |
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I xA,yA,uTrans,vTrans,wTrans,maskup, |
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I K13,K23,KappaZS,KapGM, |
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U af,df,fZon,fMer,fVerS, |
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I myThid ) |
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C /==========================================================\ |
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C | SUBROUTINE CALC_GS | |
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C | o Calculate the salt tendency terms. | |
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C |==========================================================| |
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C | A procedure called EXTERNAL_FORCING_S is called from | |
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C | here. These procedures can be used to add per problem | |
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C | E-P flux source terms. | |
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C | Note: Although it is slightly counter-intuitive the | |
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C | EXTERNAL_FORCING routine is not the place to put | |
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C | file I/O. Instead files that are required to | |
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C | calculate the external source terms are generally | |
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C | read during the model main loop. This makes the | |
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C | logisitics of multi-processing simpler and also | |
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C | makes the adjoint generation simpler. It also | |
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C | allows for I/O to overlap computation where that | |
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C | is supported by hardware. | |
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C | Aside from the problem specific term the code here | |
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C | forms the tendency terms due to advection and mixing | |
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C | The baseline implementation here uses a centered | |
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C | difference form for the advection term and a tensorial | |
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C | divergence of a flux form for the diffusive term. The | |
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C | diffusive term is formulated so that isopycnal mixing and| |
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C | GM-style subgrid-scale terms can be incorporated b simply| |
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C | setting the diffusion tensor terms appropriately. | |
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C \==========================================================/ |
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IMPLICIT NONE |
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|
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C == GLobal variables == |
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#include "SIZE.h" |
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#include "DYNVARS.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "GRID.h" |
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|
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C == Routine arguments == |
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C fZon - Work array for flux of temperature in the east-west |
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C direction at the west face of a cell. |
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C fMer - Work array for flux of temperature in the north-south |
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C direction at the south face of a cell. |
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C fVerS - Flux of salt (S) in the vertical |
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C direction at the upper(U) and lower(D) faces of a cell. |
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C maskUp - Land mask used to denote base of the domain. |
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C xA - Tracer cell face area normal to X |
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C yA - Tracer cell face area normal to X |
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C uTrans - Zonal volume transport through cell face |
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C vTrans - Meridional volume transport through cell face |
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C wTrans - Vertical volume transport through cell face |
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C af - Advective flux component work array |
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C df - Diffusive flux component work array |
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C bi, bj, iMin, iMax, jMin, jMax - Range of points for which calculation |
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C results will be set. |
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C myThid - Instance number for this innvocation of CALC_GT |
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_RL fZon (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL fMer (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL fVerS (1-OLx:sNx+OLx,1-OLy:sNy+OLy,2) |
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_RS xA (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RS yA (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL uTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL vTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL wTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RS maskUp(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL K13 (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nz) |
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_RL K23 (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nz) |
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_RL KappaZS(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nz) |
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_RL KapGM (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL af (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL df (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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INTEGER k,kUp,kDown,kM1 |
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INTEGER bi,bj,iMin,iMax,jMin,jMax |
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INTEGER myThid |
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CEndOfInterface |
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|
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C == Local variables == |
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C I, J, K - Loop counters |
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INTEGER i,j |
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LOGICAL TOP_LAYER |
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_RL afFacS, dfFacS |
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_RL dSdx(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL dSdy(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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|
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afFacS = 1. _d 0 |
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dfFacS = 1. _d 0 |
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TOP_LAYER = K .EQ. 1 |
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|
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C--- Calculate advective and diffusive fluxes between cells. |
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|
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C-- Zonal flux (fZon is at west face of "salt" cell) |
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C Advective component of zonal flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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af(i,j) = |
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& uTrans(i,j)*(salt(i,j,k,bi,bj)+salt(i-1,j,k,bi,bj))*0.5 _d 0 |
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ENDDO |
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ENDDO |
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C Zonal tracer gradient |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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dSdx(i,j) = _rdxC(i,j,bi,bj)* |
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& (salt(i,j,k,bi,bj)-salt(i-1,j,k,bi,bj)) |
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ENDDO |
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ENDDO |
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C Diffusive component of zonal flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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df(i,j) = -(diffKhS+0.5*(KapGM(i,j)+KapGM(i-1,j)))* |
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& xA(i,j)*dSdx(i,j) |
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ENDDO |
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ENDDO |
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C Net zonal flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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fZon(i,j) = afFacS*af(i,j) + dfFacS*df(i,j) |
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ENDDO |
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ENDDO |
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|
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C-- Meridional flux (fMer is at south face of "salt" cell) |
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C Advective component of meridional flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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C Advective component of meridional flux |
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af(i,j) = |
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& vTrans(i,j)*(salt(i,j,k,bi,bj)+salt(i,j-1,k,bi,bj))*0.5 _d 0 |
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ENDDO |
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ENDDO |
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C Zonal tracer gradient |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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dSdy(i,j) = _rdyC(i,j,bi,bj)* |
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& (salt(i,j,k,bi,bj)-salt(i,j-1,k,bi,bj)) |
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ENDDO |
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ENDDO |
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C Diffusive component of meridional flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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df(i,j) = -(diffKhS+0.5*(KapGM(i,j)+KapGM(i,j-1)))* |
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& yA(i,j)*dSdy(i,j) |
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ENDDO |
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ENDDO |
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C Net meridional flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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fMer(i,j) = afFacS*af(i,j) + dfFacS*df(i,j) |
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ENDDO |
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ENDDO |
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|
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C-- Interpolate terms for Redi/GM scheme |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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dSdx(i,j) = 0.5*( |
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& +0.5*(_maskW(i+1,j,k,bi,bj)*_rdxC(i+1,j,bi,bj)* |
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& (salt(i+1,j,k,bi,bj)-salt(i,j,k,bi,bj)) |
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& +_maskW(i,j,k,bi,bj)*_rdxC(i,j,bi,bj)* |
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& (salt(i,j,k,bi,bj)-salt(i-1,j,k,bi,bj))) |
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& +0.5*(_maskW(i+1,j,km1,bi,bj)*_rdxC(i+1,j,bi,bj)* |
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& (salt(i+1,j,km1,bi,bj)-salt(i,j,km1,bi,bj)) |
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& +_maskW(i,j,km1,bi,bj)*_rdxC(i,j,bi,bj)* |
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& (salt(i,j,km1,bi,bj)-salt(i-1,j,km1,bi,bj))) |
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& ) |
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ENDDO |
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ENDDO |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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dSdy(i,j) = 0.5*( |
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& +0.5*(_maskS(i,j,k,bi,bj)*_rdyC(i,j,bi,bj)* |
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& (salt(i,j,k,bi,bj)-salt(i,j-1,k,bi,bj)) |
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& +_maskS(i,j+1,k,bi,bj)*_rdyC(i,j+1,bi,bj)* |
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& (salt(i,j+1,k,bi,bj)-salt(i,j,k,bi,bj))) |
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& +0.5*(_maskS(i,j,km1,bi,bj)*_rdyC(i,j,bi,bj)* |
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& (salt(i,j,km1,bi,bj)-salt(i,j-1,km1,bi,bj)) |
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& +_maskS(i,j+1,km1,bi,bj)*_rdyC(i,j+1,bi,bj)* |
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& (salt(i,j+1,km1,bi,bj)-salt(i,j,km1,bi,bj))) |
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& ) |
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ENDDO |
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ENDDO |
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|
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C-- Vertical flux (fVerS) above |
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C Advective component of vertical flux |
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C Note: For K=1 then KM1=1 this gives a barZ(T) = T |
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C (this plays the role of the free-surface correction) |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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af(i,j) = |
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& wTrans(i,j)*(salt(i,j,k,bi,bj)+salt(i,j,kM1,bi,bj))*0.5 _d 0 |
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ENDDO |
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ENDDO |
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C Diffusive component of vertical flux |
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C Note: For K=1 then KM1=1 this gives a dS/dz = 0 upper |
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C boundary condition. |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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df(i,j) = _zA(i,j,bi,bj)*( |
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& -KapGM(i,j)*K13(i,j,k)*dSdx(i,j) |
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& -KapGM(i,j)*K23(i,j,k)*dSdy(i,j) |
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& ) |
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ENDDO |
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ENDDO |
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IF (.NOT.implicitDiffusion) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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df(i,j) = df(i,j) + _zA(i,j,bi,bj)*( |
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& -KappaZS(i,j,k)*rdzC(k) |
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& *(salt(i,j,kM1,bi,bj)-salt(i,j,k,bi,bj)) |
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& ) |
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ENDDO |
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ENDDO |
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ENDIF |
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C Net vertical flux |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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fVerS(i,j,kUp) = ( afFacS*af(i,j)+ dfFacS*df(i,j) )*maskUp(i,j) |
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ENDDO |
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ENDDO |
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IF ( TOP_LAYER ) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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fVerS(i,j,kUp) = afFacS*af(i,j)*freeSurfFac |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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C-- Tendency is minus divergence of the fluxes. |
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C Note. Tendency terms will only be correct for range |
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C i=iMin+1:iMax-1, j=jMin+1:jMax-1. Edge points |
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C will contain valid floating point numbers but |
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C they are not algorithmically correct. These points |
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C are not used. |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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C & -_rhFacC(i,j,k,bi,bj)*rdzF(k)*_rdxF(i,j,bi,bj)*_rdyF(i,j,bi,bj) |
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C & -_rhFacC(i,j,k,bi,bj)*rdzF(k)/_zA(i,j,bi,bj) |
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C #define _rVolS(i,j,k,bi,bj) _rhFacC(i,j,k,bi,bj)*rdzF(k)*_rdxF(i,j,bi,bj)*_rdyF(i,j,bi,bj) |
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#define _rVolS(i,j,k,bi,bj) _rhFacC(i,j,k,bi,bj)*rdzF(k)/_zA(i,j,bi,bj) |
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gS(i,j,k,bi,bj)= |
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& -_rVolS(i,j,k,bi,bj) |
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& *( |
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& +( fZon(i+1,j)-fZon(i,j) ) |
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& +( fMer(i,j+1)-fMer(i,j) ) |
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& +( fVerS(i,j,kUp)-fVerS(i,j,kDown) ) |
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& ) |
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ENDDO |
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ENDDO |
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|
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C-- External P-E forcing term(s) |
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|
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RETURN |
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END |