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C $Header: /u/gcmpack/models/MITgcmUV/model/src/timestep.F,v 1.25 2001/07/31 15:01:33 adcroft Exp $ |
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C $Name: $ |
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|
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#include "CPP_OPTIONS.h" |
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|
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C /==========================================================\ |
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C | S/R TIMESTEP | |
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C | o Step model fields forward in time | |
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C \==========================================================/ |
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SUBROUTINE TIMESTEP( bi, bj, iMin, iMax, jMin, jMax, K, |
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I phiHyd, phiSurfX, phiSurfY, |
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I myIter, myThid ) |
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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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#include "SURFACE.h" |
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|
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C == Routine Arguments == |
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C phiHyd - Hydrostatic Potential (ocean: pressure/rho) |
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C (atmos: geopotentiel) |
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C phiSurfX, - gradient of Surface potentiel (Pressure/rho, ocean) |
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C phiSurfY or geopotentiel (atmos) in X and Y direction |
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INTEGER bi,bj,iMin,iMax,jMin,jMax |
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INTEGER K |
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_RL phiHyd(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) |
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_RL phiSurfX(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL phiSurfY(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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INTEGER myIter, myThid |
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|
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C == Local variables == |
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INTEGER i,j |
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_RL ab15,ab05 |
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_RL phxFac,phyFac, psFac |
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_RL gUtmp(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL gVtmp(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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|
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C Adams-Bashforth timestepping weights |
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IF (myIter .EQ. 0) THEN |
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ab15=1.0 |
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ab05=0.0 |
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ELSE |
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ab15=1.5+abeps |
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ab05=-0.5-abeps |
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ENDIF |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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C- Compute effective gU term (including Adams-Bashforth weights) : |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gUtmp(i,j) = ab15*gU(i,j,k,bi,bj) |
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& + ab05*gUNm1(i,j,k,bi,bj) |
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#ifdef INCLUDE_CD_CODE |
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& + guCD(i,j,k,bi,bj) |
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#endif |
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ENDDO |
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ENDDO |
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|
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#ifdef NONLIN_FRSURF |
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IF (.NOT. vectorInvariantMomentum |
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& .AND. nonlinFreeSurf.GT.1) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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IF ( k.EQ.ksurfW(i,j,bi,bj) ) THEN |
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gUtmp(i,j) = gUtmp(i,j) |
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& *hFacW(i,j,k,bi,bj)/hFac_surfW(i,j,bi,bj) |
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ENDIF |
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ENDDO |
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ENDDO |
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ENDIF |
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#endif |
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|
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C Step forward zonal velocity (store in Gu) |
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psFac = pfFacMom*(1. _d 0 - implicSurfPress) |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gUNm1(i,j,k,bi,bj) = uVel(i,j,k,bi,bj) |
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& +deltaTmom*( |
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& gUtmp(i,j) |
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& - psFac*phiSurfX(i,j) |
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& )*_maskW(i,j,k,bi,bj) |
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ENDDO |
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ENDDO |
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|
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IF (staggerTimeStep) THEN |
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C-- -grad Phi_Hyd has not been incorporated to gU and is added here: |
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phxFac = pfFacMom*deltaTmom |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gUNm1(i,j,k,bi,bj)=gUNm1(i,j,k,bi,bj) |
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& - _recip_dxC(i,j,bi,bj) |
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& *(phiHyd(i,j,k)-phiHyd(i-1,j,k))*phxFac |
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& *_maskW(i,j,k,bi,bj) |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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C- Compute effective gV term (including Adams-Bashforth weights) : |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gVtmp(i,j) = ab15*gV(i,j,k,bi,bj) |
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& + ab05*gVNm1(i,j,k,bi,bj) |
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#ifdef INCLUDE_CD_CODE |
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& + gvCD(i,j,k,bi,bj) |
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#endif |
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ENDDO |
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ENDDO |
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|
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#ifdef NONLIN_FRSURF |
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IF (.NOT. vectorInvariantMomentum |
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& .AND. nonlinFreeSurf.GT.1) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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IF ( k.EQ.ksurfS(i,j,bi,bj) ) THEN |
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gVtmp(i,j) = gVtmp(i,j) |
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& *hFacS(i,j,k,bi,bj)/hFac_surfS(i,j,bi,bj) |
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ENDIF |
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ENDDO |
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ENDDO |
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ENDIF |
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#endif |
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|
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C Step forward meridional velocity (store in Gv) |
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psFac = pfFacMom*(1. _d 0 - implicSurfPress) |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gVNm1(i,j,k,bi,bj) = vVel(i,j,k,bi,bj) |
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& +deltaTmom*( |
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& gVtmp(i,j) |
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& - psFac*phiSurfY(i,j) |
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& )*_maskS(i,j,k,bi,bj) |
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ENDDO |
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ENDDO |
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|
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IF (staggerTimeStep) THEN |
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C-- -grad Phi_Hyd has not been incorporated to gV and is added here: |
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phyFac = pfFacMom*deltaTmom |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gVNm1(i,j,k,bi,bj)=gVNm1(i,j,k,bi,bj) |
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& - _recip_dyC(i,j,bi,bj) |
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& *(phiHyd(i,j,k)-phiHyd(i,j-1,k))*phyFac |
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& *_maskS(i,j,k,bi,bj) |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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RETURN |
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END |