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C $Header: /u/gcmpack/MITgcm/model/src/timestep.F,v 1.30 2003/02/09 02:00:50 jmc 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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CBOP |
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C !ROUTINE: TIMESTEP |
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C !INTERFACE: |
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SUBROUTINE TIMESTEP( bi, bj, iMin, iMax, jMin, jMax, K, |
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I dPhiHydX,dPhiHydY, phiSurfX, phiSurfY, |
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I myIter, myThid ) |
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C !DESCRIPTION: \bv |
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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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C \ev |
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|
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C !USES: |
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IMPLICIT NONE |
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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 !INPUT/OUTPUT PARAMETERS: |
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C == Routine Arguments == |
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C dPhiHydX,Y :: Gradient (X & Y directions) of Hydrostatic Potential |
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C phiSurfX :: gradient of Surface potential (Pressure/rho, ocean) |
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C phiSurfY :: or geopotential (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 dPhiHydX(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL dPhiHydY(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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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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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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CEOP |
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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-- stagger time step: grad Phi_Hyp is not in gU,gV => add it in this S/R |
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IF (staggerTimeStep) THEN |
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phxFac = pfFacMom |
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phyFac = pfFacMom |
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ELSE |
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phxFac = 0. |
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phyFac = 0. |
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ENDIF |
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|
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C-- explicit part of the surface potential gradient is added in this S/R |
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psFac = pfFacMom*(1. _d 0 - implicSurfPress) |
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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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IF (select_rStar.GT.0) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gUtmp(i,j) = gUtmp(i,j)/rStarExpW(i,j,bi,bj) |
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ENDDO |
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ENDDO |
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ELSE |
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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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#endif |
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|
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C Step forward zonal velocity (store in Gu) |
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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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& - phxFac*dPhiHydX(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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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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IF (select_rStar.GT.0) THEN |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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gVtmp(i,j) = gVtmp(i,j)/rStarExpS(i,j,bi,bj) |
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ENDDO |
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ENDDO |
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ELSE |
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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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#endif |
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|
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C Step forward meridional velocity (store in Gv) |
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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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& - phyFac*dPhiHydY(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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RETURN |
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END |
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