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C $Header: /u/u0/gcmpack/MITgcm/pkg/mom_fluxform/mom_v_sidedrag.F,v 1.3 2001/09/26 19:05:21 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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CBOP | 
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C !ROUTINE: MOM_V_SIDEDRAG | 
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 | 
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C !INTERFACE: ========================================================== | 
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      SUBROUTINE MOM_V_SIDEDRAG( | 
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     I        bi,bj,k, | 
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     I        vFld, del2v, hFacZ, | 
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     O        vDragTerms, | 
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     I        myThid) | 
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 | 
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C !DESCRIPTION: | 
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C Calculates the drag terms due to the no-slip condition on viscous stresses: | 
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C \begin{equation*} | 
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C G^v_{drag} = - \frac{2}{\Delta x_v} (A_h v - A_4 \nabla^2 v) | 
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C \end{equation*} | 
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 | 
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C !USES: =============================================================== | 
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      IMPLICIT NONE | 
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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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#include "GRID.h" | 
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 | 
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C !INPUT PARAMETERS: =================================================== | 
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C  bi,bj                :: tile indices | 
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C  k                    :: vertical level | 
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C  uvld                 :: meridional flow | 
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C  del2v                :: Laplacian of meridional flow | 
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C  hFacZ                :: fractional open water at vorticity points | 
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C  myThid               :: thread number | 
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      INTEGER bi,bj,k | 
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      _RL vFld(1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
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      _RL del2v(1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
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      _RS hFacZ(1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
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      INTEGER myThid | 
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 | 
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C !OUTPUT PARAMETERS: ================================================== | 
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C  vDragTerms           :: drag term | 
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      _RL vDragTerms(1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
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 | 
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C !LOCAL VARIABLES: ==================================================== | 
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C  i,j                  :: loop indices | 
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C  hFacZClosedE         :: fractional open water to east | 
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C  hFacZClosedW         :: fractional open water to west | 
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      INTEGER I,J | 
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      _RS hFacZClosedE,hFacZClosedW | 
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      _RS gridScalingA4 | 
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      _RS gridScalingAh | 
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CEOP | 
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 | 
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C     - Laplacian  and bi-harmonic terms | 
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      DO j=1-Oly,sNy+Oly-1 | 
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       DO i=1-Olx,sNx+Olx-1 | 
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        hFacZClosedW = _hFacS(i,j,k,bi,bj) - hFacZ(i,j) | 
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        hFacZClosedE = _hFacS(i,j,k,bi,bj) - hFacZ(i+1,j) | 
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        gridScalingA4 = (_dxV(i,j,bi,bj)**4)/(5000.**4)   ! Really should split this loop for a more precise formulation | 
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        gridScalingAh = (_dxV(i,j,bi,bj)**2)/(5000.**2)   ! Really should split this loop for a more precise formulation | 
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        vDragTerms(i,j) = | 
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     &   -_recip_hFacS(i,j,k,bi,bj) | 
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     &   *recip_drF(k)*recip_rAs(i,j,bi,bj) | 
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     &   *( hFacZClosedW*_dyU( i ,j,bi,bj) | 
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     &      *_recip_dxV( i ,j,bi,bj) | 
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     &     +hFacZClosedE*_dyU(i+1,j,bi,bj) | 
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     &      *_recip_dxV(i+1,j,bi,bj) ) | 
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     &   *drF(k)*2.*( | 
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     &                viscAh*vFld(i,j)*cosFacV(J,bi,bj) | 
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     &                      *gridScalingAh | 
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     &               -viscA4*del2v(i,j)*cosFacV(J,bi,bj) | 
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     &                      *gridScalingA4 | 
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#ifdef COSINEMETH_III | 
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     &               -viscA4*del2v(i,j)*sqcosFacV(J,bi,bj) | 
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#else | 
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     &               -viscA4*del2v(i,j)*cosFacV(J,bi,bj) | 
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#endif | 
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     &              ) | 
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       ENDDO | 
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      ENDDO | 
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 | 
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      RETURN | 
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      END |