C $Header: /u/gcmpack/MITgcm/pkg/mom_vecinv/mom_vi_v_coriolis.F,v 1.13 2008/05/05 22:45:00 jmc Exp $
C $Name: $
#include "MOM_VECINV_OPTIONS.h"
CBOP
C !ROUTINE: MOM_VI_V_CORIOLIS
C !INTERFACE:
SUBROUTINE MOM_VI_V_CORIOLIS(
I bi, bj, k,
I uFld, omega3, hFacZ, r_hFacZ,
O vCoriolisTerm,
I myThid )
C !DESCRIPTION: \bv
C *==========================================================*
C | S/R MOM_VI_V_CORIOLIS
C |==========================================================*
C | o Calculate flux (in X-dir.) of vorticity at V point
C | using 2nd order interpolation
C *==========================================================*
C \ev
C !USES:
IMPLICIT NONE
C == Global variables ==
#include "SIZE.h"
#include "EEPARAMS.h"
#include "GRID.h"
#include "PARAMS.h"
C !INPUT/OUTPUT PARAMETERS:
C == Routine arguments ==
INTEGER bi, bj, k
_RL uFld (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL omega3 (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RS hFacZ (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RS r_hFacZ (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL vCoriolisTerm(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
INTEGER myThid
CEOP
C == Local variables ==
C msgBuf :: Informational/error meesage buffer
CHARACTER*(MAX_LEN_MBUF) msgBuf
LOGICAL upwindVort3
INTEGER i, j
_RL uBarXY, uBarYm, uBarYp
_RL vort3v
_RL vort3im, vort3ij, vort3pm, vort3pj
_RL oneThird, tmpFac
_RS epsil
PARAMETER( upwindVort3 = .FALSE. )
epsil = 1. _d -9
tmpFac = 1. _d 0
c oneThird = 1. _d 0 / ( 1. _d 0 + 2.*tmpFac )
oneThird = 1. _d 0 / 3. _d 0
IF ( selectVortScheme.EQ.0 ) THEN
C-- using enstrophy conserving scheme (Shallow-Water Eq.) by Sadourny, JAS 75
DO j=2-Oly,sNy+Oly
DO i=1-Olx,sNx+Olx-1
uBarXY=0.25*(
& (uFld( i , j )*dyG( i , j ,bi,bj)*_hFacW( i , j ,k,bi,bj)
& +uFld( i ,j-1)*dyG( i ,j-1,bi,bj)*_hFacW( i ,j-1,k,bi,bj))
& +(uFld(i+1, j )*dyG(i+1, j ,bi,bj)*_hFacW(i+1, j ,k,bi,bj)
& +uFld(i+1,j-1)*dyG(i+1,j-1,bi,bj)*_hFacW(i+1,j-1,k,bi,bj))
& )
IF (upwindVort3) THEN
IF (uBarXY.GT.0.) THEN
vort3v=omega3(i,j)*r_hFacZ(i,j)
ELSE
vort3v=omega3(i+1,j)*r_hFacZ(i+1,j)
ENDIF
ELSE
vort3v=0.5*(omega3(i,j)*r_hFacZ(i,j)
& +omega3(i+1,j)*r_hFacZ(i+1,j))
ENDIF
vCoriolisTerm(i,j)= -vort3v*uBarXY*recip_dyC(i,j,bi,bj)
& * _maskS(i,j,k,bi,bj)
ENDDO
ENDDO
ELSEIF ( selectVortScheme.EQ.1 ) THEN
C-- same as above, with different formulation (relatively to hFac)
DO j=2-Oly,sNy+Oly
DO i=1-Olx,sNx+Olx-1
uBarXY= 0.5*(
& (uFld( i , j )*dyG( i , j ,bi,bj)*hFacZ( i ,j)
& +uFld( i ,j-1)*dyG( i ,j-1,bi,bj)*hFacZ( i ,j))
& +(uFld(i+1, j )*dyG(i+1, j ,bi,bj)*hFacZ(i+1,j)
& +uFld(i+1,j-1)*dyG(i+1,j-1,bi,bj)*hFacZ(i+1,j))
& )/MAX( epsil, hFacZ(i,j)+hFacZ(i+1,j) )
IF (upwindVort3) THEN
IF (uBarXY.GT.0.) THEN
vort3v=omega3(i,j)
ELSE
vort3v=omega3(i+1,j)
ENDIF
ELSE
vort3v=0.5*(omega3(i,j)+omega3(i+1,j))
ENDIF
vCoriolisTerm(i,j)= -vort3v*uBarXY*recip_dyC(i,j,bi,bj)
& * _maskS(i,j,k,bi,bj)
ENDDO
ENDDO
ELSEIF ( selectVortScheme.EQ.2 ) THEN
C-- using energy conserving scheme (used by Sadourny in JAS 75 paper)
DO j=2-Oly,sNy+Oly
DO i=1-Olx,sNx+Olx-1
uBarYm=0.5*(
& uFld( i , j )*dyG( i , j ,bi,bj)*_hFacW( i , j ,k,bi,bj)
& +uFld( i ,j-1)*dyG( i ,j-1,bi,bj)*_hFacW( i ,j-1,k,bi,bj) )
uBarYp=0.5*(
& uFld(i+1, j )*dyG(i+1, j ,bi,bj)*_hFacW(i+1, j ,k,bi,bj)
& +uFld(i+1,j-1)*dyG(i+1,j-1,bi,bj)*_hFacW(i+1,j-1,k,bi,bj) )
IF (upwindVort3) THEN
IF ( (uBarYm+uBarYp) .GT.0.) THEN
vort3v=uBarYm*r_hFacZ( i ,j)*omega3( i ,j)
ELSE
vort3v=uBarYp*r_hFacZ(i+1,j)*omega3(i+1,j)
ENDIF
ELSE
vort3v = ( uBarYm*r_hFacZ( i ,j)*omega3( i ,j)
& +uBarYp*r_hFacZ(i+1,j)*omega3(i+1,j)
& )*0.5 _d 0
ENDIF
vCoriolisTerm(i,j)= -vort3v*recip_dyC(i,j,bi,bj)
& * _maskS(i,j,k,bi,bj)
ENDDO
ENDDO
ELSEIF ( selectVortScheme.EQ.3 ) THEN
C-- using energy & enstrophy conserving scheme
C (from Sadourny, described by Burridge & Haseler, ECMWF Rep.4, 1977)
C domain where vCoriolisTerm is valid :
C [ 2-Olx : sNx+Olx-1 ] x [ 3-Oly : sNy+Oly-1 ]
C (=> might need overlap of 3 if using CD-scheme)
DO j=2-Oly,sNy+Oly-1
DO i=1-Olx,sNx+Olx-1
vort3im= ( r_hFacZ(i, j )*omega3(i, j )
& +(r_hFacZ(i+1,j)*omega3(i+1,j)
& +r_hFacZ(i,j-1)*omega3(i,j-1)
& ))*oneThird
c & )*tmpFac)*oneThird
& *uFld( i ,j-1)*dyG( i ,j-1,bi,bj)*_hFacW( i ,j-1,k,bi,bj)
vort3ij= ( r_hFacZ(i, j )*omega3(i, j )
& +(r_hFacZ(i+1,j)*omega3(i+1,j)
& +r_hFacZ(i,j+1)*omega3(i,j+1)
& ))*oneThird
c & )*tmpFac)*oneThird
& *uFld( i , j )*dyG( i , j ,bi,bj)*_hFacW( i , j ,k,bi,bj)
vort3pm= ( r_hFacZ(i+1,j)*omega3(i+1,j)
& +(r_hFacZ(i, j )*omega3(i, j )
& +r_hFacZ(i+1,j-1)*omega3(i+1,j-1)
& ))*oneThird
c & )*tmpFac)*oneThird
& *uFld(i+1,j-1)*dyG(i+1,j-1,bi,bj)*_hFacW(i+1,j-1,k,bi,bj)
vort3pj= ( r_hFacZ(i+1,j)*omega3(i+1,j)
& +(r_hFacZ(i, j )*omega3(i, j )
& +r_hFacZ(i+1,j+1)*omega3(i+1,j+1)
& ))*oneThird
c & )*tmpFac)*oneThird
& *uFld(i+1, j )*dyG(i+1, j ,bi,bj)*_hFacW(i+1, j ,k,bi,bj)
C---
vCoriolisTerm(i,j)= -( (vort3im+vort3ij)+(vort3pm+vort3pj) )
& *0.25 _d 0 *recip_dyC(i,j,bi,bj)
& * _maskS(i,j,k,bi,bj)
ENDDO
ENDDO
ELSE
WRITE(msgBuf,'(A,I5,A)')
& 'MOM_VI_V_CORIOLIS: selectVortScheme=', selectVortScheme,
& ' not implemented'
CALL PRINT_ERROR( msgBuf, myThid )
STOP 'ABNORMAL END: S/R MOM_VI_V_CORIOLIS'
ENDIF
IF ( useJamartMomAdv ) THEN
DO j=2-Oly,sNy+Oly-1
DO i=1-Olx,sNx+Olx-1
vCoriolisTerm(i,j) = vCoriolisTerm(i,j)
& * 4. _d 0 * _hFacS(i,j,k,bi,bj)
& / MAX( epsil,
& (_hFacW( i ,j,k,bi,bj)+_hFacW( i ,j-1,k,bi,bj))
& +(_hFacW(i+1,j,k,bi,bj)+_hFacW(i+1,j-1,k,bi,bj))
& )
ENDDO
ENDDO
ENDIF
RETURN
END