C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/mom_fluxform/mom_u_coriolis.F,v 1.3 2001/09/26 19:05:21 adcroft Exp $
C $Name:  $

#include "CPP_OPTIONS.h"

CBOP
C !ROUTINE: MOM_U_CORIOLIS

C !INTERFACE: ==========================================================
      SUBROUTINE MOM_U_CORIOLIS( 
     I        bi,bj,k,vFld,
     U        uCoriolisTerm,
     I        myThid)

C !DESCRIPTION:
C Calculates the horizontal Coriolis term in the zonal equation:
C \begin{equation*}
C \overline{f}^i \overline{v}^{ij}
C \end{equation*}

C !USES: ===============================================================
      IMPLICIT NONE
#include "SIZE.h"
#include "DYNVARS.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "GRID.h"
#include "SURFACE.h"

C !INPUT PARAMETERS: ===================================================
C  bi,bj                :: tile indices
C  k                    :: vertical level
C  vFld                 :: meridional flow
C  myThid               :: thread number
      INTEGER bi,bj,K
      _RL vFld(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      INTEGER myThid

C !OUTPUT PARAMETERS: ==================================================
C  uCoriolisTerm        :: Coriolis term
      _RL uCoriolisTerm(1-OLx:sNx+OLx,1-OLy:sNy+OLy)

C !LOCAL VARIABLES: ====================================================
C  i,j                  :: loop indices
      INTEGER I,J
CEOP

      DO j=1-Oly,sNy+Oly-1
       DO i=1-Olx+1,sNx+Olx
        uCoriolisTerm(i,j) =
     &     0.5*( _fCori( i ,j,bi,bj) +
     &           _fCori(i-1,j,bi,bj)  )
     &   *0.25*(
     &     vFld( i ,j)+vFld( i ,j+1)
     &    +vFld(i-1,j)+vFld(i-1,j+1)
     &         )
       ENDDO
      ENDDO

      RETURN
      END