C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_diff_r.F,v 1.7 2014/08/18 12:22:46 jmc Exp $
C $Name: $
#include "GAD_OPTIONS.h"
CBOP
C !ROUTINE: GAD_DIFF_R
C !INTERFACE: ==========================================================
SUBROUTINE GAD_DIFF_R(
I bi, bj, k,
I KappaR,
I tracer,
O dfr,
I myThid )
C !DESCRIPTION:
C Calculates the area integrated vertical flux due to down-gradient
C diffusion of a tracer:
C \begin{equation*}
C F^r_{diff} = - A^r \kappa_r \frac{1}{\Delta r_c} \delta_k \theta
C \end{equation*}
C !USES: ===============================================================
IMPLICIT NONE
#include "SIZE.h"
#include "GRID.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
C !INPUT PARAMETERS: ===================================================
C bi,bj :: tile indices
C k :: vertical level
C KappaR :: vertical diffusivity
C tracer :: tracer field
C myThid :: thread number
INTEGER bi,bj,k
_RL KappaR(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
INTEGER myThid
C !OUTPUT PARAMETERS: ==================================================
C dfr :: vertical diffusive flux
_RL dfr (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
C !LOCAL VARIABLES: ====================================================
C i,j :: loop indices
C km1 :: =k+1 for k-Nr
INTEGER i,j,km1
CEOP
km1=MAX(1,k-1)
IF (k.EQ.1 .OR. k.GT.Nr) THEN
DO j=1-OLy,sNy+OLy
DO i=1-OLx,sNx+OLx
dfr(i,j) = 0.
ENDDO
ENDDO
ELSE
DO j=1-OLy,sNy+OLy
DO i=1-OLx,sNx+OLx
dfr(i,j) = -KappaR(i,j)
& *_rA(i,j,bi,bj)*deepFac2F(k)*rhoFacF(k)
& *recip_drC(k)
& *(tracer(i,j,k)-tracer(i,j,km1))*rkSign
ENDDO
ENDDO
ENDIF
RETURN
END