C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_diff_x.F,v 1.4 2006/12/05 05:26:46 jmc Exp $ C $Name: $ #include "GAD_OPTIONS.h" CBOP C !ROUTINE: GAD_DIFF_X C !INTERFACE: ========================================================== SUBROUTINE GAD_DIFF_X( I bi,bj,k, I xA, diffKh, I tracer, O dfx, I myThid ) C !DESCRIPTION: C Calculates the area integrated zonal flux due to down-gradient diffusion C of a tracer: C \begin{equation*} C F^x_{diff} = - A^x \kappa_h \frac{1}{\Delta x_c} \delta_i \theta C \end{equation*} C !USES: =============================================================== IMPLICIT NONE #include "SIZE.h" #include "GRID.h" C !INPUT PARAMETERS: =================================================== C bi,bj :: tile indices C k :: vertical level C xA :: area of face at U points C diffKh :: horizontal diffusivity C tracer :: tracer field C myThid :: thread number INTEGER bi,bj,k _RS xA (1-OLx:sNx+OLx,1-OLy:sNy+OLy) _RL diffKh _RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy) INTEGER myThid C !OUTPUT PARAMETERS: ================================================== C dfx :: zonal diffusive flux _RL dfx (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 dfx(1-Olx,j)=0. DO i=1-Olx+1,sNx+Olx dfx(i,j) = -diffKh*xA(i,j) & *_recip_dxC(i,j,bi,bj)*recip_deepFacC(k) & *(tracer(i,j)-tracer(i-1,j)) & *cosFacU(j,bi,bj) ENDDO ENDDO RETURN END