C $Header: /u/gcmpack/MITgcm/pkg/cheapaml/gad_diff_2d_x.F,v 1.6 2012/08/27 19:07:55 jmc Exp $ C $Name: $ #include "GAD_OPTIONS.h" CBOP C !ROUTINE: GAD_DIFF_2d_X C !INTERFACE: ========================================================== SUBROUTINE GAD_DIFF_2D_X( I bi,bj, I 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 diffKh :: horizontal diffusivity C tracer :: tracer field C myThid :: thread number INTEGER bi,bj _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 & *_recip_dxC(i,j,bi,bj) & *(Tracer(i,j)-Tracer(i-1,j)) & *CosFacU(j,bi,bj) ENDDO ENDDO RETURN END