C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_fluxlimit_adv_r.F,v 1.12 2006/12/05 22:25:41 jmc Exp $ C $Name: $ #include "GAD_OPTIONS.h" CBOP C !ROUTINE: GAD_FLUXLIMIT_ADV_R C !INTERFACE: ========================================================== SUBROUTINE GAD_FLUXLIMIT_ADV_R( I bi,bj,k,dTarg, I rTrans, wFld, I tracer, O wT, I myThid ) C !DESCRIPTION: C Calculates the area integrated vertical flux due to advection of a tracer C using second-order interpolation with a flux limiter: C \begin{equation*} C F^x_{adv} = W \overline{ \theta }^k C - \frac{1}{2} \left( C [ 1 - \psi(C_r) ] |W| C + W \frac{w \Delta t}{\Delta r_c} \psi(C_r) C \right) \delta_k \theta C \end{equation*} C where the $\psi(C_r)$ is the limiter function and $C_r$ is C the slope ratio. 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 rTrans :: vertical volume transport C wFld :: vertical flow C tracer :: tracer field C myThid :: thread number INTEGER bi,bj,k _RL dTarg _RL rTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) _RL wFld (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 wT :: vertical advective flux _RL wT (1-OLx:sNx+OLx,1-OLy:sNy+OLy) C !LOCAL VARIABLES: ==================================================== C i,j :: loop indices C kp1 :: =min( k+1 , Nr ) C km1 :: =max( k-1 , 1 ) C km2 :: =max( k-2 , 1 ) C bi,bj :: tile indices or (1,1) depending on use C Cr :: slope ratio C Rjm,Rj,Rjp :: differences at i-1,i,i+1 C wLoc :: velocity, vertical component INTEGER i,j,kp1,km1,km2 _RL Cr,Rjm,Rj,Rjp _RL wLoc, wCFL C Statement function provides Limiter(Cr) #include "GAD_FLUX_LIMITER.h" CEOP km2=MAX(1,k-2) km1=MAX(1,k-1) kp1=MIN(Nr,k+1) IF ( k.GT.Nr) THEN DO j=1-Oly,sNy+Oly DO i=1-Olx,sNx+Olx wT(i,j) = 0. ENDDO ENDDO ELSE DO j=1-Oly,sNy+Oly DO i=1-Olx,sNx+Olx wLoc = wFld(i,j) wCFL = ABS( wLoc*dTarg*recip_drC(k) ) Rjp=(tracer(i,j,kp1)-tracer(i,j,k)) & *maskC(i,j,kp1,bi,bj) Rj= (tracer(i,j,k) -tracer(i,j,kM1)) Rjm=(tracer(i,j,km1)-tracer(i,j,kM2)) & *maskC(i,j,km2,bi,bj) IF (Rj.NE.0.) THEN IF (rTrans(i,j).LT.0.) THEN Cr=Rjm/Rj ELSE Cr=Rjp/Rj ENDIF ELSE IF (rTrans(i,j).LT.0.) THEN Cr=Rjm*1.E20 ELSE Cr=Rjp*1.E20 ENDIF ENDIF Cr=Limiter(Cr) wT(i,j) = maskC(i,j,kM1,bi,bj)*( & rTrans(i,j)* & (tracer(i,j,k)+tracer(i,j,kM1))*0.5 _d 0 & +ABS(rTrans(i,j))*((1.-Cr)+wCFL*Cr) & *Rj*0.5 _d 0 ) ENDDO ENDDO ENDIF RETURN END