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C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_dst3fl_adv_r.F,v 1.7 2006/06/18 23:31:35 jmc Exp $ |
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C $Name: $ |
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|
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#include "GAD_OPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: GAD_DST3FL_ADV_R |
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|
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C !INTERFACE: ========================================================== |
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SUBROUTINE GAD_DST3FL_ADV_R( |
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I bi,bj,k,dTarg, |
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I rTrans, wFld, |
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I tracer, |
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O wT, |
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I myThid ) |
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|
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C !DESCRIPTION: |
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C Calculates the area integrated vertical flux due to advection of a tracer |
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C using 3rd Order DST Scheme with flux limiting |
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|
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C !USES: =============================================================== |
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IMPLICIT NONE |
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|
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C == GLobal variables == |
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#include "SIZE.h" |
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#include "GRID.h" |
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#include "GAD.h" |
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|
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C == Routine arguments == |
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C !INPUT PARAMETERS: =================================================== |
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C bi,bj :: tile indices |
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C k :: vertical level |
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C deltaTloc :: local time-step (s) |
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C rTrans :: vertical volume transport |
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C wFld :: vertical flow |
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C tracer :: tracer field |
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C myThid :: thread number |
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INTEGER bi,bj,k |
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_RL dTarg |
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_RL rTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL wFld (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) |
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INTEGER myThid |
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|
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C !OUTPUT PARAMETERS: ================================================== |
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C wT :: vertical advective flux |
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_RL wT (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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|
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C == Local variables == |
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C !LOCAL VARIABLES: ==================================================== |
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C i,j :: loop indices |
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C km1 :: =max( k-1 , 1 ) |
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C wLoc :: velocity, vertical component |
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C wCFL :: Courant-Friedrich-Levy number |
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INTEGER i,j,kp1,km1,km2 |
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_RL Rjm,Rj,Rjp,cfl,d0,d1 |
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_RL psiP,psiM,thetaP,thetaM |
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_RL wLoc |
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_RL thetaMax |
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PARAMETER( thetaMax = 1.D+20 ) |
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|
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km2=MAX(1,k-2) |
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km1=MAX(1,k-1) |
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kp1=MIN(Nr,k+1) |
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|
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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Rjp=(tracer(i,j,k)-tracer(i,j,kp1)) |
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& *maskC(i,j,kp1,bi,bj) |
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Rj =(tracer(i,j,km1)-tracer(i,j,k)) |
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& *maskC(i,j,k,bi,bj)*maskC(i,j,km1,bi,bj) |
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Rjm=(tracer(i,j,km2)-tracer(i,j,km1)) |
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& *maskC(i,j,km1,bi,bj) |
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|
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wLoc = wFld(i,j) |
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c wLoc = rTrans(i,j)*recip_rA(i,j,bi,bj) |
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cfl=abs(wLoc*dTarg*recip_drC(k)) |
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d0=(2. _d 0 -cfl)*(1. _d 0 -cfl)*oneSixth |
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d1=(1. _d 0 -cfl*cfl)*oneSixth |
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|
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C- the old version: can produce overflow, division by zero, |
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C and is wrong for tracer with low concentration: |
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c thetaP=Rjm/(1.D-20+Rj) |
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c thetaM=Rjp/(1.D-20+Rj) |
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C- the right expression, but not bounded: |
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c thetaP=0.D0 |
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c thetaM=0.D0 |
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c IF (Rj.NE.0.D0) thetaP=Rjm/Rj |
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c IF (Rj.NE.0.D0) thetaM=Rjp/Rj |
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C- prevent |thetaP,M| to reach too big value: |
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IF ( ABS(Rj)*thetaMax .LE. ABS(Rjm) ) THEN |
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thetaP=SIGN(thetaMax,Rjm*Rj) |
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ELSE |
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thetaP=Rjm/Rj |
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ENDIF |
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IF ( ABS(Rj)*thetaMax .LE. ABS(Rjp) ) THEN |
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thetaM=SIGN(thetaMax,Rjp*Rj) |
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ELSE |
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thetaM=Rjp/Rj |
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ENDIF |
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|
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psiP=d0+d1*thetaP |
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psiP=MAX(0. _d 0,MIN(MIN(1. _d 0,psiP), |
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& thetaP*(1. _d 0 -cfl)/(cfl+1. _d -20) )) |
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psiM=d0+d1*thetaM |
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psiM=MAX(0. _d 0,MIN(MIN(1. _d 0,psiM), |
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& thetaM*(1. _d 0 -cfl)/(cfl+1. _d -20) )) |
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|
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wT(i,j)= |
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& 0.5*(rTrans(i,j)+abs(rTrans(i,j))) |
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& *( tracer(i,j, k ) + psiM*Rj ) |
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& +0.5*(rTrans(i,j)-abs(rTrans(i,j))) |
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& *( tracer(i,j,km1) - psiP*Rj ) |
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|
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ENDDO |
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ENDDO |
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|
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RETURN |
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END |
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