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C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_dst3fl_adv_r.F,v 1.4 2002/03/06 01:29:36 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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SUBROUTINE GAD_DST3FL_ADV_R( |
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I bi_arg,bj_arg,k,dTarg, |
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I rTrans, wVel, |
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I tracer, |
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O wT, |
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I myThid ) |
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C /==========================================================\ |
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C | SUBROUTINE GAD_DST3_ADV_R | |
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C | o Compute Vertical advective Flux of Tracer using | |
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C | 3rd Order DST Sceheme with flux limiting | |
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C |==========================================================| |
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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 "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "GAD.h" |
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|
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C == Routine arguments == |
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INTEGER bi_arg,bj_arg,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 wVel(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL wT (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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INTEGER myThid |
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|
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C == Local variables == |
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C wFld :: velocity, vertical component |
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INTEGER i,j,kp1,km1,km2,bi,bj |
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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 wFld |
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_RL thetaMax |
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PARAMETER( thetaMax = 1.D+20 ) |
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|
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IF (.NOT. multiDimAdvection) THEN |
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C If using the standard time-stepping/advection schemes (ie. AB-II) |
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C then the data-structures are all global arrays |
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bi=bi_arg |
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bj=bj_arg |
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ELSE |
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C otherwise if using the multi-dimensional advection schemes |
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C then the data-structures are all local arrays except |
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C for maskC(...) and wVel(...) |
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bi=1 |
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bj=1 |
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ENDIF |
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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,bi,bj)-tracer(i,j,kp1,bi,bj)) |
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& *maskC(i,j,kp1,bi_arg,bj_arg) |
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Rj =(tracer(i,j,km1,bi,bj)-tracer(i,j,k,bi,bj)) |
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& *maskC(i,j,k,bi_arg,bj_arg)*maskC(i,j,km1,bi_arg,bj_arg) |
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Rjm=(tracer(i,j,km2,bi,bj)-tracer(i,j,km1,bi,bj)) |
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& *maskC(i,j,km1,bi_arg,bj_arg) |
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|
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c wFld = wVel(i,j,k,bi_arg,bj_arg) |
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wFld = rTrans(i,j)*recip_rA(i,j,bi_arg,bj_arg) |
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cfl=abs(wFld*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 ,bi,bj) + psiM*Rj ) |
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& +0.5*(rTrans(i,j)-abs(rTrans(i,j))) |
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& *( Tracer(i,j,km1,bi,bj) - 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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