pkg/generic_advdiff/gad_dst3fl_adv_x.F

C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_dst3fl_adv_x.F,v 1.4 2001/11/08 23:39:34 heimbach Exp $
C $Name:  $

#include "GAD_OPTIONS.h"

      SUBROUTINE GAD_DST3FL_ADV_X( 
     I           bi,bj,k,deltaT,
     I           uTrans, uVel,
     I           tracer,
     O           uT,
     I           myThid )
C     /==========================================================\
C     | SUBROUTINE GAD_DST3FL_ADV_X                              |
C     | o Compute Zonal advective Flux of Tracer using           |
C     |   3rd Order DST Sceheme with flux limiting               |
C     |==========================================================|
      IMPLICIT NONE

C     == GLobal variables ==
#include "SIZE.h"
#include "GRID.h"
#include "GAD.h"

C     == Routine arguments ==
      INTEGER bi,bj,k
      _RL deltaT
      _RL uTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL uVel(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy)
      _RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL uT    (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      INTEGER myThid

C     == Local variables ==
      INTEGER i,j
      _RL Rjm,Rj,Rjp,cfl,d0,d1,psiP,psiM,thetaP,thetaM

      DO j=1-Oly,sNy+Oly
       uT(1-Olx,j)=0.D0
       uT(2-Olx,j)=0.D0
       uT(sNx+Olx,j)=0.D0
       DO i=1-Olx+2,sNx+Olx-1
        Rjp=(tracer(i+1,j)-tracer(i,j))*maskW(i+1,j,k,bi,bj)
        Rj =(tracer(i,j)-tracer(i-1,j))*maskW(i,j,k,bi,bj)
        Rjm=(tracer(i-1,j)-tracer(i-2,j))*maskW(i-1,j,k,bi,bj)

        cfl=abs(uVel(i,j,k,bi,bj)*deltaT*recip_dxc(i,j,bi,bj))
        d0=(2.D0-cfl)*(1.D0-cfl)*oneSixth
        d1=(1.D0-cfl*cfl)*oneSixth
c       thetaP=0.D0
c       IF (Rj.NE.0.D0) thetaP=Rjm/Rj
        thetaP=Rjm/(1.D-20+Rj)
        psiP=d0+d1*thetaP
        psiP=max(0.D0, min(min(1.D0,psiP),
     &       (1.D0-cfl)/(1.D-20+cfl)*thetaP))
        thetaM=Rjp/(1.D-20+Rj)
c       thetaM=0.D0
c       IF (Rj.NE.0.D0) thetaM=Rjp/Rj
        psiM=d0+d1*thetaM
        psiM=max(0.D0, min(min(1.D0,psiM),
     &       (1.D0-cfl)/(1.D-20+cfl)*thetaM))
        uT(i,j)=
     &   0.5*(uTrans(i,j)+abs(uTrans(i,j)))
     &      *( Tracer(i-1,j) + psiP*Rj )
     &  +0.5*(uTrans(i,j)-abs(uTrans(i,j)))
     &      *( Tracer( i ,j) - psiM*Rj )

       ENDDO
      ENDDO

      RETURN
      END
1	C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_dst3fl_adv_x.F,v 1.4 2001/11/08 23:39:34 heimbach Exp $
2	C $Name: $
3
4	#include "GAD_OPTIONS.h"
5
6	SUBROUTINE GAD_DST3FL_ADV_X(
7	I bi,bj,k,deltaT,
8	I uTrans, uVel,
9	I tracer,
10	O uT,
11	I myThid )
12	C /==========================================================\
13	C \| SUBROUTINE GAD_DST3FL_ADV_X \|
14	C \| o Compute Zonal advective Flux of Tracer using \|
15	C \| 3rd Order DST Sceheme with flux limiting \|
16	C \|==========================================================\|
17	IMPLICIT NONE
18
19	C == GLobal variables ==
20	#include "SIZE.h"
21	#include "GRID.h"
22	#include "GAD.h"
23
24	C == Routine arguments ==
25	INTEGER bi,bj,k
26	_RL deltaT
27	_RL uTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
28	_RL uVel(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy)
29	_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
30	_RL uT (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
31	INTEGER myThid
32
33	C == Local variables ==
34	INTEGER i,j
35	_RL Rjm,Rj,Rjp,cfl,d0,d1,psiP,psiM,thetaP,thetaM
36
37	DO j=1-Oly,sNy+Oly
38	uT(1-Olx,j)=0.D0
39	uT(2-Olx,j)=0.D0
40	uT(sNx+Olx,j)=0.D0
41	DO i=1-Olx+2,sNx+Olx-1
42	Rjp=(tracer(i+1,j)-tracer(i,j))*maskW(i+1,j,k,bi,bj)
43	Rj =(tracer(i,j)-tracer(i-1,j))*maskW(i,j,k,bi,bj)
44	Rjm=(tracer(i-1,j)-tracer(i-2,j))*maskW(i-1,j,k,bi,bj)
45
46	cfl=abs(uVel(i,j,k,bi,bj)deltaTrecip_dxc(i,j,bi,bj))
47	d0=(2.D0-cfl)(1.D0-cfl)oneSixth
48	d1=(1.D0-cflcfl)oneSixth
49	c thetaP=0.D0
50	c IF (Rj.NE.0.D0) thetaP=Rjm/Rj
51	thetaP=Rjm/(1.D-20+Rj)
52	psiP=d0+d1*thetaP
53	psiP=max(0.D0, min(min(1.D0,psiP),
54	& (1.D0-cfl)/(1.D-20+cfl)*thetaP))
55	thetaM=Rjp/(1.D-20+Rj)
56	c thetaM=0.D0
57	c IF (Rj.NE.0.D0) thetaM=Rjp/Rj
58	psiM=d0+d1*thetaM
59	psiM=max(0.D0, min(min(1.D0,psiM),
60	& (1.D0-cfl)/(1.D-20+cfl)*thetaM))
61	uT(i,j)=
62	& 0.5*(uTrans(i,j)+abs(uTrans(i,j)))
63	& ( Tracer(i-1,j) + psiPRj )
64	& +0.5*(uTrans(i,j)-abs(uTrans(i,j)))
65	& ( Tracer( i ,j) - psiMRj )
66
67	ENDDO
68	ENDDO
69
70	RETURN
71	END