pkg/generic_advdiff/gad_fluxlimit_adv_x.F

C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_fluxlimit_adv_x.F,v 1.11 2007/04/04 01:39:06 jmc Exp $
C $Name:  $

#include "GAD_OPTIONS.h"

CBOP
C !ROUTINE: GAD_FLUXLIMIT_ADV_X

C !INTERFACE: ==========================================================
      SUBROUTINE GAD_FLUXLIMIT_ADV_X(
     I           bi,bj,k, calcCFL, deltaTloc,
     I           uTrans, uFld,
     I           maskLocW, tracer,
     O           uT,
     I           myThid )

C !DESCRIPTION:
C Calculates the area integrated zonal flux due to advection of a tracer
C using second-order interpolation with a flux limiter:
C \begin{equation*}
C F^x_{adv} = U \overline{ \theta }^i
C - \frac{1}{2} \left(
C     [ 1 - \psi(C_r) ] |U|
C    + U \frac{u \Delta t}{\Delta x_c} \psi(C_r)
C              \right) \delta_i \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"

C !INPUT PARAMETERS: ===================================================
C  bi,bj             :: tile indices
C  k                 :: vertical level
C  calcCFL           :: =T: calculate CFL number ; =F: take uFld as CFL
C  deltaTloc         :: local time-step (s)
C  uTrans            :: zonal volume transport
C  uFld              :: zonal flow / CFL number
C  tracer            :: tracer field
C  myThid            :: thread number
      INTEGER bi,bj,k
      LOGICAL calcCFL
      _RL deltaTloc
      _RL uTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL uFld  (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RS maskLocW(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      INTEGER myThid

C !OUTPUT PARAMETERS: ==================================================
C  uT                :: zonal advective flux
      _RL uT    (1-OLx:sNx+OLx,1-OLy:sNy+OLy)

C !LOCAL VARIABLES: ====================================================
C  i,j               :: loop indices
C  Cr                :: slope ratio
C  Rjm,Rj,Rjp        :: differences at i-1,i,i+1
      INTEGER i,j
      _RL Cr,Rjm,Rj,Rjp
      _RL uCFL
C Statement function provides Limiter(Cr)
#include "GAD_FLUX_LIMITER.h"
CEOP

      DO j=1-Oly,sNy+Oly
       uT(1-Olx,j)=0.
       uT(2-Olx,j)=0.
       uT(sNx+Olx,j)=0.
      ENDDO
      DO j=1-Oly,sNy+Oly
       DO i=1-Olx+2,sNx+Olx-1

        uCFL = uFld(i,j)
        IF ( calcCFL ) uCFL = ABS( uFld(i,j)*deltaTloc
     &                  *recip_dxC(i,j,bi,bj)*recip_deepFacC(k) )
        Rjp=(tracer(i+1,j)-tracer( i ,j))*maskLocW(i+1,j)
        Rj =(tracer( i ,j)-tracer(i-1,j))*maskLocW( i ,j)
        Rjm=(tracer(i-1,j)-tracer(i-2,j))*maskLocW(i-1,j)

        IF (Rj.NE.0.) THEN
         IF (uTrans(i,j).GT.0) THEN
           Cr=Rjm/Rj
         ELSE
           Cr=Rjp/Rj
         ENDIF
        ELSE
         IF (uTrans(i,j).GT.0) THEN
           Cr=Rjm*1.E20
         ELSE
           Cr=Rjp*1.E20
         ENDIF
        ENDIF
        Cr=Limiter(Cr)
        uT(i,j) =
     &   uTrans(i,j)*(Tracer(i,j)+Tracer(i-1,j))*0.5 _d 0
     &   -ABS(uTrans(i,j))*((1.-Cr)+uCFL*Cr)
     &                    *Rj*0.5 _d 0
       ENDDO
      ENDDO

      RETURN
      END
1	mlosch	1.12	C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_fluxlimit_adv_x.F,v 1.11 2007/04/04 01:39:06 jmc Exp $
2	jmc	1.2	C $Name: $
3	adcroft	1.1
4			#include "GAD_OPTIONS.h"
5
6	adcroft	1.3	CBOP
7			C !ROUTINE: GAD_FLUXLIMIT_ADV_X
8
9			C !INTERFACE: ==========================================================
10	jmc	1.8	SUBROUTINE GAD_FLUXLIMIT_ADV_X(
11	jmc	1.11	I bi,bj,k, calcCFL, deltaTloc,
12	jmc	1.8	I uTrans, uFld,
13	jmc	1.5	I maskLocW, tracer,
14	adcroft	1.1	O uT,
15			I myThid )
16	adcroft	1.3
17			C !DESCRIPTION:
18			C Calculates the area integrated zonal flux due to advection of a tracer
19			C using second-order interpolation with a flux limiter:
20			C \begin{equation*}
21	jmc	1.8	C F^x_{adv} = U \overline{ \theta }^i
22	adcroft	1.3	C - \frac{1}{2} \left(
23			C [ 1 - \psi(C_r) ] \|U\|
24			C + U \frac{u \Delta t}{\Delta x_c} \psi(C_r)
25			C \right) \delta_i \theta
26			C \end{equation*}
27			C where the $\psi(C_r)$ is the limiter function and $C_r$ is
28			C the slope ratio.
29
30			C !USES: ===============================================================
31	adcroft	1.1	IMPLICIT NONE
32			#include "SIZE.h"
33			#include "GRID.h"
34
35	adcroft	1.3	C !INPUT PARAMETERS: ===================================================
36	jmc	1.11	C bi,bj :: tile indices
37			C k :: vertical level
38			C calcCFL :: =T: calculate CFL number ; =F: take uFld as CFL
39			C deltaTloc :: local time-step (s)
40			C uTrans :: zonal volume transport
41			C uFld :: zonal flow / CFL number
42			C tracer :: tracer field
43			C myThid :: thread number
44	adcroft	1.1	INTEGER bi,bj,k
45	jmc	1.11	LOGICAL calcCFL
46	heimbach	1.6	_RL deltaTloc
47	adcroft	1.1	_RL uTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
48	jmc	1.8	_RL uFld (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
49	jmc	1.5	_RS maskLocW(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
50	adcroft	1.1	_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
51	adcroft	1.3	INTEGER myThid
52
53			C !OUTPUT PARAMETERS: ==================================================
54	jmc	1.11	C uT :: zonal advective flux
55	adcroft	1.1	_RL uT (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
56
57	adcroft	1.3	C !LOCAL VARIABLES: ====================================================
58	jmc	1.11	C i,j :: loop indices
59			C Cr :: slope ratio
60			C Rjm,Rj,Rjp :: differences at i-1,i,i+1
61	adcroft	1.1	INTEGER i,j
62			_RL Cr,Rjm,Rj,Rjp
63	jmc	1.11	_RL uCFL
64	adcroft	1.3	C Statement function provides Limiter(Cr)
65	adcroft	1.1	#include "GAD_FLUX_LIMITER.h"
66	adcroft	1.3	CEOP
67	adcroft	1.1
68			DO j=1-Oly,sNy+Oly
69			uT(1-Olx,j)=0.
70	jmc	1.2	uT(2-Olx,j)=0.
71			uT(sNx+Olx,j)=0.
72	mlosch	1.12	ENDDO
73			DO j=1-Oly,sNy+Oly
74	jmc	1.2	DO i=1-Olx+2,sNx+Olx-1
75	jmc	1.4
76	jmc	1.11	uCFL = uFld(i,j)
77			IF ( calcCFL ) uCFL = ABS( uFld(i,j)*deltaTloc
78	jmc	1.10	& recip_dxC(i,j,bi,bj)recip_deepFacC(k) )
79	jmc	1.5	Rjp=(tracer(i+1,j)-tracer( i ,j))*maskLocW(i+1,j)
80			Rj =(tracer( i ,j)-tracer(i-1,j))*maskLocW( i ,j)
81			Rjm=(tracer(i-1,j)-tracer(i-2,j))*maskLocW(i-1,j)
82	jmc	1.4
83	adcroft	1.1	IF (Rj.NE.0.) THEN
84			IF (uTrans(i,j).GT.0) THEN
85			Cr=Rjm/Rj
86			ELSE
87			Cr=Rjp/Rj
88			ENDIF
89			ELSE
90			IF (uTrans(i,j).GT.0) THEN
91			Cr=Rjm*1.E20
92			ELSE
93			Cr=Rjp*1.E20
94			ENDIF
95			ENDIF
96			Cr=Limiter(Cr)
97	jmc	1.8	uT(i,j) =
98	adcroft	1.1	& uTrans(i,j)(Tracer(i,j)+Tracer(i-1,j))0.5 _d 0
99	jmc	1.10	& -ABS(uTrans(i,j))((1.-Cr)+uCFLCr)
100			& Rj0.5 _d 0
101	adcroft	1.1	ENDDO
102			ENDDO
103
104			RETURN
105			END