pkg/generic_advdiff/gad_biharm_x.F

C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_biharm_x.F,v 1.3 2004/12/16 22:29:35 jmc Exp $
C $Name:  $

#include "GAD_OPTIONS.h"

CBOP
C !ROUTINE: GAD_BIHARM_X

C !INTERFACE: ==========================================================
      SUBROUTINE GAD_BIHARM_X(
     I           bi,bj,k,
     I           xA,del2T,diffK4,
     U           dfx,
     I           myThid )

C !DESCRIPTION:
C Calculates the zonal flux due to bi-harmonic diffusion of a tracer.
C Routine takes the laplacian of the tracer as argument and calculates
C the zonal gradient:
C \begin{equation*}
C F^x_{diff} = \kappa_4 \partial_x \nabla^2 \theta
C \end{equation*}

C !USES: ===============================================================
      IMPLICIT NONE
#include "SIZE.h"
#include "GRID.h"

C !INPUT PARAMETERS: ===================================================
C  bi,bj                :: tile indices
C  k                    :: vertical level
C  xA                   :: area of face at U points
C  del2T                :: Laplacian of tracer
C  myThid               :: thread number
      INTEGER bi,bj,k
      _RS xA   (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL del2T(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL diffK4
      INTEGER myThid

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

C !LOCAL VARIABLES: ====================================================
C  i,j                  :: loop indices
      INTEGER i,j
CEOP

C     Difference of zonal fluxes ...
      DO j=1-Oly,sNy+Oly
c      dfx(1-Olx,j) = 0.
       DO i=1-Olx+1,sNx+Olx
c        dfx(i,j) = diffK4*xA(i,j)
         dfx(i,j) = dfx(i,j) + diffK4*xA(i,j)
     &    *_recip_dxC(i,j,bi,bj)*recip_deepFacC(k)
     &    *(del2T(i,j)-del2T(i-1,j))
#ifdef COSINEMETH_III
     &    *sqCosFacU(j,bi,bj)
#else
     &    *cosFacU(j,bi,bj)
#endif
       ENDDO
      ENDDO

      RETURN
      END
1	C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_biharm_x.F,v 1.3 2004/12/16 22:29:35 jmc Exp $
2	C $Name: $
3
4	#include "GAD_OPTIONS.h"
5
6	CBOP
7	C !ROUTINE: GAD_BIHARM_X
8
9	C !INTERFACE: ==========================================================
10	SUBROUTINE GAD_BIHARM_X(
11	I bi,bj,k,
12	I xA,del2T,diffK4,
13	U dfx,
14	I myThid )
15
16	C !DESCRIPTION:
17	C Calculates the zonal flux due to bi-harmonic diffusion of a tracer.
18	C Routine takes the laplacian of the tracer as argument and calculates
19	C the zonal gradient:
20	C \begin{equation*}
21	C F^x_{diff} = \kappa_4 \partial_x \nabla^2 \theta
22	C \end{equation*}
23
24	C !USES: ===============================================================
25	IMPLICIT NONE
26	#include "SIZE.h"
27	#include "GRID.h"
28
29	C !INPUT PARAMETERS: ===================================================
30	C bi,bj :: tile indices
31	C k :: vertical level
32	C xA :: area of face at U points
33	C del2T :: Laplacian of tracer
34	C myThid :: thread number
35	INTEGER bi,bj,k
36	_RS xA (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
37	_RL del2T(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
38	_RL diffK4
39	INTEGER myThid
40
41	C !OUTPUT PARAMETERS: ==================================================
42	C dfx :: zonal diffusive flux
43	_RL dfx (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
44
45	C !LOCAL VARIABLES: ====================================================
46	C i,j :: loop indices
47	INTEGER i,j
48	CEOP
49
50	C Difference of zonal fluxes ...
51	DO j=1-Oly,sNy+Oly
52	c dfx(1-Olx,j) = 0.
53	DO i=1-Olx+1,sNx+Olx
54	c dfx(i,j) = diffK4*xA(i,j)
55	dfx(i,j) = dfx(i,j) + diffK4*xA(i,j)
56	& _recip_dxC(i,j,bi,bj)recip_deepFacC(k)
57	& *(del2T(i,j)-del2T(i-1,j))
58	#ifdef COSINEMETH_III
59	& *sqCosFacU(j,bi,bj)
60	#else
61	& *cosFacU(j,bi,bj)
62	#endif
63	ENDDO
64	ENDDO
65
66	RETURN
67	END