pkg/generic_advdiff/gad_biharm_x.F

C $Header: /u/gcmpack/models/MITgcmUV/pkg/generic_advdiff/gad_biharm_x.F,v 1.1 2001/05/30 19:34:48 adcroft 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,
     O           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
       dfx(1-Olx,j) = 0.
       DO i=1-Olx+1,sNx+Olx
         dfx(i,j) = diffK4
     &    *xA(i,j)
     &    *(del2T(i,j)-del2T(i-1,j))*_recip_dxC(i,j,bi,bj)
#ifdef COSINEMETH_III
     &    *sqCosFacU(j,bi,bj)
#else
     &    *CosFacU(j,bi,bj)
#endif
       ENDDO
      ENDDO

      RETURN
      END
1	adcroft	1.2	C $Header: /u/gcmpack/models/MITgcmUV/pkg/generic_advdiff/gad_biharm_x.F,v 1.1 2001/05/30 19:34:48 adcroft Exp $
2			C $Name: $
3	adcroft	1.1
4			#include "GAD_OPTIONS.h"
5
6	adcroft	1.2	CBOP
7			C !ROUTINE: GAD_BIHARM_X
8
9			C !INTERFACE: ==========================================================
10	adcroft	1.1	SUBROUTINE GAD_BIHARM_X(
11			I bi,bj,k,
12			I xA,del2T,diffK4,
13			O dfx,
14			I myThid )
15	adcroft	1.2
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	adcroft	1.1	IMPLICIT NONE
26			#include "SIZE.h"
27			#include "GRID.h"
28
29	adcroft	1.2	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	adcroft	1.1	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	adcroft	1.2	INTEGER myThid
40
41			C !OUTPUT PARAMETERS: ==================================================
42			C dfx :: zonal diffusive flux
43	adcroft	1.1	_RL dfx (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
44
45	adcroft	1.2	C !LOCAL VARIABLES: ====================================================
46			C i,j :: loop indices
47	adcroft	1.1	INTEGER i,j
48	adcroft	1.2	CEOP
49	adcroft	1.1
50			C Difference of zonal fluxes ...
51			DO j=1-Oly,sNy+Oly
52			dfx(1-Olx,j) = 0.
53			DO i=1-Olx+1,sNx+Olx
54			dfx(i,j) = diffK4
55			& *xA(i,j)
56			& (del2T(i,j)-del2T(i-1,j))_recip_dxC(i,j,bi,bj)
57			#ifdef COSINEMETH_III
58			& *sqCosFacU(j,bi,bj)
59			#else
60			& *CosFacU(j,bi,bj)
61			#endif
62			ENDDO
63			ENDDO
64
65			RETURN
66			END