natl_12/code/gad_diff_x.F

C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_diff_x.F,v 1.3 2001/09/21 13:11:43 adcroft Exp $
C $Name: checkpoint51c_post $

#include "GAD_OPTIONS.h"

CBOP
C !ROUTINE: GAD_DIFF_X

C !INTERFACE: ==========================================================
      SUBROUTINE GAD_DIFF_X( 
     I           bi,bj,k,
     I           xA, diffKh,
     I           tracer,
     O           dfx,
     I           myThid )

C !DESCRIPTION:
C Calculates the area integrated zonal flux due to down-gradient diffusion
C of a tracer:
C \begin{equation*}
C F^x_{diff} = - A^x \kappa_h \frac{1}{\Delta x_c} \delta_i \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  diffKh               :: horizontal diffusivity
C  tracer               :: tracer field
C  myThid               :: thread number
      INTEGER bi,bj,k
      _RS xA    (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL diffKh
      _RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      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
      _RS     gridScalingAh
CEOP

      DO j=1-Oly,sNy+Oly
       dfx(1-Olx,j)=0.
       DO i=1-Olx+1,sNx+Olx
        gridScalingAh = (_dxC(i,j,bi,bj)**2)/(5000.**2)
        dfx(i,j) = -diffKh*xA(i,j)
     &      *_recip_dxC(i,j,bi,bj)
     &      *(Tracer(i,j)-Tracer(i-1,j))
     &      *CosFacU(j,bi,bj)
       ENDDO
      ENDDO

      RETURN
      END
1	C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_diff_x.F,v 1.3 2001/09/21 13:11:43 adcroft Exp $
2	C $Name: checkpoint51c_post $
3
4	#include "GAD_OPTIONS.h"
5
6	CBOP
7	C !ROUTINE: GAD_DIFF_X
8
9	C !INTERFACE: ==========================================================
10	SUBROUTINE GAD_DIFF_X(
11	I bi,bj,k,
12	I xA, diffKh,
13	I tracer,
14	O dfx,
15	I myThid )
16
17	C !DESCRIPTION:
18	C Calculates the area integrated zonal flux due to down-gradient diffusion
19	C of a tracer:
20	C \begin{equation*}
21	C F^x_{diff} = - A^x \kappa_h \frac{1}{\Delta x_c} \delta_i \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 diffKh :: horizontal diffusivity
34	C tracer :: tracer field
35	C myThid :: thread number
36	INTEGER bi,bj,k
37	_RS xA (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
38	_RL diffKh
39	_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
40	INTEGER myThid
41
42	C !OUTPUT PARAMETERS: ==================================================
43	C dfx :: zonal diffusive flux
44	_RL dfx (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
45
46	C !LOCAL VARIABLES: ====================================================
47	C i,j :: loop indices
48	INTEGER i,j
49	_RS gridScalingAh
50	CEOP
51
52	DO j=1-Oly,sNy+Oly
53	dfx(1-Olx,j)=0.
54	DO i=1-Olx+1,sNx+Olx
55	gridScalingAh = (_dxC(i,j,bi,bj)2)/(5000.2)
56	dfx(i,j) = -diffKh*xA(i,j)
57	& *_recip_dxC(i,j,bi,bj)
58	& *(Tracer(i,j)-Tracer(i-1,j))
59	& *CosFacU(j,bi,bj)
60	ENDDO
61	ENDDO
62
63	RETURN
64	END