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C $Header: /u/gcmpack/models/MITgcmUV/pkg/generic_advdiff/gad_grad_x.F,v 1.2 2001/09/20 20:07:06 adcroft Exp $ |
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C $Name: $ |
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|
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#include "GAD_OPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: GAD_GRAD_X |
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|
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C !INTERFACE: ========================================================== |
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SUBROUTINE GAD_GRAD_X( |
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I bi,bj,k, |
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I xA, |
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I tracer, |
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O dTdx, |
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I myThid ) |
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|
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C !DESCRIPTION: |
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C Calculates the zonal gradient of a tracer: $\partial_x \theta |
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C = \frac{1}{\Delta x_c} \delta_i \theta$ |
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C and multiplies by the area. |
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|
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C !USES: =============================================================== |
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IMPLICIT NONE |
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#include "SIZE.h" |
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#include "GRID.h" |
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|
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C !INPUT PARAMETERS: =================================================== |
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C bi,bj :: tile indices |
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C k :: vertical level |
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C tracer :: tracer field |
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C myThid :: thread number |
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INTEGER bi,bj,k |
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_RS xA (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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INTEGER myThid |
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|
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C !OUTPUT PARAMETERS: ================================================== |
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C dTdx :: zonal gradient |
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_RL dTdx (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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|
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C !LOCAL VARIABLES: ==================================================== |
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C i,j :: loop indices |
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INTEGER i,j |
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CEOP |
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|
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C o Zonal tracer gradient |
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DO j=1-Oly,sNy+Oly |
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dTdx(1-Olx,j)=0. |
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DO i=1-Olx+1,sNx+Olx |
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dTdx(i,j) = _recip_dxC(i,j,bi,bj)*xA(i,j) |
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& *(tracer(i,j)-tracer(i-1,j)) |
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#ifdef COSINEMETH_III |
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& *sqCosFacU(j,bi,bj) |
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#endif |
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ENDDO |
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ENDDO |
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|
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RETURN |
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END |