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C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_c4_adv_r.F,v 1.4 2001/09/21 13:11:43 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_C4_ADV_R |
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|
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C !INTERFACE: ========================================================== |
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SUBROUTINE GAD_C4_ADV_R( |
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I bi,bj,k, |
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I rTrans, |
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I tracer, |
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O wT, |
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I myThid ) |
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|
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C !DESCRIPTION: |
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C Calculates the area integrated vertical flux due to advection of a tracer |
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C using centered fourth-order interpolation: |
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C \begin{equation*} |
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C F^r_{adv} = W \overline{ \theta - \frac{1}{6} \delta_{kk} \theta }^k |
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C \end{equation*} |
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C Near boundaries, the scheme reduces to a second if the flow is away |
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C from the boundary and to third order if the flow is towards |
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C the boundary. |
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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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#include "GAD.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 rTrans :: vertical volume transport |
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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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_RL rTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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INTEGER myThid |
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|
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C !OUTPUT PARAMETERS: ================================================== |
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C wT :: vertical advective flux |
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_RL wT (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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C kp1 :: =min( k+1 , Nr ) |
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C km1 :: =max( k-1 , 1 ) |
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C km2 :: =max( k-2 , 1 ) |
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C Rjm,Rj,Rjp :: differences at i-1,i,i+1 |
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C Rjjm,Rjjp :: second differences at i-1,i |
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C maskP1 :: =1 for k<Nr, =0 for k>=Nr |
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INTEGER i,j,kp1,km1,km2 |
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_RL Rjm,Rj,Rjp,Rjjm,Rjjp |
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_RL maskPM, maskBound |
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CEOP |
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|
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km2=MAX(1,k-2) |
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km1=MAX(1,k-1) |
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kp1=MIN(Nr,k+1) |
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maskPM = 1. |
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IF (k.LE.2 .OR. k.GE.Nr) maskPM = 0. |
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|
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IF ( k.EQ.1 .OR. k.GT.Nr) THEN |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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wT(i,j) = 0. |
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ENDDO |
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ENDDO |
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ELSE |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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maskBound = maskPM*maskC(i,j,km2,bi,bj)*maskC(i,j,kp1,bi,bj) |
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Rjp=(tracer(i,j,kp1,bi,bj)-tracer(i,j,k,bi,bj)) |
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& *maskC(i,j,kp1,bi,bj) |
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Rj =(tracer(i,j,k,bi,bj)-tracer(i,j,km1,bi,bj)) |
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Rjm=(tracer(i,j,km1,bi,bj)-tracer(i,j,km2,bi,bj)) |
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& *maskC(i,j,km1,bi,bj) |
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Rjjp=(Rjp-Rj) |
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Rjjm=(Rj-Rjm) |
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wT(i,j) = maskC(i,j,km1,bi,bj)*( |
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& rTrans(i,j)*( |
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& (Tracer(i,j,k,bi,bj)+Tracer(i,j,km1,bi,bj))*0.5 _d 0 |
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& -oneSixth*(Rjjm+Rjjp)*0.5 _d 0 ) |
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& +ABS(rTrans(i,j))* |
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& oneSixth*(Rjjm-Rjjp)*0.5 _d 0*(1. _d 0 - maskBound) |
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& ) |
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ENDDO |
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ENDDO |
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ENDIF |
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|
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RETURN |
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END |