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C $Header: /u/gcmpack/MITgcm/pkg/fizhi/CtoA.F,v 1.3 2004/05/05 00:39:21 edhill Exp $ |
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C $Name: $ |
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|
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subroutine CtoA(myThid,fieldin1,fieldin2,mask1,mask2,im1,im2,jm1, |
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. jm2,numlevs,Nsx,Nsy,idim1,idim2,jdim1,jdim2,fieldout1,fieldout2) |
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c---------------------------------------------------------------------- |
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c Subroutine CtoA - Routine to map a velocity component quantity |
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c from the C-Grid to the A-Grid. |
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c This includes doing an exchange to fill the halo region, and |
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c then a linear average with the appropriate topography mask. |
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c Also: Set up "bi, bj loop" here. |
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c |
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c Input: myThid |
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c fieldin1 Field on c-grid to move to a-grid (1st component) |
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c fieldin2 Field on c-grid to move to a-grid (2nd component) |
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c mask1 Topography [0,1] mask - 1 to indicate above ground |
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c mask2 Topography [0,1] mask - 1 to indicate above ground |
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c im1,im2,jm1,jm2 Indeces in x and y for computations |
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c numlevs Number of vertical levels |
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c Nsx, Nsy |
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c idim1,idim2,jdim1,jdim2 Span of fields in x and y |
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c |
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c Output: fieldout1 Field mapped to A-Grid (1st component) |
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c fieldout2 Field mapped to A-Grid (2nd component) |
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c |
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c Call: exchange on c-grid |
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c----------------------------------------------------------------------- |
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implicit none |
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#include "CPP_OPTIONS.h" |
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#include "EEPARAMS.h" |
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|
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integer myThid, numlevs |
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integer im1, im2, jm1, jm2, idim1, idim2, jdim1, jdim2 |
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integer Nsx, Nsy |
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_RS mask1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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_RS mask2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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_RL fieldin1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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_RL fieldin2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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_RL fieldout1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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_RL fieldout2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) |
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|
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integer i, j, L, bi, bj |
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logical withSigns |
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data withSigns/.TRUE./ |
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|
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c Call the c-grid exchange routine to fill in the halo regions |
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call exch_uv_xyz_RL(fieldin1,fieldin2,withSigns,myThid) |
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|
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c Now take average |
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do bj = myByLo(myThid), myByHi(myThid) |
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do bi = myBxLo(myThid), myBxHi(myThid) |
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|
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do L = 1,numlevs |
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do j = jdim1,jdim2 |
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do i = idim1,idim2 |
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if( (mask1(i,j,L,bi,bj).ne.0.) .or. |
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. (mask1(i+1,j,L,bi,bj).ne.0.) ) then |
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fieldout1(i,j,L,bi,bj) = |
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. ( fieldin1(i,j,L,bi,bj)*mask1(i,j,L,bi,bj) + |
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. fieldin1(i+1,j,L,bi,bj)*mask1(i+1,j,L,bi,bj) ) / |
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. ( mask1(i,j,L,bi,bj) + mask1(i+1,j,L,bi,bj) ) |
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else |
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fieldout1(i,j,L,bi,bj) = 0. |
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endif |
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if( (mask2(i,j,L,bi,bj).ne.0.) .or. |
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. (mask2(i,j+1,L,bi,bj).ne.0.) ) then |
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fieldout2(i,j,L,bi,bj) = |
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. ( fieldin2(i,j,L,bi,bj)*mask2(i,j,L,bi,bj) + |
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. fieldin2(i,j+1,L,bi,bj)*mask2(i,j+1,L,bi,bj) ) / |
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. ( mask2(i,j,L,bi,bj) + mask2(i,j+1,L,bi,bj) ) |
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else |
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fieldout2(i,j,L,bi,bj) = 0. |
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endif |
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enddo |
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enddo |
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enddo |
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|
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enddo |
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enddo |
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|
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return |
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end |