| 1 | molod | 1.1 | C $Header: /u/gcmpack/MITgcm/pkg/fizhi/CtoA.F,v 1.3 2004/05/05 00:39:21 edhill Exp $ | 
| 2 |  |  | C $Name:  $ | 
| 3 |  |  |  | 
| 4 |  |  | subroutine CtoA(myThid,fieldin1,fieldin2,mask1,mask2,im1,im2,jm1, | 
| 5 |  |  | .  jm2,numlevs,Nsx,Nsy,idim1,idim2,jdim1,jdim2,fieldout1,fieldout2) | 
| 6 |  |  | c---------------------------------------------------------------------- | 
| 7 |  |  | c  Subroutine CtoA - Routine to map a velocity component quantity | 
| 8 |  |  | c         from the C-Grid to the A-Grid. | 
| 9 |  |  | c         This includes doing an exchange to fill the halo region, and | 
| 10 |  |  | c         then a linear average with the appropriate topography mask. | 
| 11 |  |  | c         Also: Set up "bi, bj loop" here. | 
| 12 |  |  | c | 
| 13 |  |  | c  Input: myThid | 
| 14 |  |  | c         fieldin1    Field on c-grid to move to a-grid (1st component) | 
| 15 |  |  | c         fieldin2    Field on c-grid to move to a-grid (2nd component) | 
| 16 |  |  | c         mask1       Topography [0,1] mask - 1 to indicate above ground | 
| 17 |  |  | c         mask2       Topography [0,1] mask - 1 to indicate above ground | 
| 18 |  |  | c         im1,im2,jm1,jm2   Indeces in x and y for computations | 
| 19 |  |  | c         numlevs     Number of vertical levels | 
| 20 |  |  | c         Nsx, Nsy | 
| 21 |  |  | c         idim1,idim2,jdim1,jdim2   Span of fields in x and y | 
| 22 |  |  | c | 
| 23 |  |  | c Output: fieldout1   Field mapped to A-Grid (1st component) | 
| 24 |  |  | c         fieldout2   Field mapped to A-Grid (2nd component) | 
| 25 |  |  | c | 
| 26 |  |  | c Call: exchange on c-grid | 
| 27 |  |  | c----------------------------------------------------------------------- | 
| 28 |  |  | implicit none | 
| 29 |  |  | #include "CPP_OPTIONS.h" | 
| 30 |  |  | #include "EEPARAMS.h" | 
| 31 |  |  |  | 
| 32 |  |  | integer myThid, numlevs | 
| 33 |  |  | integer im1, im2, jm1, jm2, idim1, idim2, jdim1, jdim2 | 
| 34 |  |  | integer Nsx, Nsy | 
| 35 |  |  | _RS mask1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 36 |  |  | _RS mask2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 37 |  |  | _RL fieldin1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 38 |  |  | _RL fieldin2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 39 |  |  | _RL fieldout1(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 40 |  |  | _RL fieldout2(im1:im2,jm1:jm2,numlevs,Nsx,Nsy) | 
| 41 |  |  |  | 
| 42 |  |  | integer i, j, L, bi, bj | 
| 43 |  |  | logical withSigns | 
| 44 |  |  | data withSigns/.TRUE./ | 
| 45 |  |  |  | 
| 46 |  |  | c Call the c-grid exchange routine to fill in the halo regions | 
| 47 |  |  | call exch_uv_xyz_RL(fieldin1,fieldin2,withSigns,myThid) | 
| 48 |  |  |  | 
| 49 |  |  | c Now take average | 
| 50 |  |  | do bj = myByLo(myThid), myByHi(myThid) | 
| 51 |  |  | do bi = myBxLo(myThid), myBxHi(myThid) | 
| 52 |  |  |  | 
| 53 |  |  | do L = 1,numlevs | 
| 54 |  |  | do j = jdim1,jdim2 | 
| 55 |  |  | do i = idim1,idim2 | 
| 56 |  |  | if( (mask1(i,j,L,bi,bj).ne.0.) .or. | 
| 57 |  |  | .                               (mask1(i+1,j,L,bi,bj).ne.0.) ) then | 
| 58 |  |  | fieldout1(i,j,L,bi,bj) = | 
| 59 |  |  | .        ( fieldin1(i,j,L,bi,bj)*mask1(i,j,L,bi,bj) + | 
| 60 |  |  | .          fieldin1(i+1,j,L,bi,bj)*mask1(i+1,j,L,bi,bj) ) / | 
| 61 |  |  | .            ( mask1(i,j,L,bi,bj) + mask1(i+1,j,L,bi,bj) ) | 
| 62 |  |  | else | 
| 63 |  |  | fieldout1(i,j,L,bi,bj) = 0. | 
| 64 |  |  | endif | 
| 65 |  |  | if( (mask2(i,j,L,bi,bj).ne.0.) .or. | 
| 66 |  |  | .                               (mask2(i,j+1,L,bi,bj).ne.0.) ) then | 
| 67 |  |  | fieldout2(i,j,L,bi,bj) = | 
| 68 |  |  | .        ( fieldin2(i,j,L,bi,bj)*mask2(i,j,L,bi,bj) + | 
| 69 |  |  | .          fieldin2(i,j+1,L,bi,bj)*mask2(i,j+1,L,bi,bj) ) / | 
| 70 |  |  | .            ( mask2(i,j,L,bi,bj) + mask2(i,j+1,L,bi,bj) ) | 
| 71 |  |  | else | 
| 72 |  |  | fieldout2(i,j,L,bi,bj) = 0. | 
| 73 |  |  | endif | 
| 74 |  |  | enddo | 
| 75 |  |  | enddo | 
| 76 |  |  | enddo | 
| 77 |  |  |  | 
| 78 |  |  | enddo | 
| 79 |  |  | enddo | 
| 80 |  |  |  | 
| 81 |  |  | return | 
| 82 |  |  | end |