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C $Header: /u/gcmpack/MITgcm/model/src/ini_spherical_polar_grid.F,v 1.26 2009/01/27 15:35:27 jmc Exp $ |
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C $Name: $ |
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|
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c#include "PACKAGES_CONFIG.h" |
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#include "CPP_OPTIONS.h" |
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|
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#undef USE_BACKWARD_COMPATIBLE_GRID |
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|
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CBOP |
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C !ROUTINE: INI_SPHERICAL_POLAR_GRID |
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C !INTERFACE: |
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SUBROUTINE INI_SPHERICAL_POLAR_GRID( myThid ) |
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|
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C !DESCRIPTION: \bv |
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C *==========================================================* |
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C | SUBROUTINE INI_SPHERICAL_POLAR_GRID |
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C | o Initialise model coordinate system arrays |
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C *==========================================================* |
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C | These arrays are used throughout the code in evaluating |
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C | gradients, integrals and spatial avarages. This routine |
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C | is called separately by each thread and initialise only |
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C | the region of the domain it is "responsible" for. |
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C | Under the spherical polar grid mode primitive distances |
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C | in X and Y are in degrees. Distance in Z are in m or Pa |
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C | depending on the vertical gridding mode. |
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C *==========================================================* |
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C \ev |
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|
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C !USES: |
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IMPLICIT NONE |
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "GRID.h" |
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c#ifdef ALLOW_EXCH2 |
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c#include "W2_EXCH2_SIZE.h" |
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c#include "W2_EXCH2_TOPOLOGY.h" |
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c#include "W2_EXCH2_PARAMS.h" |
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c#endif /* ALLOW_EXCH2 */ |
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|
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C !INPUT/OUTPUT PARAMETERS: |
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C == Routine arguments == |
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C myThid :: my Thread Id Number |
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INTEGER myThid |
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|
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C !LOCAL VARIABLES: |
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C == Local variables == |
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C xG0,yG0 :: coordinate of South-West tile-corner |
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C iG, jG :: Global coordinate index. Usually used to hold |
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C :: the south-west global coordinate of a tile. |
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C lat :: Temporary variables used to hold latitude values. |
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C bi,bj :: tile indices |
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C i, j :: loop counters |
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INTEGER iG, jG |
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INTEGER bi, bj |
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INTEGER i, j |
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_RL lat, dlat, dlon, xG0, yG0 |
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|
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C "Long" real for temporary coordinate calculation |
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C NOTICE the extended range of indices!! |
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_RL xGloc(1-Olx:sNx+Olx+1,1-Oly:sNy+Oly+1) |
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_RL yGloc(1-Olx:sNx+Olx+1,1-Oly:sNy+Oly+1) |
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|
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C The functions iGl, jGl return the "global" index with valid values beyond |
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C halo regions |
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C cnh wrote: |
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C > I dont understand why we would ever have to multiply the |
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C > overlap by the total domain size e.g |
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C > OLx*Nx, OLy*Ny. |
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C > Can anybody explain? Lines are in ini_spherical_polar_grid.F. |
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C > Surprised the code works if its wrong, so I am puzzled. |
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C jmc replied: |
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C Yes, I can explain this since I put this modification to work |
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C with small domain (where Oly > Ny, as for instance, zonal-average |
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C case): |
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C This has no effect on the acuracy of the evaluation of iGl(I,bi) |
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C and jGl(j,bj) since we take mod(a+OLx*Nx,Nx) and mod(b+OLy*Ny,Ny). |
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C But in case a or b is negative, then the FORTRAN function "mod" |
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C does not return the matematical value of the "modulus" function, |
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C and this is not good for your purpose. |
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C This is why I add +OLx*Nx and +OLy*Ny to be sure that the 1rst |
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C argument of the mod function is positive. |
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INTEGER iGl,jGl |
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iGl(i,bi) = 1+MOD(myXGlobalLo-1+(bi-1)*sNx+i+Olx*Nx-1,Nx) |
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jGl(j,bj) = 1+MOD(myYGlobalLo-1+(bj-1)*sNy+j+Oly*Ny-1,Ny) |
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c#ifdef ALLOW_EXCH2 |
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c INTEGER tN |
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c#endif /* ALLOW_EXCH2 */ |
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CEOP |
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|
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C For each tile ... |
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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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C-- "Global" index (place holder) |
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jG = myYGlobalLo + (bj-1)*sNy |
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iG = myXGlobalLo + (bi-1)*sNx |
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c#ifdef ALLOW_EXCH2 |
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c IF ( W2_useE2ioLayOut ) THEN |
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cC- note: does not work for non-uniform delX or delY |
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c tN = W2_myTileList(bi,bj) |
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c iG = exch2_txGlobalo(tN) |
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c jG = exch2_tyGlobalo(tN) |
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c ENDIF |
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c#endif /* ALLOW_EXCH2 */ |
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|
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C-- First find coordinate of tile corner (meaning outer corner of halo) |
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xG0 = xgOrigin |
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C Find the X-coordinate of the outer grid-line of the "real" tile |
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DO i=1, iG-1 |
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xG0 = xG0 + delX(i) |
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ENDDO |
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C Back-step to the outer grid-line of the "halo" region |
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DO i=1, Olx |
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xG0 = xG0 - delX( 1+MOD(Olx*Nx-1+iG-i,Nx) ) |
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ENDDO |
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C Find the Y-coordinate of the outer grid-line of the "real" tile |
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yG0 = ygOrigin |
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DO j=1, jG-1 |
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yG0 = yG0 + delY(j) |
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ENDDO |
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C Back-step to the outer grid-line of the "halo" region |
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DO j=1, Oly |
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yG0 = yG0 - delY( 1+MOD(Oly*Ny-1+jG-j,Ny) ) |
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ENDDO |
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|
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C-- Calculate coordinates of cell corners for N+1 grid-lines |
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DO j=1-Oly,sNy+Oly +1 |
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xGloc(1-Olx,j) = xG0 |
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DO i=1-Olx,sNx+Olx |
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c xGloc(i+1,j) = xGloc(i,j) + delX(1+mod(Nx-1+iG-1+i,Nx)) |
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xGloc(i+1,j) = xGloc(i,j) + delX( iGl(i,bi) ) |
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ENDDO |
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ENDDO |
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DO i=1-Olx,sNx+Olx +1 |
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yGloc(i,1-Oly) = yG0 |
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DO j=1-Oly,sNy+Oly |
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c yGloc(i,j+1) = yGloc(i,j) + delY(1+mod(Ny-1+jG-1+j,Ny)) |
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yGloc(i,j+1) = yGloc(i,j) + delY( jGl(j,bj) ) |
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ENDDO |
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ENDDO |
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|
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C-- Make a permanent copy of [xGloc,yGloc] in [xG,yG] |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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xG(i,j,bi,bj) = xGloc(i,j) |
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yG(i,j,bi,bj) = yGloc(i,j) |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [xC,yC], coordinates of cell centers |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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C by averaging |
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xC(i,j,bi,bj) = 0.25 _d 0*( |
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& xGloc(i,j)+xGloc(i+1,j)+xGloc(i,j+1)+xGloc(i+1,j+1) ) |
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yC(i,j,bi,bj) = 0.25 _d 0*( |
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& yGloc(i,j)+yGloc(i+1,j)+yGloc(i,j+1)+yGloc(i+1,j+1) ) |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [dxF,dyF], lengths between cell faces (through center) |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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C by averaging |
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c dxF(i,j,bi,bj) = 0.5*(dxG(i,j,bi,bj)+dxG(i,j+1,bi,bj)) |
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c dyF(i,j,bi,bj) = 0.5*(dyG(i,j,bi,bj)+dyG(i+1,j,bi,bj)) |
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C by formula |
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lat = yC(i,j,bi,bj) |
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dlon = delX( iGl(i,bi) ) |
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dlat = delY( jGl(j,bj) ) |
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dxF(i,j,bi,bj) = rSphere*COS(deg2rad*lat)*dlon*deg2rad |
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#ifdef USE_BACKWARD_COMPATIBLE_GRID |
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dxF(i,j,bi,bj) = delX(iGl(i,bi))*deg2rad*rSphere* |
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& COS(yC(i,j,bi,bj)*deg2rad) |
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#endif /* USE_BACKWARD_COMPATIBLE_GRID */ |
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dyF(i,j,bi,bj) = rSphere*dlat*deg2rad |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [dxG,dyG], lengths along cell boundaries |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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C by averaging |
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c dxG(i,j,bi,bj) = 0.5*(dxF(i,j,bi,bj)+dxF(i,j-1,bi,bj)) |
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c dyG(i,j,bi,bj) = 0.5*(dyF(i,j,bi,bj)+dyF(i-1,j,bi,bj)) |
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C by formula |
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lat = 0.5 _d 0*(yGloc(i,j)+yGloc(i+1,j)) |
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dlon = delX( iGl(i,bi) ) |
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dlat = delY( jGl(j,bj) ) |
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dxG(i,j,bi,bj) = rSphere*COS(deg2rad*lat)*dlon*deg2rad |
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if (dxG(i,j,bi,bj).LT.1.) dxG(i,j,bi,bj)=0. |
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dyG(i,j,bi,bj) = rSphere*dlat*deg2rad |
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ENDDO |
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ENDDO |
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|
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C-- The following arrays are not defined in some parts of the halo |
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C region. We set them to zero here for safety. If they are ever |
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C referred to, especially in the denominator then it is a mistake! |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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dxC(i,j,bi,bj) = 0. |
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dyC(i,j,bi,bj) = 0. |
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dxV(i,j,bi,bj) = 0. |
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dyU(i,j,bi,bj) = 0. |
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rAw(i,j,bi,bj) = 0. |
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rAs(i,j,bi,bj) = 0. |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [dxC], zonal length between cell centers |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx+1,sNx+Olx ! NOTE range |
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C by averaging |
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dxC(i,j,bi,bj) = 0.5 _d 0*(dxF(i,j,bi,bj)+dxF(i-1,j,bi,bj)) |
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C by formula |
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c lat = 0.5*(yC(i,j,bi,bj)+yC(i-1,j,bi,bj)) |
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c dlon = 0.5*(delX( iGl(i,bi) ) + delX( iGl(i-1,bi) )) |
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c dxC(i,j,bi,bj) = rSphere*COS(deg2rad*lat)*dlon*deg2rad |
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C by difference |
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c lat = 0.5*(yC(i,j,bi,bj)+yC(i-1,j,bi,bj)) |
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c dlon = (xC(i,j,bi,bj)+xC(i-1,j,bi,bj)) |
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c dxC(i,j,bi,bj) = rSphere*COS(deg2rad*lat)*dlon*deg2rad |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [dyC], meridional length between cell centers |
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DO j=1-Oly+1,sNy+Oly ! NOTE range |
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DO i=1-Olx,sNx+Olx |
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C by averaging |
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dyC(i,j,bi,bj) = 0.5 _d 0*(dyF(i,j,bi,bj)+dyF(i,j-1,bi,bj)) |
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C by formula |
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c dlat = 0.5*(delY( jGl(j,bj) ) + delY( jGl(j-1,bj) )) |
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c dyC(i,j,bi,bj) = rSphere*dlat*deg2rad |
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C by difference |
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c dlat = (yC(i,j,bi,bj)+yC(i,j-1,bi,bj)) |
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c dyC(i,j,bi,bj) = rSphere*dlat*deg2rad |
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ENDDO |
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ENDDO |
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|
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C-- Calculate [dxV,dyU], length between velocity points (through corners) |
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DO j=1-Oly+1,sNy+Oly ! NOTE range |
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DO i=1-Olx+1,sNx+Olx ! NOTE range |
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C by averaging (method I) |
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dxV(i,j,bi,bj) = 0.5 _d 0*(dxG(i,j,bi,bj)+dxG(i-1,j,bi,bj)) |
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dyU(i,j,bi,bj) = 0.5 _d 0*(dyG(i,j,bi,bj)+dyG(i,j-1,bi,bj)) |
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C by averaging (method II) |
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c dxV(i,j,bi,bj) = 0.5*(dxG(i,j,bi,bj)+dxG(i-1,j,bi,bj)) |
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c dyU(i,j,bi,bj) = 0.5*(dyC(i,j,bi,bj)+dyC(i-1,j,bi,bj)) |
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ENDDO |
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ENDDO |
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|
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C-- Calculate vertical face area (tracer cells) |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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lat=0.5 _d 0*(yGloc(i,j)+yGloc(i+1,j)) |
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dlon=delX( iGl(i,bi) ) |
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dlat=delY( jGl(j,bj) ) |
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rA(i,j,bi,bj) = rSphere*rSphere*dlon*deg2rad |
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& *ABS( SIN((lat+dlat)*deg2rad)-SIN(lat*deg2rad) ) |
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#ifdef USE_BACKWARD_COMPATIBLE_GRID |
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lat=yC(i,j,bi,bj)-delY( jGl(j,bj) )*0.5 _d 0 |
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lon=yC(i,j,bi,bj)+delY( jGl(j,bj) )*0.5 _d 0 |
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rA(i,j,bi,bj) = dyF(i,j,bi,bj) |
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& *rSphere*(SIN(lon*deg2rad)-SIN(lat*deg2rad)) |
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#endif /* USE_BACKWARD_COMPATIBLE_GRID */ |
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ENDDO |
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ENDDO |
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|
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C-- Calculate vertical face area (u cells) |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx+1,sNx+Olx ! NOTE range |
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C by averaging |
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rAw(i,j,bi,bj) = 0.5 _d 0*(rA(i,j,bi,bj)+rA(i-1,j,bi,bj)) |
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C by formula |
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c lat=yGloc(i,j) |
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c dlon=0.5*( delX( iGl(i,bi) ) + delX( iGl(i-1,bi) ) ) |
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c dlat=delY( jGl(j,bj) ) |
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c rAw(i,j,bi,bj) = rSphere*rSphere*dlon*deg2rad |
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c & *abs( sin((lat+dlat)*deg2rad)-sin(lat*deg2rad) ) |
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ENDDO |
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ENDDO |
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|
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C-- Calculate vertical face area (v cells) |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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C by formula |
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lat=yC(i,j,bi,bj) |
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dlon=delX( iGl(i,bi) ) |
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dlat=0.5 _d 0*( delY( jGl(j,bj) ) + delY( jGl(j-1,bj) ) ) |
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rAs(i,j,bi,bj) = rSphere*rSphere*dlon*deg2rad |
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& *ABS( SIN(lat*deg2rad)-SIN((lat-dlat)*deg2rad) ) |
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#ifdef USE_BACKWARD_COMPATIBLE_GRID |
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lon=yC(i,j,bi,bj)-delY( jGl(j,bj) ) |
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lat=yC(i,j,bi,bj) |
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rAs(i,j,bi,bj) = rSphere*delX(iGl(i,bi))*deg2rad |
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& *rSphere*(SIN(lat*deg2rad)-SIN(lon*deg2rad)) |
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#endif /* USE_BACKWARD_COMPATIBLE_GRID */ |
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IF (ABS(lat).GT.90..OR.ABS(lat-dlat).GT.90.) rAs(i,j,bi,bj)=0. |
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ENDDO |
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ENDDO |
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|
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C-- Calculate vertical face area (vorticity points) |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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C by formula |
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lat =0.5 _d 0*(yGloc(i,j)+yGloc(i,j+1)) |
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dlon=0.5 _d 0*( delX( iGl(i,bi) ) + delX( iGl(i-1,bi) ) ) |
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dlat=0.5 _d 0*( delY( jGl(j,bj) ) + delY( jGl(j-1,bj) ) ) |
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rAz(i,j,bi,bj) = rSphere*rSphere*dlon*deg2rad |
| 312 |
& *ABS( SIN(lat*deg2rad)-SIN((lat-dlat)*deg2rad) ) |
| 313 |
IF (ABS(lat).GT.90..OR.ABS(lat-dlat).GT.90.) rAz(i,j,bi,bj)=0. |
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ENDDO |
| 315 |
ENDDO |
| 316 |
|
| 317 |
C-- Calculate trigonometric terms & grid orientation: |
| 318 |
DO j=1-Oly,sNy+Oly |
| 319 |
DO i=1-Olx,sNx+Olx |
| 320 |
lat=0.5 _d 0*(yGloc(i,j)+yGloc(i,j+1)) |
| 321 |
tanPhiAtU(i,j,bi,bj)=TAN(lat*deg2rad) |
| 322 |
lat=0.5 _d 0*(yGloc(i,j)+yGloc(i+1,j)) |
| 323 |
tanPhiAtV(i,j,bi,bj)=TAN(lat*deg2rad) |
| 324 |
angleCosC(i,j,bi,bj) = 1. |
| 325 |
angleSinC(i,j,bi,bj) = 0. |
| 326 |
ENDDO |
| 327 |
ENDDO |
| 328 |
|
| 329 |
C-- Cosine(lat) scaling |
| 330 |
DO j=1-OLy,sNy+OLy |
| 331 |
jG = myYGlobalLo + (bj-1)*sNy + j-1 |
| 332 |
jG = MIN(MAX(1,jG),Ny) |
| 333 |
IF (cosPower.NE.0.) THEN |
| 334 |
cosFacU(j,bi,bj)=COS(yC(1,j,bi,bj)*deg2rad) |
| 335 |
& **cosPower |
| 336 |
cosFacV(j,bi,bj)=COS((yC(1,j,bi,bj)-0.5*delY(jG))*deg2rad) |
| 337 |
& **cosPower |
| 338 |
cosFacU(j,bi,bj)=ABS(cosFacU(j,bi,bj)) |
| 339 |
cosFacV(j,bi,bj)=ABS(cosFacV(j,bi,bj)) |
| 340 |
sqcosFacU(j,bi,bj)=SQRT(cosFacU(j,bi,bj)) |
| 341 |
sqcosFacV(j,bi,bj)=SQRT(cosFacV(j,bi,bj)) |
| 342 |
ELSE |
| 343 |
cosFacU(j,bi,bj)=1. |
| 344 |
cosFacV(j,bi,bj)=1. |
| 345 |
sqcosFacU(j,bi,bj)=1. |
| 346 |
sqcosFacV(j,bi,bj)=1. |
| 347 |
ENDIF |
| 348 |
ENDDO |
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|
| 350 |
ENDDO ! bi |
| 351 |
ENDDO ! bj |
| 352 |
|
| 353 |
IF ( rotateGrid ) THEN |
| 354 |
CALL ROTATE_SPHERICAL_POLAR_GRID( xC, yC, myThid ) |
| 355 |
CALL ROTATE_SPHERICAL_POLAR_GRID( xG, yG, myThid ) |
| 356 |
CALL CALC_ANGLES( myThid ) |
| 357 |
ENDIF |
| 358 |
|
| 359 |
RETURN |
| 360 |
END |
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