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C $Header: /u/u0/gcmpack/MITgcm/model/src/ini_spherical_polar_grid.F,v 1.20 2001/09/27 18:14:52 adcroft Exp $ |
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C $Name: checkpoint48 $ |
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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_CYLINDER |
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C !INTERFACE: |
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SUBROUTINE INI_CYLINDER( myThid ) |
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C !DESCRIPTION: \bv |
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C /==========================================================\ |
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C | SUBROUTINE INI_CYLINDER |
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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 is in degrees and Y in meters. | |
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C | 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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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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|
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C !INPUT/OUTPUT PARAMETERS: |
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C == Routine arguments == |
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C myThid - Number of this instance of INI_CYLINDER |
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INTEGER myThid |
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CEndOfInterface |
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|
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C !LOCAL VARIABLES: |
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C == Local variables == |
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C xG, yG - Global coordinate location. |
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C xBase - South-west corner location for process. |
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C yBase |
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C zUpper - Work arrays for upper and lower |
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C zLower cell-face heights. |
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C phi - Temporary scalar |
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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 bi,bj - Loop counters |
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C zUpper - Temporary arrays holding z coordinates of |
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C zLower upper and lower faces. |
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C xBase - Lower coordinate for this threads cells |
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C yBase |
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C lat, latN, - Temporary variables used to hold latitude |
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C latS values. |
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C I,J,K |
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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 dtheta, thisRad, xG0, yG0 |
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CHARACTER*(MAX_LEN_MBUF) msgBuf |
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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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CEOP |
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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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|
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C-- First find coordinate of tile corner (meaning outer corner of halo) |
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xG0 = thetaMin |
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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 = 0 |
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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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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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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*( |
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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*( |
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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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thisRad = yC(I,J,bi,bj) |
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dtheta = delX( iGl(I,bi) ) |
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dXF(I,J,bi,bj) = thisRad*dtheta*deg2rad |
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dYF(I,J,bi,bj) = delY( jGl(J,bj) ) |
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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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thisRad = 0.5*(yGloc(I,J)+yGloc(I+1,J)) |
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dtheta = delX( iGl(I,bi) ) |
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dXG(I,J,bi,bj) = thisRad*dtheta*deg2rad |
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dYG(I,J,bi,bj) = delY( jGl(J,bj) ) |
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ENDDO |
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ENDDO |
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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) = 0.5D0*(dXF(I,J,bi,bj)+dXF(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 [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*(dYF(I,J,bi,bj)+dYF(I,J-1,bi,bj)) |
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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*(dXG(I,J,bi,bj)+dXG(I-1,J,bi,bj)) |
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dYU(I,J,bi,bj) = 0.5*(dYG(I,J,bi,bj)+dYG(I,J-1,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 |
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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 All r(dr)(dtheta) |
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rA (I,J,bi,bj) = dxF(I,J,bi,bj)*dyF(I,J,bi,bj) |
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rAw(I,J,bi,bj) = dxC(I,J,bi,bj)*dyG(I,J,bi,bj) |
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rAs(I,J,bi,bj) = dxG(I,J,bi,bj)*dyC(I,J,bi,bj) |
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rAz(I,J,bi,bj) = dxV(I,J,bi,bj)*dyU(I,J,bi,bj) |
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tanPhiAtU(I,J,bi,bj) = 0. |
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tanPhiAtV(I,J,bi,bj) = 0. |
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ENDDO |
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ENDDO |
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|
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C-- Cosine(lat) scaling |
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DO J=1-OLy,sNy+OLy |
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cosFacU(J,bi,bj)=1. |
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cosFacV(J,bi,bj)=1. |
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sqcosFacU(J,bi,bj)=1. |
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sqcosFacV(J,bi,bj)=1. |
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ENDDO |
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|
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ENDDO ! bi |
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ENDDO ! bj |
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|
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RETURN |
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END |
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