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C $Header: /u/gcmpack/models/MITgcmUV/model/src/ini_spherical_polar_grid.F,v 1.13 1999/03/16 16:37:42 adcroft Exp $ |
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#include "CPP_OPTIONS.h" |
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CStartOfInterface |
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SUBROUTINE INI_SPHERICAL_POLAR_GRID( myThid ) |
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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 | |
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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 | Notes: | |
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C | Two examples are included. One illustrates the | |
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C | initialisation of a cartesian grid. The other shows the | |
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C | inialisation of a spherical polar grid. Other orthonormal| |
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C | grids can be fitted into this design. In this case | |
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C | custom metric terms also need adding to account for the | |
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C | projections of velocity vectors onto these grids. | |
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C | The structure used here also makes it possible to | |
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C | implement less regular grid mappings. In particular | |
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C | o Schemes which leave out blocks of the domain that are | |
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C | all land could be supported. | |
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C | o Multi-level schemes such as icosohedral or cubic | |
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C | grid projections onto a sphere can also be fitted | |
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C | within the strategy we use. | |
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C | Both of the above also require modifying the support | |
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C | routines that map computational blocks to simulation | |
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C | domain blocks. | |
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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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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 == Routine arguments == |
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C myThid - Number of this instance of INI_CARTESIAN_GRID |
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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 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 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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_RL xG, yG |
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_RL xBase, yBase |
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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, latS, latN |
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C-- Example of inialisation for spherical polar grid |
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C-- First set coordinates of cell centers |
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C This operation is only performed at start up so for more |
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C complex configurations it is usually OK to pass iG, jG to a custom |
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C function and have it return xG and yG. |
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C Set up my local grid first |
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C Note: In the spherical polar case delX and delY are given in |
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C degrees and are relative to some starting latitude and |
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C longitude - phiMin and thetaMin. |
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xC0 = thetaMin |
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yC0 = phiMin |
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DO bj = myByLo(myThid), myByHi(myThid) |
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jG = myYGlobalLo + (bj-1)*sNy |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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iG = myXGlobalLo + (bi-1)*sNx |
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yBase = phiMin |
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xBase = thetaMin |
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DO i=1,iG-1 |
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xBase = xBase + delX(i) |
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ENDDO |
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DO j=1,jG-1 |
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yBase = yBase + delY(j) |
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ENDDO |
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yG = yBase |
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DO J=1,sNy |
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xG = xBase |
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DO I=1,sNx |
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xc(I,J,bi,bj) = xG + delX(iG+i-1)*0.5 _d 0 |
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yc(I,J,bi,bj) = yG + delY(jG+j-1)*0.5 _d 0 |
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xG = xG + delX(iG+I-1) |
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dxF(I,J,bi,bj) = delX(iG+i-1)*deg2rad |
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& *rSphere*COS(yc(I,J,bi,bj)*deg2rad) |
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dyF(I,J,bi,bj) = delY(jG+j-1)*deg2rad*rSphere |
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ENDDO |
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yG = yG + delY(jG+J-1) |
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ENDDO |
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ENDDO |
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ENDDO |
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C Now sync. and get edge regions from other threads and/or processes. |
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C Note: We could just set the overlap regions ourselves here but |
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C exchanging edges is safer and is good practice! |
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_EXCH_XY_R4( xc, myThid ) |
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_EXCH_XY_R4( yc, myThid ) |
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_EXCH_XY_R4(dxF, myThid ) |
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_EXCH_XY_R4(dyF, myThid ) |
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C-- Calculate separation between other points |
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C dxG, dyG are separations between cell corners along cell faces. |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO J=1,sNy |
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DO I=1,sNx |
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jG = myYGlobalLo + (bj-1)*sNy + J-1 |
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iG = myXGlobalLo + (bi-1)*sNx + I-1 |
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lat = yc(I,J,bi,bj)-delY(jG) * 0.5 _d 0 |
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dxG(I,J,bi,bj) = rSphere*COS(lat*deg2rad)*delX(iG)*deg2rad |
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dyG(I,J,bi,bj) = (dyF(I,J,bi,bj)+dyF(I-1,J,bi,bj))*0.5 _d 0 |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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_EXCH_XY_R4(dxG, myThid ) |
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_EXCH_XY_R4(dyG, myThid ) |
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C dxC, dyC is separation between cell centers |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO J=1,sNy |
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DO I=1,sNx |
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dxC(I,J,bi,bj) = (dxF(I,J,bi,bj)+dxF(I-1,J,bi,bj))*0.5 _d 0 |
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dyC(I,J,bi,bj) = (dyF(I,J,bi,bj)+dyF(I,J-1,bi,bj))*0.5 _d 0 |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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_EXCH_XY_R4(dxC, myThid ) |
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_EXCH_XY_R4(dyC, myThid ) |
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C dxV, dyU are separations between velocity points along cell faces. |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO J=1,sNy |
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DO I=1,sNx |
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dxV(I,J,bi,bj) = (dxG(I,J,bi,bj)+dxG(I-1,J,bi,bj))*0.5 _d 0 |
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#ifdef OLD_UV_GEOMETRY |
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dyU(I,J,bi,bj) = (dyG(I,J,bi,bj)+dyG(I,J-1,bi,bj))*0.5 _d 0 |
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#else |
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dyU(I,J,bi,bj) = (dyC(I,J,bi,bj)+dyC(I-1,J,bi,bj))*0.5 _d 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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ENDDO |
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_EXCH_XY_R4(dxV, myThid ) |
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_EXCH_XY_R4(dyU, myThid ) |
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C Calculate vertical face area and trigonometric terms |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO J=1,sNy |
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DO I=1,sNx |
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jG = myYGlobalLo + (bj-1)*sNy + J-1 |
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iG = myXGlobalLo + (bi-1)*sNx + I-1 |
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latS = yc(i,j,bi,bj)-delY(jG)*0.5 _d 0 |
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latN = yc(i,j,bi,bj)+delY(jG)*0.5 _d 0 |
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#ifdef OLD_UV_GEOMETRY |
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rA(I,J,bi,bj) = dyF(I,J,bi,bj) |
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& *rSphere*(SIN(latN*deg2rad)-SIN(latS*deg2rad)) |
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#else |
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rA(I,J,bi,bj) = rSphere*delX(iG)*deg2rad |
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& *rSphere*(SIN(latN*deg2rad)-SIN(latS*deg2rad)) |
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#endif |
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C Area cannot be zero but sin can be if lat if < -90. |
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IF ( rA(I,J,bi,bj) .LT. 0. ) rA(I,J,bi,bj) = -rA(I,J,bi,bj) |
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tanPhiAtU(i,j,bi,bj)=tan(_yC(i,j,bi,bj)*deg2rad) |
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tanPhiAtV(i,j,bi,bj)=tan(latS*deg2rad) |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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_EXCH_XY_R4 (rA , myThid ) |
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_EXCH_XY_R4 (tanPhiAtU , myThid ) |
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_EXCH_XY_R4 (tanPhiAtV , myThid ) |
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DO bj = myByLo(myThid), myByHi(myThid) |
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DO bi = myBxLo(myThid), myBxHi(myThid) |
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DO J=1,sNy |
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DO I=1,sNx |
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iG = myXGlobalLo + (bi-1)*sNx + I-1 |
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jG = myYGlobalLo + (bj-1)*sNy + J-1 |
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latS = yc(i,j-1,bi,bj) |
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latN = yc(i,j,bi,bj) |
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#ifdef OLD_UV_GEOMETRY |
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rAw(I,J,bi,bj) = 0.5*(rA(I,J,bi,bj)+rA(I-1,J,bi,bj)) |
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rAs(I,J,bi,bj) = 0.5*(rA(I,J,bi,bj)+rA(I,J-1,bi,bj)) |
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#else |
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rAw(I,J,bi,bj) = 0.5*(rA(I,J,bi,bj)+rA(I-1,J,bi,bj)) |
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rAs(I,J,bi,bj) = rSphere*delX(iG)*deg2rad |
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& *rSphere*(SIN(latN*deg2rad)-SIN(latS*deg2rad)) |
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#endif |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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_EXCH_XY_R4 (rAw , myThid ) |
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_EXCH_XY_R4 (rAs , myThid ) |
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C |
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RETURN |
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END |
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