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C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_ocean_stress.F,v 1.15 2007/04/24 17:54:44 heimbach Exp $ |
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C $Name: $ |
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|
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#include "SEAICE_OPTIONS.h" |
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|
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CStartOfInterface |
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SUBROUTINE SEAICE_OCEAN_STRESS( |
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I myTime, myIter, myThid ) |
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C /==========================================================\ |
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C | SUBROUTINE SEAICE_OCEAN_STRESS | |
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C | o Calculate ocean surface stresses | |
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C | - C-grid version | |
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C |==========================================================| |
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C \==========================================================/ |
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IMPLICIT NONE |
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|
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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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#include "FFIELDS.h" |
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#include "SEAICE.h" |
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#include "SEAICE_PARAMS.h" |
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|
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C === Routine arguments === |
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C myTime - Simulation time |
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C myIter - Simulation timestep number |
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C myThid - Thread no. that called this routine. |
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_RL myTime |
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INTEGER myIter |
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INTEGER myThid |
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CEndOfInterface |
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|
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#ifdef SEAICE_CGRID |
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C === Local variables === |
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C i,j,bi,bj - Loop counters |
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|
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INTEGER i, j, bi, bj |
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_RL SINWAT, COSWAT, SINWIN, COSWIN |
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_RL fuIceLoc, fvIceLoc, FX, FY |
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_RL areaW, areaS |
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|
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_RL e11 (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
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_RL e22 (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
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_RL e12 (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
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_RL press (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
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_RL sig11 (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL sig22 (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL sig12 (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL eplus, eminus |
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|
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c introduce turning angle (default is zero) |
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SINWAT=SIN(SEAICE_waterTurnAngle*deg2rad) |
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COSWAT=COS(SEAICE_waterTurnAngle*deg2rad) |
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SINWIN=SIN(SEAICE_airTurnAngle*deg2rad) |
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COSWIN=COS(SEAICE_airTurnAngle*deg2rad) |
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|
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C-- Update overlap regions |
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CALL EXCH_UV_XY_RL(WINDX, WINDY, .TRUE., myThid) |
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|
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#ifndef SEAICE_EXTERNAL_FLUXES |
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C-- Interpolate wind stress (N/m^2) from C-points of C-grid |
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C to U and V points of C-grid for forcing the ocean model. |
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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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fu(I,J,bi,bj)=0.5*(WINDX(I,J,bi,bj) + WINDX(I-1,J,bi,bj)) |
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fv(I,J,bi,bj)=0.5*(WINDY(I,J,bi,bj) + WINDY(I,J-1,bi,bj)) |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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#endif /* ifndef SEAICE_EXTERNAL_FLUXES */ |
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|
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IF ( useHB87StressCoupling ) THEN |
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C |
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C use an intergral over ice and ocean surface layer to define |
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C surface stresses on ocean following Hibler and Bryan (1987, JPO) |
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C |
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C recompute strain rates, viscosities, etc. from updated ice velocities |
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IF ( .NOT. SEAICEuseEVP ) THEN |
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C only for EVP we already have the stress components otherwise we need |
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C to recompute them here |
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CALL SEAICE_CALC_STRAINRATES( |
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I uIce(1-Olx,1-Oly,1,1,1), vIce(1-Olx,1-Oly,1,1,1), |
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O e11, e22, e12, |
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I myThid ) |
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|
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CALL SEAICE_CALC_VISCOSITIES( |
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I e11, e22, e12, zMin, zMax, hEffM, press0, |
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O eta, zeta, press, |
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I myThid ) |
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ENDIF |
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C re-compute internal stresses with updated ice velocities |
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DO bj=myByLo(myThid),myByHi(myThid) |
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DO bi=myBxLo(myThid),myBxHi(myThid) |
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IF ( .NOT. SEAICEuseEVP ) THEN |
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C only for EVP we already have computed the stress divergences, for |
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C anything else we have to do it here |
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DO j=1-Oly,sNy+Oly |
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DO i=1-Olx,sNx+Olx |
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sig11(I,J) = 0. _d 0 |
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sig22(I,J) = 0. _d 0 |
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sig12(I,J) = 0. _d 0 |
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ENDDO |
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ENDDO |
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|
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DO j=1-Oly+1,sNy+Oly-1 |
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DO i=1-Olx+1,sNx+Olx-1 |
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eplus = e11(I,J,bi,bj) + e22(I,J,bi,bj) |
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eminus= e11(I,J,bi,bj) - e22(I,J,bi,bj) |
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sig11(I,J) = zeta(I,J,bi,bj)*eplus + eta(I,J,bi,bj)*eminus |
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& - 0.5 _d 0 * PRESS(I,J,bi,bj) |
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sig22(I,J) = zeta(I,J,bi,bj)*eplus - eta(I,J,bi,bj)*eminus |
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& - 0.5 _d 0 * PRESS(I,J,bi,bj) |
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sig12(I,J) = 2. _d 0 * e12(I,J,bi,bj) * |
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& ( eta(I,J ,bi,bj) + eta(I-1,J ,bi,bj) |
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& + eta(I,J-1,bi,bj) + eta(I-1,J-1,bi,bj) ) |
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& /MAX(1. _d 0, |
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& hEffM(I,J ,bi,bj) + hEffM(I-1,J ,bi,bj) |
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& + hEffM(I,J-1,bi,bj) + hEffM(I-1,J-1,bi,bj)) |
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ENDDO |
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ENDDO |
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C evaluate divergence of stress and apply to forcing |
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DO J=1,sNy |
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DO I=1,sNx |
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FX = ( sig11(I ,J ) * _dyF(I ,J ,bi,bj) |
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& - sig11(I-1,J ) * _dyF(I-1,J ,bi,bj) |
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& + sig12(I ,J+1) * _dxV(I ,J+1,bi,bj) |
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& - sig12(I ,J ) * _dxV(I ,J ,bi,bj) |
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& ) * recip_rAw(I,J,bi,bj) |
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& - |
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& ( sig12(I,J) + sig12(I,J+1) ) |
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& * _tanPhiAtU(I,J,bi,bj) * recip_rSphere |
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& + |
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& ( sig22(I,J) + sig22(I-1,J) ) * 0.5 _d 0 |
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& * _tanPhiAtU(I,J,bi,bj) * recip_rSphere |
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C one metric term missing for general curvilinear coordinates |
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FY = ( sig22(I ,J ) * _dxF(I ,J ,bi,bj) |
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& - sig22(I ,J-1) * _dxF(I ,J-1,bi,bj) |
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& + sig12(I+1,J ) * _dyU(I+1,J ,bi,bj) |
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& - sig12(I ,J ) * _dyU(I ,J ,bi,bj) |
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& ) * recip_rAs(I,J,bi,bj) |
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& - |
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& ( sig22(I,J) + sig22(I,J-1) ) * 0.5 _d 0 |
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& * _tanPhiAtV(I,J,bi,bj) * recip_rSphere |
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C two metric terms missing for general curvilinear coordinates |
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C average wind stress over ice and ocean and apply averaged wind |
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C stress and internal ice stresses to surface layer of ocean |
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areaW = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
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& * SEAICEstressFactor |
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areaS = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
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& * SEAICEstressFactor |
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fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj) |
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& + areaW*taux(I,J,bi,bj) |
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& + FX * SEAICEstressFactor |
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fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj) |
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& + areaS*tauy(I,J,bi,bj) |
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& + FY * SEAICEstressFactor |
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C save stress divergence for later |
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#ifdef SEAICE_ALLOW_EVP |
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stressDivergenceX(I,J,bi,bj) = FX |
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stressDivergenceY(I,J,bi,bj) = FY |
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#endif /* SEAICE_ALLOW_EVP */ |
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ENDDO |
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ENDDO |
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ELSE |
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#ifdef SEAICE_ALLOW_EVP |
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DO J=1,sNy |
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DO I=1,sNx |
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C average wind stress over ice and ocean and apply averaged wind |
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C stress and internal ice stresses to surface layer of ocean |
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areaW = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
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& * SEAICEstressFactor |
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areaS = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
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& * SEAICEstressFactor |
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fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj) |
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& + areaW*taux(I,J,bi,bj) |
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& + stressDivergenceX(I,J,bi,bj) * SEAICEstressFactor |
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fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj) |
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& + areaS*tauy(I,J,bi,bj) |
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& + stressDivergenceY(I,J,bi,bj) * SEAICEstressFactor |
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ENDDO |
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ENDDO |
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#endif /* SEAICE_ALLOW_EVP */ |
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ENDIF |
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ENDDO |
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ENDDO |
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ELSE |
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|
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C-- Compute ice-affected wind stress (interpolate to U/V-points) |
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C by averaging wind stress and ice-ocean stress according to |
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C ice cover |
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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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fuIceLoc=HALF*( DWATN(I,J,bi,bj)+DWATN(I,J+1,bi,bj) )* |
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& COSWAT * |
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& ( UICE(I,J,1,bi,bj)-GWATX(I,J,bi,bj) ) |
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& - SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
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& ( DWATN(I ,J,bi,bj) * |
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& 0.5 _d 0*(vIce(I ,J ,1,bi,bj)-GWATY(I ,J ,bi,bj) |
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& +vIce(I ,J+1,1,bi,bj)-GWATY(I ,J+1,bi,bj)) |
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& + DWATN(I-1,J,bi,bj) * |
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& 0.5 _d 0*(vIce(I-1,J ,1,bi,bj)-GWATY(I-1,J ,bi,bj) |
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& +vIce(I-1,J+1,1,bi,bj)-GWATY(I-1,J+1,bi,bj)) |
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& ) |
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fvIceLoc=HALF*( DWATN(I,J,bi,bj)+DWATN(I+1,J,bi,bj) )* |
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& COSWAT * |
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& ( VICE(I,J,1,bi,bj)-GWATY(I,J,bi,bj) ) |
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& + SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
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& ( DWATN(I,J ,bi,bj) * |
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& 0.5 _d 0*(uIce(I ,J ,1,bi,bj)-GWATX(I ,J ,bi,bj) |
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& +uIce(I+1,J ,1,bi,bj)-GWATX(I+1,J ,bi,bj)) |
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& + DWATN(I,J-1,bi,bj) * |
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& 0.5 _d 0*(uIce(I ,J-1,1,bi,bj)-GWATX(I ,J-1,bi,bj) |
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& +uIce(I+1,J-1,1,bi,bj)-GWATX(I+1,J-1,bi,bj)) |
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& ) |
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areaW = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
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& * SEAICEstressFactor |
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areaS = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
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& * SEAICEstressFactor |
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fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj)+areaW*fuIceLoc |
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fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj)+areaS*fvIceLoc |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDIF |
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CALL EXCH_UV_XY_RS(fu, fv, .TRUE., myThid) |
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|
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#endif /* not SEAICE_CGRID */ |
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|
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RETURN |
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END |
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