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C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_ocean_stress.F,v 1.6 2006/03/16 14:25:40 mlosch 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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#include "SEAICE_FFIELDS.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 fuIce, fvIce, FX, FY |
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_RL areaW, areaS |
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|
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_RL press (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
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_RL etaPlusZeta (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL zetaMinusEta(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL etaMeanZ (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL etaMeanU (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL etaMeanV (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL dVdx (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL dVdy (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL dUdx (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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_RL dUdy (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
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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 viscosities from updated ice velocities |
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CALL SEAICE_CALC_VISCOSITIES( |
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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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I zMin, zMax, hEffM, press0, |
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O eta, zeta, press, |
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I myThid ) |
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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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DO j=1-Oly+1,sNy+Oly-1 |
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DO i=1-Olx+1,sNx+Olx-1 |
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etaPlusZeta (I,J) = eta(I,J,bi,bj) + zeta(I,J,bi,bj) |
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zetaMinusEta(I,J) = zeta(I,J,bi,bj) - eta(I,J,bi,bj) |
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etaMeanU (I,J) = |
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& HALF*(ETA (I,J,bi,bj) + ETA (I-1,J ,bi,bj)) |
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etaMeanV (I,J) = |
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& HALF*(ETA (I,J,bi,bj) + ETA (I ,J-1,bi,bj)) |
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etaMeanZ (I,J) = QUART * |
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& ( eta(I ,J,bi,bj) + eta(I ,J-1,bi,bj) |
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& + eta(I-1,J,bi,bj) + eta(I-1,J-1,bi,bj) ) |
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dUdx(I,J) = ( uIce(I+1,J,1,bi,bj) - uIce(I,J,1,bi,bj) ) |
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& * _recip_dxF(I,J,bi,bj) |
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dUdy(I,J) = ( uIce(I,J+1,1,bi,bj) - uIce(I,J,1,bi,bj) ) |
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& * _recip_dyU(I,J+1,bi,bj) |
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dVdx(I,J) = ( vIce(I+1,J,1,bi,bj) - vIce(I,J,1,bi,bj) ) |
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& * _recip_dxV(I+1,J,bi,bj) |
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dVdy(I,J) = ( vIce(I,J+1,1,bi,bj) - vIce(I,J,1,bi,bj) ) |
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& * _recip_dyF(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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DO J = 1,sNy |
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DO I = 1,sNx |
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C First FX = (d/dx)*sigma |
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C + d/dx[ eta+zeta d/dx ] U |
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FX = _recip_dxC(I,J,bi,bj) * |
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& ( etaPlusZeta(I ,J) * dUdx(I ,J) |
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& - etaPlusZeta(I-1,J) * dUdx(I-1,J) ) |
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C + (d/dy)[eta*(d/dy + tanphi/a)] U (also on UVRT1/2) |
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FX = FX + _recip_dyG(I,J,bi,bj) * ( |
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& ( etaMeanZ(I,J+1) * dUdy(I,J+1) |
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& - etaMeanZ(I,J ) * dUdy(I,J ) |
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& ) |
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& - ( etaMeanZ(I,J+1) |
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& * ( uIce(I,J+1,1,bi,bj)+uIce(I,J,1,bi,bj) ) |
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& - etaMeanZ(I,J ) |
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& * ( uIce(I,J-1,1,bi,bj)+uIce(I,J,1,bi,bj) ) ) |
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& * 0.5 _d 0 * _tanPhiAtU(I,J,bi,bj) |
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& * recip_rSphere ) |
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C - 2*eta*(tanphi/a) * ( tanphi/a ) U |
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FX = FX - TWO * uIce(I,J,1,bi,bj) |
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& * etaMeanU(I,J)*recip_rSphere*recip_rSphere |
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& * _tanPhiAtU(I,J,bi,bj) * _tanPhiAtU(I,J,bi,bj) |
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C + d/dx[ (zeta-eta) dV/dy] |
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FX = FX + |
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& ( zetaMinusEta(I ,J ) * dVdy(I ,J ) |
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& - zetaMinusEta(I-1,J ) * dVdy(I-1,J ) |
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& ) * _recip_dxC(I,J,bi,bj) |
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C + d/dy[ eta dV/x ] |
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FX = FX + ( |
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& etaMeanZ(I,J+1) |
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& * ( vIce(I ,J+1,1,bi,bj) - vIce(I-1,J+1,1,bi,bj) ) |
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& * _recip_dxV(I,J+1,bi,bj) |
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& - etaMeanZ(I,J ) |
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& * ( vIce(I ,J,1,bi,bj) - vIce(I-1,J,1,bi,bj) ) |
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& * _recip_dxV(I,J,bi,bj) |
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& ) * _recip_dyG(I,J,bi,bj) |
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C - d/dx[ (eta+zeta) * v * (tanphi/a) ] |
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FX = FX - ( |
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& etaPlusZeta(I ,J) |
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& * 0.5 * (vIce(I ,J,1,bi,bj)+vIce(I ,J+1,1,bi,bj)) |
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& * 0.5 * ( _tanPhiAtU(I ,J,bi,bj) |
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& + _tanPhiAtU(I+1,J,bi,bj) ) |
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& - etaPlusZeta(I-1,J) * |
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& * 0.5 * (vIce(I-1,J,1,bi,bj)+vIce(I-1,J+1,1,bi,bj)) |
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& * 0.5 * ( _tanPhiAtU(I-1,J,bi,bj) |
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& + _tanPhiAtU(I ,J,bi,bj) ) |
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& )* _recip_dxC(I,J,bi,bj)*recip_rSphere |
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C - 2*eta*(tanphi/a) * dV/dx |
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FX = FX |
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& -TWO * etaMeanU(I,J) * _tanPhiAtV(I,J,bi,bj) |
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& *recip_rSphere |
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& *(vIce(I ,J,1,bi,bj) + vIce(I ,J+1,1,bi,bj) |
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& - vIce(I-1,J,1,bi,bj) - vIce(I-1,J+1,1,bi,bj)) |
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& * _recip_dxC(I,J,bi,bj) |
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C - (d/dx) P/2 |
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FX = _maskW(I,J,1,bi,bj) * ( FX - _recip_dxC(I,J,bi,bj) |
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& * ( press(I,J,bi,bj) - press(I-1,J,bi,bj) ) ) |
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C |
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C then FY = (d/dy)*sigma |
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C + d/dy [(eta+zeta) d/dy] V |
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FY = _recip_dyC(I,J,bi,bj) * |
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& ( dVdy(I,J ) * etaPlusZeta(I,J ) |
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& - dVdy(I,J-1) * etaPlusZeta(I,J-1) ) |
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C + d/dx [eta d/dx] V |
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FY = FY + _recip_dxC(I,J,bi,bj) * |
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& ( eta(I ,J,bi,bj) * dVdx(I ,J) |
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& - eta(I-1,J,bi,bj) * dVdx(I-1,J) ) |
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C - d/dy [(zeta-eta) tanphi/a] V |
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FY = FY - _recip_dyC(I,J,bi,bj) * recip_rSphere * ( |
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& zetaMinusEta(I,J ) * tanPhiAtU(I,J ,bi,bj) |
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& * 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J+1,1,bi,bj)) |
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& - zetaMinusEta(I,J-1) * tanPhiAtU(I,J-1,bi,bj) |
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& * 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J-1,1,bi,bj)) ) |
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C 2*eta tanphi/a ( - tanphi/a - d/dy) V |
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FY = FY - TWO*etaMeanV(I,J) * recip_rSphere |
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& * _tanPhiAtV(I,J,bi,bj) * ( |
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& _tanPhiAtV(I,J,bi,bj) * recip_rSphere |
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& + _recip_dyC(I,J,bi,bj) * |
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& ( 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J+1,1,bi,bj)) |
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& - 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J-1,1,bi,bj)) ) ) |
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C + d/dy[ (zeta-eta) dU/dx ] |
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FY = FY + |
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& ( zetaMinusEta(I,J )*dUdx(I,J ) |
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& - zetaMinusEta(I,J-1)*dUdx(I,J-1) ) |
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& * _recip_dyC(I,J,bi,bj) |
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C + d/dx[ eta dU/dy ] |
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FY = FY + _recip_dxG(I,J,bi,bj) * |
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& ( etaMeanZ(I+1,J) * dUdy(I+1,J) |
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& - etaMeanZ(I ,J) * dUdy(I ,J) ) |
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C + d/dx[ eta * (tanphi/a) * U ] |
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FY = FY + ( |
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& etaMeanZ(I+1,J) * 0.5 * |
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& ( uIce(I+1,J ,1,bi,bj) * _tanPhiAtU(I+1,J ,bi,bj) |
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& + uIce(I+1,J-1,1,bi,bj) * _tanPhiAtU(I+1,J-1,bi,bj) ) |
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& - etaMeanZ(I ,J) * 0.5 * |
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& ( uIce(I ,J ,1,bi,bj) * _tanPhiAtU(I ,J ,bi,bj) |
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& + uIce(I ,J-1,1,bi,bj) * _tanPhiAtU(I ,J ,bi,bj) ) |
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& ) * _recip_dxG(I,J,bi,bj)*recip_rSphere |
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C + 2*eta*(tanphi/a) dU/dx |
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FY = FY + |
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& TWO * etaMeanV(I,J)*TWO * _tanPhiAtV(I,J,bi,bj) |
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& * ( uIce(I+1,J,1,bi,bj)+uIce(I+1,J-1,1,bi,bj) |
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& - uIce(I ,J,1,bi,bj)-uIce(I ,J-1,1,bi,bj) ) |
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& * _recip_dxG(I,J,bi,bj) * recip_rSphere |
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C - (d/dy) P/2 |
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FY = _maskS(I,J,1,bi,bj) * ( FY - _recip_dyC(I,J,bi,bj) |
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& * ( press(I,J,bi,bj) - press(I,J-1,bi,bj) ) ) |
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C |
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C recompute wind stress over ice (done already in seaice_dynsolver, |
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C but not saved) |
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fuIce = 0.5 _d 0 * |
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& ( DAIRN(I ,J,bi,bj)*( |
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& COSWIN*uWind(I ,J,bi,bj) |
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& -SIGN(SINWIN, _fCori(I ,J,bi,bj))*vWind(I ,J,bi,bj) ) |
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& + DAIRN(I-1,J,bi,bj)*( |
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& COSWIN*uWind(I-1,J,bi,bj) |
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& -SIGN(SINWIN, _fCori(I-1,J,bi,bj))*vWind(I-1,J,bi,bj) ) |
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& ) |
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fvIce = 0.5 _d 0 * |
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& ( DAIRN(I,J ,bi,bj)*( |
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& SIGN(SINWIN, _fCori(I ,J,bi,bj))*uWind(I,J ,bi,bj) |
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& +COSWIN*vWind(I,J ,bi,bj) ) |
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& + DAIRN(I,J-1,bi,bj)*( |
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& SIGN(SINWIN, _fCori(I,J-1,bi,bj))*uWind(I,J-1,bi,bj) |
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& +COSWIN*vWind(I,J-1,bi,bj) ) |
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& ) |
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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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areaS = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
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fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj)+areaW*fuIce + FX |
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fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj)+areaS*fvIce + FY |
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END DO |
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END DO |
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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 |
| 259 |
DO i=1,sNx |
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fuIce=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) ) |
| 263 |
& - SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
| 264 |
& ( DWATN(I ,J,bi,bj) * |
| 265 |
& 0.5 _d 0*(vIce(I ,J ,1,bi,bj)-GWATY(I ,J ,bi,bj) |
| 266 |
& +vIce(I ,J+1,1,bi,bj)-GWATY(I ,J+1,bi,bj)) |
| 267 |
& + DWATN(I-1,J,bi,bj) * |
| 268 |
& 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)) |
| 270 |
& ) |
| 271 |
fvIce=HALF*( DWATN(I,J,bi,bj)+DWATN(I+1,J,bi,bj) )* |
| 272 |
& COSWAT * |
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& ( VICE(I,J,1,bi,bj)-GWATY(I,J,bi,bj) ) |
| 274 |
& + SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
| 275 |
& ( DWATN(I,J ,bi,bj) * |
| 276 |
& 0.5 _d 0*(uIce(I ,J ,1,bi,bj)-GWATX(I ,J ,bi,bj) |
| 277 |
& +uIce(I+1,J ,1,bi,bj)-GWATX(I+1,J ,bi,bj)) |
| 278 |
& + DWATN(I,J-1,bi,bj) * |
| 279 |
& 0.5 _d 0*(uIce(I ,J-1,1,bi,bj)-GWATX(I ,J-1,bi,bj) |
| 280 |
& +uIce(I+1,J-1,1,bi,bj)-GWATX(I+1,J-1,bi,bj)) |
| 281 |
& ) |
| 282 |
areaW = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
| 283 |
areaS = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
| 284 |
fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj)+areaW*fuIce |
| 285 |
fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj)+areaS*fvIce |
| 286 |
ENDDO |
| 287 |
ENDDO |
| 288 |
ENDDO |
| 289 |
ENDDO |
| 290 |
ENDIF |
| 291 |
CALL EXCH_UV_XY_RS(fu, fv, .TRUE., myThid) |
| 292 |
|
| 293 |
#endif /* not SEAICE_CGRID */ |
| 294 |
|
| 295 |
RETURN |
| 296 |
END |
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