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C $Header: /u/gcmpack/MITgcm/pkg/dic/dic_surfforcing.F,v 1.11 2006/09/12 19:58:02 stephd Exp $ |
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C $Name: $ |
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|
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#include "DIC_OPTIONS.h" |
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#include "PTRACERS_OPTIONS.h" |
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#include "GCHEM_OPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: DIC_SURFFORCING |
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|
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C !INTERFACE: ========================================================== |
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SUBROUTINE DIC_SURFFORCING( PTR_CO2 , PTR_ALK, PTR_PO4, GDC, |
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I bi,bj,imin,imax,jmin,jmax, |
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I myIter,myTime,myThid) |
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|
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C !DESCRIPTION: |
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C Calculate the carbon air-sea flux terms |
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C following external_forcing_dic.F (OCMIP run) from Mick |
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|
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C !USES: =============================================================== |
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IMPLICIT NONE |
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#include "SIZE.h" |
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#include "DYNVARS.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 "DIC_ABIOTIC.h" |
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|
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C !INPUT PARAMETERS: =================================================== |
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C myThid :: thread number |
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C myIter :: current timestep |
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C myTime :: current time |
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c PTR_CO2 :: DIC tracer field |
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INTEGER myIter, myThid |
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_RL myTime |
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_RL PTR_CO2(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) |
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_RL PTR_ALK(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) |
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_RL PTR_PO4(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) |
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INTEGER iMin,iMax,jMin,jMax, bi, bj |
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|
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C !OUTPUT PARAMETERS: =================================================== |
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c GDC :: tendency due to air-sea exchange |
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_RL GDC(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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|
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#ifdef ALLOW_PTRACERS |
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|
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C !LOCAL VARIABLES: ==================================================== |
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INTEGER I,J, kLev, it |
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C Number of iterations for pCO2 solvers... |
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C Solubility relation coefficients |
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_RL SchmidtNoDIC(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL pCO2sat(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL Kwexch(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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C local variables for carbon chem |
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_RL surfalk(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL surfphos(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL surfsi(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL VirtualFlux(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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CEOP |
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|
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cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc |
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|
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kLev=1 |
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|
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C PRE-INDUSTRIAL STEADY STATE pCO2 = 278.0 ppmv |
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DO j=1-OLy,sNy+OLy |
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DO i=1-OLx,sNx+OLx |
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AtmospCO2(i,j,bi,bj)=278.0d-6 |
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ENDDO |
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ENDDO |
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|
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|
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C ================================================================= |
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C determine inorganic carbon chem coefficients |
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DO j=jmin,jmax |
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DO i=imin,imax |
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|
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#ifdef DIC_BIOTIC |
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cQQQQ check ptracer numbers |
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surfalk(i,j) = PTR_ALK(i,j,klev) |
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& * maskC(i,j,kLev,bi,bj) |
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surfphos(i,j) = PTR_PO4(i,j,klev) |
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& * maskC(i,j,kLev,bi,bj) |
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#else |
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surfalk(i,j) = 2.366595 * salt(i,j,kLev,bi,bj)/gsm_s |
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& * maskC(i,j,kLev,bi,bj) |
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surfphos(i,j) = 5.1225e-4 * maskC(i,j,kLev,bi,bj) |
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#endif |
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C FOR NON-INTERACTIVE Si |
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surfsi(i,j) = SILICA(i,j,bi,bj) * maskC(i,j,kLev,bi,bj) |
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ENDDO |
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ENDDO |
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|
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CALL CARBON_COEFFS( |
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I theta,salt, |
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I bi,bj,iMin,iMax,jMin,jMax) |
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C==================================================================== |
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|
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c pCO2 solver... |
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C$TAF LOOP = parallel |
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DO j=jmin,jmax |
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C$TAF LOOP = parallel |
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DO i=imin,imax |
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|
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IF(maskC(i,j,kLev,bi,bj) .NE. 0.)THEN |
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CALL CALC_PCO2_APPROX( |
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I theta(i,j,kLev,bi,bj),salt(i,j,kLev,bi,bj), |
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I PTR_CO2(i,j,kLev), surfphos(i,j), |
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I surfsi(i,j),surfalk(i,j), |
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I ak1(i,j,bi,bj),ak2(i,j,bi,bj), |
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I ak1p(i,j,bi,bj),ak2p(i,j,bi,bj),ak3p(i,j,bi,bj), |
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I aks(i,j,bi,bj),akb(i,j,bi,bj),akw(i,j,bi,bj), |
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I aksi(i,j,bi,bj),akf(i,j,bi,bj),ff(i,j,bi,bj), |
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I bt(i,j,bi,bj),st(i,j,bi,bj),ft(i,j,bi,bj), |
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U pH(i,j,bi,bj),pCO2(i,j,bi,bj) ) |
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ELSE |
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pCO2(i,j,bi,bj)=0. _d 0 |
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END IF |
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ENDDO |
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ENDDO |
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|
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DO j=jmin,jmax |
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DO i=imin,imax |
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|
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IF (maskC(i,j,kLev,bi,bj).NE.0.) THEN |
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C calculate SCHMIDT NO. for CO2 |
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SchmidtNoDIC(i,j) = |
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& sca1 |
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& + sca2 * theta(i,j,kLev,bi,bj) |
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& + sca3 * theta(i,j,kLev,bi,bj)*theta(i,j,kLev,bi,bj) |
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& + sca4 * theta(i,j,kLev,bi,bj)*theta(i,j,kLev,bi,bj) |
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& *theta(i,j,kLev,bi,bj) |
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|
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C Determine surface flux (FDIC) |
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C first correct pCO2at for surface atmos pressure |
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pCO2sat(i,j) = |
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& AtmosP(i,j,bi,bj)*AtmospCO2(i,j,bi,bj) |
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c find exchange coefficient |
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c account for schmidt number and and varible piston velocity |
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pisvel(i,j,bi,bj) =0.337*wind(i,j,bi,bj)**2/3.6d5 |
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Kwexch(i,j) = |
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& pisvel(i,j,bi,bj) |
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& / sqrt(SchmidtNoDIC(i,j)/660.0) |
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c OR use a constant coeff |
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c Kwexch(i,j) = 5e-5 |
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c ice influence |
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Kwexch(i,j) =(1.d0-Fice(i,j,bi,bj))*Kwexch(i,j) |
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|
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|
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C Calculate flux in terms of DIC units using K0, solubility |
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C Flux = Vp * ([CO2sat] - [CO2]) |
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C CO2sat = K0*pCO2atmos*P/P0 |
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C Converting pCO2 to [CO2] using ff, as in CALC_PCO2 |
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FluxCO2(i,j,bi,bj) = |
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& maskC(i,j,kLev,bi,bj)*Kwexch(i,j)*( |
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& ak0(i,j,bi,bj)*pCO2sat(i,j) - |
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& ff(i,j,bi,bj)*pCO2(i,j,bi,bj) |
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& ) |
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ELSE |
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FluxCO2(i,j,bi,bj) = 0. |
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ENDIF |
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C convert flux (mol kg-1 m s-1) to (mol m-2 s-1) |
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FluxCO2(i,j,bi,bj) = FluxCO2(i,j,bi,bj)/permil |
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|
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IF (maskC(i,j,kLev,bi,bj).NE.0.) THEN |
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c calculate virtual flux |
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c EminusPforV = dS/dt*(1/Sglob) |
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C NOTE: Be very careful with signs here! |
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C Positive EminusPforV => loss of water to atmos and increase |
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C in salinity. Thus, also increase in other surface tracers |
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C (i.e. positive virtual flux into surface layer) |
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C ...so here, VirtualFLux = dC/dt! |
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VirtualFlux(i,j)=gsm_DIC*surfaceForcingS(i,j,bi,bj)/gsm_s |
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c OR |
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c let virtual flux be zero |
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c VirtualFlux(i,j)=0.d0 |
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c |
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ELSE |
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VirtualFlux(i,j)=0. _d 0 |
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ENDIF |
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ENDDO |
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ENDDO |
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|
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C update tendency |
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DO j=jmin,jmax |
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DO i=imin,imax |
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GDC(i,j)= maskC(i,j,kLev,bi,bj)*recip_drF(kLev)* |
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& recip_hFacC(i,j,kLev,bi,bj)*( |
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& FluxCO2(i,j,bi,bj) + VirtualFlux(i,j) |
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& ) |
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ENDDO |
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ENDDO |
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|
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#endif |
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RETURN |
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END |