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C $Header: /u/gcmpack/MITgcm/pkg/aim_v23/phy_suflux_sice.F,v 1.5 2004/07/22 22:58:38 jmc Exp $ |
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C $Name: $ |
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|
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#include "AIM_OPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: SUFLUX_SICE |
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C !INTERFACE: |
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SUBROUTINE SUFLUX_SICE( |
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I PSA, FMASK, EMISloc, |
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I Tsurf, dTskin, SSR, SLRD, |
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I T1, T0, Q0, DENVV, |
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O SHF, EVAP, SLRU, |
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O Shf0, dShf, Evp0, dEvp, Slr0, dSlr, sFlx, |
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O TSFC, TSKIN, |
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I bi,bj,myThid) |
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|
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C !DESCRIPTION: \bv |
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C *==========================================================* |
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C | S/R SUFLUX_SICE |
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C | o compute surface flux over sea-ice |
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C *==========================================================* |
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C | o contains part of original S/R SUFLUX (Speedy code) |
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C *==========================================================* |
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C \ev |
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|
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C !USES: |
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IMPLICIT NONE |
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|
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C Resolution parameters |
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|
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C-- size for MITgcm & Physics package : |
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#include "AIM_SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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|
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C-- Physics package |
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#include "AIM_PARAMS.h" |
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|
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C Physical constants + functions of sigma and latitude |
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#include "com_physcon.h" |
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|
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C Surface flux constants |
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#include "com_sflcon.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-- Input: |
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C PSA :: norm. surface pressure [p/p0] (2-dim) |
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C FMASK :: fractional land-sea mask (2-dim) |
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C EMISloc:: longwave surface emissivity |
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C Tsurf :: surface temperature (2-dim) |
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C dTskin :: temp. correction for daily-cycle heating [K] |
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C SSR :: sfc sw radiation (net flux) (2-dim) |
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C SLRD :: sfc lw radiation (downward flux)(2-dim) |
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C T1 :: near-surface air temperature (from Pot.temp) |
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C T0 :: near-surface air temperature (2-dim) |
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C Q0 :: near-surface sp. humidity [g/kg](2-dim) |
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C DENVV :: surface flux (sens,lat.) coeff. (=Rho*|V|) [kg/m2/s] |
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C-- Output: |
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C SHF :: sensible heat flux (2-dim) |
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C EVAP :: evaporation [g/(m^2 s)] (2-dim) |
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C SLRU :: sfc lw radiation (upward flux) (2-dim) |
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C Shf0 :: sensible heat flux over freezing surf. |
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C dShf :: sensible heat flux derivative relative to surf. temp |
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C Evp0 :: evaporation computed over freezing surface (Ts=0.oC) |
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C dEvp :: evaporation derivative relative to surf. temp |
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C Slr0 :: upward long wave radiation over freezing surf. |
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C dSlr :: upward long wave rad. derivative relative to surf. temp |
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C sFlx :: net heat flux (+=down) except SW, function of surf. temp Ts: |
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C 0: Flux(Ts=0.oC) ; 1: Flux(Ts^n) ; 2: d.Flux/d.Ts(Ts^n) |
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C TSFC :: surface temperature (clim.) (2-dim) |
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C TSKIN :: skin surface temperature (2-dim) |
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C-- Input: |
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C bi,bj :: tile index |
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C myThid :: Thread number for this instance of the routine |
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C-- |
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_RL PSA(NGP), FMASK(NGP), EMISloc |
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_RL Tsurf(NGP), dTskin(NGP) |
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_RL SSR(NGP), SLRD(NGP) |
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_RL T1(NGP), T0(NGP), Q0(NGP), DENVV(NGP) |
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|
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_RL SHF(NGP), EVAP(NGP), SLRU(NGP) |
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_RL Shf0(NGP), dShf(NGP), Evp0(NGP), dEvp(NGP) |
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_RL Slr0(NGP), dSlr(NGP), sFlx(NGP,0:2) |
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_RL TSFC(NGP), TSKIN(NGP) |
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|
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INTEGER bi,bj,myThid |
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CEOP |
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|
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#ifdef ALLOW_AIM |
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|
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C-- Local variables: |
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C CDENVV :: surf. heat flux (sens.,lat.) coeff including stability effect |
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C ALHevp :: Latent Heat of evaporation |
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_RL CDENVV(NGP), RDTH, FSSICE |
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_RL ALHevp, Fstb0, dTstb, dFstb |
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_RL QSAT0(NGP,2) |
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_RL QDUMMY(1), RDUMMY(1), TS2 |
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INTEGER J |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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|
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ALHevp = ALHC |
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C Evap of snow/ice: account for Latent Heat of freezing : |
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IF ( aim_energPrecip .OR. useThSIce ) ALHevp = ALHC + ALHF |
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|
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C 1.5 Define effective skin temperature to compensate for |
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C non-linearity of heat/moisture fluxes during the daily cycle |
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|
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DO J=1,NGP |
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c TSKIN(J) = Tsurf(J) + dTskin(J) |
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c TSFC(J)=273.16 _d 0 + dTskin(J) |
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TSKIN(J) = Tsurf(J) |
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TSFC(J)=273.16 _d 0 |
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ENDDO |
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|
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C-- 2. Computation of fluxes over land and sea |
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|
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C 2.1 Stability correction |
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|
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RDTH = FSTAB/DTHETA |
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|
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DO J=1,NGP |
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FSSICE=1.+MIN(DTHETA,MAX(-DTHETA,TSKIN(J)-T1(J)))*RDTH |
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CDENVV(J)=CHS*DENVV(J)*FSSICE |
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ENDDO |
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|
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IF ( dTstab.GT.0. _d 0 ) THEN |
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C- account for stability function derivative relative to Tsurf: |
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C note: to avoid discontinuity in the derivative (because of min,max), compute |
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C the derivative using the discrete form: F(Ts+dTstab)-F(Ts-dTstab)/2.dTstab |
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DO J=1,NGP |
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Fstb0 = 1.+MIN(DTHETA,MAX(-DTHETA,TSFC(J) -T1(J)))*RDTH |
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Shf0(J) = CHS*DENVV(J)*Fstb0 |
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dTstb = ( DTHETA+dTstab-ABS(TSKIN(J)-T1(J)) )/dTstab |
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dFstb = RDTH*MIN(1. _d 0, MAX(0. _d 0, dTstb*0.5 _d 0)) |
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dShf(J) = CHS*DENVV(J)*dFstb |
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ENDDO |
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C- deBug part: |
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c J = 6 + (17-1)*sNx |
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c IF ( bi.EQ.3 .AND. J.LE.NGP ) |
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c & WRITE(6,1020)'SUFLUX_SICE: Stab=',Shf0(J),CDENVV(J),dShf(J) |
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ENDIF |
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|
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C 2.2 Evaporation |
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|
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CALL SHTORH (2, NGP, TSKIN, PSA, 1. _d 0, QDUMMY, dEvp, |
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& QSAT0(1,1), myThid) |
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CALL SHTORH (0, NGP, TSFC, PSA, 1. _d 0, QDUMMY, RDUMMY, |
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& QSAT0(1,2), myThid) |
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|
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IF ( dTstab.GT.0. _d 0 ) THEN |
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C- account for stability function derivative relative to Tsurf: |
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DO J=1,NGP |
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EVAP(J) = CDENVV(J)*(QSAT0(J,1)-Q0(J)) |
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Evp0(J) = Shf0(J)*(QSAT0(J,2)-Q0(J)) |
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dEvp(J) = CDENVV(J)*dEvp(J) |
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& + dShf(J)*(QSAT0(J,1)-Q0(J)) |
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ENDDO |
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ELSE |
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DO J=1,NGP |
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EVAP(J) = CDENVV(J)*(QSAT0(J,1)-Q0(J)) |
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Evp0(J) = CDENVV(J)*(QSAT0(J,2)-Q0(J)) |
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dEvp(J) = CDENVV(J)*dEvp(J) |
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ENDDO |
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ENDIF |
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|
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C 2.3 Sensible heat flux |
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|
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IF ( dTstab.GT.0. _d 0 ) THEN |
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C- account for stability function derivative relative to Tsurf: |
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DO J=1,NGP |
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SHF(J) = CDENVV(J)*CP*(TSKIN(J)-T0(J)) |
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Shf0(J) = Shf0(J)*CP*(TSFC(J) -T0(J)) |
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dShf(J) = CDENVV(J)*CP |
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& + dShf(J)*CP*(TSKIN(J)-T0(J)) |
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dShf(J) = MAX( dShf(J), 0. _d 0 ) |
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C-- do not allow negative derivative vs Ts of Sensible+Latent H.flux: |
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C a) quiet unrealistic ; |
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C b) garantee positive deriv. of total H.flux (needed for implicit solver) |
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dEvp(J) = MAX( dEvp(J), -dShf(J)/ALHevp ) |
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ENDDO |
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ELSE |
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DO J=1,NGP |
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SHF(J) = CDENVV(J)*CP*(TSKIN(J)-T0(J)) |
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Shf0(J) = CDENVV(J)*CP*(TSFC(J) -T0(J)) |
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dShf(J) = CDENVV(J)*CP |
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ENDDO |
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ENDIF |
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|
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C 2.4 Emission of lw radiation from the surface |
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|
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DO J=1,NGP |
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TS2 = TSFC(J)*TSFC(J) |
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Slr0(J) = SBC*TS2*TS2 |
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TS2 = TSKIN(J)*TSKIN(J) |
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SLRU(J) = SBC*TS2*TS2 |
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dSlr(J) = 4. _d 0 *SBC*TS2*TSKIN(J) |
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ENDDO |
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|
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C-- Compute net surface heat flux and its derivative ./. surf. temp. |
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DO J=1,NGP |
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sFlx(J,0)= ( SLRD(J) - EMISloc*Slr0(J) ) |
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& - ( Shf0(J) + ALHevp*Evp0(J) ) |
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sFlx(J,1)= ( SLRD(J) - EMISloc*SLRU(J) ) |
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& - ( SHF(J) + ALHevp*EVAP(J) ) |
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sFlx(J,2)= -EMISloc*dSlr(J) |
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& - ( dShf(J) + ALHevp*dEvp(J) ) |
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ENDDO |
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|
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C- deBug part: ----------------- |
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c1010 FORMAT(A,I3,2F10.3,F10.4) |
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c1020 FORMAT(A,1P4E11.3) |
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c J = 6 + (17-1)*sNx |
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c IF ( bi.EQ.3 .AND. J.LE.NGP ) THEN |
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c WRITE(6,1010) 'SUFLUX_SICE: 1,sFlx=', 1, |
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c & sFlx(J,0),sFlx(J,1),sFlx(J,2) |
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c WRITE(6,1010) 'SUFLUX_SICE: 0,Evap=', 0,Evp0(J),EVAP(J),dEvp(J) |
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c WRITE(6,1010) 'SUFLUX_SICE: -,LWup=',-1,Slr0(J),SLRU(J),dSlr(J) |
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c WRITE(6,1010) 'SUFLUX_SICE: -, SHF=',-1,Shf0(J),SHF(J), dShf(J) |
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c WRITE(6,1010) 'SUFLUX_SICE: -, LAT=',-1, |
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c & ALHevp*Evp0(J),ALHevp*EVAP(J),ALHevp*dEvp(J) |
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c ENDIF |
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|
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C-- 3. Adjustment of skin temperature and fluxes over land |
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C-- based on energy balance (to be implemented) |
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C <= done separately for each surface type (land,ocean,sea-ice) |
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|
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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#endif /* ALLOW_AIM */ |
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|
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RETURN |
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END |
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