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C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_calc_ice_strength.F,v 1.9 2015/01/07 13:27:10 mlosch Exp $ |
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C $Name: $ |
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|
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#include "SEAICE_OPTIONS.h" |
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#ifdef ALLOW_AUTODIFF |
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# include "AUTODIFF_OPTIONS.h" |
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#endif |
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|
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CBOP |
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C !ROUTINE: SEAICE_CALC_ICE_STRENGTH |
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C !INTERFACE: ========================================================== |
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SUBROUTINE SEAICE_CALC_ICE_STRENGTH( |
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I bi, bj, myTime, myIter, myThid ) |
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|
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C !DESCRIPTION: \bv |
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C *===========================================================* |
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C | SUBROUTINE SEAICE_CALC_ICE_STRENGTH |
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C | o compute ice strengh PRESS0 |
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C | according to |
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C | (a) Hibler (1979) |
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C | (b) Thorndyke et al (1975) and Hibler (1980) |
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C | (c) Bitz et al (2001) and Lipscomb et al (2007) |
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C | |
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C | Martin Losch, Apr. 2014, Martin.Losch@awi.de |
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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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#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 "SEAICE_SIZE.h" |
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#include "SEAICE_PARAMS.h" |
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#include "SEAICE.h" |
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|
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C !INPUT PARAMETERS: =================================================== |
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C === Routine arguments === |
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C bi, bj :: outer loop counters |
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C myTime :: current time |
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C myIter :: iteration number |
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C myThid :: Thread no. that called this routine. |
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INTEGER bi,bj |
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_RL myTime |
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INTEGER myIter |
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INTEGER myThid |
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CEOP |
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|
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C !LOCAL VARIABLES: ==================================================== |
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C === Local variables === |
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C i,j,k :: inner loop counters |
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C i/jMin/Max :: loop boundaries |
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C |
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INTEGER i, j |
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INTEGER iMin, iMax, jMin, jMax |
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_RL tmpscal1, tmpscal2 |
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#ifdef SEAICE_ITD |
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C variables related to ridging schemes |
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C ridgingModeNorm :: norm to ensure convervation (N in Lipscomb et al 2007) |
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C partFunc :: participation function (a_n in Lipscomb et al 2007) |
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C ridgeRatio :: mean ridge thickness/ thickness of ridging ice |
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C hrMin :: min ridge thickness |
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C hrMax :: max ridge thickness (SEAICEredistFunc = 0) |
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C hrExp :: ridge e-folding scale (SEAICEredistFunc = 1) |
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C hActual :: HEFFITD/AREAITD |
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INTEGER k |
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_RL ridgingModeNorm (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
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_RL partFunc (1-OLx:sNx+OLx,1-OLy:sNy+OLy,0:nITD) |
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_RL hrMin (1-OLx:sNx+OLx,1-OLy:sNy+OLy,1:nITD) |
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_RL hrMax (1-OLx:sNx+OLx,1-OLy:sNy+OLy,1:nITD) |
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_RL hrExp (1-OLx:sNx+OLx,1-OLy:sNy+OLy,1:nITD) |
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_RL ridgeRatio (1-OLx:sNx+OLx,1-OLy:sNy+OLy,1:nITD) |
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_RL hActual (1-OLx:sNx+OLx,1-OLy:sNy+OLy,1:nITD) |
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#endif /* SEAICE_ITD */ |
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#ifdef SEAICE_CGRID |
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C compute tensile strength |
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_RL recip_tensilDepth |
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#endif /* SEAICE_CGRID */ |
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CEOP |
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|
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C loop boundaries |
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iMin=1-OLx |
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iMax=sNx+OLx |
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jMin=1-OLy |
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jMax=sNy+OLy |
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|
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#ifdef SEAICE_ITD |
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C compute the fraction of open water as early as possible, i.e. |
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C before advection, but also before it is used in calculating the ice |
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C strength according to Rothrock (1975), hidden in S/R seaice_repare_ridging |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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opnWtrFrac(i,j,bi,bj) = 1. _d 0 - AREA(i,j,bi,bj) |
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ENDDO |
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ENDDO |
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|
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IF ( useHibler79IceStrength ) THEN |
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#else |
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IF ( .TRUE. ) THEN |
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#endif /* SEAICE_ITD */ |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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C-- now set up ice pressure and viscosities |
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IF ( (HEFF(i,j,bi,bj).LE.SEAICEpresH0).AND. |
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& (SEAICEpresPow0.NE.1) ) THEN |
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tmpscal1=MAX(HEFF(i,j,bi,bj)/SEAICEpresH0,ZERO) |
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tmpscal2=SEAICEpresH0*(tmpscal1**SEAICEpresPow0) |
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ELSEIF ( (HEFF(i,j,bi,bj).GT.SEAICEpresH0).AND. |
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& (SEAICEpresPow1.NE.1) ) THEN |
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tmpscal1=MAX(HEFF(i,j,bi,bj)/SEAICEpresH0,ZERO) |
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tmpscal2=SEAICEpresH0*(tmpscal1**SEAICEpresPow1) |
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ELSE |
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tmpscal2=HEFF(i,j,bi,bj) |
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ENDIF |
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PRESS0(I,J,bi,bj)=SEAICE_strength*tmpscal2 |
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& *EXP(-SEAICE_cStar*(SEAICE_area_max-AREA(i,j,bi,bj))) |
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ZMAX(I,J,bi,bj) = SEAICE_zetaMaxFac*PRESS0(I,J,bi,bj) |
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ZMIN(I,J,bi,bj) = SEAICE_zetaMin |
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PRESS0(I,J,bi,bj)= PRESS0(I,J,bi,bj)*HEFFM(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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#ifdef SEAICE_ITD |
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ELSE |
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C not useHiber79IceStrength |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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PRESS0(i,j,bi,bj) = 0. _d 0 |
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ENDDO |
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ENDDO |
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CALL SEAICE_PREPARE_RIDGING( |
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O hActual, |
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O hrMin, hrMax, hrExp, ridgeRatio, ridgingModeNorm, partFunc, |
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I iMin, iMax, jMin, jMax, bi, bj, myTime, myIter, myThid ) |
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IF ( SEAICEredistFunc .EQ. 0 ) THEN |
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tmpscal1 = 1. _d 0 / 3. _d 0 |
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DO k = 1, nITD |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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C replace (hrMax**3-hrMin**3)/(hrMax-hrMin) by identical |
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C hrMax**2+hrMin**2 + hrMax*hrMin to avoid division by potentially |
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C small number |
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IF ( partFunc(i,j,k) .GT. 0. _d 0 ) |
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& PRESS0(i,j,bi,bj) = PRESS0(i,j,bi,bj) |
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& + partFunc(i,j,k) * ( - hActual(i,j,k)**2 |
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& + ( hrMax(i,j,k)**2 + hrMin(i,j,k)**2 |
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& + hrMax(i,j,k)*hrMin(i,j,k) )*tmpscal1 |
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& / ridgeRatio(i,j,k) ) |
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ENDDO |
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ENDDO |
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ENDDO |
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ELSEIF ( SEAICEredistFunc .EQ. 1 ) THEN |
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DO k = 1, nITD |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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PRESS0(i,j,bi,bj) = PRESS0(i,j,bi,bj) |
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& + partFunc(i,j,k) * ( - hActual(i,j,k)**2 + |
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& ( hrMin(i,j,k)*hrMin(i,j,k) |
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& + 2. _d 0 * hrMin(i,j,k)*hrExp(i,j,k) |
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& + 2. _d 0 * hrExp(i,j,k)*hrExp(i,j,k) |
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& )/ridgeRatio(i,j,k) ) |
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ENDDO |
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ENDDO |
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ENDDO |
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ENDIF |
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C |
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tmpscal1 = SEAICE_cf*0.5*gravity*(rhoConst-SEAICE_rhoIce) |
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& * SEAICE_rhoIce/rhoConst |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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PRESS0(i,j,bi,bj) = PRESS0(i,j,bi,bj)/ridgingModeNorm(i,j) |
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& *tmpscal1 |
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ZMAX(I,J,bi,bj) = SEAICE_zetaMaxFac*PRESS0(I,J,bi,bj) |
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ZMIN(I,J,bi,bj) = SEAICE_zetaMin |
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PRESS0(I,J,bi,bj)= PRESS0(I,J,bi,bj)*HEFFM(I,J,bi,bj) |
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ENDDO |
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ENDDO |
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#endif /* SEAICE_ITD */ |
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ENDIF |
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|
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#ifdef SEAICE_CGRID |
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C compute tensile strength |
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IF ( SEAICE_tensilFac .NE. 0. _d 0 ) THEN |
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recip_tensilDepth = 0. _d 0 |
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IF ( SEAICE_tensilDepth .GT. 0. _d 0 ) |
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& recip_tensilDepth = 1. _d 0 / SEAICE_tensilDepth |
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DO j=jMin,jMax |
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DO i=iMin,iMax |
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tensileStrength(i,j,bi,bj)=PRESS0(I,J,bi,bj)*SEAICE_tensilFac |
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& *exp(-ABS(R_low(I,J,bi,bj))*recip_tensilDepth) |
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ENDDO |
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ENDDO |
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ENDIF |
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#endif /* SEAICE_CGRID */ |
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|
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RETURN |
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END |
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