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C $Header: /u/gcmpack/MITgcm/pkg/thsice/thsice_extend.F,v 1.1 2004/04/07 23:40:34 jmc Exp $ |
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C $Name: $ |
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|
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#include "THSICE_OPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: THSICE_EXTEND |
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C !INTERFACE: |
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SUBROUTINE THSICE_EXTEND( |
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I esurp, Tf, |
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U sst, compact, iceThick, snowThick, qicen, |
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O qleft, fresh, fsalt, |
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I dBugFlag, myThid ) |
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C !DESCRIPTION: \bv |
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C *==========================================================* |
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C | S/R THSICE_EXTEND |
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C | o Extend sea-ice area incresing ice fraction |
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C *==========================================================* |
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C | o incorporate surplus of energy to |
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C | make new ice or make ice grow laterally |
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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 == Global variables == |
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#include "EEPARAMS.h" |
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#include "THSICE_SIZE.h" |
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#include "THSICE_PARAMS.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 esurp :: energy available for freezing [W/m2] |
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C Tf :: freezing temperature [oC] |
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C sst :: Sea Surf Temp. [oC] |
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C compact :: fraction of grid area covered in ice |
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C iceThick :: ice height [m] |
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C snowThick:: snow height [m] |
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C qicen :: ice enthalpy [J/m3] |
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C qleft :: (additional) heat flux to ocean [W/m2] |
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C fsalt :: (additional) salt flux to ocean [ g/m2/s] |
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C fresh :: (additional) fresh water flux to ocean [kg/m2/s] |
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C dBugFlag :: allow to print debugging stuff (e.g. on 1 grid point). |
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C myThid :: thread number for this instance of the routine. |
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_RL esurp |
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_RL Tf |
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_RL sst |
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_RL compact |
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_RL iceThick |
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_RL snowThick |
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_RL qicen(nlyr) |
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_RL qleft |
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_RL fresh |
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_RL fsalt |
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LOGICAL dBugFlag |
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INTEGER myThid |
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CEOP |
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|
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#ifdef ALLOW_THSICE |
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|
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C !LOCAL VARIABLES: |
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C == Local variables == |
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C qicAv :: mean enthalphy of ice (layer 1 & 2) [J/kg] |
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_RL deltaTice ! time-step for ice model |
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_RL newIce |
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_RL newIceFrac |
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_RL iceFraction |
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_RL qicAv |
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LOGICAL dBug |
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|
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1010 FORMAT(A,I3,3F8.3) |
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1020 FORMAT(A,1P4E11.3) |
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dBug = .FALSE. |
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c dBug = dBugFlag |
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|
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C-- start ice |
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deltaTice = thSIce_deltaT |
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iceFraction = compact |
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newIceFrac = 0. _d 0 |
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|
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C- enthalpy of new ice to form : |
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IF ( compact.LE.0. _d 0 ) THEN |
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qicen(1)= -cpwater*Tmlt1 |
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& + cpice *(Tmlt1-Tf) + Lfresh*(1. _d 0-Tmlt1/Tf) |
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qicen(2)= -cpice *Tf + Lfresh |
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ENDIF |
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qicAv = rhoi*(qicen(1)+qicen(2))*0.5 _d 0 |
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newIce = esurp*deltaTice/qicAv |
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|
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IF (iceFraction.EQ.0. _d 0) THEN |
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c IF (newIce.GE.himin*iceMaskmax) THEN |
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C- jmc: above is the original version, but below seems more logical: |
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IF (newIce.GE.himin0*iceMaskmin) THEN |
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C- if there is no ice in grid and enough ice to form: |
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iceThick = MAX(himin0,newIce/iceMaskmax) |
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newIceFrac = MIN(newIce/himin0,iceMaskmax) |
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compact = newIceFrac |
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sst=Tf |
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ENDIF |
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ELSE |
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C- if there is already some ice |
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newIceFrac=MIN(newIce/iceThick,iceMaskmax-iceFraction) |
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compact = iceFraction + newIceFrac |
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C- spread snow out over ice |
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snowThick = snowThick*iceFraction/compact |
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sst=(1. _d 0-newIceFrac)*sst+newIceFrac*Tf |
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ENDIF |
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qleft= iceThick*newIceFrac*qicAv/deltaTice |
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fresh=-(rhoi*iceThick)*newIceFrac/deltaTice |
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fsalt=-(rhoi*iceThick*saltice)*newIceFrac/deltaTice |
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|
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IF (dBug) WRITE(6,1020) 'ThSI_EXT: iceH, newIce, newIceFrac=', |
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& iceThick, newIce, newIceFrac |
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|
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#endif /* ALLOW_THSICE */ |
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|
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RETURN |
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END |