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C $Header: /u/gcmpack/MITgcm/pkg/aim/phy_convmf.F,v 1.4 2001/09/25 19:50:28 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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cmolt SUBROUTINE CONVMF (PSA,SE,QA,QSAT, |
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SUBROUTINE CONVMF (PSA,Ta,QA,QSAT, |
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* IDEPTH,CBMF,PRECNV,DFSE,DFQA, |
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I myThid) |
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C-- |
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C-- SUBROUTINE CONVMF (PSA,SE,QA,QSAT, |
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C-- * IDEPTH,CBMF,PRECNV,DFSE,DFQA) |
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C-- |
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C-- Purpose: Compute convective fluxes of dry static energy and moisture |
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C-- using a simplified mass-flux scheme |
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C-- Input: PSA = norm. surface pressure [p/p0] (2-dim) |
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C-- SE = dry static energy (3-dim) |
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C-- QA = specific humidity [g/kg] (3-dim) |
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C-- QSAT = saturation spec. hum. [g/kg] (3-dim) |
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C-- Output: IDEPTH = convection depth in layers (2-dim) |
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C-- CBMF = cloud-base mass flux (2-dim) |
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C-- PRECNV = convective precipitation [g/(m^2 s)] (2-dim) |
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C-- DFSE = net flux of d.s.en. into each atm. layer (3-dim) |
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C-- DFQA = net flux of sp.hum. into each atm. layer (3-dim) |
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C-- |
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|
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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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|
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#include "EEPARAMS.h" |
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|
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#include "AIM_GRID.h" |
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|
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C Physical constants + functions of sigma and latitude |
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C |
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#include "com_physcon.h" |
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C |
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C Convection constants |
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C |
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#include "com_cnvcon.h" |
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|
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C-- Routine arguments: |
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_RL PSA(NGP), Ta(NGP,NLEV), QA(NGP,NLEV), QSAT(NGP,NLEV) |
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INTEGER IDEPTH(NGP) |
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_RL CBMF(NGP), PRECNV(NGP), DFSE(NGP,NLEV), DFQA(NGP,NLEV) |
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INTEGER myThid |
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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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INTEGER ITOP(NGP) |
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c REAL SM(NGP,NLEV), SE(NGP,NLEV) |
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_RL ENTR(NGP,2:NLEV-1) |
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_RL FM0(NGP), DENTR(NGP) |
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C |
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_RL Th(NGP,NLEV) |
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_RL dThdp(NGP,NLEV), dThdpHat(NGP,NLEV) |
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_RL stab(NGP,NLEV) |
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_RL Prefw(NLEV), Prefs(NLEV) |
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DATA Prefs / 75., 250., 500., 775., 950./ |
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DATA Prefw / 0., 150., 350., 650., 900./ |
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_RL Pground |
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DATA pground /1000./ |
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_RL FDMUS |
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|
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INTEGER J, K, K1 |
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|
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C- jmc: declare all local variables: |
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_RL QB, DQSAT, FMASS, FUQ, FDQ, ENMASS, QSATB |
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C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
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|
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C |
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C 1. Initialization of output and workspace arrays |
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C |
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DO J=1,NGP |
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FM0(J)=0. |
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IF ( NLEVxy(J,myThid) .NE. 0 ) THEN |
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FM0(J)=P0*DSIG(NLEVxy(J,myThid))/(GG*TRCNV*3600) |
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ENDIF |
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DENTR(J)=ENTMAX/(SIG(NLEV-1)-0.5) |
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ENDDO |
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C |
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DO K=1,NLEV |
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DO J=1,NGP |
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DFSE(J,K)=0.0 |
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DFQA(J,K)=0.0 |
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ENDDO |
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ENDDO |
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C |
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C |
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DO J=1,NGP |
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ITOP(J) =NLEVxy(J,myThid) |
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CBMF(J) =0.0 |
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PRECNV(J)=0.0 |
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ENDDO |
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C |
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C Saturation moist static energy |
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cmolt DO J=1,NGP |
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cmolt DO K=1,NLEVxy(J,myThid) |
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cmolt SM(J,K)=SE(J,K)+ALHC*QSAT(J,K) |
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cmolt ENDDO |
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cmolt ENDDO |
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C |
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C Entrainment profile (up to sigma = 0.5) |
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DO J=1,NGP |
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DO K=2,NLEVxy(J,myThid)-1 |
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ENTR(J,K)=MAX(0. _d 0,SIG(K)-0.5 _d 0)*DENTR(J) |
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ENDDO |
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ENDDO |
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C |
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C-- 2. Check of conditions for convection |
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C |
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C 2.1 Conditional instability |
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C |
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cmolt DO J=1,NGP |
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cmolt DO K=NLEVxy(J,myThid)-2,2,-1 |
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cmolt SMB=SM(J,K)+WVI(K,2)*(SM(J,K+1)-SM(J,K)) |
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cmolt IF (SM(J,NLEVxy(J,myThid)).GT.SMB) ITOP(J)=K |
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cmolt ENDDO |
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cmolt ENDDO |
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C |
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C New writing of the Conditional stability |
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C ---------------------------------------- |
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DO J=1,NGP |
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DO k=1,NLEVxy(J,myThid) |
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Th(J,K)=Ta(J,K)*(Pground/Prefs(k))**(RD/CP) |
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ENDDO |
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ENDDO |
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C |
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DO J=1,NGP |
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dThdp(J,1)=0. |
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IF ( NLEVxy(J,myThid) .NE. 0 ) THEN |
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dThdp(J,NLEVxy(J,myThid))=0. |
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ENDIF |
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DO k=2,NLEVxy(J,myThid) |
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dThdp(J,K-1)=(Th(J,K-1)-Th(J,K)) |
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& *((Prefw(k)/Pground)**(RD/CP))*CP |
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ENDDO |
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ENDDO |
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C |
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DO J=1,NGP |
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IF ( NLEVxy(J,myThid) .NE. 0 ) THEN |
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dThdpHat(J,NLEVxy(J,myThid))=dThdp(J,NLEVxy(J,myThid)) |
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ENDIF |
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ENDDO |
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C |
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DO J=1,NGP |
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DO k=NLEVxy(J,myThid)-1,2,-1 |
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dThdpHat(J,K)=dThdpHat(J,K+1)+dThdp(J,k) |
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ENDDO |
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ENDDO |
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C |
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DO J=1,NGP |
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DO k=2,NLEVxy(J,myThid)-1 |
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stab(J,K)= |
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& dThdpHat(J,K)+ALHC*(QSAT(J,K)-QSAT(J,NLEVxy(J,myThid))) |
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& -WVI(K,2)*(dThdp(J,K) +ALHC*(QSAT(J,K) -QSAT(J,K+1)) ) |
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ENDDO |
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ENDDO |
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C |
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DO J=1,NGP |
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DO K=NLEVxy(J,myThid)-2,2,-1 |
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if(stab(J,K).lt.0.) ITOP(J)=K |
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ENDDO |
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ENDDO |
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C |
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C 2.2 Humidity exceeding prescribed threshold |
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C |
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DO J=1,NGP |
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IF ( NLEVxy(J,myThid) .NE. 0 ) THEN |
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IF (QA(J,NLEVxy(J,myThid)).LT.RHBL*QSAT(J,NLEVxy(J,myThid))) |
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& ITOP(J)=NLEVxy(J,myThid) |
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ENDIF |
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IDEPTH(J)=NLEVxy(J,myThid)-ITOP(J) |
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ENDDO |
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C |
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C-- 3. Convection over selected grid-points |
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C |
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DO 300 J=1,NGP |
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IF (ITOP(J).EQ.NLEVxy(J,myThid)) GO TO 300 |
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C |
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C 3.1 Boundary layer (cloud base) |
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C |
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K =NLEVxy(J,myThid) |
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K1=K-1 |
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C |
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C Dry static energy and moisture at upper boundary |
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cch SB=SE(J,K1)+WVI(K1,2)*(SE(J,K)-SE(J,K1)) |
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QB=QA(J,K1)+WVI(K1,2)*(QA(J,K)-QA(J,K1)) |
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cch QB=QA(J,K1) |
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C |
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C Cloud-base mass flux |
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DQSAT=MAX(QSAT(J,K)-QB, 0.05 _d 0*QSAT(J,K)) |
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FMASS=FM0(J)*PSA(J)*(QA(J,K)-RHBL*QSAT(J,K))/DQSAT |
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CBMF(J)=FMASS |
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C |
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C Upward fluxes at upper boundary |
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cch FUS=FMASS*SE(J,K) |
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#ifdef OLD_AIM_INTERFACE |
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FUQ=FMASS*QSAT(J,K) |
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#else |
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FUQ=FMASS*MAX( QSAT(J,K), MIN(QB,QA(J,K)) ) |
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#endif |
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C |
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C Downward fluxes at upper boundary |
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cch FDS=FMASS*SB |
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FDQ=FMASS*QB |
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C |
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C Net flux of dry static energy and moisture |
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cch DFSE(J,K)=FDS-FUS |
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DFSE(J,K)=FMASS*dThdp(J,K1)*(1-WVI(K1,2)) |
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FDMUS=FMASS*dThdp(J,K1)*(1-WVI(K1,2)) |
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DFQA(J,K)=FDQ-FUQ |
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C |
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C 3.2 Intermediate layers (entrainment) |
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C |
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DO K=NLEVxy(J,myThid)-1,ITOP(J)+1,-1 |
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K1=K-1 |
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C |
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C Fluxes at lower boundary |
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cch DFSE(J,K)=FUS-FDS |
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DFQA(J,K)=FUQ-FDQ |
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C |
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C Mass entrainment |
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ENMASS=ENTR(J,K)*PSA(J)*FMASS |
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FMASS=FMASS+ENMASS |
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C |
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C Upward fluxes at upper boundary |
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cch FUS=FUS+ENMASS*SE(J,K) |
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FUQ=FUQ+ENMASS*QA(J,K) |
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C |
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C Downward fluxes at upper boundary |
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cch SB=SE(J,K1)+WVI(K1,2)*(SE(J,K)-SE(J,K1)) |
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QB=QA(J,K1)+WVI(K1,2)*(QA(J,K)-QA(J,K1)) |
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cch QB=QA(J,K1) |
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cch FDS=FMASS*SB |
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FDQ=FMASS*QB |
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C |
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C Net flux of dry static energy and moisture |
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cch DFSE(J,K)=DFSE(J,K)+FDS-FUS |
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DFSE(J,K)=FMASS*(1-WVI(K1,2))*dThdp(J,K1)+ |
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& (FMASS-ENMASS)*WVI(K,2)*dThdp(J,K) |
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FDMUS=FDMUS+ FMASS*(1-WVI(K1,2))*dThdp(J,K1)+ |
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& (FMASS-ENMASS)*WVI(K,2)*dThdp(J,K) |
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DFQA(J,K)=DFQA(J,K)+FDQ-FUQ |
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C |
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ENDDO |
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c |
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C 3.3 Top layer (condensation and detrainment) |
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C |
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K=ITOP(J) |
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C |
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C Flux of convective precipitation |
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QSATB=QSAT(J,K)+WVI(K,2)*(QSAT(J,K+1)-QSAT(J,K)) |
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PRECNV(J)=MAX(FUQ-FMASS*QSATB, 0. _d 0) |
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C |
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C Net flux of dry static energy and moisture |
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cch DFSE(J,K)=FUS-FDS+ALHC*PRECNV(J) |
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DFSE(J,K)=-FDMUS+ALHC*PRECNV(J) |
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DFQA(J,K)=FUQ-FDQ-PRECNV(J) |
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C |
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300 CONTINUE |
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|
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#endif /* ALLOW_AIM */ |
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|
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RETURN |
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END |