C $Header: /u/gcmpack/MITgcm/pkg/aim_v23/phy_convmf.F,v 1.1 2002/11/22 17:17:03 jmc Exp $
C $Name: $
#include "AIM_OPTIONS.h"
SUBROUTINE CONVMF (PSA,dpFac,SE,QA,QSAT, 1
O IDEPTH,CBMF,PRECNV,DFSE,DFQA,
I kGrd,bi,bj,myThid)
C--
C-- SUBROUTINE CONVMF (PSA,SE,QA,QSAT,
C-- * IDEPTH,CBMF,PRECNV,DFSE,DFQA)
C--
C-- Purpose: Compute convective fluxes of dry static energy and moisture
C-- using a simplified mass-flux scheme
C-- Input: PSA = norm. surface pressure [p/p0] (2-dim)
C dpFac = cell delta_P fraction (3-dim)
C-- SE = dry static energy (3-dim)
C-- QA = specific humidity [g/kg] (3-dim)
C-- QSAT = saturation spec. hum. [g/kg] (3-dim)
C-- Output: IDEPTH = convection depth in layers (2-dim)
C-- CBMF = cloud-base mass flux (2-dim)
C-- PRECNV = convective precipitation [g/(m^2 s)] (2-dim)
C-- DFSE = net flux of d.s.en. into each atm. layer (3-dim)
C-- DFQA = net flux of sp.hum. into each atm. layer (3-dim)
C Input: kGrd = Ground level index (2-dim)
C bi,bj = tile index
C myThid = Thread number for this instance of the routine
C-------
C Note: dry static energy has been replaced by Pot.Temp.
C-------
IMPLICIT NONE
C Resolution parameters
C-- size for MITgcm & Physics package :
#include "AIM_SIZE.h"
#include "EEPARAMS.h"
C Physical constants + functions of sigma and latitude
#include "com_physcon.h"
C Convection constants
#include "com_cnvcon.h"
C-- Routine arguments:
_RL PSA(NGP), SE(NGP,NLEV), QA(NGP,NLEV), QSAT(NGP,NLEV)
_RL dpFac(NGP,NLEV)
INTEGER IDEPTH(NGP)
_RL CBMF(NGP), PRECNV(NGP), DFSE(NGP,NLEV), DFQA(NGP,NLEV)
INTEGER kGrd(NGP)
INTEGER bi,bj,myThid
#ifdef ALLOW_AIM
C-- Local variables:
INTEGER ITOP(NGP)
c_FM REAL SM(NGP,NLEV), QATHR(NGP), ENTR(2:NLEV-1)
_RL QATHR(NGP), ENTR(2:NLEV-1)
_RL ENTR_PS(NGP,2:NLEV-1), FM0(NGP)
INTEGER J, K, K1, Ktmp
_RL dSEdp(NGP,NLEV), factP, PSA_1
_RL dSEdpTot, stab_crit, FDMUS
C- jmc: declare all local variables:
_RL QMAX, DELQ, QB, QSATB, FMASS, ENMASS, SENTR
_RL FPSA, FQMAX, RDPS, FUQ, FDQ, FSQ
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
C-- 1. Initialization of output and workspace arrays
PSA_1 = 1.
FQMAX= 5.
RDPS = 2. _d 0 /(1. _d 0 - PSMIN)
c_FM FM0=P0*DSIG(NLEV)/(GG*TRCNV*3600)
c_FM FPSA=PSA(J)*MIN(1.,(PSA(J)-PSMIN)*RDPS)
C- compute FM0(J) = FM0*FPSA
DO J=1,NGP
FM0(J)=0.
Ktmp = kGrd(J)
IF ( Ktmp .NE. 0 ) THEN
FPSA = MIN(1. _d 0 ,(PSA(J)-PSMIN)*RDPS)
FM0(J)=P0*DSIG(Ktmp)*dpFac(J,Ktmp)/(GG*TRCNV*3600. _d 0)
ENDIF
ENDDO
DO K=1,NLEV
DO J=1,NGP
DFSE(J,K)=0.0
DFQA(J,K)=0.0
ENDDO
ENDDO
DO K=2,NLEV-1
DO J=1,NGP
ENTR_PS(J,K)=0.
ENDDO
ENDDO
DO J=1,NGP
ITOP(J) =kGrd(J)
CBMF(J) =0.0
PRECNV(J)=0.0
ENDDO
C Saturation moist static energy
c_FM DO K=1,NLEV
c_FM DO J=1,NGP
c_FM SM(J,K)=SE(J,K)+ALHC*QSAT(J,K)
c_FM ENDDO
c_FM ENDDO
C ---------------------------------------------
C Write Conditional stability based on Pot.Temp :
C dSEdp(K) = Delta[Static-Energy] between 2 Plevels(k,k+1)
C and corresponds to SE(K+1)-SE(K) in the original code
C -------
DO K=1,NLEV-1
factP = CP*SIGH(K)**(RD/CP)
DO J=1,NGP
dSEdp(J,K)=(SE(J,K+1)-SE(J,K))*factP
ENDDO
ENDDO
C Entrainment profile (up to sigma = 0.5)
c_FM SENTR=0.
c_FM DO K=2,NLEV-1
c_FM ENTR(K)=( MAX( 0. _d 0, SIG(K)-0.5 _d 0) )**2
c_FM SENTR=SENTR+ENTR(K)
c_FM ENDDO
c_FM SENTR=ENTMAX/SENTR
c_FM DO K=2,NLEV-1
c_FM ENTR(K)=ENTR(K)*SENTR
c_FM ENDDO
DO J=1,NGP
DO K=2,NLEV-1
ENTR_PS(J,K)=0.
ENDDO
Ktmp = kGrd(J)
IF (Ktmp.GT.2) THEN
SENTR=0.
DO K=2,Ktmp-1
ENTR(K)= ( MAX( 0. _d 0, SIG(K)/PSA(J) - 0.5 _d 0) )**2
SENTR=SENTR+ENTR(K)
ENDDO
IF (SENTR.GT.0.) THEN
SENTR=ENTMAX/SENTR
DO K=2,Ktmp-1
ENTR_PS(J,K) = ENTR(K)*SENTR*PSA(J)
ENDDO
ENDIF
ENDIF
ENDDO
C-- 2. Check of conditions for convection
C 2.1 Conditional instability
c_FM DO K=NLEV-2,2,-1
c_FM DO J=1,NGP
c_FM SMB=SM(J,K)+WVI(K,2)*(SM(J,K+1)-SM(J,K))
c_FM IF (SM(J,NLEV).GT.SMB) ITOP(J)=K
c_FM ENDDO
c_FM ENDDO
DO J=1,NGP
Ktmp = kGrd(J)
IF ( Ktmp .GE. 2 ) THEN
dSEdpTot = dSEdp(J,Ktmp-1)
DO k=Ktmp-2,2,-1
dSEdpTot = dSEdpTot + dSEdp(J,K)
stab_crit = dSEdpTot + ALHC*(QSAT(J,Ktmp)-QSAT(J,K))
& -WVI(K,2)*(dSEdp(J,K) + ALHC*(QSAT(J,K+1)-QSAT(J,K)) )
IF (stab_crit.GT.0.) ITOP(J) = K
ENDDO
ENDIF
ENDDO
C 2.2 Humidity exceeding prescribed threshold
DO J=1,NGP
Ktmp = kGrd(J)
IF ( Ktmp .NE. 0 ) THEN
QATHR(J)=MIN(QBL,RHBL*QSAT(J,Ktmp))
IF (QA(J,Ktmp).LT.QATHR(J).OR.PSA(J).LT.PSMIN)
& ITOP(J)=Ktmp
ENDIF
IDEPTH(J)=Ktmp-ITOP(J)
ENDDO
C-- 3. Convection over selected grid-points
DO 300 J=1,NGP
Ktmp = kGrd(J)
IF (ITOP(J).EQ.Ktmp) GO TO 300
C- 3.1 Boundary layer (cloud base)
K = Ktmp
K1=K-1
C Maximum specific humidity in the PBL
QMAX=MAX(1.01 _d 0 *QA(J,K),QSAT(J,K))
C Dry static energy and moisture at upper boundary
c_FM SB=SE(J,K1)+WVI(K1,2)*(SE(J,K)-SE(J,K1))
QB=QA(J,K1)+WVI(K1,2)*(QA(J,K)-QA(J,K1))
QB=MIN(QB,QA(J,K))
C Cloud-base mass flux, computed to satisfy:
C fmass*(qmax-qb)*(g/dp)=(q-qthr)/trcnv
c_FM FPSA=PSA(J)*MIN(1.,(PSA(J)-PSMIN)*RDPS)
c_FM FMASS=FM0*FPSA*MIN(FQMAX,(QA(J,K)-QATHR(J))/(QMAX-QB))
FMASS = FM0(J)*MIN(FQMAX,(QA(J,K)-QATHR(J))/(QMAX-QB))
CBMF(J)=FMASS
C Upward fluxes at upper boundary
c_FM FUS=FMASS*SE(J,K)
FUQ=FMASS*QMAX
C Downward fluxes at upper boundary
c_FM FDS=FMASS*SB
FDQ=FMASS*QB
C Net flux of dry static energy and moisture
FDMUS = FMASS*dSEdp(J,K1)*(WVI(K1,2)-1.)
DFSE(J,K)=FDMUS
c_FM DFSE(J,K)=FDS-FUS
DFQA(J,K)=FDQ-FUQ
C- 3.2 Intermediate layers (entrainment)
DO K=Ktmp-1,ITOP(J)+1,-1
K1=K-1
C Fluxes at lower boundary
c_FM DFSE(J,K)=FUS-FDS
DFQA(J,K)=FUQ-FDQ
C Mass entrainment
c_FM ENMASS=ENTR(K)*PSA(J)*CBMF(J)
ENMASS=ENTR_PS(J,K) * CBMF(J)
FMASS=FMASS+ENMASS
C Upward fluxes at upper boundary
c_FM FUS=FUS+ENMASS*SE(J,K)
FUQ=FUQ+ENMASS*QA(J,K)
C Downward fluxes at upper boundary
c_FM SB=SE(J,K1)+WVI(K1,2)*(SE(J,K)-SE(J,K1))
QB=QA(J,K1)+WVI(K1,2)*(QA(J,K)-QA(J,K1))
c_FM FDS=FMASS*SB
FDQ=FMASS*QB
C Net flux of dry static energy and moisture
DFSE(J,K) = FMASS*(WVI(K1,2)-1.)*dSEdp(J,K1)
& -(FMASS-ENMASS)*WVI(K,2)*dSEdp(J,K)
FDMUS = FDMUS + DFSE(J,K)
c_FM DFSE(J,K)=DFSE(J,K)+FDS-FUS
DFQA(J,K)=DFQA(J,K)+FDQ-FUQ
C Secondary moisture flux
DELQ=RHIL*QSAT(J,K)-QA(J,K)
IF (DELQ.GT.0.0) THEN
FSQ=SMF*CBMF(J)*DELQ
DFQA(J,K) =DFQA(J,K) +FSQ
DFQA(J,Ktmp)=DFQA(J,Ktmp)-FSQ
ENDIF
ENDDO
C- 3.3 Top layer (condensation and detrainment)
K=ITOP(J)
C Flux of convective precipitation
QSATB=QSAT(J,K)+WVI(K,2)*(QSAT(J,K+1)-QSAT(J,K))
PRECNV(J)=MAX(FUQ-FMASS*QSATB, 0. _d 0)
C Net flux of dry static energy and moisture
DFSE(J,K)= -FDMUS+ALHC*PRECNV(J)
c_FM DFSE(J,K)=FUS-FDS+ALHC*PRECNV(J)
DFQA(J,K)=FUQ-FDQ-PRECNV(J)
300 CONTINUE
#endif /* ALLOW_AIM */
RETURN
END