source: LMDZ.3.3/trunk/libf/phylmd/newmicro.F @ 1620

      SUBROUTINE newmicro (paprs, pplay,ok_newmicro,
     .                  t, pqlwp, pclc, pcltau, pclemi,
     .                  pch, pcl, pcm, pct, pctlwp)
      IMPLICIT none
c======================================================================
c Auteur(s): Z.X. Li (LMD/CNRS) date: 19930910
c Objet: Calculer epaisseur optique et emmissivite des nuages
c======================================================================
c Arguments:
c t-------input-R-temperature
c pqlwp---input-R-eau liquide nuageuse dans l'atmosphere (kg/kg)
c pclc----input-R-couverture nuageuse pour le rayonnement (0 a 1)
c 
c pcltau--output-R-epaisseur optique des nuages
c pclemi--output-R-emissivite des nuages (0 a 1)
c======================================================================
C
#include "YOMCST.h"
c
#include "dimensions.h"
#include "dimphy.h"
#include "nuage.h"
      REAL paprs(klon,klev+1), pplay(klon,klev)
      REAL t(klon,klev)
c
      REAL pclc(klon,klev)
      REAL pqlwp(klon,klev)
      REAL pcltau(klon,klev), pclemi(klon,klev)
c
      REAL pct(klon), pctlwp(klon), pch(klon), pcl(klon), pcm(klon)
c
      LOGICAL lo
c
      REAL cetahb, cetamb
      PARAMETER (cetahb = 0.45, cetamb = 0.80)
C
      INTEGER i, k
      REAL zflwp, zradef, zfice, zmsac
c
      REAL radius, rad_chaud
cc      PARAMETER (rad_chau1=13.0, rad_chau2=9.0, rad_froid=35.0)
ccc      PARAMETER (rad_chaud=15.0, rad_froid=35.0)
c sintex initial      PARAMETER (rad_chaud=10.0, rad_froid=30.0)
      REAL coef, coef_froi, coef_chau
      PARAMETER (coef_chau=0.13, coef_froi=0.09)
      REAL seuil_neb, t_glace
      PARAMETER (seuil_neb=0.001, t_glace=273.0-15.0)
      INTEGER nexpo ! exponentiel pour glace/eau
      PARAMETER (nexpo=6)
ccc      PARAMETER (nexpo=1)

c -- sb:
      logical ok_newmicro
c     parameter (ok_newmicro=.FALSE.)
      real rel, tc, rei, zfiwp
      real k_liq, k_ice0, k_ice, DF
      parameter (k_liq=0.0903, k_ice0=0.005) ! units=m2/g
      parameter (DF=1.66) ! diffusivity factor
c sb --

c
c Calculer l'epaisseur optique et l'emmissivite des nuages
c
      DO k = 1, klev
      DO i = 1, klon
         rad_chaud = rad_chau1
         IF (k.LE.3) rad_chaud = rad_chau2
         pclc(i,k) = MAX(pclc(i,k), seuil_neb)
         zflwp = 1000.*pqlwp(i,k)/RG/pclc(i,k)
     .          *(paprs(i,k)-paprs(i,k+1))
         zfice = 1.0 - (t(i,k)-t_glace) / (273.13-t_glace)
         zfice = MIN(MAX(zfice,0.0),1.0)
         zfice = zfice**nexpo
         radius = rad_chaud * (1.-zfice) + rad_froid * zfice
         coef = coef_chau * (1.-zfice) + coef_froi * zfice
         pcltau(i,k) = 3.0/2.0 * zflwp / radius
         pclemi(i,k) = 1.0 - EXP( - coef * zflwp)

         if (ok_newmicro) then

c -- liquid/ice cloud water paths:

         zfice = 1.0 - (t(i,k)-t_glace) / (273.13-t_glace)
         zfice = MIN(MAX(zfice,0.0),1.0)

         zflwp = 1000.*(1.-zfice)*pqlwp(i,k)/pclc(i,k)
     :          *(paprs(i,k)-paprs(i,k+1))/RG
         zfiwp = 1000.*zfice*pqlwp(i,k)/pclc(i,k)
     :          *(paprs(i,k)-paprs(i,k+1))/RG

c -- effective cloud droplet radius (microns):

c for liquid water clouds: 
         rel = rad_chaud

c for ice clouds: as a function of the ambiant temperature
c [formula used by Iacobellis and Somerville (2000), with an 
c asymptotical value of 3.5 microns at T<-81.4 C added to be 
c consistent with observations of Heymsfield et al. 1986]:
         tc = t(i,k)-273.15
         rei = 0.71*tc + 61.29 
         if (tc.le.-81.4) rei = 3.5 

c -- cloud optical thickness :

c [for liquid clouds, traditional formula, 
c  for ice clouds, Ebert & Curry (1992)] 

         if (zflwp.eq.0.) rel = 1. 
         if (zfiwp.eq.0. .or. rei.le.0.) rei = 1. 
         pcltau(i,k) = 3.0/2.0 * ( zflwp/rel )
     .             + zfiwp * (3.448e-03  + 2.431/rei)

c -- cloud infrared emissivity:

c [the broadband infrared absorption coefficient is parameterized
c  as a function of the effective cld droplet radius]

c Ebert and Curry (1992) formula as used by Kiehl & Zender (1995):
         k_ice = k_ice0 + 1.0/rei

         pclemi(i,k) = 1.0
     .      - EXP( - coef_chau*zflwp - DF*k_ice*zfiwp )

         endif ! ok_newmicro

         lo = (pclc(i,k) .LE. seuil_neb)
         IF (lo) pclc(i,k) = 0.0
         IF (lo) pcltau(i,k) = 0.0
         IF (lo) pclemi(i,k) = 0.0
      ENDDO
      ENDDO
ccc      DO k = 1, klev
ccc      DO i = 1, klon
ccc         t(i,k) = t(i,k)
ccc         pclc(i,k) = MAX( 1.e-5 , pclc(i,k) )
ccc         lo = pclc(i,k) .GT. (2.*1.e-5)
ccc         zflwp = pqlwp(i,k)*1000.*(paprs(i,k)-paprs(i,k+1))
ccc     .          /(rg*pclc(i,k))
ccc         zradef = 10.0 + (1.-sigs(k))*45.0
ccc         pcltau(i,k) = 1.5 * zflwp / zradef
ccc         zfice=1.0-MIN(MAX((t(i,k)-263.)/(273.-263.),0.0),1.0)
ccc         zmsac = 0.13*(1.0-zfice) + 0.08*zfice
ccc         pclemi(i,k) = 1.-EXP(-zmsac*zflwp)
ccc         if (.NOT.lo) pclc(i,k) = 0.0
ccc         if (.NOT.lo) pcltau(i,k) = 0.0
ccc         if (.NOT.lo) pclemi(i,k) = 0.0
ccc      ENDDO
ccc      ENDDO
cccccc      print*, 'pas de nuage dans le rayonnement'
cccccc      DO k = 1, klev
cccccc      DO i = 1, klon
cccccc         pclc(i,k) = 0.0
cccccc         pcltau(i,k) = 0.0
cccccc         pclemi(i,k) = 0.0
cccccc      ENDDO
cccccc      ENDDO
C
C COMPUTE CLOUD LIQUID PATH AND TOTAL CLOUDINESS
C
      DO i = 1, klon
         pct(i)=1.0
         pch(i)=1.0
         pcm(i) = 1.0
         pcl(i) = 1.0
         pctlwp(i) = 0.0
      ENDDO
C
      DO k = klev, 1, -1
      DO i = 1, klon
         pctlwp(i) = pctlwp(i) 
     .             + pqlwp(i,k)*(paprs(i,k)-paprs(i,k+1))/RG
         pct(i) = pct(i)*(1.0-pclc(i,k))
         if (pplay(i,k).LE.cetahb*paprs(i,1))
     .      pch(i) = pch(i)*(1.0-pclc(i,k))
         if (pplay(i,k).GT.cetahb*paprs(i,1) .AND.
     .       pplay(i,k).LE.cetamb*paprs(i,1)) 
     .      pcm(i) = pcm(i)*(1.0-pclc(i,k))
         if (pplay(i,k).GT.cetamb*paprs(i,1))
     .      pcl(i) = pcl(i)*(1.0-pclc(i,k))
      ENDDO
      ENDDO
C
      DO i = 1, klon
         pct(i)=1.-pct(i)
         pch(i)=1.-pch(i)
         pcm(i)=1.-pcm(i)
         pcl(i)=1.-pcl(i)
      ENDDO
C
      RETURN
      END