! $Header$ SUBROUTINE clift(p, t, rr, rs, plcl, dplcldt, dplcldq) USE yomcst_mod_h IMPLICIT NONE ! *************************************************************** ! * * ! * CLIFT : COMPUTE LIFTING CONDENSATION LEVEL AND ITS * ! * DERIVATIVES RELATIVE TO T AND R * ! * (WITHIN 0.2% OF FORMULA OF BOLTON, MON. WEA. REV.,1980) * ! * * ! * written by : GRANDPEIX Jean-Yves, 17/11/98, 12.39.01 * ! * modified by : * ! *************************************************************** ! * ! *Arguments : ! * ! * Input : P = pressure of level from wich lifting is performed ! * T = temperature of level P ! * RR = vapour mixing ratio at level P ! * RS = vapour saturation mixing ratio at level P ! * ! * Output : PLCL = lifting condensation level ! * DPLCLDT = derivative of PLCL relative to T ! * DPLCLDQ = derivative of PLCL relative to R ! * ! cccccccccccccccccccccc ! constantes coherentes avec le modele du Centre Europeen ! RD = 1000.0 * 1.380658E-23 * 6.0221367E+23 / 28.9644 ! RV = 1000.0 * 1.380658E-23 * 6.0221367E+23 / 18.0153 ! CPD = 3.5 * RD ! CPV = 4.0 * RV ! CL = 4218.0 ! CI=2090.0 ! CPVMCL=CL-CPV ! CLMCI=CL-CI ! EPS=RD/RV ! ALV0=2.5008E+06 ! ALF0=3.34E+05 ! on utilise les constantes thermo du Centre Europeen: (sb) real :: p,t,rr,rs,plcl,dplcldt,dplcldq,cpd,cpv,cl,cpvmcl,eps,alv0,a,b real :: rh,chi,alv cpd = rcpd cpv = rcpv cl = rcw cpvmcl = cl - cpv eps = rd/rv alv0 = rlvtt ! Bolton formula coefficients : a = 1669.0 b = 122.0 rh = rr/rs chi = t/(a-b*rh-t) plcl = p*(rh**chi) alv = alv0 - cpvmcl*(t-273.15) ! -- sb: correction: ! DPLCLDQ = PLCL*CHI*( 1./RR - B*CHI/T/RS*ALOG(RH) ) dplcldq = plcl*chi*(1./rr+b*chi/t/rs*alog(rh)) ! sb -- dplcldt = plcl*chi*((a-b*rh*(1.+alv/rv/t))/t**2*chi*alog(rh)-alv/rv/t**2) RETURN END SUBROUTINE clift