source: trunk/LMDZ.GENERIC/libf/phystd/largescale.F90 @ 1974

Last change on this file since 1974 was 1830, checked in by mlefevre, 7 years ago

MESOSCALE GENERIC. changed parameters for cloud condensation. within precomp flag MESOSCALE.

File size: 6.3 KB
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1      subroutine largescale(ngrid,nlayer,nq,ptimestep, pplev, pplay,    &
2                    pt, pq, pdt, pdq, pdtlsc, pdqvaplsc, pdqliqlsc, rneb)
3
4
5      use ioipsl_getin_p_mod, only: getin_p
6      use watercommon_h, only : RLVTT, RCPD, RVTMP2,  &
7          T_h2O_ice_clouds,T_h2O_ice_liq,Psat_waterDP,Lcpdqsat_waterDP
8      USE tracer_h
9      IMPLICIT none
10
11!==================================================================
12!     
13!     Purpose
14!     -------
15!     Calculates large-scale (stratiform) H2O condensation.
16!     
17!     Authors
18!     -------
19!     Adapted from the LMDTERRE code by R. Wordsworth (2009)
20!     Original author Z. X. Li (1993)
21!     
22!==================================================================
23
24      INTEGER ngrid,nlayer,nq
25
26!     Arguments
27      REAL ptimestep                 ! intervalle du temps (s)
28      REAL pplev(ngrid,nlayer+1) ! pression a inter-couche
29      REAL pplay(ngrid,nlayer)   ! pression au milieu de couche
30      REAL pt(ngrid,nlayer)      ! temperature (K)
31      REAL pq(ngrid,nlayer,nq) ! tracer mixing ratio (kg/kg)
32      REAL pdt(ngrid,nlayer)     ! physical temperature tenedency (K/s)
33      REAL pdq(ngrid,nlayer,nq)! physical tracer tenedency (K/s)
34      REAL pdtlsc(ngrid,nlayer)  ! incrementation de la temperature (K)
35      REAL pdqvaplsc(ngrid,nlayer) ! incrementation de la vapeur d'eau
36      REAL pdqliqlsc(ngrid,nlayer) ! incrementation de l'eau liquide
37      REAL rneb(ngrid,nlayer)    ! fraction nuageuse
38
39
40!     Options du programme
41      REAL, SAVE :: ratqs   ! determine largeur de la distribution de vapeur
42!$OMP THREADPRIVATE(ratqs)
43
44!     Variables locales
45      REAL CBRT
46      EXTERNAL CBRT
47      INTEGER i, k , nn
48      INTEGER,PARAMETER :: nitermax=5000
49      DOUBLE PRECISION,PARAMETER :: alpha=.1,qthreshold=1.d-8
50      ! JL13: if "careful, T<Tmin in psat water" appears often, you may want to stabilise the model by
51      !                   decreasing alpha and increasing nitermax accordingly
52      DOUBLE PRECISION zt(ngrid), zq(ngrid)
53      DOUBLE PRECISION zcond(ngrid),zcond_iter
54      DOUBLE PRECISION zdelq(ngrid)
55      DOUBLE PRECISION zqs(ngrid), zdqs(ngrid)
56      DOUBLE PRECISION local_p,psat_tmp,dlnpsat_tmp,Lcp
57     
58! evaporation calculations
59      REAL dqevap(ngrid,nlayer),dtevap(ngrid,nlayer)     
60      REAL qevap(ngrid,nlayer,nq)
61      REAL tevap(ngrid,nlayer)
62
63      DOUBLE PRECISION zx_q(ngrid)
64      LOGICAL,SAVE :: firstcall=.true.
65!$OMP THREADPRIVATE(firstcall)
66
67
68      IF (firstcall) THEN
69
70         write(*,*) "value for ratqs? "
71         ratqs=0.2 ! default value
72         call getin_p("ratqs",ratqs)
73         write(*,*) " ratqs = ",ratqs
74
75         firstcall = .false.
76      ENDIF
77
78!     GCM -----> subroutine variables, initialisation of outputs
79
80      pdtlsc(1:ngrid,1:nlayer)  = 0.0
81      pdqvaplsc(1:ngrid,1:nlayer)  = 0.0
82      pdqliqlsc(1:ngrid,1:nlayer) = 0.0
83      rneb(1:ngrid,1:nlayer) = 0.0
84      Lcp=RLVTT/RCPD
85
86
87      ! Evaporate cloud water/ice
88      call evap(ngrid,nlayer,nq,ptimestep,pt,pq,pdq,pdt,dqevap,dtevap,qevap,tevap)
89      ! note: we use qevap but not tevap in largescale/moistadj
90            ! otherwise is a big mess
91
92
93!  Boucle verticale (du haut vers le bas)
94   DO k = nlayer, 1, -1
95
96      zt(1:ngrid)=pt(1:ngrid,k)+(pdt(1:ngrid,k)+dtevap(1:ngrid,k))*ptimestep
97      zq(1:ngrid)=qevap(1:ngrid,k,igcm_h2o_vap) !liquid water is included in qevap
98
99!     Calculer la vapeur d'eau saturante et
100!     determiner la condensation partielle
101      DO i = 1, ngrid
102
103         local_p=pplay(i,k)
104         if(zt(i).le.15.) then
105            print*,'in lsc',i,k,zt(i)
106!           zt(i)=15.   ! check too low temperatures
107         endif
108         call Psat_waterDP(zt(i),local_p,psat_tmp,zqs(i))
109 
110         zdelq(i) = MAX(MIN(ratqs * zq(i),1.-zq(i)),1.d-12)
111         rneb(i,k) = (zq(i)+zdelq(i)-zqs(i)) / (2.0*zdelq(i))
112#ifdef MESOSCALE
113         if (rneb(i,k).lt.0.01) then  !no clouds MESO
114#else
115         if (rneb(i,k).lt.0.) then  !no clouds
116#endif
117
118            rneb(i,k)=0.
119            zcond(i)=0.
120
121         else if ((rneb(i,k).gt.0.99).or.(ratqs.lt.1.e-6)) then    !complete cloud cover, we start without evaporating
122            rneb(i,k)=1.
123            zt(i)=pt(i,k)+pdt(i,k)*ptimestep
124            zx_q(i) = pq(i,k,igcm_h2o_vap)+pdq(i,k,igcm_h2o_vap)*ptimestep
125            dqevap(i,k)=0.
126!           iterative process to stabilize the scheme when large water amounts JL12
127            zcond(i) = 0.0d0
128            Do nn=1,nitermax 
129               call Psat_waterDP(zt(i),local_p,psat_tmp,zqs(i))
130               call Lcpdqsat_waterDP(zt(i),local_p,psat_tmp,zqs(i),zdqs(i),dlnpsat_tmp)
131               zcond_iter = alpha*(zx_q(i)-zqs(i))/(1.d0+zdqs(i))         
132                  !zcond can be negative here
133               zx_q(i) = zx_q(i) - zcond_iter
134               zcond(i) = zcond(i) + zcond_iter
135               zt(i) = zt(i) + zcond_iter*Lcp
136               if (ABS(zcond_iter/alpha/zqs(i)).lt.qthreshold) exit
137!              if (ABS(zcond_iter/alpha).lt.qthreshold) exit
138               if (nn.eq.nitermax) print*,'itermax in largescale'
139            End do ! niter
140            zcond(i)=MAX(zcond(i),-(pq(i,k,igcm_h2o_ice)+pdq(i,k,igcm_h2o_ice)*ptimestep))
141
142         else   !standard case     
143#ifdef MESOSCALE
144            rneb(i,k)=1. !LES/MESO case
145            zx_q(i) = (zq(i)+zqs(i))/2.0d0 ! LES
146#else
147            zx_q(i) = (zq(i)+zdelq(i)+zqs(i))/2.0d0 !water vapor in cloudy sky
148#endif
149!           iterative process to stabilize the scheme when large water amounts JL12
150            zcond(i) = 0.0d0
151            Do nn=1,nitermax 
152               call Lcpdqsat_waterDP(zt(i),local_p,psat_tmp,zqs(i),zdqs(i),dlnpsat_tmp)
153               zcond_iter = MAX(0.0d0,alpha*(zx_q(i)-zqs(i))/(1.d0+zdqs(i)))       
154                  !zcond always postive! cannot evaporate clouds!
155                  !this is why we must reevaporate before largescale
156               zx_q(i) = zx_q(i) - zcond_iter
157               zcond(i) = zcond(i) + zcond_iter
158               if (ABS(zcond_iter/alpha/zqs(i)).lt.qthreshold) exit
159!              if (ABS(zcond_iter/alpha).lt.qthreshold) exit
160               zt(i) = zt(i) + zcond_iter*Lcp*rneb(i,k)
161               call Psat_waterDP(zt(i),local_p,psat_tmp,zqs(i))
162               if (nn.eq.nitermax) print*,'itermax in largescale'
163            End do ! niter
164
165         Endif
166
167         zcond(i) = zcond(i)*rneb(i,k)/ptimestep ! JL12
168
169      ENDDO
170
171!     Tendances de t et q
172         pdqvaplsc(1:ngrid,k)  = dqevap(1:ngrid,k) - zcond(1:ngrid)
173         pdqliqlsc(1:ngrid,k) = - pdqvaplsc(1:ngrid,k)
174         pdtlsc(1:ngrid,k)  = pdqliqlsc(1:ngrid,k)*real(Lcp)
175
176   Enddo ! k= nlayer, 1, -1
177 
178
179      end
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