source: LMDZ5/trunk/libf/phylmd/cdrag.F90 @ 2793

Last change on this file since 2793 was 2778, checked in by musat, 8 years ago

add max to be consistent with the rest

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1!
2!$Id: cdrag.F90 2778 2017-01-26 14:49:44Z fhourdin $
3!
4 SUBROUTINE cdrag( knon,  nsrf,   &
5     speed, t1,    q1,    zgeop1, &
6     psol,  tsurf, qsurf, z0m, z0h,  &
7     pcfm,  pcfh,  zri,   pref )
8
9  USE dimphy
10  USE indice_sol_mod
11  USE print_control_mod, ONLY: lunout, prt_level
12  IMPLICIT NONE
13! ================================================================= c
14!
15! Objet : calcul des cdrags pour le moment (pcfm) et
16!         les flux de chaleur sensible et latente (pcfh).   
17!
18! Modified histroy:
19!   27-Jan-2014: richardson number inconsistant between
20!   coefcdrag.F90 and clcdrag.F90, Fuxing WANG wrote this subroutine
21!   by merging coefcdrag and clcdrag.
22!
23! References:
24!   Louis, J. F., 1979: A parametric model of vertical eddy fluxes in the
25!     atmosphere. Boundary-Layer Meteorology. 01/1979; 17(2):187-202.
26!   Louis, J. F., Tiedtke, M. and Geleyn, J. F., 1982: `A short history of the
27!     operational PBL parametrization at ECMWF'. Workshop on boundary layer
28!     parametrization, November 1981, ECMWF, Reading, England.
29!     Page: 19. Equations in Table 1.
30!   Anton Beljaars. May 1992. The parametrization of the planetary boundary layer. 
31!     European Centre for Medium-Range Weather Forecasts.
32!     Equations: 110-113. Page 40.
33!   Miller,M.J., A.C.M.Beljaars, T.N.Palmer. 1992. The sensitivity of the ECMWF
34!     model to the parameterization of evaporation from the tropical oceans. J.
35!     Climate, 5:418-434.
36!
37! ================================================================= c
38!
39! knon----input-I- nombre de points pour un type de surface
40! nsrf----input-I- indice pour le type de surface; voir indicesol.h
41! speed---input-R- module du vent au 1er niveau du modele
42! t1------input-R- temperature de l'air au 1er niveau du modele
43! q1------input-R- humidite de l'air au 1er niveau du modele
44! zgeop---input-R- geopotentiel au 1er niveau du modele
45! psol----input-R- pression au sol
46! tsurf---input-R- temperature de l'air a la surface
47! qsurf---input-R- humidite de l'air a la surface
48! z0m, z0h---input-R- rugosite
49!! u1, v1 are removed, speed is used. Fuxing WANG, 04/03/2015,
50!! u1------input-R- vent zonal au 1er niveau du modele
51!! v1------input-R- vent meridien au 1er niveau du modele
52!
53! pcfm---output-R- cdrag pour le moment
54! pcfh---output-R- cdrag pour les flux de chaleur latente et sensible
55! zri----output-R- Richardson number
56! pref---output-R- pression au niveau zgeop/RG
57!
58! Parameters:
59! ckap-----Karman constant
60! cb,cc,cd-parameters in Louis et al., 1982
61! ================================================================= c
62!
63!
64! Parametres d'entree
65!*****************************************************************
66  INTEGER, INTENT(IN)                      :: knon, nsrf
67  REAL, DIMENSION(klon), INTENT(IN)        :: speed ! module du vent au 1er niveau du modele
68  REAL, DIMENSION(klon), INTENT(IN)        :: zgeop1! geopotentiel au 1er niveau du modele
69  REAL, DIMENSION(klon), INTENT(IN)        :: psol  ! pression au sol
70  REAL, DIMENSION(klon), INTENT(IN)        :: t1    ! temperature at 1st level
71  REAL, DIMENSION(klon), INTENT(IN)        :: q1    ! humidity at 1st level
72  REAL, DIMENSION(klon), INTENT(IN)        :: tsurf ! Surface temperature (K)
73  REAL, DIMENSION(klon), INTENT(IN)        :: qsurf ! Surface humidity (Kg/Kg)
74  REAL, DIMENSION(klon), INTENT(IN)        :: z0m, z0h ! Rugosity at surface (m)
75!  paprs, pplay u1, v1: to be deleted
76!  they were in the old clcdrag. Fuxing WANG, 04/03/2015
77!  REAL, DIMENSION(klon,klev+1), INTENT(IN) :: paprs
78!  REAL, DIMENSION(klon,klev), INTENT(IN)   :: pplay
79!  REAL, DIMENSION(klon), INTENT(IN)        :: u1, v1
80
81! Parametres de sortie
82!******************************************************************
83  REAL, DIMENSION(klon), INTENT(OUT)       :: pcfm  ! Drag coefficient for heat flux
84  REAL, DIMENSION(klon), INTENT(OUT)       :: pcfh  ! Drag coefficient for momentum
85  REAL, DIMENSION(klon), INTENT(OUT)       :: zri   ! Richardson number
86  REAL, DIMENSION(klon), INTENT(OUT)       :: pref  ! Pression au niveau zgeop/RG
87
88! Parametres local
89  INTEGER                                  :: ng_q1    ! Number of grids that q1 < 0.0
90  INTEGER                                  :: ng_qsurf ! Number of grids that qsurf < 0.0
91!  zgeop1, psol: to be deleted, they are inputs now. Fuxing WANG, 04/03/2015
92!  REAL, DIMENSION(klon)                    :: zgeop1! geopotentiel au 1er niveau du modele
93!  REAL, DIMENSION(klon)                    :: psol  ! pression au sol
94!
95! ================================================================= c
96!
97  INCLUDE "YOMCST.h"
98  INCLUDE "YOETHF.h"
99!  INCLUDE "indicesol.h"
100  INCLUDE "clesphys.h"
101!
102! Quelques constantes et options:
103!!$PB      REAL, PARAMETER :: ckap=0.35, cb=5.0, cc=5.0, cd=5.0, cepdu2=(0.1)**2
104  REAL, PARAMETER :: CKAP=0.40, CB=5.0, CC=5.0, CD=5.0, CEPDU2 = (0.1)**2
105!
106! Variables locales :
107  INTEGER               :: i
108  REAL                  :: zdu2, ztsolv
109  REAL                  :: ztvd, zscf
110  REAL                  :: zucf, zcr
111  REAL                  :: friv, frih
112  REAL, DIMENSION(klon) :: zcfm1, zcfm2 ! Drag coefficient for momentum
113  REAL, DIMENSION(klon) :: zcfh1, zcfh2 ! Drag coefficient for heat flux
114  LOGICAL, PARAMETER    :: zxli=.FALSE. ! calcul des cdrags selon Laurent Li
115  REAL, DIMENSION(klon) :: zcdn_m, zcdn_h         ! Drag coefficient in neutral conditions
116  REAL zzzcd
117!
118! Fonctions thermodynamiques et fonctions d'instabilite
119  REAL                  :: fsta, fins, x
120  fsta(x) = 1.0 / (1.0+10.0*x*(1+8.0*x))
121  fins(x) = SQRT(1.0-18.0*x)
122
123! ================================================================= c
124! Fuxing WANG, 04/03/2015, delete the calculation of zgeop1
125! (le geopotentiel du premier couche de modele).
126! zgeop1 is an input ivariable in this subroutine.
127!  DO i = 1, knon
128!     zgeop1(i) = RD * t1(i) / (0.5*(paprs(i,1)+pplay(i,1))) &
129!          * (paprs(i,1)-pplay(i,1))
130!  END DO
131! ================================================================= c
132!
133! Fuxing WANG, 04/03/2015
134! To check if there are negative q1, qsurf values.
135  ng_q1 = 0     ! Initialization
136  ng_qsurf = 0  ! Initialization
137  DO i = 1, knon
138     IF (q1(i).LT.0.0)     ng_q1 = ng_q1 + 1
139     IF (qsurf(i).LT.0.0)  ng_qsurf = ng_qsurf + 1
140  ENDDO
141  IF (ng_q1.GT.0 .and. prt_level > 5) THEN
142      WRITE(lunout,*)" *** Warning: Negative q1(humidity at 1st level) values in cdrag.F90 !"
143      WRITE(lunout,*)" The total number of the grids is: ", ng_q1
144      WRITE(lunout,*)" The negative q1 is set to zero "
145!      abort_message="voir ci-dessus"
146!      CALL abort_physic(modname,abort_message,1)
147  ENDIF
148  IF (ng_qsurf.GT.0 .and. prt_level > 5) THEN
149      WRITE(lunout,*)" *** Warning: Negative qsurf(humidity at surface) values in cdrag.F90 !"
150      WRITE(lunout,*)" The total number of the grids is: ", ng_qsurf
151      WRITE(lunout,*)" The negative qsurf is set to zero "
152!      abort_message="voir ci-dessus"
153!      CALL abort_physic(modname,abort_message,1)
154  ENDIF
155
156! Calculer le frottement au sol (Cdrag)
157  DO i = 1, knon
158!------------------------------------------------------------
159! u1, v1 are replaced by speed. Fuxing WANG, 04/03/2015,
160!     zdu2 = MAX(CEPDU2,u1(i)**2+v1(i)**2)
161!------------------------------------------------------------
162     zdu2 = MAX(CEPDU2, speed(i)**2)
163!     psol(i) = paprs(i,1)
164     pref(i) = EXP(LOG(psol(i)) - zgeop1(i)/(RD*t1(i)* &
165                 (1.+ RETV * max(q1(i),0.0))))  ! negative q1 set to zero
166!------------ the old calculations in clcdrag----------------
167!     ztsolv = tsurf(i) * (1.0+RETV*qsurf(i))
168!     ztvd = (t1(i)+zgeop1(i)/RCPD/(1.+RVTMP2*q1(i))) &
169!          *(1.+RETV*q1(i))
170!------------------------------------------------------------
171! Fuxing WANG, 04/03/2015, in this revised version,
172! the negative qsurf and q1 are set to zero (as in coefcdrag)
173     ztsolv = tsurf(i) * (1.0+RETV*max(qsurf(i),0.0)) ! negative qsurf set to zero
174     ztvd = (t1(i)+zgeop1(i)/RCPD/(1.+RVTMP2*max(q1(i),0.0))) &
175          *(1.+RETV*max(q1(i),0.0)) ! negative q1 set to zero
176     zri(i) = zgeop1(i)*(ztvd-ztsolv)/(zdu2*ztvd)
177
178
179! Coefficients CD neutres pour m et h : k^2/ln(z/z0) et k^2/(ln(z/z0)*ln(z/z0h))
180     zzzcd=CKAP/LOG(1.+zgeop1(i)/(RG*z0m(i)))
181     zcdn_m(i) = zzzcd*zzzcd
182     zcdn_h(i) = zzzcd*(CKAP/LOG(1.+zgeop1(i)/(RG*z0h(i))))
183
184     IF (zri(i) .GT. 0.) THEN      ! situation stable
185        zri(i) = MIN(20.,zri(i))
186        IF (.NOT.zxli) THEN
187           zscf = SQRT(1.+CD*ABS(zri(i)))
188           friv = AMAX1(1. / (1.+2.*CB*zri(i)/ZSCF), f_ri_cd_min)
189           zcfm1(i) = zcdn_m(i) * friv
190           frih = AMAX1(1./ (1.+3.*CB*zri(i)*ZSCF), f_ri_cd_min )
191!!$ PB     zcfh1(i) = zcdn(i) * frih
192!!$ PB     zcfh1(i) = f_cdrag_stable * zcdn(i) * frih
193           zcfh1(i) = f_cdrag_ter * zcdn_h(i) * frih
194           IF(nsrf.EQ.is_oce) zcfh1(i) = f_cdrag_oce * zcdn_h(i) * frih
195!!$ PB
196           pcfm(i) = zcfm1(i)
197           pcfh(i) = zcfh1(i)
198        ELSE
199           pcfm(i) = zcdn_m(i)* fsta(zri(i))
200           pcfh(i) = zcdn_h(i)* fsta(zri(i))
201        ENDIF
202     ELSE                          ! situation instable
203        IF (.NOT.zxli) THEN
204           zucf = 1./(1.+3.0*CB*CC*zcdn_m(i)*SQRT(ABS(zri(i)) &
205                *(1.0+zgeop1(i)/(RG*z0m(i)))))
206           zcfm2(i) = zcdn_m(i)*amax1((1.-2.0*CB*zri(i)*zucf),f_ri_cd_min)
207!!$ PB     zcfh2(i) = zcdn_h(i)*amax1((1.-3.0*cb*zri(i)*zucf),f_ri_cd_min)
208           zcfh2(i) = f_cdrag_ter*zcdn_h(i)*amax1((1.-3.0*CB*zri(i)*zucf),f_ri_cd_min)
209           pcfm(i) = zcfm2(i)
210           pcfh(i) = zcfh2(i)
211        ELSE
212           pcfm(i) = zcdn_m(i)* fins(zri(i))
213           pcfh(i) = zcdn_h(i)* fins(zri(i))
214        ENDIF
215        IF(iflag_gusts==0) THEN
216! cdrah sur l'ocean cf. Miller et al. (1992) - only active when gustiness parameterization is not active
217           zcr = (0.0016/(zcdn_m(i)*SQRT(zdu2)))*ABS(ztvd-ztsolv)**(1./3.)
218           IF(nsrf.EQ.is_oce) pcfh(i) =f_cdrag_oce* zcdn_h(i)*(1.0+zcr**1.25)**(1./1.25)
219        ENDIF
220     ENDIF
221  END DO
222
223! ================================================================= c
224     
225  ! IM cf JLD : on seuille cdrag_m et cdrag_h
226  IF (nsrf == is_oce) THEN
227     DO i=1,knon
228        pcfm(i)=MIN(pcfm(i),cdmmax)
229        pcfh(i)=MIN(pcfh(i),cdhmax)
230     END DO
231  END IF
232
233END SUBROUTINE cdrag
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