phylmd/Interface_surf/fonte_neige.f

module fonte_neige_m

  implicit none

contains

  SUBROUTINE fonte_neige(klon, knon, nisurf, dtime, tsurf, p1lay, beta, &
       coef1lay, ps, precip_rain, precip_snow, snow, qsol, t1lay, q1lay, &
       u1lay, v1lay, petAcoef, peqAcoef, petBcoef, peqBcoef, tsurf_new, evap, &
       fqcalving, ffonte, run_off_lic_0)

    ! Routine de traitement de la fonte de la neige dans le cas du traitement
    ! de sol simplifié

    ! LF 03/2001

    USE fcttre, ONLY: dqsatl, dqsats, foede, foeew, qsatl, qsats, thermcep
    USE indicesol, ONLY: epsfra, is_lic, is_sic, is_ter
    USE interface_surf, ONLY: run_off, run_off_lic, tau_calv
    USE suphec_m, ONLY: rcpd, rd, rday, retv, rkappa, rlmlt, rlstt, rlvtt, rtt
    USE yoethf_m, ONLY: r2es, r5ies, r5les, rvtmp2

    integer, intent(IN):: klon
    integer, intent(IN):: knon ! nombre de points à traiter
    integer, intent(IN):: nisurf ! surface à traiter
    real, intent(IN):: dtime ! pas de temps de la physique (en s)
    real, dimension(klon), intent(IN):: tsurf, p1lay, beta, coef1lay
    ! tsurf temperature de surface
    ! p1lay pression 1er niveau (milieu de couche)
    ! beta evap reelle
    ! coef1lay coefficient d'echange
    real, dimension(klon), intent(IN):: ps
    ! ps pression au sol

    real, intent(IN):: precip_rain(:) ! (knon)
    ! precipitation, liquid water mass flux (kg/m2/s), positive down

    real, intent(IN):: precip_snow(klon)
    ! precipitation, solid water mass flux (kg/m2/s), positive down

    real, intent(INOUT):: snow(klon) ! column-density of mass of snow, in kg m-2

    real, intent(INOUT):: qsol(:) ! (knon)
    ! column-density of water in soil, in kg m-2

    real, dimension(klon), intent(IN):: t1lay
    real, dimension(klon), intent(IN):: q1lay
    real, dimension(klon), intent(IN):: u1lay, v1lay
    real, dimension(klon), intent(IN):: petAcoef, peqAcoef
    ! petAcoef coeff. A de la resolution de la CL pour t
    ! peqAcoef coeff. A de la resolution de la CL pour q
    real, dimension(klon), intent(IN):: petBcoef, peqBcoef
    ! petBcoef coeff. B de la resolution de la CL pour t
    ! peqBcoef coeff. B de la resolution de la CL pour q

    real, intent(INOUT):: tsurf_new(klon), evap(klon)
    ! tsurf_new temperature au sol

    ! Flux d'eau "perdue" par la surface et necessaire pour que limiter la
    ! hauteur de neige, en kg/m2/s
    real, dimension(klon), intent(INOUT):: fqcalving

    ! Flux thermique utiliser pour fondre la neige
    real, dimension(klon), intent(INOUT):: ffonte

    real, dimension(klon), intent(INOUT):: run_off_lic_0
    ! run_off_lic_0 run off glacier du pas de temps précedent

    ! Local:

    real, parameter:: snow_max=3000.
    ! Masse maximum de neige (kg/m2). Au dessus de ce seuil, la neige
    ! en exces "s'ecoule" (calving)

    integer i
    real, dimension(klon):: zx_mh, zx_nh, zx_oh
    real, dimension(klon):: zx_mq, zx_nq, zx_oq
    real, dimension(klon):: zx_pkh, zx_dq_s_dt, zx_qsat, zx_coef
    real, dimension(klon):: zx_sl, zx_k1
    real, dimension(klon):: d_ts
    logical zdelta
    real zcvm5, zx_qs, zcor, zx_dq_s_dh
    real fq_fonte
    REAL bil_eau_s(knon) ! in kg m-2
    real snow_evap(klon) ! in kg m-2 s-1
    real, parameter:: t_grnd = 271.35, t_coup = 273.15
    REAL, parameter:: chasno = 3.334E5/(2.3867E6*0.15)
    REAL, parameter:: chaice = 3.334E5/(2.3867E6*0.15)
    real, parameter:: max_eau_sol = 150. ! in kg m-2
    real coeff_rel

    !--------------------------------------------------------------------

    ! Initialisations
    coeff_rel = dtime/(tau_calv * rday)
    bil_eau_s = 0.
    DO i = 1, knon
       zx_pkh(i) = (ps(i)/ps(i))**RKAPPA
       IF (thermcep) THEN
          zdelta= rtt >= tsurf(i)
          zcvm5 = merge(R5IES*RLSTT, R5LES*RLVTT, zdelta)
          zcvm5 = zcvm5 / RCPD / (1. + RVTMP2*q1lay(i))
          zx_qs= r2es * FOEEW(tsurf(i), zdelta)/ps(i)
          zx_qs=MIN(0.5, zx_qs)
          zcor=1./(1.-retv*zx_qs)
          zx_qs=zx_qs*zcor
          zx_dq_s_dh = FOEDE(tsurf(i), zdelta, zcvm5, zx_qs, zcor) /RLVTT &
               / zx_pkh(i)
       ELSE
          IF (tsurf(i) < t_coup) THEN
             zx_qs = qsats(tsurf(i)) / ps(i)
             zx_dq_s_dh = dqsats(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
          ELSE
             zx_qs = qsatl(tsurf(i)) / ps(i)
             zx_dq_s_dh = dqsatl(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
          ENDIF
       ENDIF
       zx_dq_s_dt(i) = RCPD * zx_pkh(i) * zx_dq_s_dh
       zx_qsat(i) = zx_qs
       zx_coef(i) = coef1lay(i) * (1. + SQRT(u1lay(i)**2 + v1lay(i)**2)) &
            * p1lay(i) / (RD * t1lay(i))
    ENDDO

    ! Calcul de la temperature de surface

    ! zx_sl = chaleur latente d'evaporation ou de sublimation

    do i = 1, knon
       zx_sl(i) = RLVTT
       if (tsurf(i) < RTT) zx_sl(i) = RLSTT
       zx_k1(i) = zx_coef(i)
    enddo

    do i = 1, knon
       ! Q
       zx_oq(i) = 1. - (beta(i) * zx_k1(i) * peqBcoef(i) * dtime)
       zx_mq(i) = beta(i) * zx_k1(i) * (peqAcoef(i) - zx_qsat(i) &
            + zx_dq_s_dt(i) * tsurf(i)) / zx_oq(i)
       zx_nq(i) = beta(i) * zx_k1(i) * (-1. * zx_dq_s_dt(i)) / zx_oq(i)

       ! H
       zx_oh(i) = 1. - (zx_k1(i) * petBcoef(i) * dtime)
       zx_mh(i) = zx_k1(i) * petAcoef(i) / zx_oh(i)
       zx_nh(i) = - (zx_k1(i) * RCPD * zx_pkh(i))/ zx_oh(i)
    enddo

    WHERE (precip_snow > 0.) snow = snow + precip_snow * dtime

    WHERE (evap > 0.)
       snow_evap = MIN (snow / dtime, evap)
       snow = snow - snow_evap * dtime
       snow = MAX(0., snow)
    elsewhere
       snow_evap = 0.
    end where

    bil_eau_s = precip_rain * dtime - (evap(:knon) - snow_evap(:knon)) * dtime

    ! Y'a-t-il fonte de neige?

    ffonte=0.
    do i = 1, knon
       if ((snow(i) > epsfra .OR. nisurf == is_sic &
            .OR. nisurf == is_lic) .AND. tsurf_new(i) >= RTT) then
          fq_fonte = MIN(MAX((tsurf_new(i)-RTT)/chasno, 0.), snow(i))
          ffonte(i) = fq_fonte * RLMLT/dtime
          snow(i) = max(0., snow(i) - fq_fonte)
          bil_eau_s(i) = bil_eau_s(i) + fq_fonte
          tsurf_new(i) = tsurf_new(i) - fq_fonte * chasno
          !IM cf JLD/ GKtest fonte aussi pour la glace
          IF (nisurf == is_sic .OR. nisurf == is_lic) THEN
             fq_fonte = MAX((tsurf_new(i)-RTT)/chaice, 0.)
             ffonte(i) = ffonte(i) + fq_fonte * RLMLT/dtime
             bil_eau_s(i) = bil_eau_s(i) + fq_fonte
             tsurf_new(i) = RTT
          ENDIF
          d_ts(i) = tsurf_new(i) - tsurf(i)
       endif

       ! S'il y a une hauteur trop importante de neige, elle s'écoule
       fqcalving(i) = max(0., snow(i) - snow_max)/dtime
       snow(i)=min(snow(i), snow_max)

       IF (nisurf == is_ter) then
          qsol(i) = qsol(i) + bil_eau_s(i)
          run_off(i) = run_off(i) + MAX(qsol(i) - max_eau_sol, 0.)
          qsol(i) = MIN(qsol(i), max_eau_sol)
       else if (nisurf == is_lic) then
          run_off_lic(i) = (coeff_rel * fqcalving(i)) + &
               (1. - coeff_rel) * run_off_lic_0(i)
          run_off_lic_0(i) = run_off_lic(i)
          run_off_lic(i) = run_off_lic(i) + bil_eau_s(i)/dtime
       endif
    enddo

  END SUBROUTINE fonte_neige

end module fonte_neige_m
1	guez	54	module fonte_neige_m
2
3			implicit none
4
5			contains
6
7	guez	101	SUBROUTINE fonte_neige(klon, knon, nisurf, dtime, tsurf, p1lay, beta, &
8			coef1lay, ps, precip_rain, precip_snow, snow, qsol, t1lay, q1lay, &
9			u1lay, v1lay, petAcoef, peqAcoef, petBcoef, peqBcoef, tsurf_new, evap, &
10	guez	54	fqcalving, ffonte, run_off_lic_0)
11
12			! Routine de traitement de la fonte de la neige dans le cas du traitement
13			! de sol simplifié
14
15			! LF 03/2001
16	guez	101
17			USE fcttre, ONLY: dqsatl, dqsats, foede, foeew, qsatl, qsats, thermcep
18			USE indicesol, ONLY: epsfra, is_lic, is_sic, is_ter
19			USE interface_surf, ONLY: run_off, run_off_lic, tau_calv
20			USE suphec_m, ONLY: rcpd, rd, rday, retv, rkappa, rlmlt, rlstt, rlvtt, rtt
21			USE yoethf_m, ONLY: r2es, r5ies, r5les, rvtmp2
22
23			integer, intent(IN):: klon
24			integer, intent(IN):: knon ! nombre de points à traiter
25			integer, intent(IN):: nisurf ! surface à traiter
26			real, intent(IN):: dtime ! pas de temps de la physique (en s)
27			real, dimension(klon), intent(IN):: tsurf, p1lay, beta, coef1lay
28	guez	54	! tsurf temperature de surface
29			! p1lay pression 1er niveau (milieu de couche)
30			! beta evap reelle
31			! coef1lay coefficient d'echange
32	guez	101	real, dimension(klon), intent(IN):: ps
33	guez	54	! ps pression au sol
34	guez	101
35			real, intent(IN):: precip_rain(:) ! (knon)
36			! precipitation, liquid water mass flux (kg/m2/s), positive down
37
38			real, intent(IN):: precip_snow(klon)
39			! precipitation, solid water mass flux (kg/m2/s), positive down
40
41			real, intent(INOUT):: snow(klon) ! column-density of mass of snow, in kg m-2
42
43			real, intent(INOUT):: qsol(:) ! (knon)
44			! column-density of water in soil, in kg m-2
45
46			real, dimension(klon), intent(IN):: t1lay
47			real, dimension(klon), intent(IN):: q1lay
48			real, dimension(klon), intent(IN):: u1lay, v1lay
49			real, dimension(klon), intent(IN):: petAcoef, peqAcoef
50	guez	54	! petAcoef coeff. A de la resolution de la CL pour t
51			! peqAcoef coeff. A de la resolution de la CL pour q
52	guez	101	real, dimension(klon), intent(IN):: petBcoef, peqBcoef
53	guez	54	! petBcoef coeff. B de la resolution de la CL pour t
54			! peqBcoef coeff. B de la resolution de la CL pour q
55
56	guez	101	real, intent(INOUT):: tsurf_new(klon), evap(klon)
57	guez	54	! tsurf_new temperature au sol
58
59	guez	101	! Flux d'eau "perdue" par la surface et necessaire pour que limiter la
60			! hauteur de neige, en kg/m2/s
61			real, dimension(klon), intent(INOUT):: fqcalving
62	guez	54
63			! Flux thermique utiliser pour fondre la neige
64			real, dimension(klon), intent(INOUT):: ffonte
65	guez	101
66	guez	54	real, dimension(klon), intent(INOUT):: run_off_lic_0
67	guez	101	! run_off_lic_0 run off glacier du pas de temps précedent
68
69			! Local:
70
71			real, parameter:: snow_max=3000.
72	guez	54	! Masse maximum de neige (kg/m2). Au dessus de ce seuil, la neige
73			! en exces "s'ecoule" (calving)
74
75	guez	101	integer i
76			real, dimension(klon):: zx_mh, zx_nh, zx_oh
77			real, dimension(klon):: zx_mq, zx_nq, zx_oq
78			real, dimension(klon):: zx_pkh, zx_dq_s_dt, zx_qsat, zx_coef
79			real, dimension(klon):: zx_sl, zx_k1
80			real, dimension(klon):: d_ts
81	guez	103	logical zdelta
82			real zcvm5, zx_qs, zcor, zx_dq_s_dh
83	guez	101	real fq_fonte
84			REAL bil_eau_s(knon) ! in kg m-2
85			real snow_evap(klon) ! in kg m-2 s-1
86			real, parameter:: t_grnd = 271.35, t_coup = 273.15
87			REAL, parameter:: chasno = 3.334E5/(2.3867E6*0.15)
88			REAL, parameter:: chaice = 3.334E5/(2.3867E6*0.15)
89			real, parameter:: max_eau_sol = 150. ! in kg m-2
90			real coeff_rel
91	guez	54
92	guez	101	!--------------------------------------------------------------------
93	guez	54
94			! Initialisations
95			coeff_rel = dtime/(tau_calv * rday)
96			bil_eau_s = 0.
97			DO i = 1, knon
98			zx_pkh(i) = (ps(i)/ps(i))**RKAPPA
99			IF (thermcep) THEN
100	guez	103	zdelta= rtt >= tsurf(i)
101			zcvm5 = merge(R5IESRLSTT, R5LESRLVTT, zdelta)
102	guez	101	zcvm5 = zcvm5 / RCPD / (1. + RVTMP2*q1lay(i))
103	guez	54	zx_qs= r2es * FOEEW(tsurf(i), zdelta)/ps(i)
104			zx_qs=MIN(0.5, zx_qs)
105			zcor=1./(1.-retv*zx_qs)
106			zx_qs=zx_qs*zcor
107	guez	101	zx_dq_s_dh = FOEDE(tsurf(i), zdelta, zcvm5, zx_qs, zcor) /RLVTT &
108			/ zx_pkh(i)
109	guez	54	ELSE
110	guez	101	IF (tsurf(i) < t_coup) THEN
111	guez	54	zx_qs = qsats(tsurf(i)) / ps(i)
112	guez	101	zx_dq_s_dh = dqsats(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
113	guez	54	ELSE
114			zx_qs = qsatl(tsurf(i)) / ps(i)
115	guez	101	zx_dq_s_dh = dqsatl(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
116	guez	54	ENDIF
117			ENDIF
118			zx_dq_s_dt(i) = RCPD * zx_pkh(i) * zx_dq_s_dh
119			zx_qsat(i) = zx_qs
120	guez	101	zx_coef(i) = coef1lay(i) * (1. + SQRT(u1lay(i)2 + v1lay(i)2)) &
121			* p1lay(i) / (RD * t1lay(i))
122	guez	54	ENDDO
123
124	guez	101	! Calcul de la temperature de surface
125	guez	54
126			! zx_sl = chaleur latente d'evaporation ou de sublimation
127
128			do i = 1, knon
129			zx_sl(i) = RLVTT
130	guez	101	if (tsurf(i) < RTT) zx_sl(i) = RLSTT
131	guez	54	zx_k1(i) = zx_coef(i)
132			enddo
133
134			do i = 1, knon
135			! Q
136			zx_oq(i) = 1. - (beta(i) * zx_k1(i) * peqBcoef(i) * dtime)
137	guez	101	zx_mq(i) = beta(i) * zx_k1(i) * (peqAcoef(i) - zx_qsat(i) &
138			+ zx_dq_s_dt(i) * tsurf(i)) / zx_oq(i)
139			zx_nq(i) = beta(i) * zx_k1(i) * (-1. * zx_dq_s_dt(i)) / zx_oq(i)
140	guez	54
141			! H
142			zx_oh(i) = 1. - (zx_k1(i) * petBcoef(i) * dtime)
143			zx_mh(i) = zx_k1(i) * petAcoef(i) / zx_oh(i)
144			zx_nh(i) = - (zx_k1(i) * RCPD * zx_pkh(i))/ zx_oh(i)
145			enddo
146
147	guez	101	WHERE (precip_snow > 0.) snow = snow + precip_snow * dtime
148
149			WHERE (evap > 0.)
150	guez	54	snow_evap = MIN (snow / dtime, evap)
151			snow = snow - snow_evap * dtime
152	guez	101	snow = MAX(0., snow)
153			elsewhere
154			snow_evap = 0.
155	guez	54	end where
156
157	guez	101	bil_eau_s = precip_rain * dtime - (evap(:knon) - snow_evap(:knon)) * dtime
158	guez	54
159			! Y'a-t-il fonte de neige?
160
161			ffonte=0.
162			do i = 1, knon
163	guez	101	if ((snow(i) > epsfra .OR. nisurf == is_sic &
164			.OR. nisurf == is_lic) .AND. tsurf_new(i) >= RTT) then
165			fq_fonte = MIN(MAX((tsurf_new(i)-RTT)/chasno, 0.), snow(i))
166	guez	54	ffonte(i) = fq_fonte * RLMLT/dtime
167			snow(i) = max(0., snow(i) - fq_fonte)
168			bil_eau_s(i) = bil_eau_s(i) + fq_fonte
169			tsurf_new(i) = tsurf_new(i) - fq_fonte * chasno
170			!IM cf JLD/ GKtest fonte aussi pour la glace
171	guez	101	IF (nisurf == is_sic .OR. nisurf == is_lic) THEN
172			fq_fonte = MAX((tsurf_new(i)-RTT)/chaice, 0.)
173	guez	54	ffonte(i) = ffonte(i) + fq_fonte * RLMLT/dtime
174			bil_eau_s(i) = bil_eau_s(i) + fq_fonte
175			tsurf_new(i) = RTT
176			ENDIF
177			d_ts(i) = tsurf_new(i) - tsurf(i)
178			endif
179
180	guez	101	! S'il y a une hauteur trop importante de neige, elle s'écoule
181	guez	54	fqcalving(i) = max(0., snow(i) - snow_max)/dtime
182			snow(i)=min(snow(i), snow_max)
183
184			IF (nisurf == is_ter) then
185			qsol(i) = qsol(i) + bil_eau_s(i)
186	guez	101	run_off(i) = run_off(i) + MAX(qsol(i) - max_eau_sol, 0.)
187	guez	54	qsol(i) = MIN(qsol(i), max_eau_sol)
188			else if (nisurf == is_lic) then
189			run_off_lic(i) = (coeff_rel * fqcalving(i)) + &
190			(1. - coeff_rel) * run_off_lic_0(i)
191			run_off_lic_0(i) = run_off_lic(i)
192			run_off_lic(i) = run_off_lic(i) + bil_eau_s(i)/dtime
193			endif
194			enddo
195
196			END SUBROUTINE fonte_neige
197
198			end module fonte_neige_m