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	module fonte_neige_m
2
3	implicit none
4
5	contains
6
7	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	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
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	! tsurf temperature de surface
29	! p1lay pression 1er niveau (milieu de couche)
30	! beta evap reelle
31	! coef1lay coefficient d'echange
32	real, dimension(klon), intent(IN):: ps
33	! ps pression au sol
34
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	! petAcoef coeff. A de la resolution de la CL pour t
51	! peqAcoef coeff. A de la resolution de la CL pour q
52	real, dimension(klon), intent(IN):: petBcoef, peqBcoef
53	! 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	real, intent(INOUT):: tsurf_new(klon), evap(klon)
57	! tsurf_new temperature au sol
58
59	! 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
63	! Flux thermique utiliser pour fondre la neige
64	real, dimension(klon), intent(INOUT):: ffonte
65
66	real, dimension(klon), intent(INOUT):: run_off_lic_0
67	! run_off_lic_0 run off glacier du pas de temps précedent
68
69	! Local:
70
71	real, parameter:: snow_max=3000.
72	! Masse maximum de neige (kg/m2). Au dessus de ce seuil, la neige
73	! en exces "s'ecoule" (calving)
74
75	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	logical zdelta
82	real zcvm5, zx_qs, zcor, zx_dq_s_dh
83	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
92	!--------------------------------------------------------------------
93
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	zdelta= rtt >= tsurf(i)
101	zcvm5 = merge(R5IESRLSTT, R5LESRLVTT, zdelta)
102	zcvm5 = zcvm5 / RCPD / (1. + RVTMP2*q1lay(i))
103	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	zx_dq_s_dh = FOEDE(tsurf(i), zdelta, zcvm5, zx_qs, zcor) /RLVTT &
108	/ zx_pkh(i)
109	ELSE
110	IF (tsurf(i) < t_coup) THEN
111	zx_qs = qsats(tsurf(i)) / ps(i)
112	zx_dq_s_dh = dqsats(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
113	ELSE
114	zx_qs = qsatl(tsurf(i)) / ps(i)
115	zx_dq_s_dh = dqsatl(tsurf(i), zx_qs)/RLVTT / zx_pkh(i)
116	ENDIF
117	ENDIF
118	zx_dq_s_dt(i) = RCPD * zx_pkh(i) * zx_dq_s_dh
119	zx_qsat(i) = zx_qs
120	zx_coef(i) = coef1lay(i) * (1. + SQRT(u1lay(i)2 + v1lay(i)2)) &
121	* p1lay(i) / (RD * t1lay(i))
122	ENDDO
123
124	! Calcul de la temperature de surface
125
126	! zx_sl = chaleur latente d'evaporation ou de sublimation
127
128	do i = 1, knon
129	zx_sl(i) = RLVTT
130	if (tsurf(i) < RTT) zx_sl(i) = RLSTT
131	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	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
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	WHERE (precip_snow > 0.) snow = snow + precip_snow * dtime
148
149	WHERE (evap > 0.)
150	snow_evap = MIN (snow / dtime, evap)
151	snow = snow - snow_evap * dtime
152	snow = MAX(0., snow)
153	elsewhere
154	snow_evap = 0.
155	end where
156
157	bil_eau_s = precip_rain * dtime - (evap(:knon) - snow_evap(:knon)) * dtime
158
159	! Y'a-t-il fonte de neige?
160
161	ffonte=0.
162	do i = 1, knon
163	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	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	IF (nisurf == is_sic .OR. nisurf == is_lic) THEN
172	fq_fonte = MAX((tsurf_new(i)-RTT)/chaice, 0.)
173	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	! S'il y a une hauteur trop importante de neige, elle s'écoule
181	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	run_off(i) = run_off(i) + MAX(qsol(i) - max_eau_sol, 0.)
187	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