phylmd/Interface_surf/fonte_neige.f

module fonte_neige_m

  implicit none

contains

  SUBROUTINE fonte_neige(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 simplifi\'e

    ! LF 03/2001

    USE fcttre, ONLY: 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 nr_util, only: assert_eq
    USE suphec_m, ONLY: rcpd, rday, retv, rlmlt, rlstt, rlvtt, rtt
    USE yoethf_m, ONLY: r2es, r5ies, r5les, rvtmp2

    integer, intent(IN):: nisurf ! surface \`a traiter
    real, intent(IN):: dtime ! pas de temps de la physique (en s)
    real, dimension(:), intent(IN):: tsurf, p1lay, beta, coef1lay ! (knon)
    ! tsurf temperature de surface
    ! p1lay pression 1er niveau (milieu de couche)
    ! beta evap reelle
    ! coef1lay coefficient d'echange
    real, dimension(:), intent(IN):: ps ! (knon)
    ! 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(:) ! (knon)
    ! precipitation, solid water mass flux (kg/m2/s), positive down

    real, intent(INOUT):: snow(:) ! (knon)
    ! 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(:), intent(IN):: t1lay ! (knon)
    real, dimension(:), intent(IN):: q1lay ! (knon)
    real, dimension(:), intent(IN):: u1lay, v1lay ! (knon)
    real, dimension(:), intent(IN):: petAcoef, peqAcoef ! (knon)
    ! petAcoef coeff. A de la resolution de la CL pour t
    ! peqAcoef coeff. A de la resolution de la CL pour q
    real, dimension(:), intent(IN):: petBcoef, peqBcoef ! (knon)
    ! 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(:)
    ! tsurf_new temperature au sol

    real, intent(IN):: evap(:) ! (knon)

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

    ! Flux thermique utiliser pour fondre la neige
    real, intent(OUT):: ffonte(:) ! (knon)

    real, dimension(:), intent(INOUT):: run_off_lic_0 ! (knon)
    ! run_off_lic_0 run off glacier du pas de temps pr\'ecedent

    ! Local:

    integer knon ! nombre de points \`a traiter
    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
    logical zdelta
    real zcvm5, zx_qs, zcor
    real fq_fonte
    REAL bil_eau_s(size(ps)) ! in kg m-2
    real snow_evap(size(ps)) ! 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

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

    knon = assert_eq((/size(tsurf), size(p1lay), size(beta), size(coef1lay), &
         size(ps), size(precip_rain), size(precip_snow), size(snow), &
         size(qsol), size(t1lay), size(q1lay), size(u1lay), size(v1lay), &
         size(petAcoef), size(peqAcoef), size(petBcoef), size(peqBcoef), &
         size(tsurf_new), size(evap), size(fqcalving), size(ffonte), &
         size(run_off_lic_0)/), "fonte_neige knon")

    ! Initialisations
    coeff_rel = dtime/(tau_calv * rday)
    bil_eau_s = 0.
    DO i = 1, knon
       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
       ELSE
          IF (tsurf(i) < t_coup) THEN
             zx_qs = qsats(tsurf(i)) / ps(i)
          ELSE
             zx_qs = qsatl(tsurf(i)) / ps(i)
          ENDIF
       ENDIF
    ENDDO

    ! Calcul de la temperature de surface

    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
       endif

       ! S'il y a une hauteur trop importante de neige, elle s'\'ecoule
       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	104	SUBROUTINE fonte_neige(nisurf, dtime, tsurf, p1lay, beta, coef1lay, ps, &
8			precip_rain, precip_snow, snow, qsol, t1lay, q1lay, u1lay, v1lay, &
9			petAcoef, peqAcoef, petBcoef, peqBcoef, tsurf_new, evap, fqcalving, &
10			ffonte, run_off_lic_0)
11	guez	54
12			! Routine de traitement de la fonte de la neige dans le cas du traitement
13	guez	178	! de sol simplifi\'e
14	guez	54
15			! LF 03/2001
16	guez	101
17	guez	178	USE fcttre, ONLY: foeew, qsatl, qsats, thermcep
18	guez	101	USE indicesol, ONLY: epsfra, is_lic, is_sic, is_ter
19			USE interface_surf, ONLY: run_off, run_off_lic, tau_calv
20	guez	104	use nr_util, only: assert_eq
21	guez	178	USE suphec_m, ONLY: rcpd, rday, retv, rlmlt, rlstt, rlvtt, rtt
22	guez	101	USE yoethf_m, ONLY: r2es, r5ies, r5les, rvtmp2
23
24	guez	178	integer, intent(IN):: nisurf ! surface \`a traiter
25	guez	101	real, intent(IN):: dtime ! pas de temps de la physique (en s)
26	guez	104	real, dimension(:), intent(IN):: tsurf, p1lay, beta, coef1lay ! (knon)
27	guez	54	! tsurf temperature de surface
28			! p1lay pression 1er niveau (milieu de couche)
29			! beta evap reelle
30			! coef1lay coefficient d'echange
31	guez	104	real, dimension(:), intent(IN):: ps ! (knon)
32	guez	54	! ps pression au sol
33	guez	101
34			real, intent(IN):: precip_rain(:) ! (knon)
35			! precipitation, liquid water mass flux (kg/m2/s), positive down
36
37	guez	104	real, intent(IN):: precip_snow(:) ! (knon)
38	guez	101	! precipitation, solid water mass flux (kg/m2/s), positive down
39
40	guez	104	real, intent(INOUT):: snow(:) ! (knon)
41			! column-density of mass of snow, in kg m-2
42	guez	101
43			real, intent(INOUT):: qsol(:) ! (knon)
44			! column-density of water in soil, in kg m-2
45
46	guez	104	real, dimension(:), intent(IN):: t1lay ! (knon)
47			real, dimension(:), intent(IN):: q1lay ! (knon)
48			real, dimension(:), intent(IN):: u1lay, v1lay ! (knon)
49			real, dimension(:), intent(IN):: petAcoef, peqAcoef ! (knon)
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	104	real, dimension(:), intent(IN):: petBcoef, peqBcoef ! (knon)
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	104	real, intent(INOUT):: tsurf_new(:)
57	guez	54	! tsurf_new temperature au sol
58
59	guez	104	real, intent(IN):: evap(:) ! (knon)
60
61	guez	101	! Flux d'eau "perdue" par la surface et necessaire pour que limiter la
62			! hauteur de neige, en kg/m2/s
63	guez	104	real, intent(OUT):: fqcalving(:) ! (knon)
64	guez	54
65			! Flux thermique utiliser pour fondre la neige
66	guez	104	real, intent(OUT):: ffonte(:) ! (knon)
67	guez	101
68	guez	104	real, dimension(:), intent(INOUT):: run_off_lic_0 ! (knon)
69	guez	178	! run_off_lic_0 run off glacier du pas de temps pr\'ecedent
70	guez	101
71			! Local:
72
73	guez	178	integer knon ! nombre de points \`a traiter
74	guez	101	real, parameter:: snow_max=3000.
75	guez	54	! Masse maximum de neige (kg/m2). Au dessus de ce seuil, la neige
76			! en exces "s'ecoule" (calving)
77
78	guez	101	integer i
79	guez	103	logical zdelta
80	guez	178	real zcvm5, zx_qs, zcor
81	guez	101	real fq_fonte
82	guez	104	REAL bil_eau_s(size(ps)) ! in kg m-2
83			real snow_evap(size(ps)) ! in kg m-2 s-1
84	guez	101	real, parameter:: t_grnd = 271.35, t_coup = 273.15
85			REAL, parameter:: chasno = 3.334E5/(2.3867E6*0.15)
86			REAL, parameter:: chaice = 3.334E5/(2.3867E6*0.15)
87			real, parameter:: max_eau_sol = 150. ! in kg m-2
88			real coeff_rel
89	guez	54
90	guez	101	!--------------------------------------------------------------------
91	guez	54
92	guez	104	knon = assert_eq((/size(tsurf), size(p1lay), size(beta), size(coef1lay), &
93			size(ps), size(precip_rain), size(precip_snow), size(snow), &
94			size(qsol), size(t1lay), size(q1lay), size(u1lay), size(v1lay), &
95			size(petAcoef), size(peqAcoef), size(petBcoef), size(peqBcoef), &
96			size(tsurf_new), size(evap), size(fqcalving), size(ffonte), &
97			size(run_off_lic_0)/), "fonte_neige knon")
98
99	guez	54	! Initialisations
100			coeff_rel = dtime/(tau_calv * rday)
101			bil_eau_s = 0.
102			DO i = 1, knon
103			IF (thermcep) THEN
104	guez	103	zdelta= rtt >= tsurf(i)
105			zcvm5 = merge(R5IESRLSTT, R5LESRLVTT, zdelta)
106	guez	101	zcvm5 = zcvm5 / RCPD / (1. + RVTMP2*q1lay(i))
107	guez	54	zx_qs= r2es * FOEEW(tsurf(i), zdelta)/ps(i)
108			zx_qs=MIN(0.5, zx_qs)
109			zcor=1./(1.-retv*zx_qs)
110			zx_qs=zx_qs*zcor
111			ELSE
112	guez	101	IF (tsurf(i) < t_coup) THEN
113	guez	54	zx_qs = qsats(tsurf(i)) / ps(i)
114			ELSE
115			zx_qs = qsatl(tsurf(i)) / ps(i)
116			ENDIF
117			ENDIF
118			ENDDO
119
120	guez	101	! Calcul de la temperature de surface
121	guez	54
122	guez	101	WHERE (precip_snow > 0.) snow = snow + precip_snow * dtime
123
124			WHERE (evap > 0.)
125	guez	104	snow_evap = MIN(snow / dtime, evap)
126	guez	54	snow = snow - snow_evap * dtime
127	guez	101	snow = MAX(0., snow)
128			elsewhere
129			snow_evap = 0.
130	guez	54	end where
131
132	guez	101	bil_eau_s = precip_rain * dtime - (evap(:knon) - snow_evap(:knon)) * dtime
133	guez	54
134			! Y'a-t-il fonte de neige?
135
136			ffonte=0.
137			do i = 1, knon
138	guez	101	if ((snow(i) > epsfra .OR. nisurf == is_sic &
139			.OR. nisurf == is_lic) .AND. tsurf_new(i) >= RTT) then
140			fq_fonte = MIN(MAX((tsurf_new(i)-RTT)/chasno, 0.), snow(i))
141	guez	54	ffonte(i) = fq_fonte * RLMLT/dtime
142			snow(i) = max(0., snow(i) - fq_fonte)
143			bil_eau_s(i) = bil_eau_s(i) + fq_fonte
144			tsurf_new(i) = tsurf_new(i) - fq_fonte * chasno
145			!IM cf JLD/ GKtest fonte aussi pour la glace
146	guez	101	IF (nisurf == is_sic .OR. nisurf == is_lic) THEN
147			fq_fonte = MAX((tsurf_new(i)-RTT)/chaice, 0.)
148	guez	54	ffonte(i) = ffonte(i) + fq_fonte * RLMLT/dtime
149			bil_eau_s(i) = bil_eau_s(i) + fq_fonte
150			tsurf_new(i) = RTT
151			ENDIF
152			endif
153
154	guez	178	! S'il y a une hauteur trop importante de neige, elle s'\'ecoule
155	guez	54	fqcalving(i) = max(0., snow(i) - snow_max)/dtime
156			snow(i)=min(snow(i), snow_max)
157
158			IF (nisurf == is_ter) then
159			qsol(i) = qsol(i) + bil_eau_s(i)
160	guez	101	run_off(i) = run_off(i) + MAX(qsol(i) - max_eau_sol, 0.)
161	guez	54	qsol(i) = MIN(qsol(i), max_eau_sol)
162			else if (nisurf == is_lic) then
163			run_off_lic(i) = (coeff_rel * fqcalving(i)) + &
164			(1. - coeff_rel) * run_off_lic_0(i)
165			run_off_lic_0(i) = run_off_lic(i)
166			run_off_lic(i) = run_off_lic(i) + bil_eau_s(i)/dtime
167			endif
168			enddo
169
170			END SUBROUTINE fonte_neige
171
172			end module fonte_neige_m