Changeset 4672


Ignore:
Timestamp:
Sep 4, 2023, 4:35:35 PM (15 months ago)
Author:
evignon
Message:

inclusion des recents developpements sur la neige soufflee

Location:
LMDZ6/trunk/libf
Files:
4 edited

Legend:

Unmodified
Added
Removed
  • LMDZ6/trunk/libf/phylmd/blowing_snow_ini_mod.F90

    r4529 r4672  
    88   real coef_eva_bs, expo_eva_bs, fallv_bs, zeta_bs
    99   real prt_bs, pbst_bs, qbst_bs
    10    integer :: niter_bs, iflag_saltation_bs
     10   integer :: iflag_saltation_bs
    1111
    1212   !$OMP THREADPRIVATE(prt_level, lunout)
     
    1414   !$OMP THREADPRIVATE(coef_eva_bs, expo_eva_bs, fallv_bs, zeta_bs)
    1515   !$OMP THREADPRIVATE(pbst_bs, prt_bs, qbst_bs)
    16    !$OMP THREADPRIVATE(niter_bs, iflag_saltation_bs)
     16   !$OMP THREADPRIVATE(iflag_saltation_bs)
    1717
    1818      contains
     
    4545         CALL getin_p('qbst_bs',qbst_bs)
    4646
    47          pbst_bs= 0.01
     47         pbst_bs= 0.0003
    4848         CALL getin_p('pbst_bs',pbst_bs)
    4949
     
    6464         CALL getin_p('expo_eva_bs',expo_eva_bs)
    6565
    66          niter_bs = 5
    67          CALL getin_p('niter_bs',niter_bs)
    68 
    6966         iflag_saltation_bs=0
    7067         CALL getin_p('iflag_saltation_bs',iflag_saltation_bs)
  • LMDZ6/trunk/libf/phylmd/blowing_snow_sublim_sedim.F90

    r4664 r4672  
    99
    1010use blowing_snow_ini_mod, only : coef_eva_bs,RTT,RD,RG,expo_eva_bs, fallv_bs
    11 use blowing_snow_ini_mod, only : RCPD, RLSTT, RLMLT, RLVTT, RVTMP2, niter_bs
     11use blowing_snow_ini_mod, only : RCPD, RLSTT, RLMLT, RLVTT, RVTMP2
    1212USE lmdz_lscp_tools, only : calc_qsat_ecmwf
    1313
     
    125125              ! vapor, temperature, precip fluxes update
    126126              zq(i) = zq(i) - (sedimn(i)-sedim(i))*(RG/(paprs(i,k)-paprs(i,k+1)))*dtime
    127               zqbs(i) = zqbs(i) + (sedimn(i)-sedim(i)) * (RG/(paprs(i,k)-paprs(i,k+1)))*dtime
     127              zq(i) = max(0., zq(i))
     128              !zqbs(i) = zqbs(i) + (sedimn(i)-sedim(i)) * (RG/(paprs(i,k)-paprs(i,k+1)))*dtime
     129              !zqbs(i) = max(0., zqbs(i))
    128130              ! melting
    129131              zt(i) = zt(i)                             &
     
    151153
    152154
    153               ! vapor, temperature, precip fluxes update
     155              ! vapor, temperature, precip fluxes update following sublimation
    154156              zq(i) = zq(i) - (sedimn(i)-sedim(i))*(RG/(paprs(i,k)-paprs(i,k+1)))*dtime               
    155               zqbs(i) = zqbs(i) + (sedimn(i)-sedim(i)) * (RG/(paprs(i,k)-paprs(i,k+1)))*dtime
     157              zq(i) = max(0., zq(i))
     158              !zqbs(i) = zqbs(i) + (sedimn(i)-sedim(i)) * (RG/(paprs(i,k)-paprs(i,k+1)))*dtime
     159              !zqbs(i) = max(0., zqbs(i))
    156160              zt(i) = zt(i)                             &
    157161                + (sedimn(i)-sedim(i))                      &
     
    173177    ENDDO ! loop on ngrid
    174178
    175     ! Now sedimention scheme (alike that in lscp)
    176     DO n = 1, niter_bs
    177        DO i = 1, ngrid
    178          zrho(i,k)  = pplay(i,k) / zt(i) / RD
    179          zdz(i)   = (paprs(i,k)-paprs(i,k+1)) / (zrho(i,k)*RG)
    180          velo(i,k) = fallv_bs
    181          dqsedim = dtime/REAL(niter_bs)/zdz(i)*zqbs(i)*velo(i,k)   ! dqice/dt=1/rho*d(rho*wice*qice)/dz
    182          precbs   = MIN(MAX(dqsedim,0.0),zqbs(i))
    183          zqbs(i) = MAX(zqbs(i)-1.*precbs  , 0.0)
    184        ENDDO !loop on ngrid
    185     ENDDO ! loop on niter_bs
    186 
    187     ! add to non sublimated precip
    188     DO i=1,ngrid
    189     sedim(i) = sedim(i)+max(0.,zqbsi(i)-zqbs(i))*(paprs(i,k)-paprs(i,k+1))/(RG*dtime)
     179    ! Now sedimention scheme
     180
     181    ! exact resolution of the conservation equation for qbs with the updated flux from the top (after evap)
     182    ! valid only if the fall velocity is constant
     183
     184    DO i = 1, ngrid
     185   
     186        zrho(i,k)  = pplay(i,k) / zt(i) / RD
     187        zdz(i)   = (paprs(i,k)-paprs(i,k+1)) / (zrho(i,k)*RG)
     188        velo(i,k) = fallv_bs
     189        zqbs(i) = zqbsi(i)*exp(-velo(i,k)/zdz(i)*dtime)+sedim(i)/zrho(i,k)/velo(i,k)
     190        zqbs(i) = max(zqbs(i),0.)
     191        ! flux update
     192        sedim(i) = sedim(i) + zrho(i,k)*zdz(i)/dtime*(zqbsi(i)-zqbs(i))
     193        sedim(i) = max(0.,sedim(i))
     194 
    190195    ENDDO
     196
     197! old version with bugs
     198!    DO n = 1, niter_bs
     199!       DO i = 1, ngrid
     200!         zrho(i,k)  = pplay(i,k) / zt(i) / RD
     201!         zdz(i)   = (paprs(i,k)-paprs(i,k+1)) / (zrho(i,k)*RG)
     202!         velo(i,k) = fallv_bs
     203!         dqsedim = dtime/REAL(niter_bs)/zdz(i)*zqbs(i)*velo(i,k)   ! dqice/dt=1/rho*d(rho*wice*qice)/dz
     204!         precbs   = MIN(MAX(dqsedim,0.0),zqbs(i))
     205!         zqbs(i) = MAX(zqbs(i)-1.*precbs  , 0.0)
     206!       ENDDO !loop on ngrid
     207!    ENDDO ! loop on niter_bs
     208!    ! add to non sublimated precip
     209!    DO i=1,ngrid
     210!       sedim(i) = sedim(i)+max(0.,zqbsi(i)-zqbs(i))*(paprs(i,k)-paprs(i,k+1))/(RG*dtime)
     211!    ENDDO
     212!
     213
     214
    191215
    192216    ! Outputs:
  • LMDZ6/trunk/libf/phylmd/surf_landice_mod.F90

    r4538 r4672  
    140140    REAL,DIMENSION(klon) :: precip_totsnow, evap_totsnow
    141141    REAL, DIMENSION (klon,6) :: alb6
    142     REAL                   :: rho0, rhoice, ustart0, hsalt, esalt, rhod
     142    REAL                   :: rho0, rhoice, ustart0,esalt, rhod
    143143    REAL                   :: lambdasalt,fluxsalt, csalt, nunu, aa, bb, cc
    144144    REAL                   :: tau_dens, tau_dens0, tau_densmin, rhomax, rhohard
    145     REAL, DIMENSION(klon)  :: ws1, rhos, ustart, qsalt
     145    REAL, DIMENSION(klon)  :: ws1, rhos, ustart, qsalt, hsalt, snowini
     146    REAL                   :: maxerosion ! in kg/s   
     147
    146148! End definition
    147149!****************************************************************************************
     
    364366       ustart0 = 0.211
    365367       rhoice = 920.0
    366        rho0 = 200.0
     368       rho0 = 300.0
    367369       rhomax=450.0
    368        rhohard=400.0
     370       rhohard=450.0
    369371       tau_dens0=86400.0*10.  ! 10 days by default, in s
    370        tau_densmin=86400.0 ! 1 days according to in situ obs by C. Amory
     372       tau_densmin=21600.0    ! 1/4 days according to in situ obs by C. Amory during blowing snow +
     373                              ! Marshall et al. 1999 (snow densification during rain)
    371374
    372375       ! computation of threshold friction velocity
    373376       ! which depends on surface snow density
    374        do i = 1, knon
     377       do j = 1, knon
    375378           ! estimation of snow density
    376379           ! snow density increases with snow age and
    377            ! increases even faster in case of sedimentation of blowing snow
    378            tau_dens=max(tau_densmin, tau_dens0*exp(-abs(precip_bs(i))/pbst_bs-abs(precip_rain(i))/prt_bs))
    379            rhos(i)=rho0+(rhohard-rho0)*(1.-exp(-agesno(i)*86400.0/tau_dens))
     380           ! increases even faster in case of sedimentation of blowing snow or rain
     381           tau_dens=max(tau_densmin, & tau_dens0*exp(-abs(precip_bs(j))/pbst_bs-abs(precip_rain(j))/prt_bs) &
     382                    *exp(-max(tsurf(j)-272.0,0.)))
     383           rhos(j)=rho0+(rhohard-rho0)*(1.-exp(-agesno(j)*86400.0/tau_dens))
    380384           ! blowing snow flux formula used in MAR
    381            ws1(i)=(u1(i)**2+v1(i)**2)**0.5
    382            ustar(i)=(cdragm(i)*(u1(i)**2+v1(i)**2))**0.5
    383            ustart(i)=ustart0*exp(max(rhoice/rho0-rhoice/rhos(i),0.))*exp(max(0.,rhos(i)-rhomax))
     385           ws1(j)=(u1(j)**2+v1(j)**2)**0.5
     386           ustar(j)=(cdragm(j)*(u1(j)**2+v1(j)**2))**0.5
     387           ustart(j)=ustart0*exp(max(rhoice/rho0-rhoice/rhos(j),0.))*exp(max(0.,rhos(j)-rhomax))
    384388           ! we have multiplied by exp to prevent erosion when rhos>rhomax (usefull till
    385389           ! rhohard<450)
     
    397401          cc=2.0
    398402          lambdasalt=0.45
    399           do i =1, knon
    400                rhod=p1lay(i)/RD/temp_air(i)
    401                nunu=max(ustar(i)/ustart(i),1.e-3)
    402                fluxsalt=rhod/RG*(ustar(i)**3)*(1.-nunu**(-2)) * &
     403          do j =1, knon
     404               rhod=p1lay(j)/RD/temp_air(j)
     405               nunu=max(ustar(j)/ustart(j),1.e-3)
     406               fluxsalt=rhod/RG*(ustar(j)**3)*(1.-nunu**(-2)) * &
    403407                        (aa+bb*nunu**(-2)+cc*nunu**(-1)) 
    404                csalt=fluxsalt/(2.8*ustart(i))
    405                hsalt=0.08436*ustar(i)**1.27
    406                qsalt(i)=1./rhod*csalt*lambdasalt*RG/(max(ustar(i)**2,1E-6)) &
    407                        * exp(-lambdasalt*RG*hsalt/max(ustar(i)**2,1E-6))
    408                qsalt(i)=max(qsalt(i),0.)
     408               csalt=fluxsalt/(2.8*ustart(j))
     409               hsalt(j)=0.08436*ustar(j)**1.27
     410               qsalt(j)=1./rhod*csalt*lambdasalt*RG/(max(ustar(j)**2,1E-6)) &
     411                       * exp(-lambdasalt*RG*hsalt(j)/max(ustar(j)**2,1E-6))
     412               qsalt(j)=max(qsalt(j),0.)
    409413          enddo
    410414
     
    412416       else
    413417       ! default formulation from MAR model (Amory et al. 2021, Gallee et al. 2001)       
    414           do i=1, knon
    415               esalt=1./(3.25*max(ustar(i),0.001))
    416               hsalt=0.08436*ustar(i)**1.27
    417               qsalt(i)=(max(ustar(i)**2-ustart(i)**2,0.))/(RG*hsalt)*esalt
    418               !ep=qsalt*cdragm(i)*sqrt(u1(i)**2+v1(i)**2)
     418          do j=1, knon
     419              esalt=1./(3.25*max(ustar(j),0.001))
     420              hsalt(j)=0.08436*ustar(j)**1.27
     421              qsalt(j)=(max(ustar(j)**2-ustart(j)**2,0.))/(RG*hsalt(j))*esalt
     422              !ep=qsalt*cdragm(j)*sqrt(u1(j)**2+v1(j)**2)
    419423          enddo
    420424       endif
    421425
    422         ! calculation of erosion (emission flux towards the first atmospheric level)
     426        ! calculation of erosion (flux positive towards the surface here)
    423427        ! consistent with implicit resolution of turbulent mixing equation
    424        do i=1, knon
    425               rhod=p1lay(i)/RD/temp_air(i)
    426               fluxbs(i)=rhod*ws1(i)*cdragm(i)*zeta_bs*(AcoefQBS(i)-qsalt(i)) &
    427                        / (1.-rhod*ws1(i)*zeta_bs*cdragm(i)*BcoefQBS(i)*dtime)
    428               !fluxbs(i)= zeta_bs*rhod*ws1(i)*cdragm(i)*(qbs1(i)-qsalt(i))
     428       do j=1, knon
     429              i = knindex(j)
     430              rhod=p1lay(j)/RD/temp_air(j)
     431              ! Nemoto and Nishimura 2004 show that steady-state saltation is achieved within an interval of about 10s
     432              ! we thus prevent snowerosion (snow particle transfer from the saltation layer to the first model level)
     433              ! to exceed (in intensity) integrated over 10s to exceed the total mass of snow particle in the saltation layer
     434              ! (rho*qsalt*hsalt)
     435              maxerosion=hsalt(j)*qsalt(j)*rhod/10.
     436              fluxbs(j)=rhod*ws1(j)*cdragm(j)*(AcoefQBS(j)-qsalt(j)) &
     437                       / (1.-rhod*ws1(j)*cdragm(j)*BcoefQBS(j)*dtime)
     438              !fluxbs(j)= rhod*ws1(j)*cdragm(j)*(qbs1(j)-qsalt(j))
     439              fluxbs(j)=max(-maxerosion,fluxbs(j))
     440
     441              ! for outputs
     442
     443              zxustartlic(i) = ustart(j)
     444              zxrhoslic(i) = rhos(j)
    429445       enddo
    430446
    431        ! for outputs
    432        do j = 1, knon
    433           i = knindex(j)
    434           zxustartlic(i) = ustart(j)
    435           zxrhoslic(i) = rhos(j)
    436        enddo
    437 
    438447  endif
    439448
     
    441450
    442451!****************************************************************************************
    443 ! Calculate surface snow amount
     452! Calculate snow amount
    444453!   
    445454!****************************************************************************************
     
    451460      evap_totsnow(:)=evap(:)
    452461    ENDIF
    453 
     462   
     463 
    454464    CALL fonte_neige(knon, is_lic, knindex, dtime, &
    455465         tsurf, precip_rain, precip_totsnow,  &
    456466         snow, qsol, tsurf_new, evap_totsnow)
    457 
     467   
     468   
    458469    WHERE (snow(1 : knon) .LT. 0.0001) agesno(1 : knon) = 0.                                         
    459470    zfra(1:knon) = MAX(0.0,MIN(1.0,snow(1:knon)/(snow(1:knon)+10.0))) 
  • LMDZ6/trunk/libf/phylmdiso/surf_landice_mod.F90

    r4538 r4672  
    185185    REAL,DIMENSION(klon) :: precip_totsnow, evap_totsnow
    186186    REAL, DIMENSION (klon,6) :: alb6
    187     REAL                   :: rho0, rhoice, ustart0, hsalt, esalt, rhod
     187    REAL                   :: rho0, rhoice, ustart0,esalt, rhod
    188188    REAL                   :: lambdasalt,fluxsalt, csalt, nunu, aa, bb, cc
    189189    REAL                   :: tau_dens, tau_dens0, tau_densmin, rhomax, rhohard
    190     REAL, DIMENSION(klon)  :: ws1, rhos, ustart, qsalt
     190    REAL, DIMENSION(klon)  :: ws1, rhos, ustart, qsalt, hsalt, snowini
     191    REAL                   :: maxerosion ! in kg/s
     192
    191193! End definition
    192194!****************************************************************************************
     
    453455       ustart0 = 0.211
    454456       rhoice = 920.0
    455        rho0 = 200.0
     457       rho0 = 300.0
    456458       rhomax=450.0
    457        rhohard=400.0
     459       rhohard=450.0
    458460       tau_dens0=86400.0*10.  ! 10 days by default, in s
    459        tau_densmin=86400.0 ! 1 days according to in situ obs by C. Amory
     461       tau_densmin=21600.0    ! 1/4 days according to in situ obs by C. Amory during blowing snow +
     462                              ! Marshall et al. 1999 (snow densification during rain)
    460463
    461464       ! computation of threshold friction velocity
    462465       ! which depends on surface snow density
    463        do i = 1, knon
     466       do j = 1, knon
    464467           ! estimation of snow density
    465468           ! snow density increases with snow age and
    466            ! increases even faster in case of sedimentation of blowing snow
    467            tau_dens=max(tau_densmin, tau_dens0*exp(-abs(precip_bs(i))/pbst_bs-abs(precip_rain(i))/prt_bs))
    468            rhos(i)=rho0+(rhohard-rho0)*(1.-exp(-agesno(i)*86400.0/tau_dens))
     469           ! increases even faster in case of sedimentation of blowing snow or rain
     470           tau_dens=max(tau_densmin, & tau_dens0*exp(-abs(precip_bs(j))/pbst_bs-abs(precip_rain(j))/prt_bs) &
     471                    *exp(-max(tsurf(j)-272.0,0.)))
     472           rhos(j)=rho0+(rhohard-rho0)*(1.-exp(-agesno(j)*86400.0/tau_dens))
    469473           ! blowing snow flux formula used in MAR
    470            ws1(i)=(u1(i)**2+v1(i)**2)**0.5
    471            ustar(i)=(cdragm(i)*(u1(i)**2+v1(i)**2))**0.5
    472            ustart(i)=ustart0*exp(max(rhoice/rho0-rhoice/rhos(i),0.))*exp(max(0.,rhos(i)-rhomax))
     474           ws1(j)=(u1(j)**2+v1(j)**2)**0.5
     475           ustar(j)=(cdragm(j)*(u1(j)**2+v1(j)**2))**0.5
     476           ustart(j)=ustart0*exp(max(rhoice/rho0-rhoice/rhos(j),0.))*exp(max(0.,rhos(j)-rhomax))
    473477           ! we have multiplied by exp to prevent erosion when rhos>rhomax (usefull till
    474478           ! rhohard<450)
     
    486490          cc=2.0
    487491          lambdasalt=0.45
    488           do i =1, knon
    489                rhod=p1lay(i)/RD/temp_air(i)
    490                nunu=max(ustar(i)/ustart(i),1.e-3)
    491                fluxsalt=rhod/RG*(ustar(i)**3)*(1.-nunu**(-2)) * &
     492          do j =1, knon
     493               rhod=p1lay(j)/RD/temp_air(j)
     494               nunu=max(ustar(j)/ustart(j),1.e-3)
     495               fluxsalt=rhod/RG*(ustar(j)**3)*(1.-nunu**(-2)) * &
    492496                        (aa+bb*nunu**(-2)+cc*nunu**(-1)) 
    493                csalt=fluxsalt/(2.8*ustart(i))
    494                hsalt=0.08436*ustar(i)**1.27
    495                qsalt(i)=1./rhod*csalt*lambdasalt*RG/(max(ustar(i)**2,1E-6)) &
    496                        * exp(-lambdasalt*RG*hsalt/max(ustar(i)**2,1E-6))
    497                qsalt(i)=max(qsalt(i),0.)
     497               csalt=fluxsalt/(2.8*ustart(j))
     498               hsalt(j)=0.08436*ustar(j)**1.27
     499               qsalt(j)=1./rhod*csalt*lambdasalt*RG/(max(ustar(j)**2,1E-6)) &
     500                       * exp(-lambdasalt*RG*hsalt(j)/max(ustar(j)**2,1E-6))
     501               qsalt(j)=max(qsalt(j),0.)
    498502          enddo
    499503
     
    501505       else
    502506       ! default formulation from MAR model (Amory et al. 2021, Gallee et al. 2001)       
    503           do i=1, knon
    504               esalt=1./(3.25*max(ustar(i),0.001))
    505               hsalt=0.08436*ustar(i)**1.27
    506               qsalt(i)=(max(ustar(i)**2-ustart(i)**2,0.))/(RG*hsalt)*esalt
    507               !ep=qsalt*cdragm(i)*sqrt(u1(i)**2+v1(i)**2)
     507          do j=1, knon
     508              esalt=1./(3.25*max(ustar(j),0.001))
     509              hsalt(j)=0.08436*ustar(j)**1.27
     510              qsalt(j)=(max(ustar(j)**2-ustart(j)**2,0.))/(RG*hsalt(j))*esalt
     511              !ep=qsalt*cdragm(j)*sqrt(u1(j)**2+v1(j)**2)
    508512          enddo
    509513       endif
    510514
    511         ! calculation of erosion (emission flux towards the first atmospheric level)
     515        ! calculation of erosion (flux positive towards the surface here)
    512516        ! consistent with implicit resolution of turbulent mixing equation
    513        do i=1, knon
    514               rhod=p1lay(i)/RD/temp_air(i)
    515               fluxbs(i)=rhod*ws1(i)*cdragm(i)*zeta_bs*(AcoefQBS(i)-qsalt(i)) &
    516                        / (1.-rhod*ws1(i)*zeta_bs*cdragm(i)*BcoefQBS(i)*dtime)
    517               !fluxbs(i)= zeta_bs*rhod*ws1(i)*cdragm(i)*(qbs1(i)-qsalt(i))
    518        enddo
    519 
    520        ! for outputs
    521        do j = 1, knon
    522           i = knindex(j)
    523           zxustartlic(i) = ustart(j)
    524           zxrhoslic(i) = rhos(j)
     517       do j=1, knon
     518              i = knindex(j)
     519              rhod=p1lay(j)/RD/temp_air(j)
     520              ! Nemoto and Nishimura 2004 show that steady-state saltation is achieved within an interval of about 10s
     521              ! we thus prevent snowerosion (snow particle transfer from the saltation layer to the first model level)
     522              ! to exceed (in intensity) integrated over 10s to exceed the total mass of snow particle in the saltation layer
     523              ! (rho*qsalt*hsalt)
     524              maxerosion=hsalt(j)*qsalt(j)*rhod/10.
     525              fluxbs(j)=rhod*ws1(j)*cdragm(j)*(AcoefQBS(j)-qsalt(j)) &
     526                       / (1.-rhod*ws1(j)*cdragm(j)*BcoefQBS(j)*dtime)
     527              !fluxbs(j)= rhod*ws1(j)*cdragm(j)*(qbs1(j)-qsalt(j))
     528              fluxbs(j)=max(-maxerosion,fluxbs(j))
     529
     530              ! for outputs
     531
     532              zxustartlic(i) = ustart(j)
     533              zxrhoslic(i) = rhos(j)
    525534       enddo
    526535
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