ini_surf_csts.F90

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!SFX_LIC Copyright 1994-2014 CNRS, Meteo-France and Universite Paul Sabatier
!SFX_LIC This is part of the SURFEX software governed by the CeCILL-C licence
!SFX_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt  
!SFX_LIC for details. version 1.
SUBROUTINE ini_surf_csts 
!     ##################
!
!!****  *INI_SURF_CSTS * - routine to initialize all surface parameter as
!!                         emissivity and albedo
!!
!!    PURPOSE
!!    -------
!
!!**  METHOD
!!    ------
!!      The physical constants are set to their default numerical values 
!!      or specified in namelist NAM_SURF_CSTS
!!     
!!
!!    EXTERNAL
!!    --------
!!
!!
!!    IMPLICIT ARGUMENTS
!!    ------------------
!!
!!    REFERENCE
!!    ---------
!!
!!    AUTHOR
!!    ------
!!      B. Decharme       * Meteo France *
!!
!!    MODIFICATIONS
!!    -------------
!!      Original    08/2009
!!      M Lafaysse 05/2014 : snow parameters
!!      B. Decharme    05/13 : Add NAM_SURF_REPROD_OPER for versions reproductibility
!!      P. Samuelsson 10/2014 MEB
!!      B. Decharme    01/16 : Update XCFFV
!!
!-------------------------------------------------------------------------------
!
!*       0.    DECLARATIONS
!              ------------
!
USE modd_surf_par,  ONLY : xundef
USE modd_surf_conf, ONLY : cprogname
!
USE modd_water_par
USE modd_flood_par
USE modd_meb_par,   ONLY : xtau_lw,                            &
                           xragnc_factor, xkdelta_wr
USE modd_snow_par,  ONLY : xemissn, xansmin, xansmax,          &
                           xaglamin, xaglamax, xhgla,          &
                           xwsnv, xz0sn, xz0hsn,               &
                           xtau_smelt,                         &
                           xalbice1, xalbice2, xalbice3,       &
                           xrhothreshold_ice, xz0icez0snow,    &
                           xvaging_noglacier, xvaging_glacier, &
                           xpercentagepore,                    &
                           lmebrec,                            &
                           xansfracmel, xtempans,              &
                           xansminmeb
!
USE modi_get_luout
USE modi_open_namelist
USE modi_close_namelist
USE mode_pos_surf
!
USE modd_reprod_oper,  ONLY : xeverg_rsmin, xeverg_veg, &
                                   cdgavg, cimplicit_wind,   &
                                   cqsat, ccharnock, cdgdif
USE modi_test_nam_var_surf
!
USE yomhook   ,ONLY : lhook,   dr_hook
USE parkind1  ,ONLY : jprb
!
IMPLICIT NONE
!
INTEGER               :: iluout    ! unit of output listing file
INTEGER               :: ilunam    ! namelist file  logical unit
LOGICAL               :: gfound    ! true if namelist is found
!
LOGICAL               :: lreprod_oper
!
REAL(KIND=JPRB) :: zhook_handle
!
namelist/nam_surf_csts/ xemissn, xansmin, xansmax, xaglamin, xaglamax, &
                        xalbwat, xalbcoef_ta96, xalbsca_wat, xemiswat, &
                        xalbwatice, xemiswatice, xhgla, xwsnv, xcffv,  &
                        xz0sn, xz0hsn, xtau_smelt, xalbseaice,         &
                        xz0flood, xalbwatsnow,                         &
                        lmebrec,                                       &
                        xansfracmel, xtempans, xansminmeb,             &
                        xtau_lw, xragnc_factor
!
namelist/nam_surf_snow_csts/ xz0icez0snow, xrhothreshold_ice,          &
                             xalbice1, xalbice2, xalbice3,             &
                             xvaging_noglacier, xvaging_glacier,       &
                             xpercentagepore
!
namelist/nam_reprod_oper/ lreprod_oper, xeverg_rsmin, xeverg_veg, &
                          cdgavg, cdgdif, cimplicit_wind, cqsat,  &
                          ccharnock
!
!-------------------------------------------------------------------------------
!*       0. INIT
!-------------------------------------------------------------------------------
!
IF (lhook) CALL dr_hook('INI_SURF_CSTS',0,zhook_handle)
!
xalbwat     = xundef
xalbseaice  = xundef
xalbwatice  = xundef
xalbwatsnow = xundef
xemiswat    = xundef
xemiswatice = xundef
xemissn     = xundef
!
!-------------------------------------------------------------------------------
!*       1. Default values
!-------------------------------------------------------------------------------
!
! Minimum and maximum values of the albedo of snow:
!
xansmin = 0.50 ! (-)
xansmax = 0.85 ! (-)
!
! Minimum and maximum values of the albedo of permanet snow/ice:
!
xaglamin = 0.8 ! (-)
xaglamax = 0.85 ! (-)
!
! Use recommended settings for snow albedo (FALSE = ISBA default)
! 
lmebrec=.false.
!
! Fraction of maximum value of the albedo of snow that is reached for melting
! snow
!
xansfracmel = 1.0 ! (-)
!
! Threeshold temperature above which the snow albedo starts to decrease 
!
xtempans = 274.15 ! (K)
!
! Minimum value of the albedo of snow reached under canopy vegetation:
!
xansminmeb = 0.30 ! (-)
!
! Height of aged snow in glacier case (allows Pn=1)
!
xhgla    = 33.3 !(m)
! 
! Coefficient for calculation of snow fraction over vegetation
!
xwsnv = 5.0 !(-)
!
! Water direct albedo coefficient (option "TA96")
!
xalbcoef_ta96 =  0.037
!
! Water diffuse albedo
!
xalbsca_wat =  0.06

! Coefficient for calculation of floodplain fraction over vegetation
!
xcffv = 4.0
!
! Roughness length of pure snow surface (m)
!
xz0sn = 0.001
!
! Roughness length for heat of pure snow surface (m)
!
xz0hsn = 0.0001
!
! Snow Melt timescale with D95 (s): needed to prevent time step 
! dependence of melt when snow fraction < unity.
!
xtau_smelt = 300.
!
! Extinction coefficient for view factor for long-wave radiation 
!
xtau_lw = 0.5   ! -
!
! MEB resistance increase factor for canopy air sapce.
! If=1, then NO effect. It is generally >=1
! and is needed because the original parameterization
! does not account for extremely stable conditions,
! such as over a snowpack.
!
xragnc_factor= 200. ! -
!
! MEB maximum intercepted water fraction (on vegetation)
!
xkdelta_wr   = 0.25 ! -
!
! NAM_SURF_SNOW_CSTS
!
! Roughness length ratio between ice and snow
xz0icez0snow = 10.
!
! 3 bands spectral albedo for glacier ice (CROCUS)
! Default values from Lejeune et al 2009 (Zongo, Bolivia)
xalbice1 = 0.38
xalbice2 = 0.23
xalbice3 = 0.08
!
! Gerbaux et al 2005 (Saint Sorlin)
! PALBICE1=0.23
! PALBICE2=0.16
! PALBICE3=0.05
!
! Density threshold for ice detection kg.m-3
xrhothreshold_ice = 850.
!
! Parameters for ageing effect on albedo
xvaging_noglacier = 60.
xvaging_glacier   = 900.

! percentage of the total pore volume to compute the max liquid water holding capacity   !Pahaut 1976
xpercentagepore = 0.05
!
! Roughness length for flood (m)
!
xz0flood = 0.0002
!-------------------------------------------------------------------------------
!
! * Reproductibility for SURFEX OPER
!
lreprod_oper = .false. ! default
!
! * Vegetation parameters for tropical forest
!
!XEVERG_RSMIN : old = 250. (Manzi 1993) but observations range 
!               from 140 to 180. According to Delire et al. (1997) and 
!               new tests over 6 local sites, 175. is recommended
!               Should be the default after check with AROME/ALADIN
!
xeverg_rsmin = 175.  !Rsmin
!
!XEVERG_VEG : old = 0.99 (Manzi 1993) but according to Delire et al. (1997) and 
!             new tests over 6 local sites, 1.0 is recommended because 0.99
!             induces unrealistic bare soil evaporation for Tropical forest
!             Should be the default after check with AROME/ALADIN
!
xeverg_veg   = 1.0  !Veg fraction
!
! * Soil depth average
!
 cdgavg = 'INV'
!
! * Soil depth with ISBA-DF
!
 cdgdif = 'ROOT'
!
! * wind implicitation option
!
 cimplicit_wind = 'NEW'
!
! * qsat computation
!
 cqsat = 'NEW'
!
! * Charnock parameter
!
 ccharnock = 'NEW'
!
!-------------------------------------------------------------------------------
!*       2. User values
!-------------------------------------------------------------------------------
!
 CALL get_luout(cprogname,iluout)
!
 CALL open_namelist(cprogname,ilunam)
!
 CALL posnam(ilunam,'NAM_SURF_CSTS',gfound,iluout)
IF (gfound) READ(unit=ilunam,nml=nam_surf_csts)
!
IF(lmebrec)THEN
! Fraction of maximum value of the albedo of snow that is reached for melting
! snow
!
  xansfracmel = 0.85 ! (-)
!
! Threeshold temperature above which the snow albedo starts to decrease 
!
  xtempans = 268.15 ! (K)
!
ENDIF
!
 CALL posnam(ilunam,'NAM_SURF_SNOW_CSTS',gfound,iluout)
IF (gfound) READ(unit=ilunam,nml=nam_surf_snow_csts)
!
!-------------------------------------------------------------------------------
!*       3. For Reproductibility
!-------------------------------------------------------------------------------
!
 CALL posnam(ilunam,'NAM_REPROD_OPER',gfound,iluout)
IF (gfound) READ(unit=ilunam,nml=nam_reprod_oper)
!
 CALL test_nam_var_surf(iluout,'CDGAVG',cdgavg,'ARI','INV')
 CALL test_nam_var_surf(iluout,'CDGDIF',cdgdif,'SOIL','ROOT')
 CALL test_nam_var_surf(iluout,'CIMPLICIT_WIND',cimplicit_wind,'NEW','OLD')
 CALL test_nam_var_surf(iluout,'CQSAT',cimplicit_wind,'NEW','OLD')
 CALL test_nam_var_surf(iluout,'CCHARNOCK',cimplicit_wind,'NEW','OLD')
!
 CALL test_nam_var_surf(iluout,'XEVERG_RSMIN',xeverg_rsmin,175.0,250.0)
 CALL test_nam_var_surf(iluout,'XEVERG_VEG',xeverg_veg,1.0,0.99) 
!
IF(lreprod_oper)THEN
  xeverg_rsmin   = 250.
  xeverg_veg     = 0.99
  cdgavg         = 'ARI'
  cqsat          = 'OLD'
  ccharnock      = 'OLD'
ENDIF
!
! Water global albedo (option "UNIF")
!
IF(xalbwat==xundef)THEN
  IF(lreprod_oper)THEN
    xalbwat =  0.135
  ELSE
    xalbwat =  0.065
  ENDIF
ENDIF
!
! Sea ice albedo
!
IF(xalbseaice==xundef)THEN
  IF(lreprod_oper)THEN
    xalbseaice =  0.85
  ELSE
    xalbseaice =  0.71
  ENDIF
ENDIF
!
! water ice and snow albedo
!
IF(xalbwatice==xundef)THEN
  IF(lreprod_oper)THEN
    xalbwatice =  0.85
  ELSE
    xalbwatice =  0.40
  ENDIF
ENDIF
!
IF(xalbwatsnow==xundef)THEN
  IF(lreprod_oper)THEN
    xalbwatsnow =  0.85
  ELSE
    xalbwatsnow =  0.60
  ENDIF
ENDIF
!                   
! Water emissivity
!
IF(xemiswat==xundef)THEN
  IF(lreprod_oper)THEN
    xemiswat =  0.98
  ELSE
    xemiswat =  0.96
  ENDIF
ENDIF
!
! Sea ice emissivity
!
IF(xemiswatice==xundef)THEN
  IF(lreprod_oper)THEN
    xemiswatice =  1.0
  ELSE
    xemiswatice =  0.97
  ENDIF
ENDIF
!
!
! Snow emissivity:
!
IF(xemissn==xundef)THEN
  IF(lreprod_oper)THEN
    xemissn =  1.0
  ELSE
    xemissn =  0.99
  ENDIF
ENDIF
!
!-------------------------------------------------------------------------------
!
 CALL close_namelist(cprogname,ilunam)
!
IF (lhook) CALL dr_hook('INI_SURF_CSTS',1,zhook_handle)
!
!-------------------------------------------------------------------------------
!
END SUBROUTINE ini_surf_csts