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 ! ======================================================================

 !  This module contains all the parameters used by the thermodynamics

 !  module of GELATO.

 ! ======================================================================


 MODULE modd_glt_const_thm

 !

 IMPLICIT NONE

 !

 !

 ! 1. PRESCRIBED PARAMETERS

 ! =========================

 !

 ! 1.1. Various constants (time, units, math...)

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

 !

 ! Pi

     REAL, PARAMETER ::  &

         pi = 3.141592653789     ! -

 ! First tolerance parameter

     REAL, PARAMETER ::  &

         epsil1 = 1.E-10         ! -

 ! Second tolerance parameter

     REAL, PARAMETER ::  &

         epsil2 = 1.E-20         ! -

 ! Second tolerance parameter

     REAL, PARAMETER ::  &

         epsil5 = 1.E-05         ! -

 ! Standard large number

     REAL, PARAMETER ::  &

         xbig19 = 1.E19          ! -

 ! Standard large number

     REAL, PARAMETER ::  &

         xbig20 = 1.E20          ! -

 ! Number of seconds in one day

     REAL, PARAMETER ::  &

         xday2sec = 86400.       ! -

 ! Number of days in one year

     REAL, PARAMETER ::  &

         xyear2day = 365.25      ! -

 ! Number of seconds in one month

     REAL, PARAMETER ::  &

         xmonth2sec = xyear2day/12.*xday2sec

 ! Factor to convert mm to m

     REAL, PARAMETER ::  &

         xm2mm = 1000.

 !

 !

 ! 1.2. Sea water density function parameters

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

 !

 REAL, PARAMETER ::  &

   c1 = -7.2169e-2,  &

   c2 = 4.9762e-2,  &

   c3 = 8.0560e-1,  &

   c4 = -7.5911e-3,  &

   c5 = -3.0063e-3,  &

   c6 = 3.5187e-5,  &

   c7 = 3.7297e-5

 !

 !

 ! 1.3. Thermodynamical constants

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

 !

 ! Albedo of dry, bare ice ( hsi <=hsicr )

 !   - we use a formula adapted from Flato and Brown, JGR (1996)

 ! (the threshold is just computed in glt_updasn_r routine)

 !      alb = xalf1 * hsi^xpow + albw

     REAL, PARAMETER ::  &

         xalf1 = 0.55, xpow = 0.28

 ! Albedo of dry, bare ice ( hsi > hsicr )

     REAL, PARAMETER ::   &

         albi = .71              ! -

 ! Albedo of melting sea ice

 !    REAL, PARAMETER ::  &

 !        albimlt = .50           ! -

 ! Albedo over melting snow (Curry et al., JGR-A, 2001)

 !    REAL, PARAMETER ::  &

 !        albsmlt = .77           ! -

 ! Albedo over dry snow (Curry et al., JGR-A, 2001)

 !    REAL, PARAMETER ::  &

 !        albsdry = .84           ! -

 ! Albedo over water

     REAL, PARAMETER ::  &

         albw = .065              ! -

 ! Specific heat of pure ice

     REAL, PARAMETER ::  &

         cpice0 = 2080.          ! J/(K.kg)

 ! Specific heat of sea water

     REAL, PARAMETER ::  &

         cpsw = 3987.            ! J/(K.kg)

 ! Massic heat of fusion of pure ice

     REAL, PARAMETER ::  &

         xmhofusn0 = 3.3355E+05  ! J/kg

 ! Beer Lambert's law attenuation coefficient (Ebert et al., JGR-O, 1995)

     REAL, PARAMETER ::  &

         kappa = 1.4             !

 ! Lateral melting rate (Maykut, 1987) : Mr = m1 * (tlead - t_f)**m2

     REAL, PARAMETER ::  &

         xm1 = 1.6E-06           ! m.s^-1.K^-1.36

     REAL, PARAMETER ::  &

         xm2 = 1.36              ! -

 ! Density of fresh water

     REAL, PARAMETER ::  &

         rhofw = 1000.           ! kg/m^3

 ! Density of pure ice

     REAL, PARAMETER ::  &

         rhoice0 = 917.           ! kg/m^3

 ! Average density of sea ice

     REAL, PARAMETER ::  &

         rhoice = 910.           ! kg/m^3

 ! Maximum density for old snow

     REAL, PARAMETER ::  &

         rhosnwmax = 300.        ! kg/m^3

 ! Density of fresh snow

     REAL, PARAMETER ::  &

         rhosnwmin = 100.        ! kg/m^3

 ! Ice conductivity (if function of T and S)

 !   - we use a parameterization by Pringle et al., JGR (2007)

 ! Original parameterization:

 !   rkice(T,S) = rho_sea_ice / rho_pure_ice * ( xrki1 + xrki2*T + xrki3*S/T )

 ! (up to T=-1.8)

 ! In Gelato:

 !   - the density of pure ice is rhoice0

 !   - the density of sea ice is constant ( rhoice )

 !   - for T>Tempc, Tempc=-1.8, rkice(T,S) = rkice(Tempc,S)

     REAL, PARAMETER ::  &

         xrki1 = 2.11, xrki2 = -0.011, xrki3 = 0.09, xtempc = -1.8

 ! Ice conductivity (if assumed to be a constant)

     REAL, PARAMETER ::  &

         rkice0 = 2.04            ! W/(m.K)

 ! Salt concentration per mil for sea ice (taken as constant here)

     REAL, PARAMETER ::  &

         sice = 4.               ! -

 ! Salinity of ice formed from sea water at standard salt concentration

 ! (in case the salinity scheme is not used)

     REAL, PARAMETER ::  &

         ssinew = 5.             ! -

 ! Standard salinity of sea water

     REAL, PARAMETER ::  &

         ssw0 = 34.              ! -

 ! Summer salinity equilibrium

     REAL, PARAMETER ::  &

         ssisummer0 = 2.         ! psu

 ! Winter salinity equilibrium

     REAL, PARAMETER ::  &

         ssiwinter0 = 5.         ! psu

 ! Summer salinity decrease timescale

     REAL, PARAMETER ::  &

         ssisummer_ts = 10.      ! days

 ! Winter salinity decrease timescale

     REAL, PARAMETER ::  &

         ssiwinter_ts = 20.      ! days

 ! Linear decay coef. for snow albedo

     REAL, PARAMETER ::  &

         taua = 0.008            ! -

 ! Exponential decay coef. for snow albedo

     REAL, PARAMETER ::  &

         tauf = 0.24             ! -

 ! Melting point (deg C) over sea ice salinity ratio

     REAL, PARAMETER ::  &

         mu = 0.054              ! deg C/psu

 ! 0 C in K

     REAL, PARAMETER ::  &

         t0deg = 273.15          ! K

 ! Standard melting point of ice

     REAL, PARAMETER ::  &

         tice_m = -mu*sice       ! K

 ! Minimum snowfall that allows to cover a sea ice slab totally

     REAL, PARAMETER ::  &

         wnew = 5.E-2            ! m

 ! Concentration threshold to define sea ice extension

     REAL, PARAMETER ::  &

         xfsic = 0.15            ! [0-1]

 ! Concentration threshold to define sea ice existence

     REAL, PARAMETER ::  &

         xiok = 1.e-4            ! [0-1]

 !

 ! 1.4. Parameters for melt ponds (CICE configuration)

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

 ! Albedo of melting bare ice

     REAL, PARAMETER ::  &

         xalbareimlt = 0.65      ! [0-1]

 ! Fraction of melt water captured by the ponds

     REAL, PARAMETER ::  &

         xr1 = 0.16               ! [0-1]

 ! Melt pond shrinkage exponential parameter

     REAL, PARAMETER ::  &

         xr2 = 0.03               ! -

 ! Melt pond reference temperature

     REAL, PARAMETER ::  &

         tp = -2.                ! C

 ! Ratio melt pond depth / melt pond fraction

     REAL, PARAMETER ::  &

         dpthfrac = 0.8          ! -

 ! Parameters for melt ponds depth/fraction relation

 !   depth = dptfr1 * fraction + dptfr2

     REAL, PARAMETER ::  &

         dptfr1 = 0.8, dptfr2 = -1.E-4

 !        dptfr1 = 1.16, dptfr2 = -0.09

 ! Maximum ratio melt pond depth / ice thickness

     REAL, PARAMETER ::  &

         dpthhi = 0.9            ! -

 ! Drainage rate

     REAL, PARAMETER ::  &

         drainrate = 0. !0.8E-2          ! m/day

 ! Minimum sea ice thickness allowing melt pond formation

     REAL, PARAMETER ::  &

         hsi_mp = 0.10           ! m

 ! Maximum snow depth allowing melt pond formation

     REAL, PARAMETER ::  &

         hsn_mp = 0.01 !1E-07 !0.189          ! m

 !

 ! Weights for albedo calculation (following Ebert and Curry, 1993)

     REAL, PARAMETER :: &

         xwmp1=0.519, &

         xwmp2=0.337, &

         xwmp3=0.134, &

         xwmp4=0.010

 ! Parameters for albedo formulation (alb = amp + exp(-bmp*d-cmp))

      REAL, PARAMETER :: &

         xamp1=0.150, &

         xamp2=0.054,  &

         xamp3=0.033,  &

         xamp4=0.030, &

         xbmp1=8.1, &

         xbmp2=31.8,  &

         xbmp3=2.6, &

         xcmp1=0.47, &

         xcmp2=0.94, &

         xcmp3= 3.82

 !

 !

 ! 2. PARAMETERS DEDUCED FROM THE PREVIOUS SET

 ! ============================================


 ! Volumic latent heat of fusion of pure ice

     REAL, PARAMETER ::  &

         hofusn0 = xmhofusn0 * rhoice0   ! J.m-3

 ! The inverse of the latent heat of fusion of ice

     REAL, PARAMETER ::  &

         hofusni0 = 1. / hofusn0         ! m3.J-1

 ! Product of rhoice and cpice0 (pure ice)

     REAL, PARAMETER ::  &

         rhocpice0 = rhoice0*cpice0      ! J.m-3.K-1

 ! Standard density of sea water

     REAL, PARAMETER ::  &

         rhosw = rhofw + ssw0            ! kg/m^3

 !

 END MODULE modd_glt_const_thm

modd_glt_const_thm
Definition: modd_glt_const_thm.F90:44