SoilThermProp

INTERFACE:

   subroutine SoilThermProp (tk, cv, c)

DESCRIPTION:

   Calculation of thermal conductivities and heat capacities of 
   snow/soil layers
   (1) The volumetric heat capacity is calculated as a linear combination 
       in terms of the volumetric fraction of the constituent phases. 
   (2) The thermal conductivity of soil is computed from the algorithm of
       Johansen (as reported by Farouki 1981), and of snow is from the
       formulation used in SNTHERM (Jordan 1991).
   The thermal conductivities at the interfaces between two neighboring 
   layers (j, j+1) are derived from an assumption that the flux across 
   the interface is equal to that from the node j to the interface and the 
   flux from the interface to the node j+1.

USES:

     use shr_kind_mod, only: r8 => shr_kind_r8
     use clmtype
     use clm_varcon, only : denh2o, denice, tfrz,   tkwat, tkice, tkair, &
          cpice,  cpliq,  istice, istwet
     use clm_varpar, only : nlevsoi

ARGUMENTS:

     implicit none
     type (column_type),target,intent(inout):: c		!column derived type
     real(r8), intent(out) :: cv(c%cps%snl+1:nlevsoi) ! heat capacity [J/(m2 K)]
     real(r8), intent(out) :: tk(c%cps%snl+1:nlevsoi) ! thermal conductivity [W/(m K)]\end{verbatim}{\sf CALLED FROM:}
\begin{verbatim}   subroutine SoilTemperature in this module

REVISION HISTORY:

   15 September 1999: Yongjiu Dai; Initial code
   15 December 1999:  Paul Houser and Jon Radakovich; F90 Revision 
   2/13/02, Peter Thornton: migrated to new data structures

LOCAL VARIABLES:

   local pointers to original implicit in scalars
     integer , pointer :: itypwat    !water type
     integer , pointer :: snl        !number of snow layers
     real(r8), pointer :: h2osno     !snow water (mm H2O) 
   local pointers to original implicit in arrays
     real(r8), dimension(:), pointer:: watsat       !volumetric soil water at saturation (porosity)
     real(r8), dimension(:), pointer:: tksatu       !thermal conductivity, saturated soil [W/m-K]
     real(r8), dimension(:), pointer:: tkmg         !thermal conductivity, soil minerals  [W/m-K]
     real(r8), dimension(:), pointer:: tkdry        !thermal conductivity, dry soil (W/m/Kelvin)
     real(r8), dimension(:), pointer:: csol         !heat capacity, soil solids (J/m**3/Kelvin)
     real(r8), dimension(:), pointer:: dz           !layer depth (m)
     real(r8), dimension(:), pointer:: zi           !interface level below a "z" level (m)
     real(r8), dimension(:), pointer:: z            !layer thickness (m)
     real(r8), dimension(:), pointer:: t_soisno     !soil temperature (Kelvin)
     real(r8), dimension(:), pointer:: h2osoi_liq   !liquid water (kg/m2)
     real(r8), dimension(:), pointer:: h2osoi_ice   !ice lens (kg/m2)