Combo

INTERFACE:

   subroutine Combo (dz,  wliq,  wice, t, dz2, &
                     wliq2, wice2, t2)

DESCRIPTION:

   Combines two elements and returns the following combined
   variables: dz, t, wliq, wice. 
   The combined temperature is based on the equation:
   the sum of the enthalpies of the two elements =  
   that of the combined element.

USES:

     use clm_varcon,  only : cpice, cpliq, tfrz, hfus

ARGUMENTS:

     implicit none
     real(r8), intent(in) :: dz2     ! nodal thickness of 2 elements being combined [m]
     real(r8), intent(in) :: wliq2   ! liquid water of element 2 [kg/m2]
     real(r8), intent(in) :: wice2   ! ice of element 2 [kg/m2]
     real(r8), intent(in) :: t2      ! nodal temperature of element 2 [K]
     real(r8), intent(inout) :: dz   ! nodal thickness of 1 elements being combined [m]
     real(r8), intent(inout) :: wliq ! liquid water of element 1
     real(r8), intent(inout) :: wice ! ice of element 1 [kg/m2]
     real(r8), intent(inout) :: t    ! nodel temperature of elment 1 [K]

CALLED FROM:

   subroutine CombineSnowLayers in this module 
   subroutine DivideSnowLayers in this module

REVISION HISTORY:

   15 September 1999: Yongjiu Dai; Initial code
   15 December 1999:  Paul Houser and Jon Radakovich; F90 Revision