global_sum

INTERFACE:

   real(r8) function global_sum(flux, spval)

DESCRIPTION:

   Performs a global sum of fluxes

USES:

     use clm_varsur, only : area                 !km^2

ARGUMENTS:

     implicit none
     real(r8), intent(in) :: flux(lsmlon,lsmlat) !W/m2, Kg/m2-s or N/m2
     real(r8), intent(in) :: spval               !points to not include in global sum