compute_flux1D Subroutine

  subroutine compute_flux1D(vm, flux_density, area, fraction, allsum, rc)
    type(ESMF_VM), intent(in)        :: vm
    real(ESMF_KIND_R8), pointer      :: flux_density(:) 
    real(ESMF_KIND_R8), pointer      :: area(:) 
    real(ESMF_KIND_R8), pointer      :: fraction(:) 
    real(ESMF_KIND_R8), intent(out)  :: allsum(3)
    integer, intent(out), optional   :: rc

    real(ESMF_KIND_R8)               :: sum(3)
    integer                          :: i,j, localrc

    if(present(rc)) rc = ESMF_SUCCESS

    sum = 0.
    do i = lbound(flux_density, 1), ubound(flux_density, 1)
      sum(1) = sum(1) + flux_density(i)*area(i)*fraction(i)
      sum(2) = sum(2) +                 area(i)*fraction(i)
      sum(3) = sum(3) +                 area(i)
    enddo

    call ESMF_VMAllReduce(vm, sum, allsum, 3, ESMF_REDUCE_SUM, rc=localrc)
    if (ESMF_LogFoundError(localrc, &
        ESMF_ERR_PASSTHRU, &
        ESMF_CONTEXT, rcToReturn=rc)) return

  end subroutine compute_flux1D