upstream_temperature_bound Function

  function upstream_temperature_bound(this, location) result(bound)
    !* Author: Chris MacMackin
    !  Date: July 2017
    !
    ! Returns a field containing the temperature boundary values for
    ! the specified boundary location.
    !
    class(upstream_plume_boundary), intent(in) :: this
    integer, intent(in)                        :: location
      !! Which boundary information is to be provided for.  The
      !! boundary will be the one normal to dimension of number
      !! `abs(boundary)`. If the argument is negative, then the lower
      !! boundary is returned. If positive, then the upper boundary is
      !! returned.
    class(scalar_field), pointer               :: bound
    call dummy%allocate_scalar_field(bound)
    select case(location)
    case(-1)
      bound = uniform_scalar_field(this%temperature)
    case(1)
      bound = uniform_scalar_field(0._r8)
    case default
      bound = uniform_scalar_field(0._r8)
    end select
    call bound%set_temp() ! Shouldn't need to call this, but for some
                          ! reason being set as non-temporary when
                          ! assignment subroutine returns.
  end function upstream_temperature_bound