view_factor

INTERFACE:

   subroutine view_factor (lbl, ubl, num_urbanl, filter_urbanl, canyon_hwr)

DESCRIPTION:

View factors for road and one wall WALL | ROAD | wall | --- /--- - - |-----/ | vsr / | | r | | vww / s | / | h o w | / k wall | / | wall | a | | / y |vwr / vwr| | d | |vrw / vsw ------ - - |----- road wall | <--- w --> | <-- h -->|

vsr = view factor of sky for road vrw = view factor of road for wall vwr = view factor of one wall for road vww = view factor of opposing wall for wall vsw = view factor of sky for wall vsr + vwr + vwr = 1 vrw + vww + vsw = 1

Source: Masson, V. (2000) A physically-based scheme for the urban energy budget in atmospheric models. Boundary-Layer Meteorology 94:357-397

USES:

     use shr_kind_mod, only: r8 => shr_kind_r8
     use clmtype

ARGUMENTS:

     implicit none
     integer,  intent(in) :: lbl, ubl                  ! landunit-index bounds
     integer , intent(in)  :: num_urbanl               ! number of urban landunits
     integer , intent(in)  :: filter_urbanl(ubl-lbl+1) ! urban landunit filter
     real(r8), intent(in)  :: canyon_hwr(num_urbanl)   ! ratio of building height to street width
   local pointers to original implicit out arguments (clmtype)
     real(r8), pointer :: vf_sr(:)     ! view factor of sky for road
     real(r8), pointer :: vf_wr(:)     ! view factor of one wall for road
     real(r8), pointer :: vf_sw(:)     ! view factor of sky for one wall
     real(r8), pointer :: vf_rw(:)     ! view factor of road for one wall
     real(r8), pointer :: vf_ww(:)     ! view factor of opposing wall for one wall

CALLED FROM:

   subroutine UrbanAlbedo in this module

REVISION HISTORY:

   Author: Gordon Bonan
   03/2003, Mariana Vertenstein: Migrated to clm2.2 
   01/2008, Erik Kluzek:         Migrated to clm3.5.15

LOCAL VARIABLES: