RRTMG Surface Module

This module sets up surface albedo for sw radiation and surface emissivity for lw radiation. More...

Detailed Description

Version

NCEP-Radiation_surface v5.1 Nov 2012

Variables
integer, parameter, public	module_radiation_surface::nf_albd = 4
integer, parameter, public	module_radiation_surface::imxems = 360
integer, parameter, public	module_radiation_surface::jmxems = 180
real(kind=kind_phys), parameter	module_radiation_surface::f_zero = 0.0
real(kind=kind_phys), parameter	module_radiation_surface::f_one = 1.0
real(kind=kind_phys), parameter	module_radiation_surface::rad2dg = 180.0 / con_pi
integer, dimension(:,:), allocatable	module_radiation_surface::idxems
integer	module_radiation_surface::iemslw = 0
subroutine, public	module_radiation_surface::sfc_init (me)
	This subroutine is the initialization program for surface radiation related quantities (albedo, emissivity, etc.) More...
subroutine, public	module_radiation_surface::setalb (slmsk, snowf, sncovr, snoalb, zorlf, coszf, tsknf, tairf, hprif, alvsf, alnsf, alvwf, alnwf, facsf, facwf, fice, tisfc, IMAX, sfcalb )
	This subroutine computes four components of surface albedos (i.e., vis-nir, direct-diffused) according to control flag ialbflg. 1) climatological surface albedo scheme ([9]) 2) MODIS retrieval based scheme from Boston univ. More...
subroutine, public	module_radiation_surface::setemis (xlon, xlat, slmsk, snowf, sncovr, zorlf, tsknf, tairf, hprif, IMAX, sfcemis )
	This subroutine computes surface emissivity for LW radiation. More...

Function/Subroutine Documentation

subroutine, public module_radiation_surface::setalb	(	real (kind=kind_phys), dimension(:), intent(in)	slmsk,
		real (kind=kind_phys), dimension(:), intent(in)	snowf,
		real (kind=kind_phys), dimension(:), intent(in)	sncovr,
		real (kind=kind_phys), dimension(:), intent(in)	snoalb,
		real (kind=kind_phys), dimension(:), intent(in)	zorlf,
		real (kind=kind_phys), dimension(:), intent(in)	coszf,
		real (kind=kind_phys), dimension(:), intent(in)	tsknf,
		real (kind=kind_phys), dimension(:), intent(in)	tairf,
		real (kind=kind_phys), dimension(:), intent(in)	hprif,
		real (kind=kind_phys), dimension(:), intent(in)	alvsf,
		real (kind=kind_phys), dimension(:), intent(in)	alnsf,
		real (kind=kind_phys), dimension(:), intent(in)	alvwf,
		real (kind=kind_phys), dimension(:), intent(in)	alnwf,
		real (kind=kind_phys), dimension(:), intent(in)	facsf,
		real (kind=kind_phys), dimension(:), intent(in)	facwf,
		real (kind=kind_phys), dimension(:), intent(in)	fice,
		real (kind=kind_phys), dimension(:), intent(in)	tisfc,
		integer, intent(in)	IMAX,
		real (kind=kind_phys), dimension(imax,nf_albd), intent(out)	sfcalb
	)

Parameters

slmsk	(IMAX), sea(0),land(1),ice(2) mask on fcst model grid
snowf	(IMAX), snow depth water equivalent in mm
sncovr	(IMAX), snow cover over land
snoalb	(IMAX), maximum snow albedo over land (for deep snow)
zorlf	(IMAX), surface roughness in cm
coszf	(IMAX), cosin of solar zenith angle
tsknf	(IMAX), ground surface temperature in K
tairf	(IMAX), lowest model layer air temperature in K
hprif	(IMAX), topographic sdv in m — for ialbflg=0 climtological albedo scheme —
alvsf	(IMAX), 60 degree vis albedo with strong cosz dependency
alnsf	(IMAX), 60 degree nir albedo with strong cosz dependency
alvwf	(IMAX), 60 degree vis albedo with weak cosz dependency
alnwf	(IMAX), 60 degree nir albedo with weak cosz dependency — for ialbflg=1 MODIS based land albedo scheme —
alvsf	(IMAX), visible black sky albedo at zenith 60 degree
alnsf	(IMAX), near-ir black sky albedo at zenith 60 degree
alvwf	(IMAX), visible white sky albedo
alnwf	(IMAX), near-ir white sky albedo
facsf	(IMAX), fractional coverage with strong cosz dependency
facwf	(IMAX), fractional coverage with weak cosz dependency
fice	(IMAX), sea-ice fraction
tisfc	(IMAX), sea-ice surface temperature
IMAX	array horizontal dimension
sfcalb	(IMAX,NF_ALBD), mean sfc albedo ( :, 1) - near ir direct beam albedo ( :, 2) - near ir diffused albedo ( :, 3) - uv+vis direct beam albedo ( :, 4) - uv+vis diffused albedo

General Algorithm

1. If use climatological albedo scheme:
   • Modified snow albedo scheme - units convert to m (originally snowf in mm; zorlf in cm)
   • Calculate diffused sea surface albedo
   • Calculate diffused snow albedo.
   • Calculate direct snow albedo.
   • Calculate direct sea surface albedo.
2. If use modis based albedo for land area:
   • Calculate snow cover input directly for land model, no conversion needed.
   • Calculate diffused sea surface albedo.
   • Calculate diffused snow albedo, land area use input max snow albedo.
   • Calculate direct snow albedo.
   • Calculate direct sea surface albedo, use fanglin's zenith angle treatment.

References csnow().

Here is the call graph for this function:

subroutine, public module_radiation_surface::setemis	(	real (kind=kind_phys), dimension(:), intent(in)	xlon,
		real (kind=kind_phys), dimension(:), intent(in)	xlat,
		real (kind=kind_phys), dimension(:), intent(in)	slmsk,
		real (kind=kind_phys), dimension(:), intent(in)	snowf,
		real (kind=kind_phys), dimension(:), intent(in)	sncovr,
		real (kind=kind_phys), dimension(:), intent(in)	zorlf,
		real (kind=kind_phys), dimension(:), intent(in)	tsknf,
		real (kind=kind_phys), dimension(:), intent(in)	tairf,
		real (kind=kind_phys), dimension(:), intent(in)	hprif,
		integer, intent(in)	IMAX,
		real (kind=kind_phys), dimension(:), intent(out)	sfcemis
	)

Parameters

xlon	(IMAX), longitude in radiance, ok for both 0->2pi or -pi -> +pi ranges
xlat	(IMAX), latitude in radiance, default to pi/2 -> -pi/2 range, otherwise see in-line comment
slmsk	(IMAX), sea(0),land(1),ice(2) mask on fcst model grid
snowf	(IMAX), snow depth water equivalent in mm
sncovr	(IMAX), snow cover over land
zorlf	(IMAX), surface roughness in cm
tsknf	(IMAX), ground surface temperature in K
tairf	(IMAX), lowest model layer air temperature in K
hprif	(IMAX), topographic standard deviation in m
IMAX	array horizontal dimension
sfcemis	(IMAX), surface emissivity

General Algorithm

1. Set sfcemis default to 1.0 or by surface type and condition.
2. Check for snow covered area.

subroutine, public module_radiation_surface::sfc_init

(

integer, intent(in)

me

)

Parameters

me	print control flag

General Algorithm

• Initialization of surface albedo section
  physparam::ialbflg
  • = 0: using climatology surface albedo scheme for SW
  • = 1: using MODIS based land surface albedo for SW
• Initialization of surface emissivity section
  physparam::iemsflg
  • = 0: fixed SFC emissivity at 1.0
  • = 1: input SFC emissivity type map from "semis_file"