GFS radsw Main

This module includes NCEP's modifications of the RRTMG-SW radiation code from AER. More...

Detailed Description

The SW radiation model in the current NOAA Environmental Modeling System (NEMS) was adapted from the RRTM radiation model developed by AER Inc. ([16]; [63]). It contains 14 spectral bands spanning a spectral wavenumber range of \(50000-820 cm^{-1}\) (corresponding to a wavelength range \(0.2-12.2\mu m\)), each spectral band focuses on a specific set of atmospheric absorbing species as shown in Table 1. To achieve great computation efficiency while at the same time to maintain a high degree of accuracy, the RRTM radiation model employs a corrected-k distribution method (i.e. mapping the highly spectral changing absorption coefficient, k, into a monotonic and smooth varying cumulative probability function, g). In the RRTM-SW, there are 16 unevenly distributed g points for each of the 14 bands for a total of 224 g points. The GCM version of the code (RRTMG-SW) uses a reduced number (various between 2 to 16) of g points for each of the bands that totals to 112 instead of the full set of 224. To get high quality for the scheme, many advanced techniques are used in RRTM such as carefully selecting the band structure to handle various major (key-species) and minor absorbers; deriving a binary parameter for a paired key molecular species in the same domain; and using two pressure regions (dividing level is at about 96mb) for optimal treatment of various species, etc.

Table 1. RRTMG-SW spectral bands and the corresponding absorbing species

Band #	Wavenumber Range	Lower Atm (Key)	Lower Atm (Minor)	Mid/Up Atm (Key)	Mid/Up Atm (Minor)
16	2600-3250	H2O,CH4		CH4
17	3250-4000	H2O,CO2		H2O,CO2
18	4000-4650	H2O,CH4		CH4
19	4650-5150	H2O,CO2		CO2
20	5150-6150	H2O	CH4	H2O	CH4
21	6150-7700	H2O,CO2		H2O,CO2
22	7700-8050	H2O,O2		O2
23	8050-12850	H2O		—
24	12850-16000	H2O,O2	O3	O2	O3
25	16000-22650	H2O	O3	—	O3
26	22650-29000	—		—
27	29000-38000	O3		O3
28	38000-50000	O3,O2		O3,O2
29	820-2600	H2O	CO2	CO2	H2O

scattering due to clouds greatly complicate the SW radiative transfer computations. To balance the trade-off between computation and speed, RRTMG-SW uses a two-stream approximation method with a delta-function adjustment. Several variations of the delta-two method are included in the radiation transfer code; each holds its own strength and shortcomings ([49]; [73]; [6]). The default (the same in operation runs) selection (iswmode=2) activates the Practical Improved Flux Method (PIFM) by [86] . In dealing with a column of cloudy atmosphere, two approaches are included in the RRTMG-SW. One is the commonly used treatment that sees each of the cloud contaminated layers as independent, partially and uniformly filled slabs. Cloud inhomogeneity within and the nature coherence among adjacent cloud layers are largely ignored to reduce the overwhelm complexities associated with scattering process. The effective layer reflectance and transmittance are weighted mean according to cloud fraction. The approach may overestimate cloud effect, especially for multi-layered cloud system associated with deep convection. In NEMS radiation code, to mitigate this shortcoming without increase computation cost, the cloud contaminated column is divided into two parts based on the column's total cloud coverage (a maximum-random overlapping is used in the operational models) to form a cloud free part and an overcast part. Layered clouds are then normalized by the total cloud amount before going through radiative transfer calculations. Fluxes from the cloud-free part and cloudy part are combined together to obtain the final result.
On the other hand, the Monte-Carlo Independent Column Approximation (McICA) ([71]; [72]), provides a simple and effective way to solve cloud overlapping issue without increasing computational burden. The method is based on the concept of an ICA scheme that divides each grid column into a large number of sub-columns, and statistically redistributes layered clouds (under an assumed overlapping condition, such as the maximum-random method) into the sub-columns (i.e. at any layer it will be either clear or overcast). Thus the grid domain averaged flux under ICA scheme can be expressed as:

\[ \overline{F}=\frac{1}{N}\sum_{n=1}^N F_{n} =\frac{1}{N}\sum_{n=1}^N\sum_{k=1}^K F_{n,k} \]

Where \(N\) is the number of total sub-columns, and \(K\) is the number of spectral terms in integration. \(F_{n}\) is flux obtained in the \(n^{th}\) sub-column, that is the summation of total of \(K\) spectral corresponding fluxes, \(F_{n,k}\) . The double integrations (summations) make ICA impractical for GCM applications. The McICA method is to divide a model grid into \(K\) sub-columns and randomly to pair a sub-column's cloud profile with one of the radiative spectral intervals (e.g. the g-point in RRTM). The double summations will then be reduced to only one:

\[ \overline{F}=\frac{1}{N}\sum_{n=1}^N\sum_{k=1}^K F_{n,k} \approx\overline{F}=\sum_{k=1}^K F_{S_{k},k} \]

The RRTM-SW package includes three files:

• radsw_param.f, which contains:
  • module_radsw_parameters: specifies major parameters of the spectral bands and defines the construct structures of derived-type variables for holding the output results.
• radsw_datatb.f, which contains:
  • module_radsw_ref: reference temperature and pressure
  • module_radsw_cldprtb: cloud property coefficients table
  • module_radsw_sflux: indexes and coefficients for spectral distribution of solar flux
  • module_radsw_kgbnn: absorption coefficents for 14 bands, where nn = 16-29
• radsw_main.f, which contains:
  • module_radsw_main: the main SW radiation computation source codes

Author

Eli J. Mlawer, emlaw.nosp@m.er@a.nosp@m.er.co.nosp@m.m

Jennifer S. Delamere, jdela.nosp@m.mer@.nosp@m.aer.c.nosp@m.om

Michael J. Iacono, miaco.nosp@m.no@a.nosp@m.er.co.nosp@m.m

Shepard A. Clough

Version

NCEP SW v5.1 Nov 2012 -RRTMG-SW v3.8

The authors wish to acknowledge the contributions of the following people: Steven J. Taubman, Karen Cady-Pereira, Patrick D. Brown, Ronald E. Farren, Luke Chen, Robert Bergstrom.

Copyright

2002-2007, Atmospheric & Environmental Research, Inc. (AER). This software may be used, copied, or redistributed as long as it is not sold and this copyright notice is reproduced on each copy made. This model is provided as is without any express or implied warranties. (http://www.rtweb.aer.com/)

Argument Table

local_name	standard_name	long_name	units	rank	type	kind	intent	optional
plyr	air_pressure_at_layer_for_radiation_in_hPa	air pressure layer	hPa	2	real	kind_phys	in	F
plvl	air_pressure_at_interface_for_radiation_in_hPa	air pressure level	hPa	2	real	kind_phys	in	F
tlyr	air_temperature_at_layer_for_radiation	air temperature layer	K	2	real	kind_phys	in	F
tlvl	air_temperature_at_interface_for_radiation	air temperature level	K	2	real	kind_phys	in	F
qlyr	water_vapor_specific_humidity_at_layer_for_radiation	specific humidity layer	kg kg-1	2	real	kind_phys	in	F
olyr	ozone_concentration_at_layer_for_radiation	ozone concentration layer	kg kg-1	2	real	kind_phys	in	F
gasvmr_co2	volume_mixing_ratio_co2	volume mixing ratio co2	kg kg-1	2	real	kind_phys	in	F
gasvmr_n2o	volume_mixing_ratio_n2o	volume mixing ratio no2	kg kg-1	2	real	kind_phys	in	F
gasvmr_ch4	volume_mixing_ratio_ch4	volume mixing ratio ch4	kg kg-1	2	real	kind_phys	in	F
gasvmr_o2	volume_mixing_ratio_o2	volume mixing ratio o2	kg kg-1	2	real	kind_phys	in	F
gasvmr_co	volume_mixing_ratio_co	volume mixing ratio co	kg kg-1	2	real	kind_phys	in	F
gasvmr_cfc11	volume_mixing_ratio_cfc11	volume mixing ratio cfc11	kg kg-1	2	real	kind_phys	in	F
gasvmr_cfc12	volume_mixing_ratio_cfc12	volume mixing ratio cfc12	kg kg-1	2	real	kind_phys	in	F
gasvmr_cfc22	volume_mixing_ratio_cfc22	volume mixing ratio cfc22	kg kg-1	2	real	kind_phys	in	F
gasvmr_ccl4	volume_mixing_ratio_ccl4	volume mixing ratio ccl4	kg kg-1	2	real	kind_phys	in	F
icseed	seed_random_numbers_sw	seed for random number generation for shortwave radiation	none	1	integer		in	F
aeraod	aerosol_optical_depth_for_shortwave_bands_01-16	aerosol optical depth for shortwave bands 01-16	none	3	real	kind_phys	in	F
aerssa	aerosol_single_scattering_albedo_for_shortwave_bands_01-16	aerosol single scattering albedo for shortwave bands 01-16	frac	3	real	kind_phys	in	F
aerasy	aerosol_asymmetry_parameter_for_shortwave_bands_01-16	aerosol asymmetry paramter for shortwave bands 01-16	none	3	real	kind_phys	in	F
sfcalb_nir_dir	surface_albedo_due_to_near_IR_direct	surface albedo due to near IR direct beam	frac	1	real	kind_phys	in	F
sfcalb_nir_dif	surface_albedo_due_to_near_IR_diffused	surface albedo due to near IR diffused beam	frac	1	real	kind_phys	in	F
sfcalb_uvis_dir	surface_albedo_due_to_UV_and_VIS_direct	surface albedo due to UV+VIS direct beam	frac	1	real	kind_phys	in	F
sfcalb_uvis_dif	surface_albedo_due_to_UV_and_VIS_diffused	surface albedo due to UV+VIS diffused beam	frac	1	real	kind_phys	in	F
cosz	cosine_of_zenith_angle	cosine of the solar zenit angle	none	1	real	kind_phys	in	F
solcon	solar_constant	solar constant	W m-2	0	real	kind_phys	in	F
nday	daytime_points_dimension	daytime points dimension	count	0	integer		in	F
idxday	daytime_points	daytime points	index	1	integer		in	F
npts	horizontal_loop_extent	horizontal dimension	count	0	integer		in	F
nlay	adjusted_vertical_layer_dimension_for_radiation	number of vertical layers for radiation	count	0	integer		in	F
nlp1	adjusted_vertical_level_dimension_for_radiation	number of vertical levels for radiation	count	0	integer		in	F
lprnt	flag_print	flag to print	flag	0	logical		in	F
cld_cf	total_cloud_fraction	total cloud fraction	frac	2	real	kind_phys	in	F
lsswr	flag_to_calc_sw	flag to calculate SW irradiances	flag	0	logical		in	F
hswc	tendency_of_air_temperature_due_to_shortwave_heating_on_radiation_time_step	shortwave total sky heating rate	K s-1	2	real	kind_phys	inout	F
topflx	sw_fluxes_top_atmosphere	shortwave total sky fluxes at the top of the atm	W m-2	1	topfsw_type		inout	F
sfcflx	sw_fluxes_sfc	shortwave total sky fluxes at the Earth surface	W m-2	1	sfcfsw_type		inout	F
hsw0	tendency_of_air_temperature_due_to_shortwave_heating_assuming_clear_sky_on_radiation_time_step	shortwave clear sky heating rate	K s-1	2	real	kind_phys	inout	T
hswb	sw_heating_rate_spectral	shortwave total sky heating rate (spectral)	K s-1	3	real	kind_phys	inout	T
flxprf	sw_fluxes	sw fluxes total sky / csk and up / down at levels	W m-2	2	profsw_type		inout	T
fdncmp	components_of_surface_downward_shortwave_fluxes	derived type for special components of surface downward shortwave fluxes	W m-2	1	cmpfsw_type		inout	T
cld_lwp	cloud_liquid_water_path	cloud liquid water path	g m-2	2	real	kind_phys	in	T
cld_ref_liq	mean_effective_radius_for_liquid_cloud	mean effective radius for liquid cloud	micron	2	real	kind_phys	in	T
cld_iwp	cloud_ice_water_path	cloud ice water path	g m-2	2	real	kind_phys	in	T
cld_ref_ice	mean_effective_radius_for_ice_cloud	mean effective radius for ice cloud	micron	2	real	kind_phys	in	T
cld_rwp	cloud_rain_water_path	cloud rain water path	g m-2	2	real	kind_phys	in	T
cld_ref_rain	mean_effective_radius_for_rain_drop	mean effective radius for rain drop	micron	2	real	kind_phys	in	T
cld_swp	cloud_snow_water_path	cloud snow water path	g m-2	2	real	kind_phys	in	T
cld_ref_snow	mean_effective_radius_for_snow_flake	mean effective radius for snow flake	micron	2	real	kind_phys	in	T
cld_od	cloud_optical_depth	cloud optical depth	none	2	real	kind_phys	in	T
cld_ssa	cloud_single_scattering_albedo	cloud single scattering albedo	frac	2	real	kind_phys	in	T
cld_asy	cloud_asymmetry_parameter	cloud asymmetry parameter	none	2	real	kind_phys	in	T
errmsg	error_message	error message for error handling in CCPP	none	0	character	len=*	out	F
errflg	error_flag	error flag for error handling in CCPP	flag	0	integer		out	F

RRTMG Shortwave Radiation Scheme General Algorithm

Modules
module	module_radsw_parameters
	This module is for specifying the band structures and program parameters used by the RRTMG-SW scheme.
module	module_radsw_ref
	This module contains the reference pressures (in logarithm form) at 59 vertical levels (TOA is omitted), and the mid-latitude summer (MLS) standard temperature profile for the 59 pressure layers that are used to establish pre calculated transmission tables.
module	module_radsw_cldprtb
	This module contains cloud radiative property coefficients.
module	module_radsw_sflux
	This module contains various indexes and coefficients for SW spectral bands, as well as the spectral distribution of solar flux. The values of spectral solar flux are derived based on a prescribed solar constant ( \(1368.22 W/m^2\)). Scaling will be applied for the actual inputted solar constant value.
module	module_radsw_kgb16
	This module sets up absorption coefficients for band 16: 2600-3250 cm-1 (low - h2o, ch4; high - ch4)
module	module_radsw_kgb17
	This module sets up absorption coeffients for band 17: 3250-4000 cm-1 (low - h2o,co2; high - h2o,co2)
module	module_radsw_kgb18
	This module sets up absorption coeffients for band 18: 4000-4650 cm-1 (low - h2o,ch4; high - ch4)
module	module_radsw_kgb19
	This module sets up absorption coeffients for band 19: 4650-5150 cm-1 (low - h2o,co2; high - co2)
module	module_radsw_kgb20
	This module sets up absorption coeffients for band 20: 5150-6150 cm-1 (low - h2o; high - h2o)
module	module_radsw_kgb21
	This module sets up absorption coeffients for band 21: 6150-7700 cm-1 (low - h2o,co2; high - h2o,co2)
module	module_radsw_kgb22
	This module sets up absorption coeffients for band 22: 7700-8050 cm-1 (low - h2o, o2; high - o2)
module	module_radsw_kgb23
	This module sets up absorption coeffients for band 23: 8050-12850 cm-1 (low - h2o; high - nothing)
module	module_radsw_kgb24
	This module sets up absorption coeffients for band 24: 12850-16000 cm-1 (low - h2o, o2; high - o2)
module	module_radsw_kgb25
	This module sets up absorption coeffients for band 25: 16000-22650 cm-1 (low - h2o; high - nothing)
module	module_radsw_kgb26
	This module sets up absorption coeffients for band 26: 22650-29000 cm-1 (low - nothing; high - nothing)
module	module_radsw_kgb27
	This module sets up absorption coeffients for band 27: 29000-38000 cm-1 (low - o3; high - o3)
module	module_radsw_kgb28
	This module sets up absorption coeffients for band 28: 38000-50000 cm-1 (low - o3,o2; high - o3,o2)
module	module_radsw_kgb29
	This module sets up absorption coeffients for band 29: 820-2600 cm-1 (low - h2o; high - co2)

Functions/Subroutines
subroutine, public	rrtmg_sw::rrtmg_sw_run (plyr, plvl, tlyr, tlvl, qlyr, olyr, gasvmr_co2, gasvmr_n2o, gasvmr_ch4, gasvmr_o2, gasvmr_co, gasvmr_cfc11, gasvmr_cfc12, gasvmr_cfc22, gasvmr_ccl4, icseed, aeraod, aerssa, aerasy, sfcalb_nir_dir, sfcalb_nir_dif, sfcalb_uvis_dir, sfcalb_uvis_dif, cosz, solcon, NDAY, idxday, npts, nlay, nlp1, lprnt, cld_cf, lsswr, hswc, topflx, sfcflx, HSW0, HSWB, FLXPRF, FDNCMP, cld_lwp, cld_ref_liq, cld_iwp, cld_ref_ice, cld_rwp, cld_ref_rain, cld_swp, cld_ref_snow, cld_od, cld_ssa, cld_asy, errmsg, errflg
subroutine, public	rrtmg_sw::rswinit (me)
	This subroutine initializes non-varying module variables, conversion factors, and look-up tables. More...
subroutine	rrtmg_sw::mcica_subcol (cldf, nlay, ipseed, lcloudy )
	This subroutine computes the sub-colum cloud profile flag array. More...
subroutine	rrtmg_sw::setcoef (pavel, tavel, h2ovmr, nlay, nlp1, laytrop, jp, jt, jt1, fac00, fac01, fac10, fac11, selffac, selffrac, indself, forfac, forfrac, indfor )
	This subroutine computes various coefficients needed in radiative transfer calculation. More...
subroutine	rrtmg_sw::spcvrtm (ssolar, cosz, sntz, albbm, albdf, sfluxzen, cldfmc, cf1, cf0, taug, taur, tauae, ssaae, asyae, taucw, ssacw, asycw, nlay, nlp1, fxupc, fxdnc, fxup0, fxdn0, ftoauc, ftoau0, ftoadc, fsfcuc, fsfcu0, fsfcdc, fsfcd0, sfbmc, sfdfc, sfbm0, sfdf0, suvbfc, suvbf0 )
	This subroutine computes the shortwave radiative fluxes using two-stream method of h. barder and mcica,the monte-carlo independent column approximation, for the representation of sub-grid cloud variability (i.e. cloud overlap). More...
subroutine	taumol17
	The subroutine computes the optical depth in band 17: 3250-4000 cm-1 (low - h2o,co2; high - h2o,co2)
subroutine	taumol18
	The subroutine computes the optical depth in band 18: 4000-4650 cm-1 (low - h2o,ch4; high - ch4)
subroutine	taumol19
	The subroutine computes the optical depth in band 19: 4650-5150 cm-1 (low - h2o,co2; high - co2)
subroutine	taumol20
	The subroutine computes the optical depth in band 20: 5150-6150 cm-1 (low - h2o; high - h2o)
subroutine	taumol21
	The subroutine computes the optical depth in band 21: 6150-7700 cm-1 (low - h2o,co2; high - h2o,co2)
subroutine	taumol22
	The subroutine computes the optical depth in band 22: 7700-8050 cm-1 (low - h2o,o2; high - o2)
subroutine	taumol23
	The subroutine computes the optical depth in band 23: 8050-12850 cm-1 (low - h2o; high - nothing)
subroutine	taumol24
	The subroutine computes the optical depth in band 24: 12850-16000 cm-1 (low - h2o,o2; high - o2)
subroutine	taumol25
	The subroutine computes the optical depth in band 25: 16000-22650 cm-1 (low - h2o; high - nothing)
subroutine	taumol26
	The subroutine computes the optical depth in band 26: 22650-29000 cm-1 (low - nothing; high - nothing)
subroutine	taumol27
	The subroutine computes the optical depth in band 27: 29000-38000 cm-1 (low - o3; high - o3)
subroutine	taumol28
	The subroutine computes the optical depth in band 28: 38000-50000 cm-1 (low - o3,o2; high - o3,o2)
subroutine	taumol29
	The subroutine computes the optical depth in band 29: 820-2600 cm-1 (low - h2o; high - co2)
subroutine	rrtmg_sw::cldprop (cfrac, cliqp, reliq, cicep, reice, cdat1, cdat2, cdat3, cdat4, cf1, nlay, ipseed, taucw, ssacw, asycw, cldfrc, cldfmc )
	This subroutine computes the cloud optical properties for each cloudy layer and g-point interval. More...
subroutine	rrtmg_sw::spcvrtc (ssolar, cosz, sntz, albbm, albdf, sfluxzen, cldfrc, cf1, cf0, taug, taur, tauae, ssaae, asyae, taucw, ssacw, asycw, nlay, nlp1, fxupc, fxdnc, fxup0, fxdn0, ftoauc, ftoau0, ftoadc, fsfcuc, fsfcu0, fsfcdc, fsfcd0, sfbmc, sfdfc, sfbm0, sfdf0, suvbfc, suvbf0 )
	This subroutine computes the shortwave radiative fluxes using two-stream method. More...
subroutine	rrtmg_sw::vrtqdr (zrefb, zrefd, ztrab, ztrad, zldbt, ztdbt, NLAY, NLP1, zfu, zfd )
	This subroutine is called by spcvrtc() and spcvrtm(), and computes the upward and downward radiation fluxes. More...
subroutine	rrtmg_sw::taumol (colamt, colmol, fac00, fac01, fac10, fac11, jp, jt, jt1, laytrop, forfac, forfrac, indfor, selffac, selffrac, indself, nlay, sfluxzen, taug, taur )
	This subroutine calculates optical depths for gaseous absorption and rayleigh scattering subroutine called taumol## (## = 16-29) More...
subroutine	taumol16
	The subroutine computes the optical depth in band 16: 2600-3250 cm-1 (low - h2o,ch4; high - ch4)

Function/Subroutine Documentation

subroutine rrtmg_sw::cldprop ( real (kind=kind_phys), dimension(nlay), intent(in)  cfrac, real (kind=kind_phys), dimension(nlay), intent(in)  cliqp, real (kind=kind_phys), dimension(nlay), intent(in)  reliq, real (kind=kind_phys), dimension(nlay), intent(in)  cicep, real (kind=kind_phys), dimension(nlay), intent(in)  reice, real (kind=kind_phys), dimension(nlay), intent(in)  cdat1, real (kind=kind_phys), dimension(nlay), intent(in)  cdat2, real (kind=kind_phys), dimension(nlay), intent(in)  cdat3, real (kind=kind_phys), dimension(nlay), intent(in)  cdat4, real (kind=kind_phys), intent(in)  cf1, integer, intent(in)  nlay, integer, intent(in)  ipseed, real (kind=kind_phys), dimension(nlay,nbdsw), intent(out)  taucw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(out)  ssacw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(out)  asycw, real (kind=kind_phys), dimension(nlay), intent(out)  cldfrc, real (kind=kind_phys), dimension(nlay,ngptsw), intent(out)  cldfmc  )

private

Parameters

cfrac	layer cloud fraction for physparam::iswcliq > 0 (prognostic cloud scheme) - - -
cliqp	layer in-cloud liq water path ( \(g/m^2\))
reliq	mean eff radius for liq cloud (micron)
cicep	layer in-cloud ice water path ( \(g/m^2\))
reice	mean eff radius for ice cloud (micron)
cdat1	layer rain drop water path ( \(g/m^2\))
cdat2	effective radius for rain drop (micron)
cdat3	layer snow flake water path( \(g/m^2\))
cdat4	mean eff radius for snow flake(micron) for physparam::iswcliq = 0 (diagnostic cloud scheme) - - -
cliqp	not used
cicep	not used
reliq	not used
reice	not used
cdat1	layer cloud optical depth
cdat2	layer cloud single scattering albedo
cdat3	layer cloud asymmetry factor
cdat4	optional use
cf1	effective total cloud cover at surface
nlay	vertical layer number
ipseed	permutation seed for generating random numbers (isubcsw>0)
taucw	cloud optical depth, w/o delta scaled
ssacw	weighted cloud single scattering albedo (ssa = ssacw / taucw)
asycw	weighted cloud asymmetry factor (asy = asycw / ssacw)
cldfrc	cloud fraction of grid mean value
cldfmc	cloud fraction for each sub-column

General Algorithm

1. Compute cloud radiative properties for a cloudy column.
   • Compute optical properties for rain and snow.
     For rain: tauran/ssaran/asyran
     For snow: tausnw/ssasnw/asysnw
   • Calculation of absorption coefficients due to water clouds
     For water clouds: tauliq/ssaliq/asyliq
   • Calculation of absorption coefficients due to ice clouds
     For ice clouds: tauice/ssaice/asyice
   • For Prognostic cloud scheme: sum up the cloud optical property:
     \( taucw=tauliq+tauice+tauran+tausnw \)
     \( ssacw=ssaliq+ssaice+ssaran+ssasnw \)
     \( asycw=asyliq+asyice+asyran+asysnw \)
2. if physparam::isubcsw > 0, call mcica_subcol() to distribute cloud properties to each g-point.

References rrtmg_sw::mcica_subcol().

Referenced by rrtmg_sw::rrtmg_sw_run().

Here is the call graph for this function:

subroutine rrtmg_sw::mcica_subcol ( real (kind=kind_phys), dimension(nlay), intent(in)  cldf, integer, intent(in)  nlay, integer, intent(in)  ipseed, logical, dimension(nlay,ngptsw), intent(out)  lcloudy  )

private

Parameters

cldf	layer cloud fraction
nlay	number of model vertical layers
ipseed	permute seed for random num generator
lcloudy	sub-colum cloud profile flag array

Referenced by rrtmg_sw::cldprop().

subroutine, public rrtmg_sw::rrtmg_sw_run	(	real (kind=kind_phys), dimension(npts,nlay), intent(in)	plyr,
		real (kind=kind_phys), dimension(npts,nlp1), intent(in)	plvl,
		real (kind=kind_phys), dimension(npts,nlay), intent(in)	tlyr,
		real (kind=kind_phys), dimension(npts,nlp1), intent(in)	tlvl,
		real (kind=kind_phys), dimension(npts,nlay), intent(in)	qlyr,
		real (kind=kind_phys), dimension(npts,nlay), intent(in)	olyr,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_co2,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_n2o,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_ch4,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_o2,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_co,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_cfc11,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_cfc12,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_cfc22,
		real(kind=kind_phys), dimension(npts,nlay), intent(in)	gasvmr_ccl4,
		integer, dimension(:), intent(in)	icseed,
		real(kind=kind_phys), dimension(npts,nlay,nbdsw), intent(in)	aeraod,
		real(kind=kind_phys), dimension(npts,nlay,nbdsw), intent(in)	aerssa,
		real(kind=kind_phys), dimension(npts,nlay,nbdsw), intent(in)	aerasy,
		real (kind=kind_phys), dimension(npts), intent(in)	sfcalb_nir_dir,
		real (kind=kind_phys), dimension(npts), intent(in)	sfcalb_nir_dif,
		real (kind=kind_phys), dimension(npts), intent(in)	sfcalb_uvis_dir,
		real (kind=kind_phys), dimension(npts), intent(in)	sfcalb_uvis_dif,
		real (kind=kind_phys), dimension(npts), intent(in)	cosz,
		real (kind=kind_phys), intent(in)	solcon,
		integer, intent(in)	NDAY,
		integer, dimension(:), intent(in)	idxday,
		integer, intent(in)	npts,
		integer, intent(in)	nlay,
		integer, intent(in)	nlp1,
		logical, intent(in)	lprnt,
		real (kind=kind_phys), dimension(npts,nlay), intent(in)	cld_cf,
		logical, intent(in)	lsswr,
		real (kind=kind_phys), dimension(npts,nlay), intent(inout)	hswc,
		type (topfsw_type), dimension(npts), intent(inout)	topflx,
		type (sfcfsw_type), dimension(npts), intent(inout)	sfcflx,
		real (kind=kind_phys), dimension(npts,nlay), intent(inout), optional	HSW0,
		real (kind=kind_phys), dimension(npts,nlay,nbdsw), intent(inout), optional	HSWB,
		type (profsw_type), dimension(npts,nlp1), intent(inout), optional	FLXPRF,
		type (cmpfsw_type), dimension(npts), intent(inout), optional	FDNCMP,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_lwp,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_ref_liq,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_iwp,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_ref_ice,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_rwp,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_ref_rain,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_swp,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_ref_snow,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_od,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_ssa,
		real (kind=kind_phys), dimension(npts,nlay), intent(in), optional	cld_asy,
		character(len=*), intent(out)	errmsg,
		integer, intent(out)	errflg
	)

1. Compute solar constant adjustment factor (s0fac) according to solcon.
2. Initial output arrays (and optional) as zero.
3. Change random number seed value for each radiation invocation (isubcsw =1 or 2).
4. Prepare surface albedo: bm,df - dir,dif; 1,2 - nir,uvv.
5. Prepare atmospheric profile for use in rrtm.
6. Set absorber and gas column amount, convert from volume mixing ratio to molec/cm2 based on coldry (scaled to 1.0e-20)
   • colamt(nlay,maxgas):column amounts of absorbing gases 1 to maxgas are for h2o,co2,o3,n2o,ch4,o2,co, respectively ( \( mol/cm^2 \))
7. Read aerosol optical properties from 'aerosols'.
8. Read cloud optical properties from 'clouds'.
9. Compute fractions of clear sky view:
   • random overlapping
   • max/ran overlapping
   • maximum overlapping
10. For cloudy sky column, call cldprop() to compute the cloud optical properties for each cloudy layer.
11. Call setcoef() to compute various coefficients needed in radiative transfer calculations.
12. Call taumol() to calculate optical depths for gaseous absorption and rayleigh scattering
13. Call the 2-stream radiation transfer model:
    • if physparam::isubcsw .le.0, using standard cloud scheme, call spcvrtc().
    • if physparam::isubcsw .gt.0, using mcica cloud scheme, call spcvrtm().
14. Save outputs.

References rrtmg_sw::cldprop(), rrtmg_sw::setcoef(), rrtmg_sw::spcvrtc(), rrtmg_sw::spcvrtm(), and rrtmg_sw::taumol().

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subroutine, public rrtmg_sw::rswinit

(

integer, intent(in)

me

)

Parameters

me	print control for parallel process

subroutine rrtmg_sw::setcoef ( real (kind=kind_phys), dimension(:), intent(in)  pavel, real (kind=kind_phys), dimension(:), intent(in)  tavel, real (kind=kind_phys), dimension(:), intent(in)  h2ovmr, integer, intent(in)  nlay, integer, intent(in)  nlp1, integer, intent(out)  laytrop, integer, dimension(nlay), intent(out)  jp, integer, dimension(nlay), intent(out)  jt, integer, dimension(nlay), intent(out)  jt1, real (kind=kind_phys), dimension(nlay), intent(out)  fac00, real (kind=kind_phys), dimension(nlay), intent(out)  fac01, real (kind=kind_phys), dimension(nlay), intent(out)  fac10, real (kind=kind_phys), dimension(nlay), intent(out)  fac11, real (kind=kind_phys), dimension(nlay), intent(out)  selffac, real (kind=kind_phys), dimension(nlay), intent(out)  selffrac, integer, dimension(nlay), intent(out)  indself, real (kind=kind_phys), dimension(nlay), intent(out)  forfac, real (kind=kind_phys), dimension(nlay), intent(out)  forfrac, integer, dimension(nlay), intent(out)  indfor  )

private

Parameters

pavel	layer pressure (mb)
tavel	layer temperature (k)
h2ovmr	layer w.v. volumn mixing ratio (kg/kg)
nlay	total number of vertical layers
nlp1	total number of vertical levels
laytrop	tropopause layer index (unitless)
jp	indices of lower reference pressure
jt,jt1	indices of lower reference temperatures at levels of jp and jp+1
facij	factors mltiply the reference ks,i,j=0/1 for lower/higher of the 2 appropriate temperature and altitudes.
selffac	scale factor for w. v. self-continuum equals (w.v. density)/(atmospheric density at 296k and 1013 mb)
seffrac	factor for temperature interpolation of reference w.v. self-continuum data
indself	index of lower ref temp for selffac
forfac	scale factor for w. v. foreign-continuum
forfrac	factor for temperature interpolation of reference w.v. foreign-continuum data
indfor	index of lower ref temp for forfac

Referenced by rrtmg_sw::rrtmg_sw_run().

subroutine rrtmg_sw::spcvrtc ( real (kind=kind_phys), intent(in)  ssolar, real (kind=kind_phys), intent(in)  cosz, real (kind=kind_phys), intent(in)  sntz, real (kind=kind_phys), dimension(2), intent(in)  albbm, real (kind=kind_phys), dimension(2), intent(in)  albdf, real (kind=kind_phys), dimension(ngptsw), intent(in)  sfluxzen, real (kind=kind_phys), dimension(nlay), intent(in)  cldfrc, real (kind=kind_phys), intent(in)  cf1, real (kind=kind_phys), intent(in)  cf0, real (kind=kind_phys), dimension(nlay,ngptsw), intent(in)  taug, real (kind=kind_phys), dimension(nlay,ngptsw), intent(in)  taur, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  tauae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  ssaae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  asyae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  taucw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  ssacw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  asycw, integer, intent(in)  nlay, integer, intent(in)  nlp1, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxupc, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxdnc, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxup0, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxdn0, real (kind=kind_phys), intent(out)  ftoauc, real (kind=kind_phys), intent(out)  ftoau0, real (kind=kind_phys), intent(out)  ftoadc, real (kind=kind_phys), intent(out)  fsfcuc, real (kind=kind_phys), intent(out)  fsfcu0, real (kind=kind_phys), intent(out)  fsfcdc, real (kind=kind_phys), intent(out)  fsfcd0, real (kind=kind_phys), dimension(2), intent(out)  sfbmc, real (kind=kind_phys), dimension(2), intent(out)  sfdfc, real (kind=kind_phys), dimension(2), intent(out)  sfbm0, real (kind=kind_phys), dimension(2), intent(out)  sfdf0, real (kind=kind_phys), intent(out)  suvbfc, real (kind=kind_phys), intent(out)  suvbf0  )

private

Parameters

ssolar	incoming solar flux at top
cosz	cosine solar zenith angle
sntz	secant solar zenith angle
albbm	surface albedo for direct beam radiation
albdf	surface albedo for diffused radiation
sfluxzen	spectral distribution of incoming solar flux
cldfrc	layer cloud fraction
cf1	>0: cloudy sky, otherwise: clear sky
cf0	=1-cf1
taug	spectral optical depth for gases
taur	optical depth for rayleigh scattering
tauae	aerosols optical depth
ssaae	aerosols single scattering albedo
asyae	aerosols asymmetry factor
taucw	weighted cloud optical depth
ssacw	weighted cloud single scat albedo
asycw	weighted cloud asymmetry factor
nlay,nlp1	number of layers/levels
fxupc	tot sky upward flux
fxdnc	tot sky downward flux
fxup0	clr sky upward flux
fxdn0	clr sky downward flux
ftoauc	tot sky toa upwd flux
ftoau0	clr sky toa upwd flux
ftoadc	toa downward (incoming) solar flux
fsfcuc	tot sky sfc upwd flux
fsfcu0	clr sky sfc upwd flux
fsfcdc	tot sky sfc dnwd flux
fsfcd0	clr sky sfc dnwd flux
sfbmc	tot sky sfc dnwd beam flux (nir/uv+vis)
sfdfc	tot sky sfc dnwd diff flux (nir/uv+vis)
sfbm0	clr sky sfc dnwd beam flux (nir/uv+vis)
sfdf0	clr sky sfc dnwd diff flux (nir/uv+vis)
suvbfc	tot sky sfc dnwd uv-b flux
suvbf0	clr sky sfc dnwd uv-b flux

General Algorithm

1. Initialize output fluxes.
2. Compute clear-sky optical parameters, layer reflectance and transmittance.
   • Set up toa direct beam and surface values (beam and diff)
   • Delta scaling for clear-sky condition
   • General two-stream expressions for physparam::iswmode
   • Compute homogeneous reflectance and transmittance for both conservative and non-conservative scattering
   • Pre-delta-scaling clear and cloudy direct beam transmittance
   • Call swflux() to compute the upward and downward radiation fluxes
3. Compute total sky optical parameters, layer reflectance and transmittance.
   • Set up toa direct beam and surface values (beam and diff)
   • Delta scaling for total-sky condition
   • General two-stream expressions for physparam::iswmode
   • Compute homogeneous reflectance and transmittance for conservative scattering and non-conservative scattering
   • Pre-delta-scaling clear and cloudy direct beam transmittance
   • Call swflux() to compute the upward and downward radiation fluxes
4. Process and save outputs.

References rrtmg_sw::vrtqdr().

Referenced by rrtmg_sw::rrtmg_sw_run().

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subroutine rrtmg_sw::spcvrtm ( real (kind=kind_phys), intent(in)  ssolar, real (kind=kind_phys), intent(in)  cosz, real (kind=kind_phys), intent(in)  sntz, real (kind=kind_phys), dimension(2), intent(in)  albbm, real (kind=kind_phys), dimension(2), intent(in)  albdf, real (kind=kind_phys), dimension(ngptsw), intent(in)  sfluxzen, real (kind=kind_phys), dimension(nlay,ngptsw), intent(in)  cldfmc, real (kind=kind_phys), intent(in)  cf1, real (kind=kind_phys), intent(in)  cf0, real (kind=kind_phys), dimension(nlay,ngptsw), intent(in)  taug, real (kind=kind_phys), dimension(nlay,ngptsw), intent(in)  taur, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  tauae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  ssaae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  asyae, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  taucw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  ssacw, real (kind=kind_phys), dimension(nlay,nbdsw), intent(in)  asycw, integer, intent(in)  nlay, integer, intent(in)  nlp1, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxupc, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxdnc, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxup0, real (kind=kind_phys), dimension(nlp1,nbdsw), intent(out)  fxdn0, real (kind=kind_phys), intent(out)  ftoauc, real (kind=kind_phys), intent(out)  ftoau0, real (kind=kind_phys), intent(out)  ftoadc, real (kind=kind_phys), intent(out)  fsfcuc, real (kind=kind_phys), intent(out)  fsfcu0, real (kind=kind_phys), intent(out)  fsfcdc, real (kind=kind_phys), intent(out)  fsfcd0, real (kind=kind_phys), dimension(2), intent(out)  sfbmc, real (kind=kind_phys), dimension(2), intent(out)  sfdfc, real (kind=kind_phys), dimension(2), intent(out)  sfbm0, real (kind=kind_phys), dimension(2), intent(out)  sfdf0, real (kind=kind_phys), intent(out)  suvbfc, real (kind=kind_phys), intent(out)  suvbf0  )

private

Parameters

ssolar	incoming solar flux at top
cosz	cosine solar zenith angle
sntz	secant solar zenith angle
albbm	surface albedo for direct beam radiation
albdf	surface albedo for diffused radiation
sfluxzen	spectral distribution of incoming solar flux
cldfmc	layer cloud fraction for g-point
cf1	>0: cloudy sky, otherwise: clear sky
cf0	=1-cf1
taug	spectral optical depth for gases
taur	optical depth for rayleigh scattering
tauae	aerosols optical depth
ssaae	aerosols single scattering albedo
asyae	aerosols asymmetry factor
taucw	weighted cloud optical depth
ssacw	weighted cloud single scat albedo
asycw	weighted cloud asymmetry factor
nlay,nlp1	number of layers/levels
fxupc	tot sky upward flux
fxdnc	tot sky downward flux
fxup0	clr sky upward flux
fxdn0	clr sky downward flux
ftoauc	tot sky toa upwd flux
ftoau0	clr sky toa upwd flux
ftoadc	toa downward (incoming) solar flux
fsfcuc	tot sky sfc upwd flux
fsfcu0	clr sky sfc upwd flux
fsfcdc	tot sky sfc dnwd flux
fsfcd0	clr sky sfc dnwd flux
sfbmc	tot sky sfc dnwd beam flux (nir/uv+vis)
sfdfc	tot sky sfc dnwd diff flux (nir/uv+vis)
sfbm0	clr sky sfc dnwd beam flux (nir/uv+vis)
sfdf0	clr sky sfc dnwd diff flux (nir/uv+vis)
suvbfc	tot sky sfc dnwd uv-b flux
suvbf0	clr sky sfc dnwd uv-b flux

1. Initialize output fluxes.
2. Compute clear-sky optical parameters, layer reflectance and transmittance.
   • Set up toa direct beam and surface values (beam and diff)
   • Delta scaling for clear-sky condition
   • General two-stream expressions for physparam::iswmode
   • Compute homogeneous reflectance and transmittance for both conservative and non-conservative scattering
   • Pre-delta-scaling clear and cloudy direct beam transmittance
   • Call swflux() to compute the upward and downward radiation fluxes
3. Compute total sky optical parameters, layer reflectance and transmittance.
   • Set up toa direct beam and surface values (beam and diff)
   • Delta scaling for total-sky condition
   • General two-stream expressions for physparam::iswmode
   • Compute homogeneous reflectance and transmittance for conservative scattering and non-conservative scattering
   • Pre-delta-scaling clear and cloudy direct beam transmittance
   • Call swflux() to compute the upward and downward radiation fluxes
4. Process and save outputs.

References rrtmg_sw::vrtqdr().

Referenced by rrtmg_sw::rrtmg_sw_run().

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subroutine rrtmg_sw::taumol ( real (kind=kind_phys), dimension(nlay,maxgas), intent(in)  colamt, real (kind=kind_phys), dimension(nlay), intent(in)  colmol, real (kind=kind_phys), dimension(nlay), intent(in)  fac00, real (kind=kind_phys), dimension(nlay), intent(in)  fac01, real (kind=kind_phys), dimension(nlay), intent(in)  fac10, real (kind=kind_phys), dimension(nlay), intent(in)  fac11, integer, dimension(nlay), intent(in)  jp, integer, dimension(nlay), intent(in)  jt, integer, dimension(nlay), intent(in)  jt1, integer, intent(in)  laytrop, real (kind=kind_phys), dimension(nlay), intent(in)  forfac, real (kind=kind_phys), dimension(nlay), intent(in)  forfrac, integer, dimension(nlay), intent(in)  indfor, real (kind=kind_phys), dimension(nlay), intent(in)  selffac, real (kind=kind_phys), dimension(nlay), intent(in)  selffrac, integer, dimension(nlay), intent(in)  indself, integer, intent(in)  nlay, real (kind=kind_phys), dimension(ngptsw), intent(out)  sfluxzen, real (kind=kind_phys), dimension(nlay,ngptsw), intent(out)  taug, real (kind=kind_phys), dimension(nlay,ngptsw), intent(out)  taur  )

private

Parameters

colamt	column amounts of absorbing gases the index are for h2o, co2, o3, n2o, ch4, and o2, respectively \((mol/cm^2)\)
colmol	total column amount (dry air+water vapor)
facij	for each layer, these are factors that are needed to compute the interpolation factors that multiply the appropriate reference k-values. a value of 0/1 for i,j indicates that the corresponding factor multiplies reference k-value for the lower/higher of the two appropriate temperatures, and altitudes, respectively.
jp	the index of the lower (in altitude) of the two appropriate ref pressure levels needed for interpolation.
jt,jt1	the indices of the lower of the two approp ref temperatures needed for interpolation (for pressure levels jp and jp+1, respectively)
laytrop	tropopause layer index
forfac	scale factor needed to foreign-continuum.
forfrac	factor needed for temperature interpolation
indfor	index of the lower of the two appropriate reference temperatures needed for foreign-continuum interpolation
selffac	scale factor needed to h2o self-continuum.
selffrac	factor needed for temperature interpolation of reference h2o self-continuum data
indself	index of the lower of the two appropriate reference temperatures needed for the self-continuum interpolation
nlay	number of vertical layers
sfluxzen	spectral distribution of incoming solar flux
taug	spectral optical depth for gases
taur	opt depth for rayleigh scattering

General Algorithm

• Call taumol## (##: 16-29) to calculate layer optical depth.
  • call taumol16()
  • call taumol17()
  • call taumol18()
  • call taumol19()
  • call taumol20()
  • call taumol21()
  • call taumol22()
  • call taumol23()
  • call taumol24()
  • call taumol25()
  • call taumol26()
  • call taumol27()
  • call taumol28()
  • call taumol29()

References taumol16(), taumol17(), taumol18(), taumol19(), taumol20(), taumol21(), taumol22(), taumol23(), taumol24(), taumol25(), taumol26(), taumol27(), taumol28(), and taumol29().

Referenced by rrtmg_sw::rrtmg_sw_run().

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subroutine rrtmg_sw::vrtqdr ( real (kind=kind_phys), dimension(nlp1), intent(in)  zrefb, real (kind=kind_phys), dimension(nlp1), intent(in)  zrefd, real (kind=kind_phys), dimension(nlp1), intent(in)  ztrab, real (kind=kind_phys), dimension(nlp1), intent(in)  ztrad, real (kind=kind_phys), dimension(nlp1), intent(in)  zldbt, real (kind=kind_phys), dimension(nlp1), intent(in)  ztdbt, integer, intent(in)  NLAY, integer, intent(in)  NLP1, real (kind=kind_phys), dimension(nlp1), intent(out)  zfu, real (kind=kind_phys), dimension(nlp1), intent(out)  zfd  )

private

Parameters

zrefb	layer direct beam reflectivity
zrefd	layer diffuse reflectivity
ztrab	layer direct beam transmissivity
ztrad	layer diffuse transmissivity
zldbt	layer mean beam transmittance
ztdbt	total beam transmittance at levels
NLAY,NLP1	number of layers/levels
zfu	upward flux at layer interface
zfd	downward flux at layer interface

General Algorithm

1. Link lowest layer with surface.
2. Pass from bottom to top.
3. Upper boundary conditions
4. Pass from top to bottom
5. Up and down-welling fluxes at levels.

Referenced by rrtmg_sw::spcvrtc(), and rrtmg_sw::spcvrtm().