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

Modules
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)

module	module_radsw_parameters
	This module is for specifying the band structures and program parameters used by the RRTMG-SW scheme.

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, dzlyr, delpin, de_lgth, alpha, cosz, solcon, nday, idxday, npts, nlay, nlp1, lprnt, inc_minor_gas, iswcliq, iswcice, isubcsw, iovr, top_at_1, iswmode, cld_cf, lsswr, iovr_rand, iovr_maxrand, iovr_max, iovr_dcorr, iovr_exp, iovr_exprand, hswc, topflx, sfcflx, cldtau, 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, rad_hr_units, inc_minor_gas, iswcliq, isubcsw, iovr, iovr_rand, iovr_maxrand, iovr_max, iovr_dcorr, iovr_exp, iovr_exprand, iswmode, errflg, errmsg)
	This subroutine initializes non-varying module variables, conversion factors, and look-up tables.

Detailed Description

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

The SW radiation model in the current NOAA Environmental Modeling System (NEMS) was adapted from the RRTM radiation model developed by AER Inc. ([41]; [143]). 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

The RRTMG-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:
- rrtmg_sw_run(): the main SW radiation routine
- rswinit(): the initialization routine

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

RRTMG Shortwave Radiation Scheme General Algorithm

Function/Subroutine Documentation

◆ rrtmg_sw_run()

subroutine, public rrtmg_sw::rrtmg_sw_run	(	real (kind=kind_phys), dimension(:,:), intent(in)	plyr,
		real (kind=kind_phys), dimension(:,:), intent(in)	plvl,
		real (kind=kind_phys), dimension(:,:), intent(in)	tlyr,
		real (kind=kind_phys), dimension(:,:), intent(in)	tlvl,
		real (kind=kind_phys), dimension(:,:), intent(in)	qlyr,
		real (kind=kind_phys), dimension(:,:), intent(in)	olyr,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_co2,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_n2o,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_ch4,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_o2,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_co,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_cfc11,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_cfc12,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_cfc22,
		real(kind=kind_phys), dimension(:,:), intent(in)	gasvmr_ccl4,
		integer, dimension(:), intent(in)	icseed,
		real(kind=kind_phys), dimension(:,:,:), intent(in)	aeraod,
		real(kind=kind_phys), dimension(:,:,:), intent(in)	aerssa,
		real(kind=kind_phys), dimension(:,:,:), intent(in)	aerasy,
		real (kind=kind_phys), dimension(:), intent(in)	sfcalb_nir_dir,
		real (kind=kind_phys), dimension(:), intent(in)	sfcalb_nir_dif,
		real (kind=kind_phys), dimension(:), intent(in)	sfcalb_uvis_dir,
		real (kind=kind_phys), dimension(:), intent(in)	sfcalb_uvis_dif,
		real (kind=kind_phys), dimension(:,:), intent(in)	dzlyr,
		real (kind=kind_phys), dimension(:,:), intent(in)	delpin,
		real (kind=kind_phys), dimension(npts), intent(in)	de_lgth,
		real (kind=kind_phys), dimension(npts,nlay), intent(in)	alpha,
		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,
		logical, intent(in)	inc_minor_gas,
		integer, intent(in)	iswcliq,
		integer, intent(in)	iswcice,
		integer, intent(in)	isubcsw,
		integer, intent(in)	iovr,
		logical, intent(in)	top_at_1,
		integer, intent(in)	iswmode,
		real (kind=kind_phys), dimension(:,:), intent(in)	cld_cf,
		logical, intent(in)	lsswr,
		integer, intent(in)	iovr_rand,
		integer, intent(in)	iovr_maxrand,
		integer, intent(in)	iovr_max,
		integer, intent(in)	iovr_dcorr,
		integer, intent(in)	iovr_exp,
		integer, intent(in)	iovr_exprand,
		real (kind=kind_phys), dimension(:,:), intent(inout)	hswc,
		type (topfsw_type), dimension(:), intent(inout)	topflx,
		type (sfcfsw_type), dimension(:), intent(inout)	sfcflx,
		real (kind=kind_phys), dimension(:,:), intent(inout)	cldtau,
		real (kind=kind_phys), dimension(:,:), intent(inout), optional	hsw0,
		real (kind=kind_phys), dimension(:,:,:), intent(inout), optional	hswb,
		type (profsw_type), dimension(:,:), intent(inout), optional	flxprf,
		type (cmpfsw_type), dimension(:), intent(inout), optional	fdncmp,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_lwp,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_ref_liq,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_iwp,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_ref_ice,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_rwp,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_ref_rain,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_swp,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_ref_snow,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_od,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_ssa,
		real (kind=kind_phys), dimension(:,:), intent(in), optional	cld_asy,
		character(len=*), intent(out)	errmsg,
		integer, intent(out)	errflg
	)

Compute solar constant adjustment factor (s0fac) according to solcon.

Initial output arrays (and optional) as zero.

Change random number seed value for each radiation invocation (isubcsw =1 or 2).

Prepare surface albedo: bm,df - dir,dif; 1,2 - nir,uvv.

Prepare atmospheric profile for use in rrtm.

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 ( \( mol/cm^2 \))

Read aerosol optical properties from 'aerosols'.

Read cloud optical properties from 'clouds'.

Compute fractions of clear sky view:
- random overlapping
- max/ran overlapping
- maximum overlapping

For cloudy sky column, call cldprop() to compute the cloud optical properties for each cloudy layer.

Call setcoef() to compute various coefficients needed in radiative transfer calculations.

Call taumol() to calculate optical depths for gaseous absorption and rayleigh scattering

Call the 2-stream radiation transfer model:
- if GFS_typedefs::isubcsw .le.0, using standard cloud scheme, call spcvrtc().
- if GFS_typedefs::isubcsw .gt.0, using mcica cloud scheme, call spcvrtm().

Save outputs.

Definition at line 493 of file radsw_main.F90.

◆ rswinit()

subroutine, public rrtmg_sw::rswinit	(	integer, intent(in)	me,
		integer, intent(in)	rad_hr_units,
		logical, intent(in)	inc_minor_gas,
		integer, intent(in)	iswcliq,
		integer, intent(in)	isubcsw,
		integer, intent(in)	iovr,
		integer, intent(in)	iovr_rand,
		integer, intent(in)	iovr_maxrand,
		integer, intent(in)	iovr_max,
		integer, intent(in)	iovr_dcorr,
		integer, intent(in)	iovr_exp,
		integer, intent(in)	iovr_exprand,
		integer, intent(in)	iswmode,
		integer, intent(out)	errflg,
		character(len=*), intent(out)	errmsg
	)

This subroutine initializes non-varying module variables, conversion factors, and look-up tables.

Parameters

me	print control for parallel process

rswinit General Algorithm

Setup constant factors for heating rate the 1.0e-2 is to convert pressure from mb to \(N/m^2\) .

Define exponential lookup tables for transmittance.

Definition at line 1390 of file radsw_main.F90.

Modules