Radiation Gases Module

This module sets up constant gas profiles, such as co2, ch4, n2o, o2, and those of cfc gases. All data are entered as mixing ratio by volume. More...

Modules
module	module_radiation_gases
	This module sets up constant gas rofiles, such as co2, ch4, n2o, o2, and those of cfc gases.

Functions/Subroutines
subroutine, public	module_radiation_gases::gas_init (mpicomm, mpirank, mpiroot, co2usr_file,
	This subroutine sets up co2, etc. parameters.
subroutine, public	module_radiation_gases::gas_update (iyear, imon, iday, ihour, ldoco2,
	This subroutine reads in 2-d monthly co2 data set for a specified year. Data are in a 15 degree lat/lon horizontal resolution.
subroutine, public	module_radiation_gases::getgases (plvl, xlon, xlat, imax, lmax, ico2flg,
	This subroutine sets up global distribution of radiation absorbing gases in volume mixing ratio. Currently only co2 has the options from observed values, all other gases are asigned to the climatological values.

Detailed Description

This module sets up constant gas profiles, such as co2, ch4, n2o, o2, and those of cfc gases. All data are entered as mixing ratio by volume.

Figure 1: Atmospheric radiative

forcing, relative to 1750, by long-lived greenhouse gases and the 2016 update of the NOAA Annual Greenhouse Gas Index (AGGI)" NOAA Annual Greenhouse Gas Index (AGGI) shows that from 1990 to 2016, radiative forcing by long-lived greenhouse gases (LLGHGs) increased by 40%, with \(CO_2\) accounting for about 80% of this increase (WMO Greenhouse Gas Bulletin (2017) [198]).

Operational GFS selection for gas distribution:
CO2 Distribution (namelist control parameter -ICO2=2):
ICO2=0: use prescribed global annual mean value (currently=380ppmv)

ICO2=1: use observed global annual mean value
ICO2=2: use observed monthly 2-d data table in \(15^o\) horizontal resolution

Trace Gases (currently using the global mean climatology in unit of ppmv): \(CH_4-1.50\times10^{-6}\); \(N_2O-0.31\times10^{-6}\); \(O_2-0.209\); \(CO-1.50\times10^{-8}\); \(CF12-6.36\times10^{-10}\); \(CF22-1.50\times10^{-10}\); \(CF113-0.82\times10^{-10}\); \(CCL4-1.40\times10^{-10}\)

Version

NCEP-Radiation_gases v5.1 Nov 2012

Function/Subroutine Documentation

gas_init()

subroutine, public module_radiation_gases::gas_init	(	type(mpi_comm), intent(in)	mpicomm,
		integer, intent(in)	mpirank,
		integer, intent(in)	mpiroot,
		character(len=26), intent(in)	co2usr_file
	)

This subroutine sets up co2, etc. parameters.

Parameters

me	print message control flag
co2usr_file	co2 user defined data table
co2cyc_file	co2 climotology monthly cycle data table
ictmflg	data ic time/date control flag
ico2flg	co2 data source control flag
con_pi	physical constant Pi
errflg	error flag
errmsg	error message

gas_init General Algorithm

Definition at line 210 of file radiation_gases.f.

gas_update()

subroutine, public module_radiation_gases::gas_update	(	integer, intent(in)	iyear,
		integer, intent(in)	imon,
		integer, intent(in)	iday,
		integer, intent(in)	ihour,
		logical, intent(in)	ldoco2
	)

This subroutine reads in 2-d monthly co2 data set for a specified year. Data are in a 15 degree lat/lon horizontal resolution.

Parameters

iyear	year of the requested data for fcst
imon	month of the year
iday	day of the month
ihour	hour of the day
ldoco2	co2 update control flag
me	print message control flag
co2dat_file	co2 2d monthly obsv data table
co2gbl_file	co2 global annual mean data table
ictmflg	data ic time/date control flag
ico2flg	co2 data source control flag
errflg	error flag
errmsg	error message

gas_update General Algorithm

• co2 data section

Definition at line 463 of file radiation_gases.f.

getgases()

subroutine, public module_radiation_gases::getgases	(	real (kind=kind_phys), dimension(:,:), intent(in)	plvl,
		real (kind=kind_phys), dimension(:), intent(in)	xlon,
		real (kind=kind_phys), dimension(:), intent(in)	xlat,
		integer, intent(in)	imax,
		integer, intent(in)	lmax,
		integer, intent(in)	ico2flg
	)

This subroutine sets up global distribution of radiation absorbing gases in volume mixing ratio. Currently only co2 has the options from observed values, all other gases are asigned to the climatological values.

Parameters

plvl	(IMAX,LMAX+1), pressure at model layer interfaces(mb)
xlon	(IMAX), grid longitude in radians, ok both 0->2pi or -pi -> +pi arrangements
xlat	(IMAX), grid latitude in radians, default range to pi/2 -> -pi/2, otherwise see in-line comment
IMAX	horizontal dimension for output data
LMAX	vertical dimension for output data
ico2flg	(1), co2 data source control flag
top_at_1	(1), vertical ordering flag
con_pi	(1), physical constant Pi
gasdat	(IMAX,LMAX,NF_VGAS) - gases volume mixing ratioes (:,:,1) - co2 (:,:,2) - n2o (:,:,3) - ch4 (:,:,4) - o2 (:,:,5) - co (:,:,6) - cfc11 (:,:,7) - cfc12 (:,:,8) - cfc22 (:,:,9) - ccl4 (:,:,10) - cfc113 Internal module variables : co2vmr_sav - saved monthly co2 concentration from sub gas_update co2_glb - saved global annual mean co2 value from gas_update gco2cyc - saved global seasonal variation of co2 climatology in 12-month form

getgases General Algorithm

Definition at line 834 of file radiation_gases.f.