Date: April 2004 This is an update for users of RRTM_SW, the shortwave rapid radiative transfer model developed by Atmospheric and Environmental Research, Inc. Users may obtain update information and retrieve code via the web-site http://rtweb.aer.com or via anonymous ftp to ftp.aer.com and change directory to pub/downloads/aer_rrtm_sw. Binary data transfer should be used when downloading each file. RRTM_SW v2.4.1 has been updated to RRTM_SW v2.5 * Updated DISORT v1 to DISORT v2. * Improved cloud properties routine to: a) include scattering properties of spheres, based on the parameterization by Key et al. in the STREAMER RT code. b) to output a file (OUT_CLD_RRTM) with the cloud scattering properties by layer. c) changed name of cldprop_sw.f to cldprop.f to be consistent with RRTM_LW structure. * Updated atmospheric properties module RRTATM to be compatible with the most recent version of LBLATM v8.1. * Removed unnecessary duplicate calculations which occurred for option IOUT=98. * Added new solar variability option (ISOLVAR). * Changed number of significant digits in the net flux output in OUTPUT_RRTM. * Changed format statement in subroutine readaer to allow more than 4 aerosol layers (naer, format statement 9010). * Updated instruction manual. * Modified makefiles to be double precision, as required to keep robust results from DISORT. ********************************************************************* CODE: RRTM_SW *** KEY FEATURES *** *** IN RRTM_SW *** ^ k-distributions are obtained directly from a line-by-line radiative transfer code, LBLRTM , which has been extensively validated against observations, principally at the ARM SGP site ^ fluxes and cooling rates can be calculated over fourteen contiguous bands in the shortwave (820-50000 cm-1) ^ modeled sources of extinction are water vapor, carbon dioxide, ozone, methane, oxygen, aerosols, and Rayleigh scattering, and clouds ^ liquid cloud optical properties are parameterized using the Hu and Stamnes parameterization (J. Climate, 6, 728-742, 1993) ^ ice cloud optical properties are parameterized using the Fu parameterization (J. Climate, 9, 2058 - 2082, 1996) ^ DISORT is used to perform scattering calculations (Stamnes et al., Appl. Opt. 27, 2502-2509, 1988) ^ agreement with clear-sky line-by-line calculations: 1 W/m2 for direct irradiance, 2 W/m2 for diffuse irradiance ^ Important note: Version 2.4 of RRTM_SW handles only 100% cloudy cases. Partial cloudiness is not an option at this time. ******************************************************************** ********************************************************************* RRTM_SW References Mlawer, E.J., and S.A. Clough, Shortwave and longwave enhancements in the rapid radiative transfer model, in Proceedings of the 7th Atmospheric Radiation Measurement (ARM) Science Team Meeting, U.S. Department of Energy, CONF-970365, 1998. Mlawer, E.J., and S.A. Clough, On the extension of rapid radiative transfer model to the shortwave region, in Proceedings of the 6th Atmospheric Radiation Measurement (ARM) Science Team Meeting, U.S. Department of Energy, CONF-9603149, 1997. Mlawer, E.J., S.J. Taubman, P.D. Brown, M.J. Iacono and S.A. Clough: RRTM, a validated correlated-k model for the longwave. J. Geophys. Res., 102, 16,663-16,682, 1997 *********************************************************************** *********************************************************************** Obtaining RRTM_SW Anonymous FTP of RRTM_SW via rtweb.aer.com Source Code, Makefiles, Instructions: pub/downloads/aer_rrtm_sw/aer_rrtm_sw_v2.5.tar.gz Example Run Files: pub/downloads/aer_rrtm_sw/aer_rrtm_sw_examples_v2.5.tar.gz Latest Update Description: pub/downloads/aer_rrtm_sw/update_rrtm_sw_v2.5.txt Note: To FTP directly from web brower you must have you preferences set to send email address an anonymous FTP password. Can also use anonymous FTP performing the following: ftp ftp.aer.com login: anonymous password: your email address cd pub/downloads/aer_rrtm_sw/ get aer_rrtm_sw_v2.5.tar.gz get aer_rrtm_sw_examples_v2.5.tar.gz To unpack tarred and zipped files on Unix: gunzip aer_rrtm_sw_v2.5.tar.gz tar -xvf aer_rrtm_sw_v2.5.tar gunzip aer_rrtm_sw_examples_v2.5.tar.gz tar -xvf aer_rrtm_sw_examples_v2.5.tar *********************************************************************** If you have any questions, problems, or comments, please contact either Eli Mlawer or Jennifer Delamere at Atmospheric and Environmental Research, Inc. 131 Hartwell Avenue Lexington, MA 02421 e-mail addresses: emlawer@aer.com, jdelamer@aer.com ***********************************************************************