Page History

Documentation

• The new ecRad scheme is described in a paper in JAMES (Hogan and Bozzo 2018)
• An older version is documented in in the ECMWF Technical Memorandum by 787 (Hogan and Bozzo ( 2016).
• User Guide for the offline version of ecRad
• The best way to get started with ecRad is to try the practical exercises in the package
• Five Three solvers are available: McICA (Pincus et al. 2003), Tripleclouds (Hogan and Shonk 2008) and SPARTACUS (Hogan et al. 2016)., plus the plane-parallel "homogeneous" and "cloudless" solvers
• Gas optical properties are provided by the RRTM-G model from Atmospheric and Environmental Research (AER). or the ECMWF Correlated K-Distribution (ecCKD) tool
• Radiation is documented in Part IV, Chapter 2 of the IFS Documentation (although it unfortunately hasn't yet been updated to cover ecRad)
• Scientific and technical queries should be addressed to Robin Hogan at ecrad-support@ecmwf.
• The latest version is 1.0.1: see CHANGELOG

License

• int.
• Note on SPARTACUS 3D radiation solvers: while the shortwave algorithm appears to perform well in terms of computing the 3D effect of sub-grid clouds (Hogan et al. 2019), preliminary comparison of the longwave algorithm to explicit Monte Carlo calculations reveals that it can significantly overestimate the 3D effect of high clouds, so should not be trusted until an alternative formulation addresses this issue.

Obtaining ecRad

• Latest version: ecrad-1.5.0.tar.gz (15 June 2022, CHANGELOG.txt)
• Older versions: ecrad-1.4.2.tar.gz (15 October 2021, CHANGELOG.txt), ecrad-1.4.1.tar.gz
• Access the latest development version of ecRad through GitHub

Earlier versions of ecRad were distributed The offline version of ECRAD is provided under the terms and conditions of the OpenIFS licence, which is the same license as used for the full OpenIFS model.  The key points of this license are as follows

• The license is free, but it is not an open-source license (despite the name).
• Licenses are provided per institute and require an authoritative signature from the host institution. Personal licenses are not available.
• The license permits free educational and research use to research and academic institutions.
• Commercial use of the code is not permitted, nor is dissemination of real-time data products generated using the software.
• The license is perpetual: it does not need to be renewed once signed. The license can be terminated at any time by the licensee.
• Redistribution of the software (modified or unmodified) to any non-licensed institute outside the licensed institute is forbidden.

The licence is not intended to be a barrier to the use of ECRAD so please get in touch with any licensing queries.

Getting started

• Please email ecrad-support@ecmwf.int to request a license, stating your name, institute, position, and a brief summary of what you would like to do with the ECRAD software.
• If approved, complete and sign the license agreement.
• Once a license is granted, download access will be provided to the source code.
• Scientific and technical queries should be addressed to Robin Hogan at ecrad-support@ecmwf.int.

These more restrictive licenses are still valid for those who have them. Please note that the open source Apache License only applies to ecRad version 1.4.0 and later, which has had an appropriate copyright and license statement added to each source file.

Aerosol optical property files

• 48r1: aerosol_ifs_rrtm_48R1_v2.nc

Other resources

• Sample input data file - an ERA5 pole-to-pole slice from 12 UTC, 11 July 2019, at a longitude of 5 degrees East: era5slice.nc; this is now the basis for the practical exercises available in the ecRad package since verson 1.3.0
• Greenhouse gas climatology and timeseries used operationally in IFS Cycle 47R1: greenhouse_gas_climatology_46r1.nc, greenhouse_gas_timeseries_CMIP6_SSP370_CFC11equiv_47r1.nc
• Greenhouse gas timeseries for various CMIP3, CMIP5 and CMIP6 scenarios: greenhouse_gas_timeseries_CMIP.zip
• Total solar irradiance timeseries used operational in IFS Cycle 47R1: total_solar_irradiance_CMIP6_47r1.nc
• 3D monthly aerosol climatology derived from CAMS reanalysis system as described by Bozzo et al. (2020): FTP site containing netCDF file (274 MB)
• Operational version of 3D monthly aerosol climatology (as above but with a manual reduction of absorbing aerosol over central Africa which degraded forecasts): FTP site containing netCDF file (274 MB)
• Cloud droplet optical property file with phase functions, for use with FLOTSAM-enabled branch of ecRad: mie_droplet_scattering_pf.nc.gz
• Ice particle optical property file with phase functions: baum-general-habit-mixture_ice_scattering_pf.nc.gz