This page describes how to access the offline version of the new ECMWF radiation scheme "ECRAD". ECRAD is used in ECMWF Integrated Forecasting System from Cycle 43R3. It is 30-35% faster than the McRad scheme used in earlier cycles, and its modular design allows the spectral resolution, the description of cloud and aerosol optical properties, and the solver, to be changed independently of one another. Its offline version is well suited for use as a research tool.
Use of ECRAD requires an OpenIFS license. The license is free and straightforward to complete. Once a license is granted, download access is provided to the source code. ECRAD is written in Fortran 90 and has been tested on the GNU, PGI and Cray compilers. A prerequisite is the NetCDF library.