HARMONIE-AROME Radiation Studies 2011-2016

Abstract

Introduction : The idea for a HARMONIE-AROME radiation comparison was presented five years ago at the annual EWGLAM /SRNWP meeting (Rontu, 2011). It was suggested that the best radiation parametrizations for a meso-scale NWP model are those which can optimally and consistently use information about cloud microphysical properties, cloud extent, surface radiation properties and aerosol data available in the model; this information varies rapidly in both time and space. There was a need to create a platform for the comparison of radiation parametrizations of varying complexity in a unified environment. Consequently, such a platform has been built within the AROME physics subroutine (apl_arome), where the IFS (from here onwards: IFSRADIA; ECMWF, 2006), ALARO (ACRANEB2; Mašek et al., 2016) and HIRLAM (HLRADIA, Savijärvi, 1990; Wyser et al., 1999) radiation schemes can now be called using the same input fields. In addition, each scheme generates the same output parameters. To date, nine radiation working weeks have been arranged between 2012 and 2016 in order to make comparisons of and improvements to the schemes available in HARMONIE-AROME. A summary of some of this work and outcomes is presented in this article.