UPDATES IN THE ASSIMILATION OF GEOSTATIONARY RADIANCES AT ECMWF

Currently, ECMWF assimilates clear sky radiances (CSRs) from geostationary platforms into its 4D-Var analysis system (Courtier et al, 1994), alongside other satellite and conventional data. So far, CSRs from the water vapour channels only are assimilated, which mainly generates increments in upper tropospheric relative humidity (RH). Since 2006, a number of changes have occurred in both the network of CSRs used at ECMWF and the way these are assimilated. This note presents the latest updates of the geostationary CSR assimilation in the operational system. An overview of the monitoring of EUMETSAT reprocessed CSRs in the framework of the ERA-interim project is also shown, together with the plans for the future use of geostationary CSRs at ECMWF.