Progress in the Aeolus Level-2B/C processing software and its implementation at ECMWF
Rennie, Michael¹; Isaksen, Lars¹; Stoffelen, Ad^2
1European Centre for Medium-Range Weather Forecasts (ECMWF), Reading,, UNITED KINGDOM; ²Royal Dutch Meteorological Institute (KNMI), De Bilt, NETHERLANDS

With the expected launch date of mid-2015 for ESA's Earth Explorer Aeolus Doppler wind lidar mission, developments are continuing to the Aeolus L2B/C processing software. This software retrieves horizontal line-of-sight (HLOS) wind observations suitable for use in numerical weather prediction (NWP), from the near-surface to 30 km with near-global extent. The software has been developed over many years through many contributors; however the L2B team currently consists of ECMWF and KNMI (previously it included Météo-France and DLR). ECMWF will run the L2B/C processing operationally during the mission’s three-year lifetime, with the intention of assimilating the products in the ECMWF analysis. The software is designed to be portable and easy to use. It is freely available to NWP centres so that they can implement their own observation processing. This presentation will provide an overview of the software and discuss recent changes to accommodate the continuous mode operation of Aeolus, such as a flexible averaging algorithm for the observations. We go on to present the end-to-end testing results from the Aeolus simulator/L1B/L2B processing chain, based on realistic optical properties and atmospheric inputs, using the expected mission launch-time specifications. The verification of these results is thought to provide a realistic indication of the quality of Aeolus L2B products, in particular the random and systematic errors of the winds. We will discuss how the processing is implemented within the ECMWF system and how it fits into ESA's Aeolus ground segment. Finally, we will present how the data is planned to be assimilated at ECMWF.