Aeolus

Aeolus is the fifth planned satellite in the Living Planet Programme of the European Space Agency. The mission's objective is to provide profiles of high-quality wind observations from the surface to the lower stratosphere, using a Doppler wind lidar (DWL) instrument (known as ALADIN) in a near-polar sun-synchronous, dawn-dusk orbit (320 km altitude). The wind information is the horizontal line-of-sight (HLOS) component, in the direction perpendicular to the satellite's velocity. The mission is intended to have a minimum lifetime of three years. ECMWF is contracted by ESA to develop, in collaboration with KNMI, the Aeolus Level 2B/C processing software i.e. the wind retrieval. The L2B wind retrieval algorithms have also been developed in the past in collaboration with Météo-France, DLR and LMD/IPSL. ECMWF will generate the L2B products operationally and in NRT in the L2/Met PF (Level-2/Meteorological Processing Facility; a part of the mission's Ground Segment), and will disseminate the products to ESA for further distribution to users. ECMWF will also convert the L2B Earth Explorer format products to a WMO approved BUFR format and will provide these to EUMETSAT for further distribution to the NWP/research community via the GTS. ECMWF intend to assimilate the Aeolus L2B wind observations in ECMWF's global NWP (Numerical Weather Prediction) model if they are able to improve forecast skill. ECMWF has contributed to ESA funded observation impact studies to assess the potential impact of the Aeolus data. We expect the Aeolus mission to have a positive impact on analysis and forecast quality, particularly tropical winds. Given that ALADIN is a High Spectral Resolution Lidar, it is also possible to derive information useful for atmospheric composition modelling. Aeolus will also provide information on the atmosphere's cloud and aerosol optical properties (backscatter and extinction coefficients, via the Level-2A product)