Validation of Aeolus winds using radiosonde observations and NWP model equivalents

Aeolus is a European Space Agency (ESA) Earth Explorer mission, launched on 22 August 2018 as part of the Living Planet Programme. Providing atmospheric wind profiles on a global basis, the Earth Explorer mission is expected to demonstrate improvements in the quality of numerical weather prediction (NWP). A crucial prerequisite for the use of meteorological observations in NWP data assimilation systems is a detailed characterization of the quality to minimize systematic observation errors. As part of the German initiative EVAA (Experimental Validation and Assimilation of Aeolus Observations) validation and monitoring activities for Aeolus are performed using collocated radiosonde measurements and NWP forecast equivalents from two different global models, the ICOsahedral Nonhydrostatic model (ICON) of DeutscherWetterdienst (DWD) and the European Centre for Medium-Range Weather Forecast (ECMWF) Integrated Forecast System(IFS) model, as reference data. Systematic differences and bias dependencies are investigated and estimates for the Aeolus instrumental error are determined. Furthermore, impact experiments using the global ICON model are analyzed.