Aeolus: ESA’s wind mission. Status and future challenges

The European Space Agency (ESA)’s wind mission, Aeolus, was launched on 22 August 2018. Aeolus is a member of the ESA Earth Explorer family and its main objective is to demonstrate the potential of Doppler wind Lidars in space for improving weather forecast and to understand the role of atmospheric dynamics in climate variability. Aeolus carries a single instrument called ALADIN: a high sophisticated spectral resolution Doppler wind Lidar which operates at 355 which is the first of its kind to be flown in space. It provides profiles of single horizontal line-of-sight winds (primary product) in near-real-time (NRT), and profiles of atmospheric backscatter and extinction. The instrument samples the atmosphere from about 30 km down to the Earth’s surface, or down to optically thick clouds. The required precision of the wind observations is 1-2.5 m/s in the troposphere and 3-5 m/s in the stratosphere while the systematic error requirement be less than 0.7 m/s. The mission spin-off product includes information about aerosol and cloud layers. The satellite flies in a polar dusk/dawn orbit (6 am/pm local time), providing ~16 orbits per 24 hours with an orbit repeat cycle of 7 days. Global scientific payload data acquisition is guaranteed with the combined usage of Svalbard and Troll X-band receiving stations.

The status of the Aeolus mission will be provided, including its performance assessment, planned operations and exploitation in the near future. This comprises the outcome of the instrument in its early operation phase, calibration and validation activities and a general review of the main scientific findings. Scope of the paper is also to inform about the programmatic highlights and future challenges.