Aeolus Rayleigh‐channel winds in cloudy conditions

Aeolus is the first Doppler wind lidar (DWL) to measure wind profiles from space. Aeolus is an ESA (European Space Agency) explorer mission with the objective to retrieve winds from the collected atmospheric return signal which is the result of Mie and Rayleigh scattering of laser emitted light by atmospheric molecules and particulates. During the course of the mission the quality of Aeolus winds measured in clear air conditions from Rayleigh channel collected data, so called Rayleigh‐clear winds, has improved substantially. The same is true for winds measured in cloudy and aerosol rich atmospheric conditions from Mie channel collected data, the so‐called Mie‐cloudy winds. For the latter conditions, good quality winds can in principle also be obtained from Rayleigh channel collected data, the so‐called Rayleigh‐cloudy winds, if contamination of the purely molecular signal by Mie scattering is well addressed. We assess a linear and non‐linear correction for Mie contamination, the latter with the aid of Numerical Weather Prediction (NWP) model data for determing the correction parameters. We show that the non‐linear correction is able to provide unbiased Rayleigh‐cloudy winds. This makes Rayleigh‐cloudy winds suitable for use in NWP, but also for direct comparison with other wind observations obtained in cloudy conditions such as atmospheric motion wind vectors.This article is protected by copyright. All rights reserved.