Lidar Data Assimilation and Other Things

[09-Jan-2023] Abstract  The path of science is often winding. I have started in a lidar group at University of Rome, La Sapienza in the early 90s' and ended up doing lidar data assimilation at the European Centre for Medium-Range Weather forecasts for the last 20 years, passing through Colorado State University for a PhD. I would like to share my experience working with lidar data from the point of view of the user. Examining how each choice has led to the subsequent steps can help young researchers find their own path in the field. Lidar data are a precious source of information on atmospheric aerosols and clouds. Our recent experience is with the Aeolus backscatter data. The European Space Agency (ESA) Aeolus mission focuses on wind observations, thanks to the deployment of the ALADIN wind Doppler lidar. However, it also delivers particle backscatter measurements which can be exploited to understand aerosols and clouds. At ECMWF, within the Copernicus Atmospheric Monitoring Service activities, we have been assimilation particle backscatter in a configuration which mimics the operational one since January 2022. While this is still experimental, this research enables us to get ready for aerosol-specific lidar missions such as EarthCARE and AOS. This presentation will cover (1) the pathway from a lidar lab to lidar data assimilation with (2) specific lessons learned over many years of research and development; and (3) the lessons learned from the Aeolus lidar assimilation to support air quality and Numerical Weather Prediction applications.