Recommendations and Generic Data Assimilation Tools for the Improvement of CAMS Regional Air Quality Service

Within Copernicus Atmosphere Monitoring Service (CAMS) an ensemble of 9 chemistry transport models provides daily analyses and forecasts, as well as annual reanalyses over Europe. The CAMS_61 project was developed to provide development plans, guidelines and tools for the upgrade of the models within this regional air quality service. In this study we will present the main outcomes of the CAMS_61 project with special focus on the generic data assimilation tool developed to promote the uptake of Sentinel 4 and 5 satellite observations within the service. The tool consists of a pre- and post-processor tool for the download, selection, conversion and visualisation of the satellite data and an observation operator source code that could in principle be included in any data assimilation system for the simulation of the observations using model variables. The tool has been tested on TROPOMI data within different model/assimilation systems and on a set of simulated Sentinel 4 data.