Here our main purpose is to analyze the information provided by A-Train and EarthCare observations on aerosol sources (natural and anthropogenic) and on the evolution of aerosol optical properties during transport on a regional scale (Euro-Mediterranean region) and at the high latitudes of the Northern Hemisphere. A particular emphasis will be placed on the analysis of the relative contribution of emissions from large fires. Wildfires regularly emit large amounts of aerosols during the spring and summer in Europe and in boreal forests. However, their impact is still not well quantified in chemistry transport models due to uncertainties on the emissions (amount emitted, size of the particles) but also on the injection height (as pyroconvection may lift emissions above the boundary layer for intense fires) and on the evolution during transport. Combined analysis of CALIPSO and in situ observations in Russia will help characterizing boreal fire plumes and their impact. Using both horizontal and vertical distributions of aerosol optical properties from the A-Train observations should then help improving the modeling of fire plumes and their impact.
More generally, these observations will be used to conduct a full evaluation of the aerosol simulation with the CHIMERE air quality model. The availability of near-real time future EarthCare observations could also prove extremely useful to support air quality forecasting platforms. The possibility to constrain the influence of sporadic events (dust storms or large fires) using the assimilation of the lidar observations will be evaluated.