QA4EO WP2360 AOD@440NM - Improved surface-based aerosol retrievals using NO2 correction

This work is focused on  the improvement of aerosol optical depth (AOD) and Ångström exponent (AE) datasets based on a correction using synchronous NO₂ data.  Development of this method is based on the fact that currently satellite climatological NO₂ values are used for correcting the AOD retrievals for NO2 related optical depth. However, NO₂ has high spatiotemporal variability, hence these values are rarely representative of the actual atmospheric conditions. Recently developed PGN offers reliable, high measurement frequency ground-based data for NO₂ column. These data were used to evaluate the current uncertainty of AOD and AE retrievals and produce a corrected database for two stations in Rome. These stations have more than 3 years of colocated measurements of AERONET, SKYNET and PGN, hence the corrections was applied to AOD and AE products