Validation of SeaWiFS and MODIS Aqua/Terra aerosol products in coastal regions of European marginal seas

The aerosol products associated with the ocean colour missions SeaWiFS andMODIS (both Aqua and Terra) are assessed with AERONET field measurementscollected in four European marginal seas for which fairly large uncertainties inocean colour in-water products have been documented: the northern Adriatic, theBaltic, Black and North Seas. On average, more than 500 match-ups are foundfor each basin and satellite mission, showing an overall consistency of validationstatistics across the three missions. The median absolute relative differencebetween satellite and field values of aerosol optical thickness τaat 443 nm varies from 12% to 15% for the three missions at the northernAdriatic and Black Sea sites, and from 13% to 26% for the Baltic and North Sea sites. It is in the interval 16-31% for the near-infrared band. The spectral shape of τaiswell reproduced with a median bias of the ngstr m exponent varyingbetween -15% and +14%, which represents a clear improvement with respectto previous versions of the atmospheric correction scheme. These results showthat the uncertainty associated with τa in the considered coastalwaters of the European marginal seas is comparable to global validationstatistics