Mercury Studies around the Mediterranean Sea Basin: Ten years of Measurements and Modeling results.

Only a few years ago the presence of Reactive Gaseous Mercury (RGM) was believed to be almost exclusively the result of anthropogenic emissions and that sustained high RGM concentrations in the MBL were not considered likely. During the past ten years, an in-depth investigation was carried out in the Marine Boundary Layer (MBL) of the Mediterranean Sea to quantify and possibly explain spatial and temporal patterns of Hg-species concentrations. This paper provides an overview of modeling results and atmospheric measurements performed during several cruise campaigns performed aboard the Research Vessel (RV) URANIA of the CNR over the Mediterranean sea basin. RGM concentrations have been modelled using a photochemical box model of the MBL and compared to measured data obtained during the research cruises. The comparison results supports the hypothesis that there are daytime mercury oxidation reactions occurring which have not yet been identified. Major findings of key studies carried out during ten years of ship-borne activities have been highlighted.