Eleven years of Saharan mineral dust transport at Mt. Cimone GAW station.

Mineral dust aerosol is ubiquitous in the atmosphere and globally constitutes the greatest sources of particulate matter (Huneeus et al.,2012), with Africa (in particular the Sahara and Sahel region) responsible for approximately half of its global emissions (Ginoux et al., 2012). The mobilized aerosol can be transported over large distances by the synoptic circulation, both over the Atlantic Ocean and over the Mediterranean Basin, with evident effects near the source regions and in the regions downwind of them that are both direct and indirect. However African mineral dust emissions are not steady (Chin et al., 2014) and this variations are responsible for considerable variations of the climatic impact of mineral aerosol, both on a local and global scale and underline the existing need for databases of continuous, high quality measurements to get a global overview of the impact of mineral dust on different atmospheric processes. Mt Cimone (2165 m a.s.l.) in the Italian northern Apennines, represents one of the first mountain ridges that are affected by the northward transport of mineral dust from Africa in Europe. At the Monte Cimone GAW global station (CMN), a continuous monitoring of Saharan dust transport is active since August 2002. Here we present a long-term (August 2002 - November 2012) characterization of mineral dust transport from North Africa and its impact on the atmospheric composition. The daily average number concentration of coarse particles (N1-10, 1 ?m < Dp < 10 ?m), a proxy for mineral dust at high altitude remote sites, together with the analysis of 3-D back-trajectories calculated by the FLEXTRA model and ending at CMN have been used to detect Dust Transport Events (DTE) at the measurement site. The climatological analysis of the monthly distribution of DTEs (Fig. 1) and their influence on the monthly average particle number concentration, the main sources in North Africa of the dust observed at the measurement site, the relation between the observed ozone surface (Fig. 2) concentration and the mineral dust are also discussed together with the impact that the detected DTE have on the air-quality in the Po Valley, an hot-spot region for regional climate and air-quality changes.