Significance of atmospheric fallout on the upper layer water chemistry of the North-Western Mediterranean

The atmospheric input is established for almost forty trace and major elements at a coastal site on the North-Western Mediterranean. Comparison with the Rhône River input at the scale of the Gulf of Lions shows that the total atmospheric input dominates for elements of anthropogenic origin such as Cd, Pb, Sb and Zn. Dissolved input of atmospheric origin is very important for these elements and for those of terrigenous origin (Al and Fe). In the coastal zone, both dissolved external sources (atmosphere and Rhône River) can explain the high Mediterranean Surface waters concentrations. Atmospheric input becomes rapidly the predominant factor, while the riverine influence being negligible in the few tens' kilometers outside the river mouth.Paper submitted to the 7th International Symposium of the Commission for Atmospheric Chemistry and Global Pollution on the Chemistry of the Global Atmosphere held in Chamrousse, France, from 5 to 11 September 1990.