Formation of Nitrate and Sulfate in the Plume of Berlin

Abstract

The near-ground aerosol chemical composition was studied at two stationary sites in the vicinity of Berlin during a field campaign in summer 1998. By means of analysis of the wind field, two episodes were identified which allow to study changes within individual air masses during transport. The probability of occurrence of situations during which the downwind site (50 km downwind of Berlin) would be hit by an urban plume is >7.4%. Furthermore, for the general case of rural areas in Germany it is estimated that for more than half of these there is a significant probability to be hit by an urban plume (>8%). The S (VI) formation rates are higher than explainable by homogeneous gas-phase chemistry and suggest the involvement of heterogeneous reactions of aerosol particles.