AIR MASS TRANSPORT AND PRECIPITATION CHEMICAL COMPOSITION IN SOUTH-WEST BULGARIA

The purpose of the investigation is to determine the dependency between the precipitations' chemical composition and the origin and trajectory of the precipitating air masses. The local and adjective components of precipitation pollution are illustrated through four types of precipitation situations. The contribution of local pollution to the precipitation's composition is assessed through air quality analysis before and after the precipitation.The present work investigates the chemical composition of precipitations in Bulgaria under three types of general atmospheric circulation ? WZ, SWA, and NZ according to the classification of Hess and Brezowsky and Mediterranean cyclones. A relationship between the precipitations' chemical composition and the path of the cloud systems was studied. The presence of the main anthropogenic ions in the air leading to precipitation acidity was investigated. The influence of trans-boundary factors is determined analysing the simultaneous precipitations from the same cloud systems in urban arias and the background regions. The pollution sources in South-West Bulgaria have not been investigated vis-à-vis precipitation chemical composition till now. Nor have there been comparisons between precipitations’ chemical composition in urban areas and background stations. The contribution of trans-boundary transport on the precipitation composition has not been differentiated.