Size-resolved aerosol characterization for a polluted episode at the IfT research station Melpitz in autumn 1997

Inorganic ions, organic carbon (OC), elemental carbon (EC) and a variety of organic single species in airborne particles have been determined at the research station of the Leibniz - Institut fur Tropospharenforschung (IfT) in Melpitz (Germany) in autumn 1997. Samples of eight selected measurement events were divided in two groups in order to investigate differences in the chemical composition of particles originating from southwesterly ( SW - developed EU countries) or from easterly directions ( E - less developed eastern countries). Differences between these two groups were tested statistically by Student's t-test. Five stage cascade impactor samples show nitrate as most abundant in the accumulation mode in the SW group. EC and sulphate show the most abundant mass fractions in the E group. That can be considered as a consequence of domestic coal heating and coal-fired power plant emissions in the region of westerly Poland, northern Czech Republic and easterly Germany. Higher nitrate concentrations in the SW group can be explained by stronger NOx emissions caused by the leeward plume of the conurbation of Leipzig, as well as by the still higher traffic density in western Germany. The methane sulphonic acid ( MSA) mass fraction was higher for SW air masses in accumulation mode particles, probably indicating marine origin. Succinic acid also showed higher mass fractions for the SW group. This could be caused by primary emission in automobile exhaust gases and photochemical formation during transport from SW. Indeed, during SW sampling, solar radiation intensity was higher than during E sampling. The observed differences in the particle composition are an expression of the still existing technology gradient in Europe. Future campaigns could show the development to a joint economy with smaller differences in anthropogenic emissions.