THE SIZE DISTRIBUTION AND COMPOSITION OF THE ATMOSPHERIC AEROSOL AT ARURAL AND NEARBY URBAN LOCATION

At a suburban location near Vienna and in the center of Vienna the aer osol was sampled with a 10 stage rotating cascade impactor permitting the classification of the aerosol particle sizes between aerodynamic d iameters of 15 nm and 16 mu m. Both sampling sites were at an elevated location. Gravimetric, light absorption and PIXE analysis have been p erformed for all samples. The light absorption analysis also gives the concentration of black carbon, the PIXE analysis yielded concentratio ns of Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, and Pb. The mass size distribution of the aerosol for most of the elements had tw o modes. One peak occurred between 0.2 and 0.8 mu m, the coarse partic les had a slight peak usually above 3 mu m. On occasions an indication of a third peak below 50 nm could be observed. The total mass of the submicrometer particles was more than half of the total mass, except f or calcium and iron. Little difference between the mass of the submicr ometer particles at the two locations was found, except for Ca, Pb, an d black carbon. The particles were generally larger at the suburban lo cation. The light absorbing particles mostly had only one peak at a di ameter of 0.2 pm, thus being smaller than the other particles. Soot at the suburban location was a factor of 2 less and slightly larger than at the urban site. The similarity of the size distribution for almost all elements between the urban and the suburban location, as well as similarities to the arctic haze and the aerosol in Northern Europe sug gests that the aerosol predominately originates from non-local sources and might be considered the central and north European average aeroso l. Differences to aerosol characteristics at other locations exist. On a day-to-day basis the aerosol shows a very high variability. Copyrig ht (C) 1996 Elsevier Science Ltd