SOURCES AND PHYSICOCHEMICAL CHARACTERISTICS OF THE ATMOSPHERIC AEROSOL IN SOUTHERN NORWAY

An intensive aerosol sampling campaign was carried out simultaneously at Birkenes and Nordmoen, southern Norway, from 11 April to 4 May 1988 . Two different size segregative sampling instruments were used at eac h site. Parallel analysis was performed using several methods which al lowed the determination of up to 45 components. The atmospheric concen trations were mostly found to be similar at the two sampling sites,whi ch are separated by a distance of about 250 km. During long-range tran sport episodes, the pollutant concentrations were 20-50 times higher t han during background periods. At the Birkenes site detailed informati on about the elemental and particle mass size distributions was obtain ed from Berner low-pressure impactor samples. The aerosol fine particl e mode clearly shifted to larger particle sizes when the average relat ive humidity was higher than 80% during sampling. The average fine to total elemental concentration ratios of most elements were found to be similar for the different samplers and for the two sites, although di fferences between the sires occurred depending on the origin of the ai r masses sampled. A new approach based on the size distributions measu red, the relative size distributions (RSD) method, was developed for t he assessment of local and regional aerosol sources. The RSD method an d conventional methods revealed local/regional sources of Mn, Zn, Pb, Bi, Br, I, Si and K. The interelemental concentration ratios in air ma sses of different geographical origin were studied and found to be sim ilar in this study and in southern Sweden (Swietlicki et nl., 1989) fo r air masses originating from the U.K.