The influence of Kola Peninsula, continental European and marine sources on the number concentrations and scattering coefficients of the atmospheric aerosol in Finnish Lapland

Atmospheric aerosols were measured at Sevettijärvi in Finnish Lapland in 1992–1995. The variation of aerosol concentrations in different air masses has been examined. In polluted air from the Kola peninsula particle number concentrations were often > 10000 cm– 3. In marine and continental air mean particle number concentrations were 60–350 cm– 3 and 200–1 120 cm– 3, respectively. They were lower in air from the Arctic Sea than in air from the Norwegian Sea. This is explained by the difference in the natural sulphur emissions and resulting particle production between these two areas. In marine air, the mean scattering coefficient (ssp) at 550 nm was 2–8 x 10– 6 m–1, in continental air 2–3 x 10– 5 m–1, and in pollution plumes < 9 x 10– 5 m–1. The mean backscatter fraction in marine air, continental air and in pollution plumes was 0.13, 0.11, 0.10, respectively. The impact of the air pollution sources in northern Siberia was detected despite the vicinity of Kola peninsula pollution sources.