ONE-YEAR DATA OF SUBMICRON SIZE MODES OF TROPOSPHERIC BACKGROUND AEROSOL IN SOUTHERN FINLAND

Number size distributions of submicron atmospheric aerosol were measured between February 1, 1996 and January 31, 1997 at a forest site in Southern Finland. Over 50,000 10-min spectra in the size range 3–500 nm were obtained by two parallel DMPSs. The spectra were fitted with two or three lognormal distributions. The occurrence and evolution of different size modes are described, and the seasonal variation of the modes are discussed. Particle...