Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998-2002

[摘要] During the calendar years 1998-2002, 147 clear 8nm diameter particleformation events have been identified at the SMEAR I station inVärriö, northern Finland. The events have been classified in detailaccording to the particle formation rate, growth rate, event starting time,different trace gas concentrations and pre-existing particle concentrationsas well as various meteorological conditions. The frequency of particleformation and growth events was highest during the spring months betweenMarch and May, suggesting that increasing biological activity might producethe precursor gases for particle formation. The apparent 8nm particleformation rates were around 0.1 /cm³s, and they were uncorrelated withgrowth rates that varied between 0.5 and 10nm/h. The air masses withclearly elevated sulphur dioxide concentrations (above 1.6ppb) came, asexpected, from the direction of the Nikel and Monschegorsk smelters. Only 15formation events can be explained by the pollution plume from these sources.

[学科分类] 大气科学