Estimates of the Frequency of Synoptic Variations in Aerosol Characteristics in the Arctic Atmosphere and the Contribution of Various Pollutants to Anomalously High Aerosol Concentrations

Abstract

The periodicity of synoptic-scale variations in aerosol characteristics in the atmosphere of Eurasian sector of the Arctic Ocean is analyzed on the basic of long-term measurements. Statistically significant maxima of amplitude functions in the range from 3.5 to 18 days were manifested in periodograms of the concentrations of submicron aerosol and black carbon (V_f and еВС). Cases of anomalously high еВС and V_f (5% of data), associated with long-range transports of continental pollutants, were considered in more detail. It is shown that the average duration of “anomalies” in еВС and V_f is few days, and the maximal duration attains 112 hours. The time intervals between “anomalies” are, on the average, 6–16 days, and the maximal intervals are from 28 to 69 days. Despite the short duration and rare occurrence of anomalous situations, they increase the average concentrations of aerosol and black carbon by 28–77%. Calculations showed that the major (79%) contributors to air pollution over the Kara and Barents Seas are made by the outflows of anthropogenic pollutants; and in the eastern sector of the Arctic Ocean, the contribution of smokes from wildfires is maximal. The effect of the products of associated gas combustion at gas-oil plants was manifested most strongly (up to 51%) in the atmosphere of Cape Baranov.