Eastern Asia contains many large pollution sources whose emissions can be transported over large areas of North Pacific. In order to characterize this transport, we collected a sixty‐day series of daily aerosol samples concurrently from Sapporo, Japan and Vladivostok, CIS from April to May, 1991. These were analyzed for non‐sea‐salt (nss) sulfate and nitrate. The arithmetic mean concentrations of nss‐sulfate (4.66 ± 2.68 μg m−3) and nitrate (2.58 ± 1.62 μg m−3) in Vladivostok were 70% and 40% higher than the corresponding concentrations of nss‐sulfate (2.69 ± 2.06 μg m−3) and nitrate (1.86 ± 1.42 μg m−3) in Sapporo. Several episodic peaks of nss‐sulfate and nitrate in Vladivostok corresponded to the peaks observed in Sapporo, which is located approximately 700 km east of Vladivostok. About 40% and 25% of the variance in the nss‐sulfate and nitrate concentrations at the two sites could be explained by the large‐scale transport of substances under the strong winds from the west and southwest This suggests that the high concentrations are associated with strong regional sources located to windward of these cities and that the concentrations that we measured are probably representative of a large area of the coastal western North Pacific Ocean.

Thus the estimated 0.6 Tg of ice-induced methane dynamics in northern latitudes can hardly explain this seasonal signal. However, the effects of seasonal ice cover on pulsed release of methane appear strong enough to contribute, in concert with other seasonal sources, to characteristic short-term wobbles in the atmospheric methane budget which are observed between 50øN and 60øN.

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