[1] Direct aerosol sampling of Antarctic aerosols was carried out in the free troposphere over Syowa (39.58°E, 69.00°S) and Mizuho (44.19°E, 70.41°S) stations in April and December 2000 for better understanding of aerosol constituents and their vertical distribution in the Antarctic troposphere. Individual aerosol particles were analyzed/ observed by means of a transmission electron microscope and a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. Aerosol particles containing sulfur species (probably H 2 SO 4 ) were identified as the major aerosol particles in the Antarctic free troposphere, whereas sea-salt, mineral and anthropogenic particles were minor aerosol particles. Although H 2 SO 4 and sea-salt particles were observed in the free troposphere during both April and December, mineral and anthropogenic particles were distributed only in December. Sea-salt particles show lower Cl/Na molar ratios relative to seawater because of Cl liberation. S/Na molar ratios of the particles are also low, suggesting that Cl À in the sea salt had been replaced by anions other than SO 4 2À and CH 3 SO 3 À . The Cl liberation from sea-salt particles in the Antarctic free troposphere might have occurred via the heterogeneous reactions mainly involving reactive nitrogen oxides.

Blowing dust (Fuhjin) and to a lesser degree dust devils occur with a fairly high degree of regularity each year in the Kanto Plains of Japan during late winter and early spring. The occurrence of blowing dust is in general a post cold front problem, during periods of little or no precipitation.