Individual-particle analyses of coastal Antarctic aerosols

Samplings of aerosol particles were made almost monthly throughout a year at a coastal Antarctic station Syowa (69°00’S, 39°35’E). With X-ray spectrometry, elemental composition of the individual particles is studied. The dominant aerosol constituents are sulphur species and sea salt. They are internally mixed with each other in most cases. We find seasonal variations in (1) the relative importance of sulphur and sea salt, and (2) the modification of sea salt by acidic materials. In the austral-summer samples, the number fractions of sulphur-rich particles and modified sea-salt particles are high, because the production of marine organosulfer was enhanced. In the austral-winter samples, the number fraction of unmodified sea-salt particles is high, because severe storms enhanced the production of sea salt.