Samplings of aerosol particles were made almost monthly throughout a year a
t a coastal Antarctic station Syowa (69 degrees 00'S, 39 degrees 35'E). Wit
h X-ray spectrometry. elemental composition of the individual particles is
studied. The dominant aerosol constituents are sulfur species and sea salt.
They are internally mixed with each other in most cases. We find seasonal
variations in (1) the relative importance of sulfur and sea salt, and (2) t
he modification of sea salt by acidic materials. In the austral-summer samp
les, the number fractions of sulfur-rich particles and modified sea-salt pa
rticles are high, because the production of marine organosulfer was enhance
d. In the austral-winter samples, the number fraction of unmodified sea-sal
t particles is high, because severe storms enhanced the production of sea s
alt.