Chemical characteristics of submicron aerosols observed at the King Sejong Station in the northern Antarctic Peninsula from fall to spring

The water-soluble ions and carbonaceous compounds of PM ₁ were measured at the King Sejong Station (KSG) in the northern part of Antarctic Peninsula from March to November in 2009. As the sum of all measured species including organic matter [OM; organic carbon (OC)*1.9], the PM ₁ mass reached a maximum of 936 ng m ⁻³ with the mean of 686 ± 226 ng m ⁻³ . The most abundant constituents were OM (389 ± 109 ng m ⁻³ ) and sea-salts (Na ⁺ and Cl ⁻ , 193 ± 122 ng m ⁻³ ), which comprised 85% of the PM ₁ mass. In contrast, the contribution of SO ₄ ²⁻ was below 1% and its depletion relative to Na ⁺ was prevalent particularly during winter, which was attributed to the frost flowers on newly formed sea-ice surface. The OC concentration was the highest in fall and its subcomponents OC2 and OC3 were moderately correlated with sea-salts (r = 0.5), indicating the marine biogenic source for OC. The elemental carbon (EC) concentration was much lower than OC, leading to the mean OC/EC ratio over 10. While the charred fraction of EC (EC1) was elevated by the long-range transport of biomass burning plume from nearby continent, the mass fraction of soot-EC (EC23) was increased concurrently with enhanced NO ₃ ⁻ , suggesting EC23 as a good indicator for local influence in pristine environments like Antarctic region.