Spatial Variability of Glaciochemistry along a Transect from Zhongshan Station to LGB69, Antarctica

Abstract

The spatial glaciochemical variability of snow samples collected along a transect from Zhongshan Station to Lambert Glacier Basin 69 (LGB69) in Antarctica was investigated. Sea-salt ion concentrations exponentially decreased with increasing distance from the coast and/or altitude. The observed high sea-salt ion concentrations within 20.6 km of the coast may be related to preferential wet or dry deposition of sea-salt aerosols. Methanesulfonic acid (MSA), non-sea-salt sulfate (nssSO42−), and calcium (Ca2+) concentrations decreased along the transect. The mean MSA/nssSO42− value of the surface snow samples (0.34 ± 0.08) indicates that coastal sea areas are their likely source regions. The non-sea-salt Ca2+ (nssCa2+)/Ca2+ percentages of the surface snow and LGB69 snow pit samples reveal that continental dust is the primary Ca2+ source. The δD and δ18O values decreased from the coast inland. The variation of deuterium excess (d-excess) along the transect was stable and d-excess values in the two snow pit samples were low and similar, which indicates that the moisture source region between Zhongshan Station and LGB69 is a coastal sea area. These results reveal the spatial distribution patterns and sources of ions and stable isotopes, as well as factors that influence the deposition of ions and the composition of stable isotopes, which provide important insight for further studies of ice cores drilled in Antarctic coastal regions.