Spatial distribution of marine chemicals along a transect from Zhongshan Station to the Grove Mountain area, Eastern Antarctica

Abstract

This study investigates the regional distribution of marine aerosol originated species (Na+, Cl−, nss-SO4 2− and MSA) in the snow pits (or firn cores) collected along a transect between Zhongshan Station and the Grove Mountain area (450 km inland) on the eastern side of the Lambert Glacier Basin. Concentrations of Na+ and Cl− decrease exponentially with distance from the coast to 100 km inland (i.e., 1500 m a.s.l.). Statistical results demonstrate that distance from the coast inland and elevation affect the concentration of sea-salt originated ions in inland areas significantly. Increase of Cl-/Na+ ratio and higher variability in its standard deviation suggest that there are other sources of ions in addition to sea-salt in inland areas of the Antarctic continent. The concentrations of Na+ and Cl− from nine sampling sites in the Grove Mountain area are relatively higher than those from sites along CHINARE transect, although all sites are at similar distance inland. This phenomenon indicates that the barrier effect of the mountain may be the most important factor influencing ion deposition. In addition, nss-SO4 2− and MSA vary differently, with nss-SO4 2− decreasing with distance more significantly. This implies that sources and transporting pathways influence the deposition of the two sulfur compounds considerably, being supported by the spatial pattern of correlation coefficients between the nss-SO4 2− and MSA.