Glaciochemistry of surface snow from the Ingrid Christensen Coast, East Antarctica, and its environmental implications

Abstract

Spatial variations in the ion composition were studied in 55 surface snow samples collected along three transects in the Ingrid Christensen Coast of East Antarctica. The sea-salt ion constituents revealed a drastic reduction from the ice edge to inland sites. The computed sea-salt sodium and non-sea-salt calcium concentrations suggest that while sea spray primarily contributes to the Na⁺, the crustal contribution dominates the Ca²⁺ in snow samples. The Cl^-/ssNa⁺ ratios of the snow samples from the Larsemann transect varied between 4.7 and 1.05, indicating that additional Cl^- sources like soil dust are important in the inland sites. The enrichment factors (Ef) confirm a dominant crustal source for Ca²⁺ in all transects. The Ef(K⁺) values indicate a dominant sea spray source for K⁺ in the coastal stations of the Larsemann and Publications transects. The Ef(Mg2+) values indicate the absence of any significant Mg²⁺ enrichment compared to seawater values. Secondary sulphur species (nssSO₄^2- and MSA) within the snow samples suggest that both vary independently of each other, possibly influenced by the local biological activities. The nssSO₄^2- data revealed that several summer snow deposits in the study region are significantly fractionated, apparently related to the sea ice existence during summer.