Relation between surface topography and sea-salt snow chemistry from Princess Elizabeth Land, East Antarctica

Abstract

Previous studies on variability of sea-salt records in Antarctic snow have established an unambiguous relationship with the proximity to the sea and have been directly correlated with the site specific features like elevation and distance from the coast. On the other hand, variations in Cl^-/Na⁺ 5 ratio in have been attributed with the reaction mechanisms involving atmospheric acids. In the present study, annual records of Na⁺, Cl^- and SO^2-₄ records were investigated using snow cores along a 180 km coast to inland transect in Princess Elizabeth Land, East Antarctica. Exceptionally high Na⁺ concentrations varying between 1000 and 2000 µg l−1 were observed within 50 km of the transect. Large variations in Cl^-/Na⁺ 10 ratio were observed within 50 km from the coast. A rapid increase in the elevation (0–1115 m) was noticed up to 50 km from the coast, whereas a steady elevation change (1115–2200 m) occurred between 50 and 180 km. The largest slope of the entire transect was observed (33.7 m km^-1) between 20 and 30 km and records from this area correspondingly revealed extensive modifications in snow sea-salt chemistry, with Cl^-/Na⁺ 15 ratios as low as 0.2. Statistical analysis showed a strong association between the slope of the ice sheet and variation of the sea-salt ions along the transect. While distance from coast accounted for some variability, the altitude by itself seem to have no significant control on the distribution of sea-salt ions. We suggest that the degree of slope of the ice sheet on the coastal 20 regions of Antarctica could have a major influence the sea-salt chemistry