Spatial distribution and seasonal pattern of biogenic sulphur compounds in snow from northern Victoria Land, Antarctica

This is the authors' abstract. We don't add key points for this paper.

A study of the spatial and temporal distribution of methane sulphonic aeid (MSA) and nssSO 4 2- concentrations in snow-pit samples was performed to determine the main and secondary sources, transport effects and seasonal pattern of biogenic sulphur compounds. Four snow pits, about 3 m deep, excavated at the same time at different altitudes (870-2960 m a.s.1.) in northern Victoria Land, Antarctica, gave coherent information about the effect of altitude and seasonality on the snow chemical composition. A progressive, well-defined decreasing concentration trend is shown as altitude increases, with the biggest effect in the first 1000 m a.s.1. At higher altitudes, biogenic sources make the most important contribution to the tola! sulphate balance with respect to sea- m ray input. Particular attention was paid to the relationship between MSA and nssSO 4 2- by using MSA as a univoca] biogenic marker. The nssSO 4 2- /MSA ratio was evaluated with respect to altitude and seasonality to determine the effect of transport mechanisms (such as long-range transport and fractionation) or non-dimethyl sulphide sources on nssSO 4 2- snow content.