Concentration and isotope ratio of sulfur species in snow along the route to Dome Fuji, Antarctica

Abstract:

Snow ice sample in Antarctica contains particulate matter. Particulates originate from continent, volcano, sea, space, and organism. Methanesulfonate ion and sulfate ion are major sulfur compounds packed in snow ice in Antarctica. The isotopic ratio of an element reflects the origin and the history of the particle matter. Since the isotopic ratio of sulfur species depends on the source, the information about the source contribution of particulate matter can be estimated by analyzing the isotopic ratios of sulfur species. In this research, concentrations of sulfur species and isotopic ratios of sulfur species in snow collected on the route form coastal area to Dome Fuji station in Antarctica were analyzed.

The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°01'S, 40°03'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. The snow samples were also collected from a pit dug at Dome Fuji station. Those samples were collected in the 2009/2010 austral summer. The samples were transported to Japan without thawing. Quantitative analyses of sulfur species were performed using ion chromatograph and quadrupole type mass spectrometer. The isotopic ratios of isolated sulfur species were measured using elemental analyzer and the magnetic field type mass spectrometer.

Average concentrations and maximum concentration of methanesulfonate ion in the snow samples were 17 ng/ml and 123 ng/ml, respectively. Average concentrations and maximum concentration of sulfate ion were ng/ml 63 and 419 ng/ml, respectively. Further results and discussion about the behavior and origin of sulfur species in the snow will be presented.