Thirty years of snow deposition at Talos Dome (Northern Victoria Land, East Antarctica): chemical profiles and climatic implication.

The aim of this study was to use ion chromatographic methods to measure trace species under clean conditions in Antarctic snow samples. Both anionic and cationic contents of the snow samples were measured using preconcentration columns for both the ion chromatographic systems due to the low concentrations typical of Antarctic snow and ice samples. Samples were collected from a snow-pit dug in Talos Dome (East Antarctica) during the 2003-2004 Italian Antarctic Campaign to perform a preliminary survey of the site chosen for deep drilling in the framework of the TALos Dome ICE core (TALDICE) international project. Stratigraphic dating was attempted for the entire snow-pit, covering about 30 years, in order to achieve climatic information from the chemical profiles of the measured species. In particular, ions coming mainly from biogenic sources were investigated as potential markers for historical reconstruction of parameters expressing atmospheric and oceanic circulation, such as Southern Oscillation Index (SO[). For the studied period, a good correlation between biogenic species and SOI and sea-ice extent in the Ross Sea sector was observed, suggesting that these ions, as recorded in Talos Dome, can be used as markers for the reconstruction of the oceanic and atmospheric conditions in the past.