The Weddell Sea Region: An Important Precipitation Channel to the Interior of the Antarctic Ice Sheet as Revealed by Glaciochemical Investigation of Surface Snow Along the Longest Trans-Antarctic Route

Abstract

Glaciochemical analysis of surface snow samples, collected along a profile crossing the Antarctic ice sheet from the Larsen Ice Shelf, Antarctic Peninsula, via the Antarctic Plateau through South Pole, Vostok and Komsomolskaya to Mirny station (at the east margin of East Antarctica), shows that the Weddell Sea region is an important channel for air masses to the high plateau of the Antarctic ice sheet (\u3e2000 m a.s.l.). This opinion is supported by the following. (1) The fluxes of sea-salt ions such as Na+, Mg2+ and Cl− display a decreasing trend from the west to the east of interior Antarctica. In general, as sea-salt aerosols are injected into the atmosphere over the Antarctic ice sheet from the Weddell Sea, large aerosols tend to decrease. For the inland plateau, few large particles of sea-salt aerosol reach the area, and the sea-salt concentration levels are low. (2) The high altitude of the East Antarctic plateau, as well as the polar cold high-pressure system, obstruct the intrusive air masses mainly from the South Indian Ocean sector. (3) For the coastal regions of the East Antarctic ice sheet, the elevation rises to 2000 m over a distance from several to several tens of km. High concentrations of sea salt exist in snow in East Antarctica but are limited to a narrow coastal zone. (4) Fluxes of calcium and non-sea-salt sulfate in snow from the interior plateau do not display an eastward-decreasing trend. Since calcium is mainly derived from crustal sources, and nssSO42− is a secondary aerosol, this again confirms that the eastward-declining tendency of sea-salt ions indicates the transfer direction of precipitation vapor