Brine infiltration in the snow cover of sea ice in the eastern Weddell Sea, Antarctica

Abstract

The snow cover on Antarctic sea ice often depresses the ice below sea level, allowing brine or seawater to infiltrate, or flood the snowpack. This significantly reduces the thermal insulation properties of the snow cover, and increases the ocean/ atmosphere heat flux. The subsequent refreezing of this saturated snow or slush layer, to form snow-ice, can account for a significant percentage of the total ice mass in some regions. The extent of saturated snow cannot presently be estimated from satellite remote-sensing data and, because it is often hidden by a layer of dry snow, cannot be estimated from visual observations. Here, we use non-parametric statistics to combine sea-ice and snow thickness data from drillhole measurements with routine visual observations of snow and ice characteristics to estimate the extent of brine-infiltrated snow. The data were collected during July-August 1994 from the R/V Nathaniel B. Palmer in the eastern Weddell Sea from 60°to 68°S latitude and from 20°W to 5°E longitude.