The importance of wind blown snow redistribution to snow accumulation on and mass balance of Bellingshausen Sea ice

Snow distribution is a dominating factor in sea-ice mass balance in the Bellingshausen Sea, , through its roles in insulating the ice and contributing to snow-ice production. The wind has been qualitatively recognized to influence the distribution of snow accumulation on sea ice, but the importance of drifting and blowing snow has not been quantified over Antarctic sea ice prior to study. The presence and magnitude of drifting snow were monitored continuously along with wind at two sites on an ice floe in the Bellingshausen Sea during the October 2007 Sea Ice Mass in the Antarctic (SIMBA) experiment. Contemporaneous precipitation measurements collected board the RVIB Nathaniel B. Palmer and accumulation measurements by automated ice massbalance (IMBs) allow us to document the proportion of snowfall that accumulated on level ice in the presence of high winds and blowing-snow conditions. Accumulation on the sea ice the experiment averaged <0.01mw.e. at both IMB sites, during a period when European Centre Medium-Range Weather Forecasts analyses predicted >0.03mw.e. of precipitation on the ice floe. changes on the ice floe were clearly associated with drifting snow and high winds. -snow transport during the SIMBA experiment was supply-limited. Using these results to inform preliminary study using a blowing-snow model, we show that over the entire Southern Ocean half of the precipitation over sea ice could be lost to leads.