Ice streams flowing from the Antarctic continent come in contact with the ocean where they cross the grounding line and begin to float as ice shelves. Nearly 40% of the sea surface on Antarctic continental shelves is covered by ice shelves that restrict exchange between the ocean and atmosphere. Some of these ice shelves can extend several hundred meters below sea level, which affects the waters underneath since the freezing point of sea water is significantly reduced as pressure increases. Conversely, the water below can also melt or freeze the base of the ice shelves, which (along with surface precipitation, iceberg calving, and flow from glaciers) contributes to the mass balance of the ice shelves. Studies of ice shelf basal melting have recently received more attention because of the suggestion that the ice shelves may buttress the massive continental ice sheets and that "popping the cork" (i.e. collapse of the ice shelves) could result in a much greater flow of continental ice into the ocean.

Some aspects of modeling the interaction between the ice shelves and the ocean around Antarctica will be illustrated with three numerical models here at CCPO: an idealized case for an Ice Shelf/Ocean Model Intercomparison study; a regional model of the Ross Sea; and a regional model of the west Antarctic Peninsula.