Science and Implementation Plan: Chapter 3

Additional West Antarctic-Climate Connections

Aside from their direct connection to sea level and their recording of climate history, polar ice sheets are active components of the global climate system. This is particularly true in the Southern Hemisphere, where the Antarctic ice sheet is strongly coupled to both the ocean and the atmosphere. The fierce katabatic winds generated by radiative cooling over the ice sheet force a continental-scale atmospheric circulation that couples with atmospheric behavior in mid-latitudes and even in the tropics. The formation of sea ice around the continent, promoted by the outward flow of cold air, generates cold, saline shelf water which evolves into bottom water that spreads into all ocean basins and strongly influences the global oceanic circulation. Because of such couplings, assessing the future ice-sheet behavior and its effect on and response to global climate change is a problem that requires understanding feedbacks far more complex than shifts in the relative amounts of accumulation and melting, calculated by lapse rates driven by local temperature changes-a common technique for recent climate models of Antarctica.