The Hydroclimate of Antarctica

NSF Polar Programs, The Antarctic atmospheric water cycle couples freshwater input to the Southern Ocean. The strength of ocean convective overturning (the meridonal overturning circulation) and its influence on the upwelling of heat is governed in large part by these freshwater sources. Understanding the water cycle is fundamental to estimating ocean heat uptake in the Southern Ocean and determining why Antarctic sea ice has expanded in the last ~30 years, notably different from the Arctic. The hydrologic cycle is in turn strongly coupled to the climate. Precipitation influences the albedo of sea ice, depending on whether it falls as snow or rain, and contributes freshwater to the Southern Ocean, while sea ice and sea surface temperature influence evaporation and atmospheric circulation and their association with moisture and heat transport to Antarctica.

A series of sensitivity experiments are proposed to gain understanding of the system and test means of improving model biases. The ultimate integration will utilize these model improvements to attribute Southern Ocean and Antarctic climate change over the last ~30 years

The project advances understanding of past and future climate change from rising greenhouse gas concentrations and ozone depletion. The results will inform future projections of Antarctic ice mass balance and the resulting global sea level rise.