New Approaches to Characterising the Influence of Eddies in the Southern Ocean

The waters of the Southern Ocean are dominated by a vast current that circles around the Antarctic continent, known as the Antarctic Circumpolar Current (ACC). The ACC connects together the Atlantic, Pacific and Indian Oceans. It serves an important role in transporting heat, salt, dissolved gases, nutrients and biological species between these ocean basins. The Southern Ocean also plays a critical role in the slow global overturning circulation of the world's ocean. Cold, salty dense water coming all the way from the deep North Altantic arrives in this circulation at the Southern Ocean. Here intense ocean-atmosphere-ice interactions can occur that freshen and warm the water, changing its density, before it continues back northward on its global journey. Understanding the physical processes which determine these ocean circulations is vital to accurately predict future climate. The aim of this project is to investigate some of these processes, in particular those associated with ocean eddies in the flow. What are these eddies? It is familiar to those living in Northern Europe that the prevailing wind direction is typically from west to east. Storms, familiar on weather maps as migrating regions of anomalous low pressure with sizes hundreds of kilometers, interact with this prevailing wind in complex ways. In the Southern Ocean, the analogues of these storms are the ocean eddies, although they are typically much smaller with sizes of tens of kilometers. Just as in the atmosphere, their interaction with the prevailing current, the ACC, is complex. The goal of this project is to better understand this interaction. Processes associated with the eddies are thought to be important in determining the global overturning circulation described above.