Observations of Antarctic Polynya With Unmanned Aircraft Systems



Working in the polar environment is always challenging, particularly during the winter, when environmental conditions are harshest. With hurricane force winds, frigid temperatures, and the potential to alter the global thermohaline circulation, the Terra Nova Bay region of Antarctica in the western Ross Sea is an environment where acquiring observations of local atmospheric and oceanic interactions is critical and also extremely challenging.

An important feature of Terra Nova Bay is a recurring polynya—an area of nearly ice-free water surrounded by sea ice and land. Strong katabatic winds (cold, negatively buoyant air that flows downslope under the influence of gravity) drain from the interior of the continent and blow over the open water of the polynya, resulting in large upward fluxes of heat and moisture. Sea ice production occurs as a result of the large transfer of heat from sea to air, with the newly formed sea ice blown offshore, effectively removing freshwater from the coastal ocean. The high-salinity water created through this process becomes part of the global thermohaline circulation as Antarctic bottom water. Coastal polynyas, such as the one in Terra Nova Bay, are of interest to atmospheric scientists and oceanographers due to the intense air-sea coupling and the impact of these fluxes on the state of the atmosphere and ocean.