Off the coast of Victoria Land, Antarctic an area of open water - the; Terra Nova Bay Polynya (TNBP)- persists throughout the austral winter.; The primary force driving the development of this almost ice-free; stretch of water are extreme katabatic winds flowing down the slopes of; Transantarctic Mountains. The surface-atmosphere coupling and ABL; transformation during the katabatic flow between 18-25 September 2012 in; Terra Nova Bay are studied, using observations from Aerosonde unmanned; aircraft system (UAS) observations, numerical modeling results and; Antarctic Weather Station (AWS) measurements. Our analysis demonstrates; that the intensity and persistence of katabatic winds is governed by sea; level pressure (SLP) changes in the region. Whereas the duration and; intensity of the flow, determines the polynya extent. When cold, dry air; brought with the winds interacts with relatively warm surface of the; polynya the convection starts to develop and overcomes the previously; stable atmosphere. In general, the intensity of the flow, surface; conditions in the bay and regional SLP fluctuations are all; interconnected and together modify local atmospheric and surface; conditions. The importance of valid forecast of katabatic events for; Antarctic aircraft operations is unambiguous. The Antarctic Mesoscale; Prediction System (AMPS) performs this task well, but due to exaggerated; sea ice concentrations (SIC) incorrectly represents vertical ABL; properties and air mass modification over the TNBP. Altogether, this; research provides a unique description of TNBP development and its; interactions with the atmosphere and katabatic winds, thus enhancing our; understanding of the complex processes taking place in this region.
