On the Heat Energy Fluxes in the Non-stationary Surface Boundary Layer at Hells Gate, Terra Nova Bay (Antarctica)

Within the framework of scientific activities of the Italian Antarctic Expedition at Terra Nova Bay (74° 41’ 42”S, 164° 7’ 23”E) during the southern-summer of 1994–95, an uninterrupted three week programme of measurement of sensible and latent turbulent heat fluxes has been run at two locations, 5 km apart from each other, of Hells Gate ice shelf (inner mast: 74° 50’8.3”S, 163° 44’ 2.8E, 19.85 m a.s.l.; coastal mast: 74°52’ 20.2”S, 163° 49’ 6.4”E, 12.47 m a.s.l.). The aim of the programme was to assess the transfer of heat energy (in particular, its latent component) at the air/ice interface as a function of different atmospheric forcings (wind, temperature, solar radiation) in order to describe the state and evolution of the thermal properties of the non stationary atmospheric boundary layer near the surface. To this end, a prognostic enthalpy balance model, whose input data was the information collected during the experimental programme, has been used to establish the relative role played by the different terms concurring to the heat energy budget under different meteorological conditions, ranging from moderate breeze to strong katabatic wind episodes. The experiment involved the collaboration between teams from the Department of Physics, University of Torino and the Institute of Atmospheric Physics of National Research Council in Roma. This paper reviews the experimental and analytic methodologies and discusses the most meaningful results.