Climate variables along a traverse line in Dronning Maud Land, East Antarctica

Temperature, density and accumulation data were obtained from shallow firn cores, drilled during an overland traverse through a previously unknown par t of Dronning Maud Land, East Antarctica. The traverse area is characterise d by high mountains that obstruct the ice flow, resulting in a sudden trans ition from the polar plateau to the coastal region. The spatial variations of potential temperature, near-surface firn density and accumulation sugges t that katabatic winds are active in this region. Proxy wind data derived f rom firn-density profiles confirm that annual mean wind speed is strongly r elated to the magnitude of the surface slope. The high elevation of the ice sheet south of the mountains makes for a dry, cold climate, in which mass loss owing to sublimation is small and erosion of snow by the wind has a po tentially large impact on the surface mass balance. A simple katabatic-wind model is used to explain the variations of accumulation along the traverse line in terms of divergence/convergence of the local transport of drifting snow The resulting wind- and snowdrift patterns are closely connected to t he topography of the ice sheet: ridges are especially sensitive to erosion, while ice streams and other depressions act as collectors of drifting snow .