The Cryosphere Modelling snowdrift sublimation on an Antarctic ice shelf

• Main Authors: J. T. M. Lenaerts, M. R. Van Den Broeke, S. J. Déry, J. Ettema, P. K. Munneke
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2010
• Subjects: Antarctic; Kohnen; Neumayer; Antarc*; Antarctica; Ice Shelf
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.622.2650; http://www.the-cryosphere.net/4/179/2010/tc-4-179-2010.pdf

Abstract. In this paper, we estimate the contribution of snowdrift sublimation (SUds) to the surface mass balance at Neumayer, located on the Ekström ice shelf in Eastern Antarctica. A single column version of the RACMO2-ANT model is used as a physical interpolation tool of high-quality radiosonde and surface measurements for a 15-yr period (1993–2007), and combined with a routine to calculate snow-drift sublimation and horizontal snow transport. The site is characterised by a relatively mild, wet and windy climate, so snowdrift is a common phenomenon. The modelled tim-ing and frequency of snowdrift events compares well with observations. This is further illustrated by an additional sim-ulation for Kohnen base, where the timing of snowdrift is re-alistic, although the modelled horizontal transport is overes-timated. Snowdrift sublimation is mainly dependent on wind speed, but also on relative humidity and temperature. Dur-ing high wind speeds, SUds saturates and cools the air, limit-ing its own strength. We estimate that SUds removes around 16%±8 % of the accumulated snow from the surface. The total sublimation more than triples when snowdrift is con-sidered, although snowdrift sublimation limits sublimation at the surface. SUds shows a strong seasonal cycle, as well as large inter-annual variability. This variability can be related to the variability of the atmospheric conditions in the surface layer.