Katabatic winds diminish precipitation contribution to the Antarctic ice mass balance

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Grazioli, Jacopo, Madeleine, Jean-Baptiste, Gallée, Hubert, Forbes, Richard M., Genthon, Christophe, Krinner, Gerhard, Berne, Alexis
• Format: Text
• Language: English
• Published: National Academy of Sciences 2017
• Subjects: Physical Sciences; Antarctic; East Antarctica; The Antarctic; Antarc*; Antarctica; Ice Sheet
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5642703/; http://www.ncbi.nlm.nih.gov/pubmed/28973875; https://doi.org/10.1073/pnas.1707633114

Precipitation over Antarctica remains largely unknown, despite its crucial role in the surface mass balance of the Antarctic ice sheet. Using unprecedented observations covering an entire year, this work describes a previously unknown mechanism that leads to the sublimation of a large fraction of snowfall in the lower atmosphere, resulting from the interaction of precipitation and katabatic winds. Snowfall sublimation in the atmosphere, caused by katabatic winds, is in the order of 35% in the margins of East Antarctica. This process critically affects the interpretation of satellite-based remote sensing observations close to the ground and suggests that snowfall sublimation in a warming climate may counterbalance the expected increase of precipitation.