Snowfall in Antarctica is a key term of the ice sheet mass budget that influences the sea level at global scale. Over the continental margins, persistent katabatic winds blow all year long and supply the lower troposphere with unsaturated air. We show that this dry air leads to significant low-level sublimation of snowfall. We found using unprecedented data collected over 1 year on the coast of Adélie Land and simulations from different atmospheric models that low-level sublimation accounts for a 17% reduction of total snowfall over the continent and up to 35% on the margins of East Antarctica, significantly affecting satellite-based estimations close to the ground. Our findings suggest that, as climate warming progresses, this process will be enhanced and will limit expected precipitation increases at the ground level.

中文翻译：

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Katabatic风减少了对南极冰质平衡的降水贡献

南极洲的降雪是冰盖大规模预算的一个关键术语，它会影响全球范围内的海平面。在大陆边缘，持续的卡塔巴风持续一年四季，并为对流层下部的空气提供不饱和空气。我们表明，这种干燥的空气会导致降雪的低水平升华。我们发现，通过使用一年来在AdélieLand海岸收集的空前数据以及来自不同大气模型的模拟，低空升华使整个大陆的降雪量减少了17％，在南极东部边缘的降雪量高达35％，极大地影响了接近地面的基于卫星的估计。我们的发现表明，随着气候变暖的进行，这一过程将得到加强，并会限制地面预期的降水增加。