Ryan Jonathan C, Cooper Matthew G, Cooley Sarah W, Rennermalm Åsa K, Smith Laurence C
Division of Earth and Climate Sciences, Nicholas School of the Environment, Duke University, Durham, NC, USA.
Department of Geography, University of Los Angeles, Los Angeles, CA, USA.
Nat Commun. 2025 Sep 12;16(1):8274. doi: 10.1038/s41467-025-62503-5.
Ponding of meltwater on the surface of the Greenland Ice Sheet has the potential to reduce ice sheet albedo and amplify mass loss. However, this process remains poorly constrained and is absent from models that project ice sheet mass balance. Here we demonstrate that meltwater ponding considerably increases the amount of energy available for melting the Greenland Ice Sheet. We first use satellite-derived products to show that meltwater ponding has a significant impact on spatial albedo patterns, particularly in the lower percolation zone. We then use drone imagery to demonstrate that, in the upper ablation zone, there are thousands of narrow streams and small pools (<100 m²) that collectively account for >50% of the total meltwater area. These small meltwater features are not resolved by surface water maps derived from medium-resolution satellite imagery, signifying that the radiative effect of meltwater ponding is three to four times stronger than predicted by satellite-based approaches. Our findings therefore place lower bounds on the radiative effect of meltwater ponding that could be used to advocate for the inclusion of this process into models that forecast Greenland Ice Sheet's contribution to sea-level rise.
格陵兰冰原表面融水的积水有可能降低冰原反照率并加剧质量损失。然而，这一过程仍受到很大限制，在预测冰原质量平衡的模型中并未体现。在此我们证明，融水积水显著增加了可用于融化格陵兰冰原的能量。我们首先利用卫星衍生产品表明，融水积水对空间反照率模式有显著影响，尤其是在较低的渗透区。然后我们使用无人机图像证明，在上部消融区，有成千上万条狭窄溪流和小水池（面积小于100平方米），它们共同占总融水面积的50%以上。中等分辨率卫星图像得出的地表水地图并未分辨出这些小的融水特征，这表明融水积水的辐射效应比基于卫星的方法预测的要强三到四倍。因此，我们的研究结果为融水积水的辐射效应设定了下限，可用于主张将这一过程纳入预测格陵兰冰原对海平面上升贡献的模型中。
