ICESat‐2 Meltwater Depth Estimates: Application to Surface Melt on Amery Ice Shelf, East Antarctica
ICESat‐2 Meltwater Depth Estimates: Application to Surface Melt on Amery Ice Shelf, East Antarctica
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DOI：
10.1029/2020gl090550
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发表时间：
2020-12
影响因子：
5.2
通讯作者：
H. Fricker;Philipp Arndt;K. Brunt;R. Datta;Z. Fair;M. Jasinski;J. Kingslake;L. Magruder;M. Moussavi;A. Pope;J. Spergel;J. Stoll;B. Wouters
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作者：
H. Fricker;Philipp Arndt;K. Brunt;R. Datta;Z. Fair;M. Jasinski;J. Kingslake;L. Magruder;M. Moussavi;A. Pope;J. Spergel;J. Stoll;B. Wouters
南极和格陵兰冰盖在夏季发生表面融化，但由于缺乏准确的深度估计，储存的表面融水的体积难以量化。NASA的ICESat‐2激光高度计带来了一种新的能力：光子穿透水并被水和下面的冰反射；差值提供了深度估计。ICESat‐2于2019年1月2日对Amery冰架进行了采样，并显示地表洼地的双倍回报，表明融水。对于四个熔体特征，我们比较了来自八种算法的深度估计：六种基于ICESat‐2，两种来自同步的Landsat‐8和Sentinel‐2图像。所有算法都成功地识别了相同位置的地表水。基于ICESat‐2的算法产生了最精确的深度；基于图像的算法低估了深度（30%-70%）。这意味着ICESat - 2深度可以用来调整基于图像的算法，使我们更接近于量化南极洲和格陵兰岛的融化水量。
Surface melting occurs during summer on the Antarctic and Greenland ice sheets, but the volume of stored surface meltwater has been difficult to quantify due to a lack of accurate depth estimates. NASA's ICESat‐2 laser altimeter brings a new capability: photons penetrate water and are reflected from both the water and the underlying ice; the difference provides a depth estimate. ICESat‐2 sampled Amery Ice Shelf on January 2, 2019 and showed double returns from surface depressions, indicating meltwater. For four melt features, we compared depth estimates from eight algorithms: six based on ICESat‐2 and two from coincident Landsat‐8 and Sentinel‐2 imagery. All algorithms successfully identified surface water at the same locations. Algorithms based on ICESat‐2 produced the most accurate depths; the image‐based algorithms underestimated depths (by 30%–70%). This implies that ICESat‐2 depths can be used to tune image‐based algorithms, moving us closer to quantifying stored meltwater volumes across Antarctica and Greenland.