Modeling of ocean-induced ice melt rates of five west Greenland glaciers over the past two decades
Modeling of ocean-induced ice melt rates of five west Greenland glaciers over the past two decades
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DOI：
10.1002/2016gl068784
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发表时间：
2016-06-28
影响因子：
5.2
通讯作者：
de Fleurian, B.
中科院分区：
文献类型：
--
作者：
Rignot, E.;Xu, Y.;de Fleurian, B.
使用来自马萨诸塞州理工学院大气环流模型海洋模型的高分辨率三维模拟来计算1992年至2015年格陵兰西部Umiamako、Rinks、Kangerdlugssup、Store和Kangilerngata冰川的崩解面水下融化速率。模型强迫来自海洋状态和冰盖径流的每月重建。结合水深测量、河床高程、冰锋后退和冰川速度的观测结果进行了分析。我们计算出，夏季的水下融化率是冬季的2-3倍，自20世纪90年代以来，由于冰下径流增加和海洋温度升高1.6 +/- 0.3摄氏度，融化率增加了一倍。Umiamako和Kangilerngata在2000年代迅速消退，当时水下融化速率超过了产犊速率，冰锋退回到更深的河床高程。相比之下，Store、Kangerdlugssup和Rinks保持稳定，因为它们的水下融解速率比产犊速率低3-4倍，即，冰川主要是由冰解过程所控制的。
High-resolution, three-dimensional simulations from the Massachusetts Institute of Technology general circulation model ocean model are used to calculate the subaqueous melt rate of the calving faces of Umiamako, Rinks, Kangerdlugssup, Store, and Kangilerngata glaciers, west Greenland, from 1992 to 2015. Model forcing is from monthly reconstructions of ocean state and ice sheet runoff. Results are analyzed in combination with observations of bathymetry, bed elevation, ice front retreat, and glacier speed. We calculate that subaqueous melt rates are 2-3 times larger in summer compared to winter and doubled in magnitude since the 1990s due to enhanced subglacial runoff and 1.6 +/- 0.3 degrees C warmer ocean temperature. Umiamako and Kangilerngata retreated rapidly in the 2000s when subaqueous melt rates exceeded the calving rates and ice front retreated to deeper bed elevation. In contrast, Store, Kangerdlugssup, and Rinks have remained stable because their subaqueous melt rates are 3-4 times lower than their calving rates, i.e., the glaciers are dominated by calving processes.