Complex Greenland outlet glacier flow captured.
Complex Greenland outlet glacier flow captured.
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DOI：
10.1038/ncomms10524
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发表时间：
2016-02-01
影响因子：
16.6
通讯作者：
Truffer M
中科院分区：
文献类型：
--
作者：
Aschwanden A;Fahnestock MA;Truffer M
格陵兰冰盖正在以加速的速度失去质量，这是由于地表融化的增加和出口冰川流动的加速。量化未来对海平面的动态贡献需要在冰盖模拟中准确地描绘出出口冰川，但迄今为止，对冰下地形的缺乏了解和有限的模式分辨率阻碍了出口流动复杂空间格局的再现。在这里，我们将高分辨率冰盖模型与统一应用的冰下水文和基底滑动模型相结合，并使用新的冰下地形数据集来模拟格陵兰冰盖的流动。许多出口冰川的流动模式被很好地捕获，说明了出口冰川流动的基本共性，并强调了绘制冰下地形的重要性。成功地再现当今的流动模式表明，在不需要具有不确定时间演变的空间变化参数的情况下，有可能对冰盖进行预测模拟。量化格陵兰岛未来对海平面的贡献需要在冰盖模拟中准确描绘其出口冰川。在这里，作者表明，如果冰厚受到很好的约束，并且在模型中包括垂直剪切和膜应力，则可以捕获出口冰川流量。
The Greenland Ice Sheet is losing mass at an accelerating rate due to increased surface melt and flow acceleration in outlet glaciers. Quantifying future dynamic contributions to sea level requires accurate portrayal of outlet glaciers in ice sheet simulations, but to date poor knowledge of subglacial topography and limited model resolution have prevented reproduction of complex spatial patterns of outlet flow. Here we combine a high-resolution ice-sheet model coupled to uniformly applied models of subglacial hydrology and basal sliding, and a new subglacial topography data set to simulate the flow of the Greenland Ice Sheet. Flow patterns of many outlet glaciers are well captured, illustrating fundamental commonalities in outlet glacier flow and highlighting the importance of efforts to map subglacial topography. Success in reproducing present day flow patterns shows the potential for prognostic modelling of ice sheets without the need for spatially varying parameters with uncertain time evolution. Quantifying Greenland's future contribution to sea level requires accurate portrayal of its outlet glaciers in ice sheet simulations. Here, the authors show that outlet glacier flow can be captured if ice thickness is well constrained and vertical shearing as well as membrane stresses are included in the model.