Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet System
Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet System
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DOI：
10.1007/s40641-017-0083-9
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发表时间：
2017-12-01
影响因子：
9.5
通讯作者：
Cowton, T. R.
中科院分区：
文献类型：
--
作者：
Nienow, P. W.;Sole, A. J.;Cowton, T. R.
审查的目的本审查讨论了融化水在格陵兰冰盖系统中所起的作用。冰盖的水文学很重要，因为它通过影响融水径流过程和冰的动力学来影响物质平衡。综述了我们对通过冰上、冰盖和冰下系统的水的储存和输送的理解的最新进展及其对冰盖的影响。最近的研究发现，自20世纪90年代初以来，由于气温上升和地表反照率下降，地表融水的产生和径流急剧增加。冰下排水系统中的过程与山谷冰川相似，在气候变暖的情况下，融水流向冰盖边缘的效率可能会提高。冰下排水系统的行为似乎限制了地表融化增加对冰盖在陆地上终止的部分的年冰移速度的影响，而大量融化的水在冰川下向下游生态系统输送了大量的沉积物和营养物质。然而，我们对水文-动力学耦合的理解仍然存在严重差距，特别是在潮汐-水冰川和径流过程中，这两个过程确保预测格陵兰未来的物质平衡仍然具有挑战性。
Purpose of the Review This review discusses the role that meltwater plays within the Greenland ice sheet system. The ice sheet's hydrology is important because it affects mass balance through its impact on meltwater runoff processes and ice dynamics. The review considers recent advances in our understanding of the storage and routing of water through the supraglacial, englacial, and subglacial components of the system and their implications for the ice sheet.Recent Findings There have been dramatic increases in surface meltwater generation and runoff since the early 1990s, both due to increased air temperatures and decreasing surface albedo. Processes in the subglacial drainage system have similarities to valley glaciers and in a warming climate, the efficiency of meltwater routing to the ice sheet margin is likely to increase. The behaviour of the subglacial drainage system appears to limit the impact of increased surface melt on annual rates of ice motion, in sections of the ice sheet that terminate on land, while the large volumes of meltwater routed subglacially deliver significant volumes of sediment and nutrients to downstream ecosystems.Summary Considerable advances have been made recently in our understanding of Greenland ice sheet hydrology and its wider influences. Nevertheless, critical gaps persist both in our understanding of hydrology-dynamics coupling, notably at tidewater glaciers, and in runoff processes which ensure that projecting Greenland's future mass balance remains challenging.