Collaborative Research: Behavior of Supraglacial Lakes and Their Role in Outlet Glacier Dynamics and Mass Balance of the Greenland Ice Sheet

这是由华盛顿大学和伍兹霍尔海洋研究所的首席研究员合作提出的一项建议。该提案也已提交给NASA，并将由OPP和NASA共同资助。主要研究人员将利用地球物理实地测量和遥感来调查格陵兰冰川上湖泊在向冰盖床输送融水和在短时间尺度上调节冰流方面的作用。最近的研究结果表明，冰速与地表融水通过冰穴流到冰层床之间存在相关性，这可能为格陵兰冰盖（GIS）对气候变化的快速响应提供了一种机制。冰上湖是连接地表融化和增强基流的关键环节之一，具有快速响应未来气候变化的潜力，是本研究项目的重点。知识价值：该项目的主要成果将是关于格陵兰冰川上湖泊的形成和动态以及地表融化和湖泊排水在调节冰盖流动中的作用的重要新知识。在整个地理信息系统中，该项目的结果将首次清楚地了解格陵兰周围湖泊的位置和成因，这些湖泊中储存的融水总量，以及它们与冰川出口流域的关系。在动态和气候敏感的Jakobshavn地区，结果将显示湖泊系统的年际变化以及从冰川上湖泊到冰盖床的可用融水通量。这些观察结果将用于检验关于冰上湖在冰穴形成中的作用的新假设。对局部和区域气候如何控制湖泊行为的新观察将有助于深入了解湖泊系统应对未来气候变化的潜力。地面测量和实验将：1)考虑湖泊排水在冰流变率中的作用；2)将当地气候控制与湖泊体积和冰臼形成的变化联系起来；3)为模式如何预测未来冰盖对气候变化的响应提供更好的约束。更广泛的影响：北极变化和格陵兰岛对海平面上升的贡献引起了社会的极大兴趣和关注。这项研究的结果将通过持续的首席研究员的努力向公众传播，包括K-12课堂参观、网站、新闻采访和其他机会。研究结果将直接引起致力于了解地理信息系统过去和未来变化的科学家的兴趣。他们将在专门的期刊和会议上发表研究成果，并在涉及地球科学界广泛领域的部门研讨会上发言。这项研究将有助于WHOI建立一个新的冰川学项目，并有助于华盛顿大学的新合作。

ABSTRACTDasOPP-0520077JoughinOPP-0520382 This is a collaborative proposal by Principal Investigators from the University of Washington and Woods Hole Oceanographic Institution. This proposal has also been submitted to NASA and will be jointly funded by OPP and NASA. The Principal Investigators will use geophysical field measurements and remote sensing to investigate the role of Greenland's supraglacial lakes in delivering melt water to the ice sheet's bed and in modulating ice flow on short time scales. Recent results demonstrate a correlation between ice velocity and surface melt draining through moulins to the bed, which may provide a mechanism for rapid response of the Greenland Ice Sheet (GIS) to climate change. Supraglacial lakes are one of the critical links between surface melting and enhanced basal flow, have the potential to rapidly respond to future climate change, and are the focus of the research project described here.Intellectual Merit: The major result of this project will be significant new knowledge about the formation and dynamics of Greenland's supraglacial lakes and the role of surface melt and lake drainage in modulating ice sheet flow. Over the entire GIS, the project's results will provide the first clear understanding of where and why lakes form around Greenland, the total melt-water volume stored in these lakes, and their relationship to outlet glacier drainage basins. Over the dynamic and climatically sensitive Jakobshavn region, the results will show the interannual variability in lake systems and the available melt water flux from supraglacial lakes to the ice sheet's bed. These observations will be used to test emerging hypotheses concerning the role of supraglacial lakes in moulin formation. New observations of how local and regional climate control lake behavior will yield insight into the potential for lake systems to respond to future climate change. Ground-based measurements and experiments will: 1) allow account for the role of lake drainage in ice flow variability, 2) relate local climate controls to changing lake volume and moulin formation, and 3) provide better constraint on how models predict future ice sheet response to climate change. Broader Impacts: Arctic change and Greenland's contribution to sea level rise is of great societal interest and concern. The results of this research will be disseminated to the public through ongoing Principal Investigator efforts including K-12 classroom visits, web sites, press interviews, and other opportunities. Results will be of immediate interest to scientists working to understand past and future changes to the GIS. They will present results in specialized journals and conferences, and will speak in departmental seminars that reach a broad cross-section of the earth science community. This research will contribute to the establishment of a new glaciological program at WHOI and to new collaborations at UW.