Collaborative Research: The Influence of Hydrofracture and Surface Melt Variability on Greenland Ice Sheet Flow

合作研究：水力压裂和表面融化变化对格陵兰冰盖流动的影响

• 批准号: 1023382
• 负责人: Ian Joughin
• 金额: $ 28.01万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1023382&HistoricalAwards=false
• 关键词: Collaborative; Research; Influence; Hydrofracture; Surface

Hydrofracture events associated with lake drainages in Greenland create surface-to-bed conduits through which surface melt reaches the bed at rates ranging from that of summer-long melt-stream discharge to that of large, transient pulses during sudden lake drainages. While recent work suggests that enhanced seasonal lubrication may have less of a destabilizing effect on the Greenland Ice Sheet than once feared, the interaction between surface melt and ice flow remains poorly constrained and its influence is not well represented in current ice-sheet models. This project aims to contribute toward improving future sea-level rise assessments by achieving a firm, physically based understanding of ice-sheet hydrofracture, and by characterizing the influence of surface melt on ice-sheet flow over seasonal and inter-annual time scales. Acquisition of this knowledge is an important step toward integrating the influence of increased surface melt in model-derived sea level projections. The investigators will use an experimental design of integrated ground- and satellite-based observations coupled to numerical models to determine the processes that govern hydrofracturing and use this understanding to determine whether the area of the Greenland Ice Sheet?s bed exposed to surface meltwater will increase substantially in a warming climate. The results of this research will be disseminated to the public through extensive ongoing efforts of these investigators including K-12 activities and public lectures. The direct involvement of a photographer-writer team will also bring a local dimension to understanding and communicating the impact of climate change on Greenland communities. Our results will also be of immediate interest to scientists working to understand past and future changes to the Greenland Ice Sheet, including theoretical and modeling studies. This project will also include direct graduate student involvement in field and research activities at both WHOI and UW.

与格陵兰岛湖泊排水相关的水力压裂事件形成了地表到河床的管道，地表熔体通过该管道到达河床，其速率范围从整个夏季的熔体流排放速率到湖泊突然排水期间的大的瞬态脉冲速率。虽然最近的研究表明，增强的季节性润滑对格陵兰冰盖的不稳定影响可能比以前担心的要小，但地表融化和冰流之间的相互作用仍然受到很少的限制，并且其影响在当前的冰盖模型中没有得到很好的体现。该项目旨在通过对冰盖水力压裂有一个坚实的、基于物理的理解，并描述季节性和年际时间尺度上表面融化对冰盖流动的影响，为改善未来海平面上升评估做出贡献。获取这些知识是将表面融化增加的影响整合到模型得出的海平面预测中的重要一步。研究人员将使用基于地面和卫星的综合观测与数值模型相结合的实验设计来确定控制水力压裂的过程，并利用这种理解来确定暴露于地表融水的格陵兰冰盖床的面积是否会增加基本上是在气候变暖的情况下。这项研究的结果将通过这些研究人员持续不断的努力（包括 K-12 活动和公开讲座）向公众传播。摄影师兼作家团队的直接参与也将为理解和传达气候变化对格陵兰社区的影响带来当地的影响。我们的研究结果也将引起致力于了解格陵兰冰盖过去和未来变化的科学家的直接兴趣，包括理论和模型研究。该项目还将包括研究生直接参与 WHOI 和华盛顿大学的实地和研究活动。