Collaborative Research: Glacier-Ocean Coupling in a Large East Greenland Fjord

合作研究：东格陵兰峡湾的冰川-海洋耦合

• 批准号: 0909274
• 负责人: Gordon Hamilton
• 金额: $ 62.45万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909274&HistoricalAwards=false
• 关键词: Collaborative; Research; Glacier; Ocean; Coupling

This award will support a study of glacier-fjord interactions in east Greenland. The 'Intellectual Merit' of the proposed study lies in the current understanding that the contribution of the Greenland Ice Sheet to sea level rise more than doubled in the last seven years, mostly because of a widespread and nearly simultaneous acceleration of many glaciers that terminate at tidewater in deep fjords. Understanding the causes of changes in glacier dynamics, and predicting their future trajectories is a topic of enormous scientific and societal importance. The Greenland fjords provide an intimate connection between the ice sheet and the ocean and, in turn, raise the possibility that the observed warming of the ocean around southeast and western Greenland was the trigger for recent changes in outlet glacier dynamics. A pilot study conducted by the PIs in east Greenland, and a separate study in west Greenland, found warm ocean waters in the proximity of Helheim Glacier and Jakobshavn Isbræ, respectively, supporting the hypothesis that their acceleration was triggered by ocean warming. While intriguing, the presence of warm waters in Greenland's fjords alone is not enough to conclude that the ocean is modulating glacier dynamics. A test of this hypothesis requires a more detailed understanding of glacier/fjord interactions than is possible with the limited amount of data currently available. This study will fill this gap by investigating glacier-ocean interactions in a typical glacier-fjord system in East Greenland (Sermilik Fjord and Helheim Glacier) through an intensive two-year field program. Through summer surveys and year-round moored instruments, the circulation and properties of the fjord on tidal to yearly time-scales will be mapped, and the liquid fresh water flux out of the fjord will be quantified. A collaboration with Greenlandic marine biologists will allow important ocean data in the region outside the fjord to be obtained using tagged seals. GPS methods and remote sensing will allow changes in the flow behavior of Helheim Glacier to be examined in the context of changing fjord circulation. Satellite remote sensing and field tracking of large icebergs will provide estimates of the solid export of fresh water and its variability. The proposed study has numerous 'Broader Impacts'. The are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Greenland Ice Sheet and future rates of sea level rise. The project brings together an inter-disciplinary group of investigators, involves two junior scientists embarking on their careers, and initiates an international collaboration with Greenlandic scientists. A graduate student will be trained in glaciology and physical oceanography, contributing to society's need for experts in the area of ice sheet-ocean interactions. The fieldwork utilizes local vessels and relies strongly on the knowledge of generations of local hunters who have navigated Sermilik Fjord, thus fostering a two-way exchange between the local community and foreign scientists. A non-technical report summarizing the findings of ocean-glacier measurements will distributed in the local community, which is vulnerable to rapid environmental changes affecting its primary natural resource.

该奖项将支持对格陵兰东部冰川-峡湾相互作用的研究。这项拟议研究的“学术价值”在于，目前的认识是，格陵兰冰盖对海平面上升的贡献在过去七年中增加了一倍多，这主要是因为许多冰川在深峡湾的潮水处广泛且几乎同时加速。了解冰川动态变化的原因，并预测其未来的轨迹是一个具有巨大科学和社会重要性的主题。格陵兰峡湾在冰盖和海洋之间提供了一个密切的联系，反过来，也提出了一种可能性，即格陵兰岛东南部和西部周围海洋的变暖是最近出口冰川动态变化的触发因素。PIs在格陵兰东部进行的一项试点研究，以及在格陵兰西部进行的一项单独研究，分别在海尔海姆冰川和雅各布港伊斯布雷附近发现了温暖的海水，这支持了它们的加速是由海洋变暖引发的假设。虽然很有趣，但仅格陵兰峡湾存在温暖的海水还不足以得出海洋正在调节冰川动态的结论。这一假设的检验需要对冰川/峡湾相互作用有更详细的了解，而不是目前可用的有限数据。本研究将通过为期两年的实地研究项目，调查东格陵兰岛典型冰川-峡湾系统（Sermilik峡湾和Helheim冰川）中冰川-海洋相互作用，填补这一空白。通过夏季调查和全年系泊仪器，峡湾在潮汐到每年时间尺度上的环流和特性将被绘制出来，并且从峡湾流出的液体淡水通量将被量化。与格陵兰海洋生物学家的合作将允许通过标记海豹获得峡湾外地区的重要海洋数据。GPS方法和遥感将允许在峡湾环流变化的背景下检查赫尔海姆冰川流动行为的变化。卫星遥感和对大型冰山的实地跟踪将提供淡水固体输出量及其变异性的估计。拟议的研究有许多“更广泛的影响”。它们很可能成为下一代冰盖模型的重要组成部分，这些模型旨在预测格陵兰冰盖的演变和未来海平面上升的速度。该项目汇集了一个跨学科的研究小组，涉及两名初级科学家开始他们的职业生涯，并启动了与格陵兰科学家的国际合作。研究生将接受冰川学和物理海洋学方面的培训，为社会对冰盖-海洋相互作用领域专家的需求做出贡献。实地考察利用当地船只，并在很大程度上依赖于在Sermilik峡湾航行的几代当地猎人的知识，从而促进了当地社区和外国科学家之间的双向交流。一份总结海洋冰川测量结果的非技术报告将在当地社区分发，因为当地社区容易受到影响其主要自然资源的快速环境变化的影响。