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: 0909282
• 负责人: Leigh Stearns
• 金额: $ 16.45万
• 依托单位: University of Kansas Center for Research Inc
• 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=0909282&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.

该奖项将支持格陵兰岛东部冰川与峡湾相互作用的研究。拟议研究的“智力价值”在于目前的认识，即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，这主要是因为许多终止于深峡湾潮水的冰川普遍且几乎同时加速。了解冰川动力学变化的原因并预测其未来轨迹是一个具有巨大科学和社会重要性的话题。格陵兰峡湾在冰盖和海洋之间提供了密切的联系，反过来，观察到的格陵兰岛东南部和西部周围海洋变暖可能是最近出口冰川动态变化的触发因素。 PI在格陵兰岛东部进行的一项试点研究以及在格陵兰岛西部进行的一项单独研究分别发现赫尔海姆冰川和雅各布港伊斯布雷附近的海水温暖，这支持了海洋变暖引发海水加速的假设。虽然很有趣，但格陵兰岛峡湾中温暖水域的存在并不足以得出海洋正在调节冰川动态的结论。要验证这一假设，需要对冰川/峡湾相互作用有更详细的了解，而目前可用的数据量有限。这项研究将通过为期两年的强化实地计划，调查东格陵兰岛典型冰川峡湾系统（塞尔米利克峡湾和赫尔海姆冰川）中冰川与海洋的相互作用，从而填补这一空白。通过夏季调查和全年系泊仪器，将绘制峡湾在潮汐到每年时间尺度上的循环和特性，并量化从峡湾流出的液态淡水通量。与格陵兰海洋生物学家的合作将允许使用标记的海豹获得峡湾以外地区的重要海洋数据。 GPS 方法和遥感技术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。卫星遥感和大型冰山的实地跟踪将提供对淡水固体出口及其变化的估计。拟议的研究具有许多“更广泛的影响”。它们可能是下一代冰盖模型的重要组成部分，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，涉及两名开始职业生涯的初级科学家，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，以满足社会对冰盖-海洋相互作用领域专家的需求。实地考察利用当地船只，并强烈依赖几代当地猎人在塞尔米利克峡湾航行的知识，从而促进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分发给当地社区，该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。