Greenland-wide Assessment of Proglacial Melange Variability and Implications for Glacier Retreat

格陵兰范围前冰川混杂物变异性及其对冰川退缩的影响的评估

• 批准号: 2336627
• 负责人: Michalea King
• 金额: $ 40.85万
• 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: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2336627&HistoricalAwards=false
• 关键词: Greenland; wide; Assessment; Proglacial; Melange

Over two hundred outlet glaciers line the edges of the Greenland ice sheet, where they drain thick ice from the interior into the surrounding ocean. As these glaciers retreat and speed up, they remove mass from the ice sheet at a faster rate. Therefore, to quantify and predict Greenland’s role in global sea level rise, it is important to understand what processes drive patterns of glacier advance and retreat. This project uses satellite data to study the impact of ice mélange, or the mixture of sea ice and icebergs, on the timing and magnitude of glacier retreat in Greenland. Because the distribution of mélange is not well known, this project will first measure mélange coverage, show when it forms and breaks up around the ice sheet, and create maps and time series for other scientists to use in their research. The project team will then compare these data products to measurements of changing glacier fronts through time to investigate whether mélange in front of glaciers can limit retreat, identify where mélange is most important, and quantify if mélange coverage is changing over time. Led by an early career investigator on her first NSF award, this project will promote the full participation of women in STEM and accomplish several broader impacts beyond addressing important scientific questions. The team will increase representations and public science literacy by recruiting summer undergraduate researchers through channels aimed at promoting diversity, by participating in interactive glacier-related activities at public educational events, and by volunteering in guest speaking engagements at elementary through university-level classrooms. Outlet glaciers that flow out into the surrounding ocean are an important component of the Greenland ice sheet mass balance, and changes in outlet glacier length and speed can affect how rapidly ice is removed from the ice sheet through time. In areas where icebergs break off from calving glaciers, sea ice may intermix with icebergs and form a refrozen, semi-rigid mixture called mélange. Mélange can build up in the fjord and crowd the area near the glacier calving front, potentially limiting how much and for how long retreat can occur. Despite its likely impact on changing seasonal patterns of outlet glacier retreat and speed, neither the total area of mélange nor the timing and duration of its coverage have yet been measured on an ice sheet-wide scale. This project will conduct the first robust, large-scale assessment of mélange conditions in Greenland to quantify the role of mélange in outlet glacier behavior and its net impact on glacier and ice sheet mass loss. The study will heavily utilize radar data from the Sentinel-1 satellite mission, which images most areas of the Greenland coastline every 6 to 12 days, and adapt existing methods of glacier speed tracking to function over regions of consolidated, or rigid, mélange in outlet glacier fjords. In doing so, the project will also develop and distribute important new data products that map the location of rigid mélange conditions through time and combine the ~weekly maps to measure how often mélange is present at specific sites around Greenland. Through collaborative efforts with existing datasets and tools, the project team will compare the mélange data to measurements of glacier front changes, including front position, ice thickness, and glacier shape, as well as iceberg size and distribution. These analyses will be used to better understand how the local geographic and environmental conditions relate to mélange formation, and finally, help identify where mélange formation is most important for glacier calving. Outcomes of this work will include broader impacts that extend beyond the scientific merit. In addition to adopting open science principles in the development and sharing of new datasets, the team will also integrate activities and approaches aimed at increasing the representation and participation of minoritized groups in STEM, and at improving public polar literacy and engagement in science and technology. The project’s principal investigator is an early career woman leading her first NSF-supported study, and she will work closely with existing programs designed to serve underrepresented populations when recruiting students for paid summer research experiences that are complementary to the project’s goals. The team will also participate in glacier-related demonstrations in a public-facing, community educational event, and the lead investigator will incorporate project results and outcomes into guest speaking engagements planned for elementary through university-level classrooms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

超过两百个出口冰川排在格陵兰冰盖的边缘，在那里它们从内部沥干厚厚的冰，进入周围的海洋。随着这些冰川的撤退并加快加速，它们以更快的速度从冰盖上取出质量。因此，为了量化和预测格陵兰在全球海平面上升中的作用，重要的是要了解哪些过程推动了冰川前进和撤退的模式。该项目使用卫星数据来研究冰混合的影响，或者是因为不为人知的混战的分布，因此该项目将首先测量混乱覆盖范围，显示何时形成并在冰盖周围分解，并创建地图和时间序列，以便其他科学家在其研究中使用。然后，项目团队将将这些数据产品与随着时间的流逝进行更改冰川方面的测量进行比较，以调查冰川面前是否可以限制撤退，确定Mélange最重要的位置，并量化Mélange覆盖范围是否随着时间的推移而变化。在早期职业调查员获得她的第一个NSF奖项的领导下，该项目将促进妇女在STEM中的全面参与，并在解决重要的科学问题之外实现更广泛的影响。该团队将通过旨在促进多样性的渠道招募夏季的本科研究人员，通过在公共教育活动中参加与互动式冰川相关的活动，以及通过大学级别的大学级教室在小学的嘉宾演讲活动中，通过促进多样性的渠道来提高表现和公共科学素养。流入周围海洋的出口冰川是格陵兰冰板质量平衡的重要组成部分，出口冰川的长度和速度的变化会影响如何迅速从冰盖上移除冰的速度。在冰山从产犊冰川中脱落的地区，海冰可能与冰山结合，形成一种称为Mélange的半刚性混合物。 Mélange可以在峡湾中积聚，并在冰川产犊前附近挤满了该区域，从而有可能限制发生多长时间的静修时间和时间。尽管它可能会影响不断变化的出口冰川静修和速度的季节性模式，但梅兰奇的总面积或覆盖范围的时间和持续时间尚未以冰盖范围的范围进行测量。该项目该研究将大量利用Sentinel-1卫星任务中的雷达数据，该数据每6至12天对格陵兰海岸线的大多数区域进行图像，并适应现有的冰川速度跟踪方法，以在出口冰川峡谷中的合并，僵硬的，僵硬的Mélange区域的区域内运行。在此过程中，该项目还将开发和分发重要的新数据产品，这些新数据产品可以通过时间绘制刚性混合条件的位置，并结合每周的地图，以测量在格陵兰岛特定地点呈现Mélange的频率。通过与现有数据集和工具的合作努力，项目团队将将Mélange数据与冰川前部变化的测量进行比较，包括前位置，冰层厚度和冰川形状，以及冰山的大小和分配。这些分析将用于更好地了解当地地理和环境条件与混合形成如何相关，最后，有助于确定在冰川产犊中最重要的Mélange形成。这项工作的结果将包括超出科学功绩的更广泛的影响。除了在开发和共享新数据集的开发和共享中采用开放的科学原则外，该团队还将整合旨在增加STEM中少数群体的代表性和参与以及提高公共极性识字和参与科学和技术的活动和参与。该项目的首席研究员是一名早期职业女性，领导她的第一个由NSF支持的研究，她将与现有计划紧密合作，旨在为代表性不足的人群提供服务，以招募学生获得付费夏季研究经验，这些研究经验是该项目目标的完善。该团队还将在面向公共的社区教育活动中参加与冰川相关的示威活动，首席调查员将通过大学级的课堂进行项目成果和成果纳入计划为基础课程计划的客人演讲活动。这项奖项反映了NSF的法定任务，并认为通过基金会的知识优点和广泛的criperia criperia criperia crigitia criperia criperia cripitia criperia the Issportiation take thim。