CAREER: Chasing icebergs: quantifying iceberg motion and melt in Greenland's glacial fjords

职业：追逐冰山：量化格陵兰冰川峡湾的冰山运动和融化

• 批准号: 1552232
• 负责人: Joshua Roering
• 金额: $ 79.97万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-11-01 至 2021-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1552232&HistoricalAwards=false
• 关键词: CAREER; Chasing; icebergs; quantifying; iceberg

Mass is being lost from the Greenland Ice Sheet both in the form of liquid water and solid ice. The solid ice occurs in the form of icebergs. The influence of these icebergs on the stratification and circulation of water in fjords, as well as on the freshwater content of the adjacent ocean, is poorly understood. This project will improve understanding of the role of icebergs in fjords and the coastal ocean through intensive process studies on iceberg melt and movement. These studies will include both field observations and numerical modeling experiments. The project will contribute to the development of the nation's STEM workforce by providing support for the training of a graduate student and a post-doctoral associate. To enhance the communication of science to the general public, a course in Geo-communication will be modified to include new multi-media approaches. Additionally, the project will allow the PI to extend his prior collaborations with University of Oregon's STEM CORE program to work with a local middle school on STEM-focused curricula. To enhance outreach to the broader public, the principal investigator will collaborate with a science historian to transcribe archived data into modern format that will be freely distributed, co-deliver public talks, add content to an existing website, and participate in an annual event on Climate Change and Indigenous Peoples organized by his institution.The ongoing surge in ocean-glacier interactions studies around Greenland is motivated primarily to improve our understanding of the role ocean circulation plays in outlet glacier variability. Two potential mechanisms that lead to glacier acceleration and dynamic thinning are (1) increased submarine melting due to an enhanced ocean heat transport to the glacier termini, and (2) a weakening of the ice mélange that buttresses the glacier face. Fjords act as links between these two processes with the large-scale climate forcing on one hand (both oceanic and atmospheric) and the Greenland ice sheet variability on the other. However, one key process, iceberg melt, has been largely neglected in most fjord circulation studies due to a narrow focus on plume driven circulation, as well as the overall difficulty of obtaining in situ observations. This proposal aims to gather novel observations on iceberg melt and movement in Greenland?s fjords by tracking the horizontal and vertical motion of large, deep-keeled icebergs at high temporal resolution. Tracking individual icebergs, combined with ship- and drone-based surveys, will allow quantification not only of iceberg melt rates, but also of their movement through the fjord and eventual dispersal across the shelf and into the interior ocean. Fieldwork will be conducted in relatively well-studied systems in Greenland, with the potential for rapid generalization to other systems. Complemented by numerical ocean modeling, these process studies will enable assessment of how well current parameterizations capture the melt processes occurring in Greenland's waters. Ultimately, these results will provide a solid foundation for improving understanding of the spatial and temporal picture of iceberg motion and melt and how this can be incorporated into operational iceberg trajectory models, as well as global scale climate models.

格陵兰冰盖的质量正在以液态水和固态冰的形式流失。 固体冰以冰山的形式出现。 人们对这些冰山对峡湾水的分层和循环以及邻近海洋淡水含量的影响知之甚少。 该项目将通过对冰山融化和运动的深入过程研究，增进对冰山在峡湾和沿海海洋中的作用的了解。 这些研究将包括现场观察和数值模拟实验。 该项目将通过为研究生和博士后的培训提供支持，为国家 STEM 劳动力的发展做出贡献。 为了加强向公众的科学传播，将修改地理传播课程以纳入新的多媒体方法。 此外，该项目还将允许 PI 扩展其之前与俄勒冈大学 STEM CORE 项目的合作，与当地一所中学合作开发以 STEM 为重点的课程。 为了加强对更广泛公众的影响，首席研究员将与科学历史学家合作，将存档数据转录成现代格式，以便免费分发，共同发表公开演讲，向现有网站添加内容，并参加其机构组织的气候变化和土著人民年度活动。格陵兰岛周围海洋-冰川相互作用研究的持续激增，主要是为了提高我们对海洋环流在出口中所起的作用的了解。 冰川的变化。导致冰川加速和动态变薄的两个潜在机制是（1）由于海洋热量传输到冰川终点的增强而导致海底融化增加，以及（2）支撑冰川表面的混冰减弱。峡湾是这两个过程之间的纽带，一方面是大规模的气候强迫（海洋和大气），另一方面是格陵兰冰盖的变化。然而，由于对羽流驱动的环流的狭隘关注以及获得现场观测的总体困难，冰山融化这一关键过程在大多数峡湾环流研究中基本上被忽视。该提案旨在通过以高时间分辨率跟踪大型深龙骨冰山的水平和垂直运动，收集有关格陵兰峡湾冰山融化和运动的新观察结果。跟踪单个冰山，结合船舶和无人机调查，不仅可以量化冰山融化速度，还可以量化冰山在峡湾中的移动以及最终在大陆架上的扩散并进入内海。实地工作将在格陵兰岛研究相对充分的系统中进行，具有快速推广到其他系统的潜力。辅以数值海洋模型，这些过程研究将能够评估当前参数化捕获格陵兰水域发生的融化过程的效果。最终，这些结果将为加深对冰山运动和融化的时空图景的理解以及如何将其纳入可操作的冰山轨迹模型以及全球尺度气候模型中提供坚实的基础。