Collaborative Research: Quantifying Heat/Mass Structure and Fluxes Through the Full Thickness of Greenland?s Percolation Zone

合作研究：量化格陵兰岛渗透区全层的热/质结构和通量

• 批准号: 1717939
• 负责人: Neil Humphrey
• 金额: $ 38.27万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-15 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1717939&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; Heat; Mass

Much of the snow that covers the Greenland Ice Sheet experiences melting during summer months. This meltwater percolates and refreezes within the underlying snow. Over time, this altered snow, which is referred to as firn, can reach to depths of 100 meters. These changes in firn structure consequently alter the heat flow within the ice, and between the ice sheet and the atmosphere. As yet however, the full structure of the firn layer is unclear as observations have been limited to shallow depths. To address this important lack of understanding, the investigators propose a field study focused on drilling a number of deep ice cores, with the goal of characterizing the thermal and physical properties of the deep firn ice. This information is essential to predicting ice sheet changes in volume and sea level rise. The project involves graduate and undergraduate students, an early career scientist, and includes public outreach activities.The project will test the hypothesis that the deep firn in the low elevation regions of Greenland experience densification governed by water infiltration/refreezing and thermally enhanced compaction. The project will develop a novel hot water drilling system to quickly penetrate 100 meters through the technically challenging conditions of intermixed cold and wet firn. In situ data collection will include digital temperature strings, video and core logging, and an instrumented drill stem. This work will yield a full-depth characterization of firn thickness, density, permeability, and thermal status. Moreover, drilling conducted a decade earlier in the region will permit the investigators to assess changes in firn properties over time. Ultimately, understanding meltwater retention and refreezing processes across Greenland?s accumulation area is essential for advancing prediction of ice sheet volume change,flow dynamics, and sea level change. The project will provide field and laboratory research experiences impacting a large number of undergraduate and graduate students. The project will support a newly funded young investigator, and will include outreach activities targeting the general public and middle school students in Greenland and Western Montana.

覆盖在格陵兰冰盖上的大部分积雪在夏季融化。这些融水渗透并在下面的雪中重新冻结。随着时间的推移，这种被称为雪的变化可以达到100米的深度。冰结构的这些变化改变了冰内部以及冰盖与大气之间的热流。然而，到目前为止，由于观测仅限于浅层，硬层的完整结构尚不清楚。为了解决这一重要的认识不足，研究人员提出了一项实地研究，重点是钻探一些深冰芯，目的是表征深冰的热特性和物理特性。这一信息对于预测冰盖体积变化和海平面上升至关重要。该项目涉及研究生和本科生，一名早期职业科学家，并包括公众宣传活动。该项目将测试一个假设，即格陵兰岛低海拔地区的深层冻土经历了由水渗透/再冻结和热强化压实控制的致密化。该项目将开发一种新型热水钻井系统，以快速穿透100米的冷湿混合地层技术挑战条件。现场数据收集将包括数字温度串，视频和岩心测井，以及仪表钻杆。这项工作将产生厚层、密度、渗透率和热状态的全深度表征。此外，十年前在该地区进行的钻探将使调查人员能够评估公司属性随时间的变化。最终，了解整个格陵兰岛的融水保留和再冻结过程？S积累区对于推进冰盖体积变化、流动动力学和海平面变化的预测至关重要。该项目将提供影响大量本科生和研究生的实地和实验室研究经验。该项目将支持一名新资助的年轻研究者，并将包括针对格陵兰岛和蒙大拿州西部的普通公众和中学生的外展活动。

项目成果

Horizontal ice flow impacts the firn structure of Greenland’s percolation zone

水平冰流影响格陵兰渗透区的冰结构

• DOI: 10.5194/tc-2019-234
• 发表时间: 2020
• 期刊: The cryosphere
• 作者: Rosemary Leone, Joel Harper

Physical limits to meltwater penetration in firn

雪融水渗透的物理极限

• DOI: 10.1017/jog.2021.44
• 发表时间: 2021
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: Humphrey, Neil F.;Harper, Joel T.;Meierbachtol, Toby W.
• 通讯作者: Meierbachtol, Toby W.

Hot water drilling in the firn layer of Greenland's percolation zone

格陵兰渗滤带第一层热水钻探

• DOI: 10.1017/aog.2020.75
• 发表时间: 2020
• 期刊: Annals of Glaciology
• 影响因子: 2.9
• 作者: Humphrey, Neil;Harper, Joel;Meierbachtol, Toby
• 通讯作者: Meierbachtol, Toby

Firn temperature time series to 100 m depth at two sites along the west Expéditions Glaciologiques Internationales au Groenland (EGIG) line, Greenland 2019-2021

2019-2021 年格陵兰岛 Expéditions Glaciologiques Internationales au Groenland (EGIG) 线西侧两个地点 100 m 深度的芬恩温度时间序列

• DOI: 10.18739/a25d8ng6x
• 发表时间: 2023
• 期刊: NSF Arctic Data Center
• 作者: Harper, Joel;Humphrey, Neil
• 通讯作者: Humphrey, Neil