Satellite Observations and Modelling of Surface Meltwater Flow and its Impact on Ice Shelves

表面融水流及其对冰架影响的卫星观测和建模

• 批准号: 1743310
• 负责人: Jonathan Kingslake
• 金额: $ 53.59万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1743310&HistoricalAwards=false
• 关键词: Satellite; Observations; Modelling; Surface; Meltwater

Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets lose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. Also, water refreezing within ice shelves warms the ice and could affect the flow of the ice by changing its viscosity, which depends on temperature. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project. The team will develop and test physics-based mathematical models of water flow and ice-shelf flow, closely informed by remote sensing observations, to ask (1) how drainage systems will grow in response to the increased melt rates that are predicted for this century, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The team hypothesizes that refreezing of meltwater in snow and firn will prove important for hydrology by impacting the permeability of the snow/firn and for ice-shelf dynamics by releasing latent heat within the ice and lowering ice viscosity. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) examining idealized and realistic models of ice-shelf flow. This project will support a first-time NSF PI, a post-doctoral researcher and a graduate student. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity.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.

冰架减缓了为其提供食物的地面冰盖的运动。这降低了冰盖向海洋流失质量并导致海平面上升的速度。但冰架很容易崩塌，特别是当表面融水积聚在脆弱区域时。融水湖会在冰架内产生并扩大裂缝，从而引发或加速冰架崩塌。此外，冰架内重新冻结的水会使冰变暖，并可能通过改变冰的粘度（取决于温度）来影响冰的流动。南极洲表面的排水及其积聚的地方很少受到关注。这种排水被认为是微不足道的，但最近的研究表明，融水可以穿过冰架表面并进入不会积聚融水的区域数十公里。地表融水排水可能对冰盖未来的稳定性发挥重要作用。该排水是本工程的重点。该团队将开发和测试基于物理的水流和冰架流数学模型，并通过遥感观测密切了解，以询问（1）排水系统将如何发展以应对本世纪预测的融化速度的增加，（2）这种排水如何受到冰动力学的影响，以及（3）扩大的排水系统是否可以将融水输送到容易受到水驱动塌陷的冰架区域。 研究小组假设，雪和冷杉中融水的重新冻结将通过影响雪/冷杉的渗透性来对水文学产生重要影响，并通过释放冰内的潜热并降低冰的粘度来对冰架动力学产生重要影响。该项目将通过以下方式研究这些问题：（1）对南极洲周围融水系统的结构和时间演变进行遥感调查，（2）开发和分析跨冰架水流的数学模型，以及（3）检查理想化和现实的冰架流动模型。该项目将支持一名首次担任 NSF PI、一名博士后研究员和一名研究生。一项外展活动将利用新兴的增强现实技术在三个维度上可视化冰盖的动态，以激发公众对纽约市周边外展活动中冰川学的兴趣。 随着增强现实的不断普及，这种方法将公开供更广泛的使用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Vulnerability of Antarctica’s ice shelves to meltwater-driven fracture

南极洲冰架容易受到融水驱动的断裂影响

• DOI: 10.1038/s41586-020-2627-8
• 发表时间: 2020-08-01
• 期刊: Nature
• 影响因子: 64.8
• 作者: Ching;J. Kingslake;J. Kingslake;M. Wearing;Po;P. Gentine;Harold Li;J. Spergel;J. Spergel;J. M. Wessem
• 通讯作者: J. M. Wessem

ICESat‐2 Meltwater Depth Estimates: Application to Surface Melt on Amery Ice Shelf, East Antarctica

ICESat™2 融水深度估计：应用于南极洲东部阿默里冰架表面融化

• DOI: 10.1029/2020gl090550
• 发表时间: 2020-12-11
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: H. Fricker;Philipp Arndt;K. Brunt;R. Datta;Z. Fair;M. Jasinski;J. Kingslake;L. Magruder;M. Moussavi;A. Pope;J. Spergel;J. Stoll;B. Wouters
• 通讯作者: B. Wouters

Surface meltwater drainage and ponding on Amery Ice Shelf, East Antarctica, 1973–2019

1973 年至 2019 年东南极洲埃默里冰架表面融水排水和积水

• DOI: 10.1017/jog.2021.46
• 发表时间: 2021-01
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: Spergel, Julian J.;Kingslake, Jonathan;Creyts, Timothy;van Wessem, Melchior;Fricker, Helen A.
• 通讯作者: Fricker, Helen A.

Ice‐Shelf Basal Melt Channels Stabilized by Secondary Flow

二次流稳定的冰架基底融化通道

• DOI: 10.1029/2021gl094872
• 发表时间: 2021-10
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Wearing, M. G.;Stevens, L. A.;Dutrieux, P.;Kingslake, J.
• 通讯作者: Kingslake, J.

Inside the ice shelf: using augmented reality to visualise 3D lidar and radar data of Antarctica

冰架内部：使用增强现实可视化南极洲的 3D 激光雷达和雷达数据

• DOI: 10.1111/phor.12298
• 发表时间: 2019-12
• 期刊: The Photogrammetric Record
• 作者: Boghosian, Alexandra L.;Pratt, Martin J.;Becker, Maya K.;Cordero, S. Isabel;Dhakal, Tejendra;Kingslake, Jonathan;Locke, Caitlin D.;Tinto, Kirsty J.;Bell, Robin E.
• 通讯作者: Bell, Robin E.