NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment

NSF-NERC：Thwaites-Amundsen 区域调查和网络 (TARSAN) 整合影响冰架下环境的大气-冰海过程

• 批准号: 1929991
• 负责人: Erin C Pettit
• 金额: $ 234.8万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929991&HistoricalAwards=false
• 关键词: NSF; NERC; Thwaites; Amundsen; Regional

This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. Current and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team's specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a "Live from the Ice" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations.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.

该项目为美国国家科学基金会 (NSF) 和英国自然环境研究委员会 (NERC) 发起的联合倡议做出了贡献，该倡议旨在大幅改进对源自西部思韦茨冰川的冰损失和海平面上升的十年和长期预测南极洲。 由于最近的气候变暖和海洋环流的相关变化，阿蒙森海湾的思韦特冰川和邻近的冰川正在迅速失去质量。阿蒙森海湾的质量损失可能导致南极西部冰盖最终崩溃，在短短 500 年内使全球海平面上升 2.5 米（8 英尺）。造成冰川损失的过程似乎是海洋环流变暖以及冰川宽度和流速的变化，但需要更好地了解这些变化，以完善对冰川将如何演变的预测。一个高度敏感的过程是冰川冰从陆地到海洋的过渡流动，成为漂浮的冰架。冰从接地到漂浮的流动受到气温变化和表面降雪的影响；从上游供给冰的速度和厚度；以及海洋温度、盐度、测深和冰流入的洋流。项目团队将收集每个当地环境条件的新测量结果，以便更好地预测未来空气、海洋或冰的变化将如何影响该地区海洋冰的流失。 斯韦茨冰川和附近阿蒙森海海湾地区当前和预计的近期质量损失主要归因于相对温暖的环极深水侵入冰架下空腔导致冰架下融化，导致冰架支撑减少。 。然而，这种对质量损失的预测仍然缺乏对接地区及其附近的主要过程的了解，特别是它们的空间和时间变化，以及这些过程的大气和海洋驱动因素。该项目旨在约束和比较思韦茨冰架和多特森冰架的这些过程，它们通过上游冰动力学连接，但受到不同海底槽的影响。该团队的具体目标是：1）在冰架上安装大气-冰-海洋多传感器远程自主站两年，以提供对同时发生的海洋、冰川和大气条件的亚日连续观测； 2) 测量靠近冰架前缘的大陆架上的海洋特性（使用海豹标记、滑翔机和船基调查以及现有的系泊和电导率-温度-深度铸造数据），3) 将海洋特性测量为子数据-冰架空腔（使用自动水下航行器）详细说明海洋运输和热通量； 4) 约束当前冰架和冰架下空腔的几何形状、冰流和冰架的冰特性（使用雷达、主动源地震和重力方法），以更好地了解海洋和大气的影响关于冰盖的变化。 该团队还将通过“Live from the Ice”社交媒体活动吸引公众参与，提高人们对冰冻圈这一快速变化部分的认识，公众可以从标记的海豹和自主站的角度关注行动和数据收集。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

Climatology and surface impacts of atmospheric rivers on West Antarctica

南极洲西部大气河流的气候学和地表影响

• DOI: 10.5194/tc-17-865-2023
• 发表时间: 2023-01
• 期刊: The Cryosphere
• 作者: Maclennan, Michelle L.;Lenaerts, Jan T.;Shields, Christine A.;Hoffman, Andrew O.;Wever, Nander;Thompson;Winters, Andrew C.;Pettit, Erin C.;Scambos, Theodore A.;Wille, Jonathan D.
• 通讯作者: Wille, Jonathan D.

The role of channelized basal melt in ice-shelf stability: recent progress and future priorities

通道化基底融化在冰架稳定性中的作用：近期进展和未来优先事项

• DOI: 10.1017/aog.2023.5
• 发表时间: 2023-03
• 期刊: Annals of Glaciology
• 影响因子: 2.9
• 作者: Alley, Karen E.;Scambos, Ted A.;Alley, Richard B.
• 通讯作者: Alley, Richard B.

Contribution of Atmospheric Rivers to Antarctic Precipitation

大气河流对南极降水的贡献

• DOI: 10.1029/2022gl100585
• 发表时间: 2022-09-28
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Maclennan, Michelle L.;Lenaerts, Jan T. M.;Shields, Christine;Wille, Jonathan D.
• 通讯作者: Wille, Jonathan D.

Interannual Variation of Modified Circumpolar Deep Water in the Dotson‐Getz Trough, West Antarctica

南极洲西部多特森-盖兹海槽改良绕极深水的年际变化

• DOI: 10.1029/2021jc017491
• 发表时间: 2021-12
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Kim, Tae‐Wan;Yang, Hee Won;Dutrieux, Pierre;Wåhlin, Anna K.;Jenkins, Adrian;Kim, Yeong Gi;Ha, Ho Kyung;Kim, Chang‐Sin;Cho, Kyoung‐Ho;Park, Taewook;et al
• 通讯作者: et al

Suppressed basal melting in the eastern Thwaites Glacier grounding zone

思韦茨冰川东部接地区的基底融化受到抑制

• DOI: 10.1038/s41586-022-05586-0
• 发表时间: 2023-02
• 期刊: Nature
• 影响因子: 64.8
• 作者: Davis, Peter E.;Nicholls, Keith W.;Holland, David M.;Schmidt, Britney E.;Washam, Peter;Riverman, Kiya L.;Arthern, Robert J.;Vaňková, Irena;Eayrs, Clare;Smith, James A.;et al
• 通讯作者: et al