Collaborative Research: GreenDrill: The response of the northern Greenland Ice Sheet to Arctic Warmth - Direct constrains from sub-ice bedrock

合作研究：GreenDrill：格陵兰岛北部冰盖对北极温暖的响应 - 来自冰下基岩的直接限制

• 批准号: 1933802
• 负责人: Sridhar Anandakrishnan
• 金额: $ 45.89万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1933802&HistoricalAwards=false
• 关键词: Collaborative; Research; GreenDrill; response; northern

The GreenDrill project is motivated by a need to understand past and future change in the extent of the Greenland Ice Sheet. The Greenland Ice Sheet (GrIS) holds about 24 feet (7.4 m) of sea level equivalent, yet it remains difficult to predict the rate of melt and possible tipping points in the stability of the ice sheet. In GreenDrill, the team of investigators will sample bedrock from under ice at sites in northern Greenland, analyzing cosmogenic nuclides to determine past periods of ice free conditions. These data will provide better understanding of how this region of the GrIS has responded to warm periods in the past. The team will also use these data in computer models to place results in the context of the entire ice sheet to explore mechanisms and climate forcing driving past periods of ice sheet disintegration, which in turn will inform projections of future ice sheet behavior and sea level rise. In addition to the high relevance of this research to society, the GreenDrill project includes broader impacts such as development of a new television episode called Adventures in Science, educational programs for middle and high school students via the Scientists are Superheroes program, and training for early career postdoctoral scientists, graduate students, and undergraduates.In this project, the investigators propose to gather new data to test the sensitivity of the northern Greenland Ice Sheet (GrIS) and its potential to contribute to sea level rise in the future. Specifically, data from the GreenDrill project will better constrain the response of the GrIS to past periods of warmth and address the hypothesis that the northern GrIS is more sensitive to Arctic warming than the southern GrIS. The team will drill through the ice at sites in northern Greenland, sample bedrock obtained from those cores, and analyze a suite of cosmogenic nuclides (Beryllium-10, Aluminum-26, Chlorine-36, Carbon-14, and Neon-21) that can act as signatures of changes to the GrIS margin. These data will deliver direct observations of periods when the GrIS was substantially smaller than today and ice sheet margins retreated inland. Results will be incorporated into a numerical ice sheet model with a built-in cosmogenic nuclide module to identify plausible ice sheet histories. The modeling experiments will help understand the mechanisms and climate forcing underlying past periods of ice sheet retreat and help inform predictions of the future. Based on the melting scenarios, a first-order map of sea level rise fingerprints and inundation scenarios for major port cities will be produced.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.

GreenDrill项目的动机是需要了解格陵兰冰盖范围过去和未来的变化。格陵兰冰原（GrIS）拥有大约24英尺（7.4米）的海平面当量，但仍然很难预测融化的速度和冰原稳定性的可能临界点。在GreenDrill项目中，研究小组将从格陵兰岛北部的冰层下取样基岩，分析宇宙形成的核素，以确定过去无冰状态的时期。这些数据将使我们更好地了解GrIS的这一地区过去是如何对温暖期做出反应的。该小组还将在计算机模型中使用这些数据，将结果置于整个冰盖的背景下，以探索驱动过去冰盖解体时期的机制和气候强迫，这反过来将为未来冰盖行为和海平面上升的预测提供信息。除了这项研究与社会的高度相关性之外，GreenDrill项目还包括更广泛的影响，例如开发一个名为“科学冒险”的新电视节目，通过“科学家是超级英雄”计划为初高中学生提供教育节目，以及为早期职业博士后科学家、研究生和本科生提供培训。在这个项目中，研究人员建议收集新的数据来测试格陵兰岛北部冰盖（GrIS）的敏感性及其对未来海平面上升的潜在影响。具体来说，GreenDrill项目的数据将更好地约束GrIS对过去温暖时期的反应，并解决GrIS北部比南部对北极变暖更敏感的假设。研究小组将在格陵兰岛北部的冰层上钻孔，从这些岩心中获取基岩样本，并分析一系列宇宙形成核素（铍-10、铝-26、氯-36、碳-14和氖-21），这些核素可以作为GrIS边缘变化的标志。这些数据将提供GrIS比现在小得多、冰盖边缘向内陆退缩的直接观测结果。研究结果将纳入一个内置宇宙成因核素模块的数值冰盖模型，以确定合理的冰盖历史。模拟实验将有助于了解过去冰盖退缩期的机制和气候强迫，并有助于预测未来。基于融化情景，将生成主要港口城市海平面上升指纹和淹没情景的一阶地图。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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

Drill-site selection for cosmogenic-nuclide exposure dating of the bed of the Greenland Ice Sheet

格陵兰冰盖床宇宙成因核素暴露测年钻探地点选择

• DOI: 10.5194/tc-16-3933-2022
• 发表时间: 2022
• 期刊: The Cryosphere
• 作者: Briner, Jason P.;Walcott, Caleb K.;Schaefer, Joerg M.;Young, Nicolás E.;MacGregor, Joseph A.;Poinar, Kristin;Keisling, Benjamin A.;Anandakrishnan, Sridhar;Albert, Mary R.;Kuhl, Tanner
• 通讯作者: Kuhl, Tanner