NSFGEO-NERC: Collaborative Research: Understanding the Drivers of Inert Gas Saturation to Better Constrain Ice Core-Derived Records of Past Mean Ocean Temperature

NSFGEO-NERC：合作研究：了解惰性气体饱和的驱动因素，以更好地限制冰芯衍生的过去平均海洋温度记录

• 批准号: 2049359
• 负责人: Alan Seltzer
• 金额: $ 54.37万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2049359&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Collaborative; Research; Understanding

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The integrated heat content of the global ocean is a fundamental climate variable for understanding Earth’s energy balance. Accurate estimates of past changes in the global energy budget are essential for understanding the inherent sensitivities of the Earth system. This project will address the accuracy of these estimates by carrying out computer simulations of dissolved gases in the ocean. By analyzing the outcomes of these simulations, the team aims to refine ice-core-based reconstructions of ocean heat content that rely on measurements of gases (Xenon, Krypton, and Nitrogen) in ancient air bubbles preserved in ice cores. The project aims to produce the first estimates and uncertainty ranges of saturation anomalies of Xenon, Krypton, and Nitrogen in the glacial ocean during the Last Glacial Maximum. Recent analytical advances have permitted measurement of ratios of Xenon to Nitrogen and Krypton to Nitrogen in ice cores at sufficient precision to resolve whole-atmosphere changes in these ratios that reflect warming and cooling of the global ocean at the 0.1ºC level. However, to quantitatively constrain past ocean heat content using inert gas measurements requires assumptions about long-term changes in the global ocean saturation state of these gases, which remains an entirely open problem. Consequently, the team will use the Transport Matrix Method for biogeochemical tracer simulations. They will build on a suite of previously conducted simulations of oxygen and carbon dioxide in the glacial ocean with the University of Victoria Earth System Climate Model to quantitatively constrain the glacial-interglacial change in inert gas saturation state and understand its physical drivers. In addition, the team will add independent experiments using a second model (the MIT global circulation model) and carry out several future warming experiments to consider how ongoing changes in the Earth system may affect physical air-sea gas transfer. Finally, the team will reevaluate existing ice-core inert gas records to produce best estimates of changes in ocean heat content during the Last Glacial Maximum and periods of abrupt warming throughout the last deglaciation. This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) (U.S. participants) and the Natural Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work.The NSF award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2)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.

该奖项全部或部分根据2021年美国救援计划法案（公法117-2）资助。全球海洋的综合热含量是了解地球能量平衡的一个基本气候变量。准确估计全球能源预算过去的变化对于了解地球系统的固有敏感性至关重要。 该项目将通过对海洋中溶解的气体进行计算机模拟来解决这些估计的准确性问题。 通过分析这些模拟的结果，该团队的目标是完善基于冰芯的海洋热含量重建，该重建依赖于冰芯中保存的古老气泡中的气体（氙，氪和氮）的测量。该项目旨在产生最后一次盛冰期期间冰川海洋中氙，氪和氮饱和度异常的第一个估计值和不确定性范围。最近的分析进展使得能够以足够的精度测量冰芯中氙与氮和氪与氮的比率，以解决这些比率的整个大气变化，反映全球海洋在0.1ºC水平上的变暖和变冷。然而，要使用惰性气体测量来定量限制过去的海洋热含量，需要假设这些气体在全球海洋饱和状态中的长期变化，这仍然是一个完全开放的问题。 因此，该团队将使用传输矩阵方法进行生物地球化学示踪剂模拟。他们将利用维多利亚大学地球系统气候模型对冰川海洋中的氧气和二氧化碳进行一系列模拟，以定量限制惰性气体饱和状态的冰川间冰期变化，并了解其物理驱动因素。此外，该团队还将使用第二个模型（麻省理工学院全球环流模型）进行独立实验，并进行几个未来的变暖实验，以考虑地球系统的持续变化如何影响物理的空气-海洋气体传输。最后，研究小组将重新评估现有的冰芯惰性气体记录，以最好地估计末次冰盛期和末次冰消期突然变暖期间海洋热含量的变化。 这是一个由美国国家科学基金会地球科学理事会（NSF/GEO）（美国参与者）和联合王国自然环境研究理事会（UKRI/NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。在成功共同裁定裁决后，每个机构为预算的一部分、与自己的调查人员相关的调查人员和工作的组成部分提供资金。NSF奖的全部或部分资金来自2021年的美国救援计划法案（第117-2页）该奖项反映了NSF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进行评估，被认为值得支持审查标准。