Accomplishment Based Renewal: Intensification of the Hydrologic Cycle during the Paleocene-Eocene Thermal Maximum

基于成就的更新：古新世-始新世热最大值期间水文循环的强化

• 批准号: 2103513
• 负责人: James Zachos
• 金额: $ 39.54万
• 依托单位: University of California-Santa Cruz
• 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: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103513&HistoricalAwards=false
• 关键词: Accomplishment; Based; Renewal; Intensification; Hydrologic

Earth has experienced just over 1°C of fossil fuel carbon dioxide-driven global warming to date. The impacts of this warming on the global hydrologic cycle are already evident. The projected 4-5°C of warming by 2300 under a business-as-usual fossil fuel use scenario is predicted to further intensify the hydrologic cycle. The resulting impacts on societies’ water security would be significant, and likely create widespread hardship for nations across the globe, rich and poor. Climate models, tested by their ability to replicate past changes in climate, are an important tool to plan for and minimize those impacts. The Paleocene-Eocene Thermal Maximum (PETM, roughly 55 million years ago) serves as a crucial case study to test climate models. It also provides a real-world example of the sensitivity of the climate system to a massive carbon dioxide input. The proposed project will use coastal sediments to develop proxy records of water chemistry and onshore hydrology across the PETM. These new data will be compared with climate model studies of that ancient natural climate event. The educational Broader Impacts of the proposed project include support for a graduate student and for undergraduate participants.Although considerable geologic evidence exists for a shift in hydroclimate during the PETM, additional observations are required to assess regional/local changes, particularly as relates to extremes on annual or shorter time scales. To this end, this project will estimate regional changes in coastal hydrography/chemistry along both coasts of the US utilizing shallow marine siliciclastic sections in outcrops and cores. Preliminary data indicate significant changes in runoff (& erosion) and thus precipitation, very likely in the amplitude of wet/dry cycles and/or heavy precipitation events (e.g. atmospheric rivers, extratropical cyclones). Building on prior results, in collaboration with colleagues novel isotopic and geochemical proxies will be employed, along with traditional proxies, to constrain local changes in coastal ocean hydrography/chemistry. The observations will be compared against output of recently completed GCM simulations of the PETM utilizing high resolution models including the Community Atmosphere Model. The primary focus of the comparisons will be on changes in the seasonal cycles of precipitation and frequency of extreme events (i.e., heavy precipitation or droughts).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.

迄今为止，地球经历了超过1°C的化石燃料二氧化碳驱动的全球变暖。这种变暖对全球水文周期的影响已经证明。预计，预计在业务 - 普遍的化石燃料使用方案下，预计的4-5°C的变暖将进一步增强氢化周期。由此对社会水安全的影响将是巨大的，并可能为全球，富人和穷人的国家带来宽敞的困难。气候模型根据其复制过去气候变化的能力测试，是计划和最大程度地降低这些影响的重要工具。古新世 - 新世热最大（PETM，大约5500万年前）是测试气候模型的关键案例研究。它还提供了气候系统对大量二氧化碳输入的敏感性的现实示例。拟议的项目将使用沿海沉积物来开发PETM的水化学和陆上水文学的代理记录。这些新数据将与对古代自然气候事件的气候模型研究进行比较。拟议项目的教育更广泛的影响包括对研究生和本科参与者的支持。尽管存在大量的地质证据证明PETM期间氢气气候的变化存在，但需要进行其他观察以评估区域/地方变化，尤其是与年度或更短的时间尺度相关的区域/地方变化。为此，该项目将估计沿着美国两层外套的沿海水文/化学的区域变化，利用露天和核心中的浅海硅切片。初步数据表明径流（＆侵蚀）发生了显着变化，因此降水很可能在湿/干循环和/或大沉淀事件的放大器中（例如大气河，气流周围的气旋）。在先前结果的基础上，与同事合作，新型同位素和地球化学代理将与传统代理一起限制沿海海洋水文/化学的局部变化。将观察结果与使用高分辨率模型在内的高分辨率模型（包括社区大气模型）的最近完成的GCM模拟进行比较。比较的主要重点将放在季节性降水和极端事件频率（即大沉淀或干旱的频率）的变化上。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的。

项目成果

Shelf Ecosystems Along the U.S. Atlantic Coastal Plain Prior to and During the Paleocene‐Eocene Thermal Maximum: Insights Into the Stratigraphic Architecture

古新世至始新世热最大值之前和期间美国大西洋沿海平原的陆架生态系统：对地层结构的见解

• DOI: 10.1029/2022pa004475
• 发表时间: 2022
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: Doubrawa, Monika;Stassen, Peter;Robinson, Marci M.;Babila, Tali L.;Zachos, James C.;Speijer, Robert P.
• 通讯作者: Speijer, Robert P.

Assessing environmental change associated with early Eocene hyperthermals in the Atlantic Coastal Plain, USA

• DOI: 10.5194/cp-19-1677-2023
• 发表时间: 2023-08
• 期刊: Climate of the Past
• 影响因子: 4.3
• 作者: W. Rush;J. Self‐Trail;Yang Zhang;A. Sluijs;H. Brinkhuis;J. Zachos;J. Ogg;M. Robinson