Collaborative Research: Integrating Eocene Shark Paleoecology and Climate Modeling to reveal Southern Ocean Circulation and Antarctic Glaciation

合作研究：整合始新世鲨鱼古生态学和气候模型来揭示南大洋环流和南极冰川作用

• 批准号: 1842049
• 负责人: Sora Kim
• 金额: $ 29.74万
• 依托单位: University of California - Merced
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1842049&HistoricalAwards=false
• 关键词: Collaborative; Research; Integrating; Eocene; Shark

The Earth's climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from 'greenhouse' to 'icehouse' conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty.The research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift.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.

地球的气候随着时间的流逝而发生了变化，在始新世时期（56至3400万年前），从“温室”到“冰屋”条件发生了过渡。在始新世期间，高纬度的温度转移到较冷的温度导致极性冰川化开始。这反过来影响了生物的环境。该项目旨在通过使用过去探险期间收集的化石鲨鱼牙齿的化学分析来揭示南极始新世的生物，海洋学和气候系统之间的相互作用。古生物学和地球化学分析的结合将为过去的生态和海洋条件提供见解。在此期间，将应用气候模型来测试构造，温室气体浓度和海洋循环对环境变化的作用。该研究有助于了解增加大气二氧化碳和海洋循环的相互作用。该项目还旨在通过针对本科，研究生，博士后和早期职业教师的努力来改善地球科学劳动力中的多样性，公平性和包容性。研究目标是阐明从Ecorene Greenhouse到渐新世冰屋的过程。先前对这种气候变化的解释以南极洲为中心，构造构造影响了海洋门户，海洋循环降低了热传输，并且/或温室气体下降引起了冰川的冰川。该团队将使用从西摩岛收集的化石鲨鱼牙齿中重建与南极半岛接近南极半岛的水样波动。该方法基于先前的鲨鱼古生物学研究，结合了环境重建（即温度梯度和海洋循环）的地球化学分析，并使用具有地球化学示踪剂的新型全球气候模型模拟对地球系统动力学进行了假设。该项目将通过实验来推动全球气候建模功能，这些实验考虑始新世构造构造构型在具有同位素的气候模型模拟中。对始新世气候模拟和鲨鱼牙齿的经验记录的地球化学结果的比较将揭示始新世南极气候转移中心的过程和机制。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估来审查审查标准来通过评估来支持的。