Linking terrestrial and marine carbon cycling across the Paleocene-Eocene Thermal Maximum via intermediate complexity Earth system modeling

通过中等复杂度的地球系统建模将古新世-始新世热最大值期间的陆地和海洋碳循环联系起来

• 批准号: 2202694
• 负责人: Sandra Turner
• 金额: $ 16.99万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202694&HistoricalAwards=false
• 关键词: Linking; terrestrial; marine; carbon; cycling

The Paleocene-Eocene Thermal Maximum (PETM) was a global warming event approximately 56 million years ago. The PETM was caused by the release of greenhouse gases (including carbon dioxide and/or methane) to the atmosphere and oceans. Earth system models have been employed to constrain the magnitude, timing, and impacts of PETM carbon emissions. However, the contribution of carbon cycle feedbacks to the severity of environmental changes across the PETM remains unclear. One key gap is how the terrestrial carbon cycle responded to PETM global change. This project will add a representation of the terrestrial carbon cycle to an intermediate complexity Earth system model. That model will simulate the cycling of carbon dioxide and methane between vegetation, soils, the atmosphere, and the oceans. This study will place new constraints on the sensitivity of Earth’s carbon cycle to carbon release and global warming. In addition, this project will support research experiences at UC Riverside for undergraduate students from Riverside Community College. These internships are a cornerstone of UC Riverside’s Geoscience Development program. That program targets the critical juncture between community college and 4-year programs with the goal of building a diverse population of undergraduates in the geosciences. Carbon cycle feedbacks are a key source of uncertainty in future climate change projections. Study of past global warming episodes, like the PETM, has the potential to provide crucial insight into the operation of these feedbacks on a warm Earth. By adding a representation of the terrestrial carbon cycle to an intermediate complexity Earth system model configured for the late Paleocene, the proposed research will allow evaluation of the time-dependent response of potential carbon cycle feedbacks in response to higher atmospheric CO2 and higher global temperature. In addition, the proposed research will update a current representation of ocean and atmosphere methane cycling with a modeled representation of the terrestrial production and oxidation of methane. This updated model, cGENIE-ENTS, will be used to evaluate multiple proposed PETM carbon emissions scenarios, including comparison of model output against available proxy datasets. The computational efficiency of the cGENIE-ENTS model will allow experiments to be run for the entire ~200 kyr PETM duration and thus evaluate not only the potential for terrestrial carbon cycle feedbacks during the onset of the event, but also their potential role in determining the timescale of Earth system recovery. All model components will be coupled during model integration, producing consistent output for the response of both the terrestrial and marine carbon cycle through time. New PETM simulations will provide revised estimates for PETM carbon emissions and provide constraints on the feedback behavior (both positive and negative) of the terrestrial biosphere.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.

古新世-始新世最热期 (PETM) 是大约 5600 万年前的一次全球变暖事件，是由温室气体（包括二氧化碳和/或甲烷）释放到大气和海洋中引起的。然而，碳循环反馈对整个 PETM 环境变化严重程度的贡献仍不清楚，其中一个关键差距是陆地碳循环如何响应。该项目将在中等复杂性的地球系统模型中添加陆地碳循环的表示，该模型将模拟植被、土壤、大气和海洋之间的二氧化碳和甲烷的循环。对地球碳循环对碳释放和全球变暖的敏感性提出了新的限制。此外，该项目将为河滨社区学院的本科生提供研究经验，这些实习是加州大学河滨分校地球科学发展的基石。该计划针对的是社区大学和四年制计划之间的关键时刻，其目标是培养地球科学领域的多样化本科生。碳循环反馈是未来气候变化预测的一个关键来源。通过将陆地碳循环的表示添加到为古新世晚期配置的中等复杂性地球系统模型中，像 PETM 这样的事件有可能为这些反馈在温暖的地球上的运行提供重要的见解。允许评估此外，拟议的研究将通过陆地甲烷生产和氧化的建模表示来更新海洋和大气甲烷循环的当前表示。这个更新的模型 cGENIE-ENTS 将用于评估多个拟议的 PETM 碳排放情景，包括将模型输出与可用的代理数据集进行比较。 cGENIE-ENTS 模型的计算效率将允许。实验将在整个~200 kyr PETM 持续时间内进行，从而不仅评估事件发生期间陆地碳循环反馈的潜力，而且评估它们在确定地球系统恢复的时间尺度中的潜在作用。新的 PETM 模拟将在模型集成过程中进行耦合，为陆地和海洋碳循环随时间的响应产生一致的输出，将为 PETM 碳排放提供修订的估计，并为反馈行为（正反馈和负反馈）提供约束。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。