Collaborative Research: P2C2--Continental Temperature Variability during Greenland Stadials and Interstadials from Subaqueous Speleothems

合作研究：P2C2——来自水下洞穴的格陵兰Stadials和Interstadials期间的大陆温度变化

• 批准号: 2202682
• 负责人: Benjamin Passey
• 金额: $ 11.75万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 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: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202682&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Continental; Temperature

The lack of temperature information for past episodes of climate change remains a major hinderance to narrowing uncertainties of future climate projections. This project aims to measure absolute paleo-surface temperatures for important past climate periods in both the southwestern and northern regions of the United States based on novel temperature indicators measured in cave records (speleothems). The newly generated temperature data for the late Pleistocene and Holocene can potentially provide useful constraints for climate models.Specifically, the researchers aim to provide temperature information for a large region of the North American continent using dual clumped isotope and strontium isotopes. The new temperature records will be used to address the following questions: 1) what was the extent of Holocene temperature variability in and across the continental interior of North America? To what extent does the covariation between Greenland and continental proxy-records (e.g., southwestern United States), reflect temperature changes and not water isotope variability. The researchers have already the samples in hand collected from several caves (Carlsbad Cavern-NM, Lechuguilla Cave-NM, Wind Cave-SD, Mammoth Cave-KY, Mystery Cave-MN, Hollyhock Hollow caves-NY, and lesser-known caves in these areas) extending from the Laurentide ice sheet to the Desert southwest. Accurate uranium-series dating of multiple subsample powders (~200 mg) from selected samples will provide suitable subsample powders for clumped and Sr isotope analyses of the more important time periods (e.g., Middle Holocene, Younger Dryas, Extrapolar Climate Reversal (Mystery Interval), Last Glacial Maximum, the Last Interglacial). This work will also characterize temperature gradients between the southwestern United States and the more northern sites for these periods.The potential Broader Impacts include new paleotemperature records that can be used to benchmark climate models and to evaluate the impact of temperature on hydroclimate and water resources. Additionally, the research with the application of dual clumped isotopes and strontium data can yield novel methodological approaches for quantitative paleoclimate reconstructions.The project will provide research training for two graduate students at the universities of New Mexico and Michigan. The results of this work will be disseminated to the broader public via outreach and media coverage.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.

缺乏过去气候变化事件的温度信息仍然是缩小未来气候预测不确定性的主要障碍。该项目旨在根据洞穴记录（洞穴沉积物）中测量的新型温度指标，测量美国西南部和北部地区过去重要气候时期的绝对古地表温度。新生成的更新世晚期和全新世温度数据可能为气候模型提供有用的约束。具体来说，研究人员的目标是使用双簇同位素和锶同位素为北美大陆的大片地区提供温度信息。新的温度记录将用于解决以下问题：1）全新世北美大陆内部和整个大陆内部的温度变化程度如何？ 格陵兰岛和大陆代理记录（例如美国西南部）之间的协变在多大程度上反映了温度变化而不是水同位素变化。研究人员已经从几个洞穴（新墨西哥州卡尔斯巴德洞穴、新墨西哥州 Lechuguilla 洞穴、SD 风洞、肯塔基州猛犸洞、明尼苏达神秘洞穴、纽约州蜀葵空洞以及 2019 年不太知名的洞穴）中收集了样本。这些区域）从劳伦泰德冰盖延伸到沙漠西南部。对选定样品中的多个子样品粉末（约 200 毫克）进行准确的铀系测年，将为更重要时间段（例如，全新世中期、新仙女木期、极地气候反转（神秘区间））的聚集和 Sr 同位素分析提供合适的子样品粉末，末次盛冰期，末次间冰期）。这项工作还将描述这些时期美国西南部和更北部地点之间的温度梯度。潜在的更广泛影响包括新的古温度记录，可用于基准气候模型并评估温度对水文气候和水资源的影响。此外，应用双簇同位素和锶数据的研究可以产生定量古气候重建的新方法。该项目将为新墨西哥州和密歇根大学的两名研究生提供研究培训。这项工作的结果将通过外展和媒体报道向更广泛的公众传播。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。