Collaborative Research: P2C2--Western United States Hydroclimate during the Last Interglacial: Developing Proxy Records and Using Model Intercomparison to Glimpse the Future

合作研究：P2C2——末次间冰期美国西部水文气候：开发代理记录并利用模型比对展望未来

• 批准号: 2102885
• 负责人: Warren Sharp
• 金额: $ 22.81万
• 依托单位: Berkeley Geochronology Center
• 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: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102885&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Western; United

Freshwater availability is critical to agricultural, energy and urban systems in the arid to semi-arid western U.S. Quantifying hydroclimate change during past warm periods, such as the Last Interglacial (LIG; ~129,000-116,000 years before present), is essential for evaluating climate model simulations of Earth’s past. This project aims to reconstruct variations in the spatial and seasonal distribution of precipitation in the western U.S. during the LIG during which global temperature are comparable to low-end 21st century projections. The project will include the application of novel methods (calcium and triple oxygen isotopes) on stalagmites from Lake Shasta Caverns (northern California) and Titan Cave (northern Wyoming), and will provide new chronological data and novel measurements (carbonate clumped and triple oxygen isotopes) at four lake sites in the northeast Great Basin (Bear Lake, Utah/Idaho and Bonneville Basin, Utah/Nevada), and southwest Great Basin/Mojave Desert (Lake Manix and Owens Lake, California). The anticipated results of this project are past records of changes in temperature, rainfall amount and moisture source and seasonality. These new past climate records will be integrated into a regional proxy-data network used to benchmark climate model simulations of the Last Interglacial period (127 ka).The paleoclimate modeling intercomparison (PMIP4) and coupled model intercomparison project (CMIP6) efforts of the climate modeling community include Tier 1 LIG (127ka) simulations as a benchmarking target for models with similar CO2 levels, different orbital configuration, unchanged topography and higher sea level. The validation of hydroclimate-relevant variables at a regional scale using climate models requires robustly dated and spatially distributed paleoclimate observations in order to place the LIG water cycle in the western U.S. in the context of geologic and future climate change. Yet, few quantitative estimates of paleoclimate exist for this interval, which offers geochronologic challenges too as it is beyond the limit of radiocarbon age control. This project seeks to improve our understanding of LIG climate in the western U.S. by providing: 1) new observations from speleothem records, 2) new U-Th dating of existing lake cores, and 3) the application of novel semi-quantitative proxies for temperature, precipitation and humidity to speleothems and lake sediments. Through the development of new high-resolution proxy time-series from speleothems and lake sediments, we will provide new insight into the behavior of the North American Monsoon during a past warm period and reconstruct hydroclimatic response to abrupt climatic events during the penultimate deglaciation (Termination II) and Marine Isotope Stage 5 (MIS5). The research uses existing lake cores recovered and archived by previous NSF- and USGS-funded continental drilling projects, and recently collected speleothems known to span much of MIS5 and the LIG.The potential Broader Impacts include quantifying regional hydroclimate changes during past warm periods and benchmarking of climate model simulations for the last interglacial. Other Broader Impacts include translating the project research outcomes via a workshop (paleo to policy) convening water resource managers, government agencies (e.g., USGS), climate and weather risk assessment and projection companies and early career paleoclimate researchers from across the U.S. This workshop will emphasize on the information that terrestrial past climate records (lake sediments, tree rings, speleothems) can provide in terms of hydroclimate data beyond the instrumental records needed by policy makers to assess climate variability and extreme events such as drought and floods. The researchers will produce a white paper, policy briefs for water resource managers and a presentation at an education and outreach session at a scientific meeting (American Geophysical Union). The project will provide scientific training, mentorship and professional development for two graduate students and one postdoctoral researcher. Through joint field trips and collaborations, these students and postdoc will have opportunities to develop interdisciplinary expertise in climate archives, novel proxy systems, geochronology and model-proxy comparison. In addition, the researchers will recruit undergraduate students to complete summer internships related to the project. The undergraduate students will be recruited through (1) the Earth Horizons program and partnership between Vanderbilt University and Tennessee State University, a Historically Black University (HBCU); (2) the Leadership Alliance program at Brown University funded through NSF-REU-EPSCOR. The undergraduate students will be encouraged to develop their research into presentations at regional, national and international scientific meetings (e.g., AGU, GSA).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.

淡水供应对于在过去的温暖时期（例如最后一次冰球; 〜129,000-116，000年之前）量化氢气气候变化的淡水对于农业，能源和城市系统至关重要，这对于评估地球过去的气候模型模拟至关重要。该项目的目的是重建美国西部降水的空间和季节性分布的变化，期间全球温度可与低端21世纪的项目相媲美。 The project will include the application of novel methods (calcium and triple oxygen isotopes) on stalagmites from Lake Shasta Caverns (northern California) and Titan Cave (northern Wyoming), and will provide new chronological data and novel measurements (carbonate clustered and triple oxygen isotopes) at four lake sites in the northeast Great Basin (Bear Lake, Utah/Idaho and Bonneville Basin,犹他州/内华达州）和西南大盆地/莫哈韦沙漠（加利福尼亚州的曼尼克斯湖和欧文斯湖）。该项目的预期结果是过去的温度，降雨量以及水分来源和季节性变化的记录。 These new past climate records will be integrated into a regional proxy-data network used to benchmark climate model simulations of the Last Interglacial period (127 ka).The paleoclimate modeling intercomparison (PMIP4) and coupled model intercomparison project (CMIP6) effort of the climbing modeling community include Tier 1 LIG (127ka) simulations as a benchmarking target for models with similar CO2 levels, different轨道配置，不变的地形和更高的海平面。使用攀岩模型在区域尺度上验证与氢气候相关的变量需要稳固的日期和空间分布的古气候观测，以便在地质和未来气候变化的背景下将LIG水周期放置在美国西部。然而，对于此间隔，几乎没有对古气候的定量估计值，它也提供了地球学挑战，因为它超出了放射性碳年龄控制的极限。该项目旨在通过提供：1）Speleothem Records的新观察，2）现有湖泊核心的新u-以及3）新型的半定量代理在温度，降水量和湿度在孢子和湖泊沉积物中的应用。通过开发从脾脏和湖泊沉积物中开发新的高分辨率代理时间序列，我们将在过去的温暖时期内对北美季风的行为提供新的见解，并在倒数第二阶段（终止II）和Marine Isotope第5阶段（MIS5）中重建对突然气候事件的氢化气候反应。该研究使用了以前的NSF和USGS资助的连续钻井项目回收和存档的现有湖核馆，最近已知的大部分跨越MIS5和LIG的小型钻孔。潜在的更广泛的影响包括量化过去的温暖时期的区域氢化气候变化，以及最后一次间间冰层的气候模拟模拟的基准模拟。其他更广泛的影响包括通过研讨会（政策到政策）召集水资源经理，政府机构（例如USGS），气候和天气风险评估和项目公司以及来自美国的早期职业生涯的研究人员，该研讨会将在陆地上强调的是潮湿的潮流（Splee）的信息，将其强调为Spleems for Spless for Spleste for Sple，湖泊的记录（Splemiates for Sples），将湖水列出来指示，湖泊的历史（湖泊）政策制定者需要评估气候变异性和极端事件（例如干旱和地板）所需的工具记录。研究人员将在科学会议（美国地球物理联盟）上的教育和外展课程上为水资源经理制作白皮书，政策摘要和一份演讲。该项目将为两位研究生和一名博士后研究员提供科学培训，精神训练和专业发展。通过联合实地考察和合作，这些学生和博士后将有机会在气候档案，新颖的代理系统，地质学和模型 - 培训比较方面开发跨学科的专业知识。此外，研究人员还将招募本科生来完成与该项目相关的暑期拘留所。本科生将通过（1）范德比尔特大学和田纳西州立大学（HBCU）（HBCU）之间的地球地平线计划和伙伴关系招募； （2）布朗大学的领导联盟计划通过NSF-REU-EPSCOR资助。将鼓励本科生对在区域，国家和国际科学会议（例如AGU，GSA）举行的演讲中进行研究。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准通过评估来获得的支持。