EAR-PF: Quantifying evaporation in Mono Basin: Bridging the gap between hydrologic modeling and paleoclimate records using triple oxygen and clumped isotope geochemistry

EAR-PF：量化莫诺盆地的蒸发：利用三重氧和聚集同位素地球化学弥合水文模型和古气候记录之间的差距

• 批准号: 2204433
• 负责人: Anne Fetrow
• 金额: $ 18万
• 依托单位: Fetrow, Anne C
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2204433&HistoricalAwards=false
• 关键词: EAR; PF; Quantifying; evaporation; Mono

Freshwater in the Western United States will become an increasingly precious resource and its allocation will become even more contentious as climate change accelerates and human populations expand. To be able to assist the policymakers and communities who are making water resource management decisions, we must be able to more accurately predict how freshwater resources in watersheds will fluctuate in the future. The Mono Basin watershed in eastern California is one of the main water sources for approximately 11 million people in Los Angeles and presents an important example of the need for timely and science-informed water management strategies. This project aims to improve our understanding of a critical, but commonly poorly constrained, aspect of the Mono Basin hydrologic system: the amount of water lost due to evaporation from its iconic terminal lake, Mono Lake. Misestimation of water lost to evaporation can lead to the over-allocation of existing and future water resources. This project will combine powerful geochemical and hydrologic modeling tools to better quantify evaporation in the Mono Lake watershed and extend our understanding of the variability of regional hydrology and climate in recent history. This research will provide urgently needed information to inform water allocation and conservation decisions and improve the understanding of how critical Sierra Nevadan water resources have been affected by human activity and will likely vary in the future due to the changing global climate. The research team will work closely with the outreach and education staff of the Mono Lake Committee, a key conservation group in the region, to develop citizen-science sampling opportunities and Mono Basin-focused curriculum modules for 6-12th graders to increase community engagement in issues of water resource management and build a stronger understanding of the important role that hydroclimate research can play in policy decisions. While hydrologic mass balance modeling provides a powerful tool in estimating hydrologic variability of critical watersheds, there are key parameters that remain poorly constrained, such as amount of water lost to evaporation. The lack of an accurate estimate of evaporative water loss from major reservoirs creates large uncertainties for hydrologic models and hinders the accuracy of predicting future variability of important water resources. In the face of climate change, Mono Lake and its surrounding watershed in eastern California are emblematic of the increasingly serious issues of water management and conservation. This project aims to address the need for a more accurate estimate of modern and historic evaporative water loss in Mono Basin by combining triple oxygen isotope geochemistry, hydrologic mass balance modeling, and in-situ weather and environmental (e.g., temperature, relative humidity) data collection. The first objective of this study is to quantify the spatial and temporal variability of isotopic composition of various water reservoirs in the modern Mono Basin. These isotope datasets will be then used to assess the accuracy of an isotopically enabled mass balance model in predicting the evaporative water loss from Mono Lake and evolution of water isotope compositions in the basin. Additionally, this project aims to understand how the effects of weather and environmental conditions, known from ~100 years of historic instrumental data, are recorded in the Mono Lake sediment record through the generation of stable isotope proxy data from carbonate-rich sediments. From these lake sediment records, it will be possible to estimate the amount of evaporation and lake water temperature of Mono Lake varied in the last ~500 years. An anticipated outcome of this research is improvement of model simulations of future hydroclimate scenarios for the Sierra Nevada region and our understanding of how stable isotope proxies capture climate signals from arid basins. Additionally, the project will provide an interpretive framework for hydroclimate signals in lacustrine sediment records for use in climate modeling, paleoclimate, and paleoecology studies.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.

美国西部的淡水将成为越来越宝贵的资源，随着气候变化的加速和人口的扩大，其分配将变得更加有争议。为了能够协助制定水资源管理决策的政策制定者和社区，我们必须能够更准确地预测未来流域中的淡水资源如何波动。加利福尼亚州东部的单盆地流域是洛杉矶约有1,100万人的主要水源之一，并举办了一个重要的例子，说明了需要及时和科学知识的水管理策略。该项目旨在提高我们对单盆地水文系统的关键但通常受到限制的方面的理解：由于其标志性的末端湖（Mono Lake）蒸发而损失的水量。失去蒸发的水的误解会导致现有水资源和未来水资源的过度分配。该项目将结合强大的地球化学和水文建模工具，以更好地量化Mono Lake流域中的蒸发，并扩展我们对最近历史上区域水文学和气候变异性的理解。这项研究将提供迫切需要的信息，以告知水分配和保护决策，并提高对塞拉尼瓦丹塞拉山脉水资源如何受到人类活动影响的理解，并且由于全球气候变化，将来可能会有所不同。研究团队将与该地区的主要保护小组Mono Lake委员会的外展和教育人员紧密合作，以开发公民科学的抽样机会和以单盆地为中心的课程课程模块，以增加6至12年级的学生，以提高社区参与水资源管理问题，并对氢化气候研究的重要作用提高政策的重要作用。尽管水文质量平衡建模为估计关键流域的水文变异性提供了强大的工具，但仍有关键参数仍然受到限制，例如蒸发量流失的水量。缺乏对主要水库蒸发性水损失的准确估计，这对水文模型造成了巨大的不确定性，并阻碍了预测重要水资源未来可变性的准确性。面对气候变化，单声道湖及其周围加利福尼亚州的周围流域象征着越来越严重的水管理和保护问题。该项目旨在通过结合三重氧同位素地球化学，水文质量平衡建模以及现场天气和环境（例如温度，相对湿度）数据收集来解决单盆盆地现代和历史性蒸发水分流失的需求。这项研究的第一个目的是量化现代单盆地各种水库的同位素组成的空间和时间变化。然后，这些同位素数据集将用于评估同位素启用质量平衡模型的准确性，以预测盆地中水同位素组成的蒸发性水损失和水的演变。此外，该项目旨在了解如何通过从富含碳酸盐的沉积物中产生稳定的同位素代理数据来记录在Mono Lake Sediment Record中，从大约100年的历史仪器数据中知道的天气和环境条件的影响。从这些湖泊沉积物记录中，可以估计过去约500年来，单声道湖的蒸发和湖水温度的数量各不相同。这项研究的预期结果是改善了内华达山脉地区未来氢化气候场景的模型模拟，以及我们对稳定同位素代理如何从干旱盆地捕获气候信号的理解。此外，该项目将为湖泊沉积物记录中的氢气候信号提供解释性框架，以用于气候建模，古气候和古生态学研究。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的影响审查标准来通过评估来通过评估来支持的。