Collaborative Research: RAPID--Characterizing the Water Isotope Signature of an El Nino Event for Paleoclimate and Hydroclimate Studies

合作研究：RAPID——为古气候和水文气候研究描述厄尔尼诺事件的水同位素特征

• 批准号: 2333172
• 负责人: Jeremy Rugenstein
• 金额: $ 3.34万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2333172&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Characterizing; Water

This project secures funds under the auspices of the Rapid Response Research (RAPID) program to take advantage of the strong-to-very strong El Niño/Southern Oscillation (ENSO) forecast for the water year 2023-2024 to establish a longitudinal array of precipitation and stream sampling stations to constrain the meteoric water delta oxygen-18, deuterium-excess, and delta oxygen-17 signal of a strong ENSO event. The researchers will sample precipitation and stream water monthly over the course of a year and analyze these samples for oxygen and hydrogen isotopes. They will also collect spot samples of small-stream waters across this same longitudinal transect during Fall 2023 and Spring 2024 and simulate the source and pathways of precipitation using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model while using spatial statistics to produce isoscapes of our stable isotope result across the southwestern United States (U.S.).This research is premised on the idea that substantial uncertainty remains regarding how hydroclimate (including precipitation, evapotranspiration and runoff) in the arid and semi-arid southwestern U.S. will respond to rising carbon dioxide and warmer temperatures considering that ENSO plays an outsize role in modifying wintertime southwestern U.S. hydroclimate. There is a large body of data from research that examines how ENSO will change in response to warming, utilizing both Global Climate Model (GCM) projections of future climate and paleoclimate records but these data are poorly constrained. Much of the paleoclimate evidence of southwestern U.S. hydroclimate and its links to the ENSO comes from proxy records of past meteoric water oxygen isotopes, with the typical assumption that lower proxy delta oxygen-18 corresponds with greater wintertime moisture and a shift towards ENSO conditions. Consequently, the ability to test the sensitivity of western U.S. hydroclimate to warming and its links with ENSO relies upon constraining the relationship between the ENSO and meteoric water delta oxygen-18 across the western U.S. This causal link, however, is not well-established for strong ENSO events that may dominate climate in the future. Furthermore, there is currently no data to understand how ENSO modifies delta oxygen-17 values, which is emerging as a promising analytical isotopic tool to constrain the role of moisture source dynamics and evaporative effects in carbonate and clay isotope archives of paleoclimate.The potential broader impacts include supporting two graduate students and providing a long-term monitoring dataset for improving reconstructions of the strength and frequency of ENSO events in the past which will help constrain the range of variability observed in the region necessary for future forecasts. The research fits well into the potentially transformative, high risk, and quick-response research imperative of the RAPID program.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.

This project secures funds under the auspices of the Rapid Response Research (RAPID) program to take advantage of the strong-to-very strong El Niño/Southern Oscillation (ENSO) forecast for the water year 2023-2024 to establish a longitudinal array of precipitation and stream sampling stations to constrain the meteoric water delta oxygen-18, deuterium-excess, and delta oxygen-17 signal of a strong ENSO事件。 The researchers will sample precipitation and They will also collect spot samples of small-stream waters across this same longitudinal transect during Fall 2023 and Spring 2024 and simulate the source and pathways of precipitation using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model while using spatial statistics to produce isoscapes of our stable isotope result across the southwestern United States (U.S.).This research is premised on考虑到美国西南部和半干旱西南部的氢化气候（包括降水，蒸散量和径流）仍然存在严重的不确定性，将对二氧化碳上升以及较高的温度响应，因为考虑到ENSO在改变美国西南部冬季冬季冬季冬季中发挥了巨大的作用。从研究中有大量的数据检查，使用了未来气候和古气候记录的全球气候模型（GCM）项目，ENSO将如何响应变暖，但这些数据受到了很大的限制。美国西南部氢化气候及其与ENSO的联系的许多古气候证据都来自过去的陨石氧同位素的代理记录，典型的假设是，较低的代理三角洲氧气-18与冬季的较高水分相对应，因此与美国西部的敏感性相关的能力与较大的冬季湿度相对应，并依赖于美国的敏感性，并依赖于美国的敏感性，并依赖于温暖的敏感性。然而，在美国西部，流星水氧氧气18，但是对于可能在未来可能主导气候的强大ENSO事件而言，这种灾难性的联系并没有得到良好的建立。此外，目前尚无数据来理解ENSO如何修改Delta oxygen-17值，这是一种有希望的分析同位素工具来限制水分源动态的作用以及在碳酸盐和粘土同位素档案中的有效效果的作用过去将有助于限制未来预测所必需的区域中观察到的可变性范围。该研究非常适合快速计划的潜在变革性，高风险和快速响应研究。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被认为是通过评估来获得的支持。