EAR-PF: Abrupt climate change in the alpine: Glacial and ecological responses to the Younger Dryas climate oscillation in the Teton Range, Wyoming

Sarah Crump博士获得了NSF EAR博士后奖学金，在加州大学圣克鲁斯分校和西方学院开展研究和专业发展活动。她的项目旨在评估年轻仙女木期间和之后美国西部的环境变化，这是大约12,000年前发生的一次突然的气候变化事件。她将分析怀俄明州提顿山脉湖泊海拔断面的沉积物岩芯，以调查冰川和山地生态系统如何应对随后快速变暖的长时间寒冷间隔。将讨论地球科学和生物科学中的关键问题，包括：1)高山冰川如何响应快速的气候振荡？2)树线海拔和物种范围以多快的速度变化，以与现代冰川相当的速度响应变暖？3)冰川-生态耦合系统如何在快速气候变化下共同进化？克伦普博士将通过科普文章和容易获得的公开演讲，让广大观众参与到这个气候突然变化的古代例子中来。该项目将为加州大学洛杉矶分校和西方大学的本科生提供研究机会，并为高中群体提供实地教育经验，重点是扩大对地球科学的参与。年轻的仙女木在最新更新世期间突然恢复到冰川状态约1200年，这可能是由于大西洋子午线翻转环流的暂时崩溃造成的。虽然这一事件被广泛认为是由可能在不久的将来发挥作用的机制驱动的突然气候变化的典型例子，但它对遥远的陆地环境的影响仍然很少有文献记载。利用来自蒂顿山脉生物气候梯度的湖泊网络的高分辨率湖泊沉积物记录，克伦普博士将使用扫描X射线荧光的基本数据来限制年轻仙女木之前、期间和之后的冰川范围。然后，她将分析湖心中的沉积古DNA，以随时间重建植物群落，从而限制树线对快速气候振荡的反应速度。该项目利用基因技术的最新发展来回答基本的地球科学问题，并推动分子古生态学日益增长的领域。由此产生的对推动气候突然变化的海洋环流变化的空间规模和幅度的古环境制约，将与跨越地质和生命科学的多个科学界有关。该项目通过生物科学和地质科学理事会的项目得到支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Sarah Crump has been granted an NSF EAR Postdoctoral Fellowship to carry out research and professional development activities at the University of California Santa Cruz and Occidental College. Her project is aimed at assessing environmental changes in the western US during and after the Younger Dryas, an abrupt climate change event that occurred approximately 12,000 years ago. She will analyze sediment cores from an elevational transect of lakes in the Teton Range, Wyoming, to investigate how glaciers and montane ecosystems responded to a long cold interval followed by rapid warming. Key questions in both the earth sciences and biological sciences will be addressed, including: 1) how do alpine glaciers respond to rapid climate oscillations? 2) how quickly can treeline elevation and species' ranges shift in response to warming at rates comparable to the modern? and 3) how do coupled glacial-ecological systems co-evolve under rapid climate change? Dr. Crump will engage broad audiences in this paleo-example of abrupt climate change through popular science articles and accessible public talks. This project will provide research opportunities for undergraduates at UCSC and Occidental, as well as field-based educational experiences for high school groups, with a focus on broadening participation in the earth sciences. The Younger Dryas was an abrupt ~1200-year return to glacial conditions during the latest Pleistocene that was likely caused by a temporary collapse of Atlantic Meridional Overturning Circulation. While this event is widely recognized as an archetypal example of abrupt climate change driven by a mechanism that may come into play in the near future, its impacts on distal terrestrial environments remain sparsely documented. Leveraging high-resolution lacustrine sediment records from a network of lakes spanning a bioclimate gradient in the Teton Range, Dr. Crump will use elemental data from scanning x-ray fluorescence to constrain glacier extent before, during, and after the Younger Dryas. She will then analyze sedimentary ancient DNA in the lake cores to reconstruct plant communities through time, thereby constraining the rate of treeline response to a rapid climate oscillation. This project takes advantage of recent developments in genetic techniques to answer essential earth science questions and advance the growing field of molecular paleoecology. The resulting paleoenvironmental constraints on the spatial scale and magnitude of ocean circulation changes driving abrupt climate change will be relevant to multiple scientific communities spanning the geological and life sciences. This project is supported through programs in the Directorates for Biological Sciences and Geological Sciences.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.