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博士已获得NSF博士后奖学金，在加州圣克鲁斯大学和西方学院开展研究和专业发展活动。她的项目旨在评估美国西部在新仙女木（Younger Dryas）期间和之后的环境变化，这是大约12，000年前发生的突然气候变化事件。她将分析来自怀俄明州提顿山脉湖泊垂直断面的沉积物岩心，以研究冰川和山地生态系统如何应对长时间的寒冷间隔，然后快速变暖。 地球科学和生物科学的关键问题将得到解决，包括：1）高山冰川如何应对快速的气候振荡？2)树线高度和物种分布范围的变化有多快，以与现代相当的速度对变暖作出反应？（3）在快速气候变化下，耦合的冰川生态系统如何共同演化？Crump博士将通过科普文章和可访问的公开演讲，吸引广大观众参与这一突然气候变化的古老例子。该项目将为UCSC和西方大学的本科生提供研究机会，并为高中团体提供实地教育经验，重点是扩大对地球科学的参与。新仙女木事件是最近更新世期间突然恢复到约1200年的冰川条件，可能是由大西洋经向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气候突变的典型例子，但其对远距离陆地环境的影响仍然很少记录。利用高分辨率的湖泊沉积物记录，从一个网络的湖泊跨越生物气候梯度在提顿山脉，克博士将使用扫描X射线荧光的元素数据，以限制冰川的范围之前，期间和之后的新仙女木。然后，她将分析湖泊核心中沉积的古代DNA，以重建植物群落，从而限制树木对快速气候振荡的反应速度。该项目利用遗传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的发展。由此产生的古环境对海洋环流变化的空间规模和幅度的制约，将影响到地质和生命科学领域的多个科学界。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知识价值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.