Collaborative Research: P2C2--Interrogating the Free Troposphere during the Last Deglaciation

这个项目的目的是提供第一个全球尺度的自由对流层的温度和动力学约束，它包括大约2 - 18公里的高度。具体来说，研究人员将使用新的同位素测量和三维（3D）全球模型来重建和解释最后一次冰川消融期间（距今18,000至8,000年）的高空大气温度和环流变化。该项目将使用一种来自冰芯记录的新兴示踪剂来生成古温度记录，该记录将揭示地球历史上最近主要气候转变期间对流层的状态及其与平流层的相互作用。研究目标包括：在包括几次气候突变事件在内的一段时间内，限制自由对流层的热演化；测试模拟的自由对流层对轨道和温室气体强迫的响应；并在主要气候转变过程中测试平流层到对流层的交换动力学。这种结合测量和模拟的研究将限制最近全球变化主要时期的古气候，当环流模式在不同的气候边界条件下发生变化时。潜在的更广泛的影响包括在最后一次冰消期间建立一个新的对流层自由温度记录。应用一种新的同位素示踪剂来研究平流层-对流层交换动力学对古气候研究具有潜在的变革意义。其他更广泛的影响包括研究人员参与STEM外展活动，作为他们正在进行的活动的一部分，包括与女童子军一起参加莱斯大学的年度地球日。该项目将培养一名本科生和两名研究生，并支持两名早期职业研究人员。该奖项反映了美国国家科学基金会的法定使命，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。

This project aims to provide the first global-scale constraints on temperature and dynamics of the free- troposphere- which comprises altitudes ranging from about 2 - 18 km. Specifically, the researcher will use new isotopic measurements and 3 Dimensional (3D) global modeling to reconstruct and interpret high-altitude atmospheric temperature and circulation changes during the last deglaciation (18,000 to 8,000 years before present). This project will use an emerging tracer from ice-core records to generate a paleo-temperature record that will reveal the state of the troposphere and its interaction with the stratosphere across the most recent major climate transition in Earth history. Research goals include constraining the thermal evolution of the free troposphere during a time period that includes several episodes of abrupt climate change; testing modeled free-troposphere responses to orbital and greenhouse-gas forcing; and testing stratosphere-to- troposphere exchange dynamics across major climate transitions. This combined measurement-modeling study will constrain the paleoclimate at altitude during the most recent major episode of global change, when circulation patterns shifted under different climatic boundary conditions. The potential Broader Impacts include developing a new temperature record of the free troposphere during the last deglaciation. The application of a new isotopic tracer to investigate the dynamics of stratosphere-troposphere exchange is potentially transformative for paleoclimate research. Other broader impacts include participation of the researchers in STEM outreach events as part of their ongoing activities, including participation in the department’s annual Earth Day at Rice University with the Girl Scouts. The project will train one undergraduate and two graduate students, and support two early career researchers.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.