AGS-PRF: The Impacts of Hemispheric Moisture Transport and Atmospheric Dynamics on Millennial-Scale Arctic Hydroclimate through the Holocene

北极正在以全球平均速度的两倍变暖，预计将经历最高的降水增长率。在当地，北极水文循环是对冰盖质量平衡、生态系统以及淡水和辐射平衡的基本控制，从而影响全球海洋和大气环流的反馈。该项目旨在综合全新世期间北极地区过去的水文气候变化，目的是填补在了解控制北极水分供应的机制方面的关键空白。具体而言，研究人员将1）促进北极全新世水分敏感记录数据库的管理，2）应用基于机制的模型来约束从过去气候记录中推断的降水变化幅度，以及3）合成水分敏感记录与全球全新世气候重建和气候模型模拟进行比较。本研究将采用资料综合与资料-模型比较的方法来检验以下假设：1。北极的湿度敏感的数据表明，气候连贯的千年尺度全新世的变化。支持这一假设表明，北极水分的可用性是敏感的大规模纬向大气传输模式，而低的空间一致性代理记录沿着线的子午线可能表明当地的过程驱动的空间变异性。2.在全新世早期至中期，一个减弱和更曲折的西风急流减少了水分输送到北大西洋地区，同时促进强水分输送到东白令海峡和其他北极地区。减少中纬度气旋活动与减弱西风急流可能有助于北美干旱早中期全新世。在北极，这一机制可能会减少北大西洋东部地区的气旋活动，同时加强对欧亚大陆和北极西部的水分平流。或者，所有部门的类似变化可能意味着，与较暖大气中大气水分容量增加的热力学影响相比，动态影响微不足道。潜在的更广泛影响包括更好地了解北极地区水文气候和湿度变化的长期时空变化及其与中高纬度大气遥相关的联系。该项目将建立一个涵盖全新世的北极地区湿度敏感记录的精心策划的数据库，并将向公众提供。其他更广泛的影响包括与部落环境专业人员研究所（北方亚利桑那大学）合作编写教材，为北方亚利桑那州的k-12和部落大学教师举办的关于气候变化和可变性对社会和人类影响的讲习班创建一个模块。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。

The Arctic is warming at twice the global average rate and is projected to experience among the highest rates of precipitation increase. Locally, the Arctic hydrological cycle is an underlying control on ice sheet mass balance, ecosystems, and freshwater and radiative balances, and thereby influences feedbacks in global oceanic and atmospheric circulation. This project aims to develop a synthesis of past hydroclimate variability in the Arctic region during the Holocene with the goal to fill critical gaps in understanding of the mechanisms controlling Arctic moisture availability. Specifically, the researcher will 1) Contribute to curation of Arctic Holocene moisture-sensitive record database, 2) Apply mechanistic-based models to constrain the magnitude of precipitation changes inferred from past climate records, and 3) Synthesize moisture-sensitive records for comparison with a global Holocene climate reconstruction and climate model simulations. The data synthesis and data-model comparison will be used to test the following hypotheses:1. Arctic moisture-sensitive data demonstrate meridionally-coherent millennial-scale Holocene variability. Support for this hypothesis would suggest Arctic moisture availability was sensitive to large-scale meridional atmospheric transport patterns, whereas low spatial coherence among proxy records along lines of meridian could indicate local processes drove spatial variability. 2. In the early- to mid-Holocene, a weakened and more meandering westerly jet reduced moisture transport to the North Atlantic region, while promoting strong moisture transport to eastern Beringia and other Arctic sectors. Reduced mid-latitude cyclone activity linked to a weakened westerly jet may have contributed to North American aridity in the early to mid-Holocene. In the Arctic, this mechanism would likely reduce cyclone activity in the eastern North Atlantic region, while enhancing moisture advection to Eurasia and the western Arctic. Alternatively, similar changes across all sectors may imply dynamic impacts were trivial in comparison to the thermodynamic impact of increased atmospheric moisture capacity in a warmer atmosphere. The potential Broader Impacts include a greater understanding of long-term spatiotemporal variability of hydroclimate and moisture variability in the arctic region and their link to mid- to high-latitude atmospheric teleconnections. The project will produce a curated database of moisture sensitive records in the arctic region covering the Holocene which will be made publicly available. Other Broader Impacts include the development of educational materials in partnership with the Institute for Tribal Environmental Professionals (Northern Arizona University), creating a module for a workshop for k-12 and tribal college teachers in Northern Arizona on climate change and variability with social and human implications. The research and outreach activities will provide scientific and professional development for an early career scientist.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.