Quantifying the relationship between erosion and permafrost thaw in a changing Arctic environment

北极的环境正在发生迅速的变化。例如，永久冻土的融化会向大气中释放大量的碳，导致大范围的土壤侵蚀。侵蚀使深层永冻土暴露出来，反过来又会使沉积物和水在陆地和河流系统中重新分布。研究人员将采取综合方法，分析时空上的古气候波动和流域地形，以了解气候，永久冻土融化和土壤侵蚀之间的关系。研究结果将提高我们预测北极系统变化的能力。对K-12学校的教育推广将涉及为一个基于卡车的移动的科学实验室设计动手实验，该实验室访问匹兹堡及其周边地区的学校，包括为少数民族和代表性不足的人口服务的学校。作为本研究的一部分，研究生和本科生将参与研究和推广活动，培养新一代科学家。 多年冻土融化对土壤侵蚀的影响在很大程度上是无法量化的日期，是多年冻土融化和土壤侵蚀的地形属性，纬度位置和气候的依赖。这项研究的目的是：（1）在古气候波动的背景下量化北极环境中土壤侵蚀和永久冻土融化之间的关系;（2）探索这些过程对地形属性和纬度位置的依赖性;（3）评估和改进景观演变模型模拟北极环境侵蚀的能力。为了实现这些目标，研究人员将从阿拉斯加不同纬度的两个湖泊群中取样并分析沉积物岩心。他们将把地形分析和地貌建模与来自融化的永久冻土和保存在湖泊沉积物中的老化碳的化学特征相结合。这种方法将改善和指导未来的建模工作，以预测北极系统对不断变化的环境的响应。该奖项反映了NSF的法定使命，并被认为是值得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的支持。

Arctic environments are undergoing rapid change. The thawing of permafrost soils, for example, can release vast amounts of carbon to the atmosphere and cause widespread soil erosion. Erosion that exposes deep permafrost soil can in turn redistribute sediment and water across terrestrial and riverine systems. The investigators will take an integrative approach, analyzing paleoclimate fluctuations and watershed topography across space and time, to understand the relationship among climate, permafrost thaw, and soil erosion. Results will improve our ability to predict Arctic system change. Educational outreach to K-12 schools will involve designing hands-on experiments for a truck-based mobile science laboratory that visits schools in and around Pittsburgh, including those serving minorities and under-represented populations. Graduate and undergraduate students supported as part of this study will participate in both research and outreach activities, training a new generation of scientists. The influence of permafrost thaw on soil erosion is largely unquantified to date, as is the dependence of permafrost thaw and soil erosion on topographic attributes, latitudinal location, and climate. This study seeks to: (1) quantify the relationship between soil erosion and permafrost thaw in Arctic environments in the context of paleoclimate fluctuations; (2) explore the dependence of these processes on topographic attributes and latitudinal location; and (3) evaluate and improve the capability of landscape evolution models to simulate erosion in Arctic environments. To accomplish these objectives, the investigators will sample and analyze sediment cores from two clusters of lakes at different latitudinal locations in Alaska. They will integrate topographic analysis and geomorphologic modeling with the chemical signature of aged carbon that is sourced in thawed permafrost and preserved in lake sediments. This approach will improve and guide future modeling efforts to predict the response of the Arctic system to a changing environment.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.