Collaborative Research: Exploring the Dynamics of the Active Layer and Near-Surface Permafrost across the North Slope of Alaska

拟议研究的总体目标是利用干涉合成孔径雷达调查阿拉斯加北坡活动层和富冰永久冻土顶层的动态变化。我们将使用C波段和L波段的数据，在过去的二十年（1991-2011年）获得。具体而言，（i）我们将实施干涉合成孔径雷达冻土算法（干涉合成孔径雷达FGA），以检测ALT和近地表永久冻土的变化，（ii）我们将通过钻孔、机械探测和探地雷达（GPR）调查ALT和近地表永久冻土的地面冰含量的空间变化。 从这次野外工作中获得的数据和信息也将用于干涉合成孔径雷达FGA验证和校准，（iii）结合干涉合成孔径雷达FGA输出，现场数据，和现有的气候数据，我们将调查空间和时间的变化和变化的活动层和近地表永久冻土及其对气候变化的响应，从1991年到2011年在阿拉斯加北坡。拟议的研究的预期结果将提供（i）一个有效的干涉合成孔径雷达FGA区域规模的活动层和冻土研究有用;（ii）ALT的时间序列及其在研究期间的变化，（1991-2011）阿拉斯加北坡ALT的平均值，和（iv）阿拉斯加北坡富冰永久冻土顶层潜在的地冰融化，分辨率从几十米到几百米。 这项研究的结果将是模型输入和验证的理想选择，并可用于评估北极人类基础设施的风险。 博士后刘将通过指导地球科学与工程项目夏季研究的本科生获得教育经验，结果将通过NSIDC所有关于冻土的网站以及通过菲斯克天文馆和博尔德公共图书馆的讲座向公众传播。

The overall objective of the proposed research is to investigate changes in the dynamics of the active layer and the top layers of ice-rich permafrost on the North Slope of Alaska using InSAR (Interferometric Synthetic Aperture Radar). We will use both C-band and L-band data, acquired during the last two decades (1991-2011). More specifically, (i) we will implement the InSAR Frozen Ground Algorithm (InSAR FGA) to detect changes in ALT and near-surface permafrost, (ii) we will investigate spatial variations of ALT and ground ice content of the near-surface permafrost through drilling, mechanical probing, and ground penetration radar (GPR). Data and information obtained from this fieldwork will also be used for InSAR FGA validation and calibration, (iii) combining InSAR FGA outputs, field data, and available climate data, we will investigate spatial and temporal changes and variations of the active layer and near-surface permafrost and their response to climate change from 1991 through 2011 on the North Slope of Alaska. The expected results of the proposed research will provide (i) a validated InSAR FGA useful for regional-scale active layer and permafrost studies; (ii) time series of ALT and their changes over the study period, (iii) long-term (1991-2011) mean of ALT across the North Slope of Alaska, and (iv) potential ground-ice melting in the top layers of ice-rich permafrost across the North Slope of Alaska with a resolution of from tens of meters to hundreds of meters. The results from this study will be ideal for model inputs and validation and can be used to assess risk to human infrastructure in the Arctic. The postdoc Liu will gain educational experience by mentoring an undergraduate student in the Summer Research in Geoscience and Engineering program, and results will be disseminated to the public through the NSIDC All about Frozen Ground website and via lectures at the Fiske Planetarium and Boulder Public Library.