Quantifying multi-scale impacts of winter extreme events on the atmosphere-snow-ground interface in the Arctic

在过去的40年里，在冰冻圈观察到了全球气候变化和变化的第一个也是最强烈的迹象，这导致了各种与气候有关的强烈反馈。气温变暖的直接后果是冬季极端事件(WEE)的发生增加，如雨雪、热浪和暴风雪，预计这些事件将持续更长时间。因此，拟议研究的总体目标是利用40年来的卫星遥感数据(微波、多光谱)和不同尺度的建模，在冰冻圈建立一个小型监测网络。为了使所提议的网络实现其目标，我的方法有两个：1)计划进行野外工作，以测量和表征WEE对地表状态变量和相关电磁响应的影响，以便开发卫星探测算法。然后将从太空监测WEE，以确定事件发生的空间和时间趋势；2)将获得的结果与雪模型模拟进行比较，以评估WEE对雪特性的影响以及这些影响如何影响Peary北美驯鹿的栖息地。这项拟议研究的新颖性在于，尽管它对现已被列为濒危物种的佩里驯鹿产生了重大影响，但尚未使用遥感技术研究冰冻圈中是否存在WEE。这主要是由于冬季恶劣的工作条件下缺乏数据和专业知识。从科学(例如，气候情景发展)、经济(例如，对基础设施的破坏)和社会(例如，公共安全和自然灾害)的角度来看，我们具有特别重要的意义。在气候变化和人们对自然资源的兴趣日益增加的背景下，拟议的研究计划提供了一个独特的机会来满足这些紧迫需求。将开发的遥感科学将改善我们目前对冰冻圈状况的了解，并将对决策者和北方利益攸关方具有重大意义。

The first and strongest signs of global climate variability and change have been observed in the cryosphere over the past four decades, which has led to a variety of strong climate-related feedbacks. A direct consequence of warming temperatures is the increased occurrence of winter extreme events (WEE) such as rain-on-snow, heat waves and blizzards that are expected to last longer. Hence, the overarching goal of the proposed research is to develop a WEE monitoring network in the cryosphere using 40 years of satellite remote sensing data (microwave, multispectral) and modeling at various scales. In order for the proposed network to achieve its goals, my approach is twofold: 1) fieldwork is planned to measure and characterize impacts of WEE on surface state variables and the associated electromagnetic responses in order to develop satellite detection algorithms. The WEE will then be monitored from space in order to identify spatial and temporal trends in event occurrence; 2) the obtained results will be compared with snow model simulations to evaluate the impact of WEE on snow properties and how these impacts affect Peary caribou habitat. The novelty of the proposed research resides in the fact that the occurrence of WEE in the cryosphere has not been studied using remote sensing despite its significant impacts on Peary caribou, a specie now listed at risk. This is mostly due to a lack of data and expertise given the harsh winter working conditions. WEE are of particular relevance from scientific (e.g., climate scenario development), economic (e.g., damage to infrastructure) and social (e.g., public safety and natural hazards) perspectives. The proposed research program provides a unique opportunity to address these urgent needs in the context of climate change and the increased interest in natural resources. The remote sensing science that would be developed will improve our current knowledge of the state of the cryosphere and will be of significant relevance to decision-makers and northern stakeholders.