Study of arctic and subarctic winter extreme events in a changing climate/Étude des évènements extrêmes hivernaux en régions arctiques et subarctiques dans un climat en changement

在过去30年里，在北方地区观测到了全球气候变率和变化的最早和最强烈的迹象，这导致了各种与气候有关的强烈反馈。北方气温变暖的一个直接后果是，预计持续时间更长的冬季极端事件（WEE）发生率增加，如雨雪、热浪、暴风雪和大雪。因此，拟议的研究的总体目标是监测WEE在亚北极和北极环境中使用30年的卫星遥感数据（微波，多光谱）和各种尺度的建模。为了使拟议的研究，以实现其目标，我的方法是双重的：1）数据场收集计划观察和描述极端事件对地表属性和相关的电磁响应的影响，以开发WEE检测算法使用遥感。然后将从空间监测WEE，以确定事件发生的趋势; 2）将所获得的结果与雪模型模拟进行比较，以评估其在模拟WEE方面的性能，并确定气候情景中的相关偏差。拟议的研究的新奇在于这样一个事实，即WEE在北极和亚北极地区的发生尚未使用遥感研究，尽管其在各个层面上的重大影响。这主要是由于冬季工作条件恶劣，缺乏数据和专门知识。亚北极和北极WEE与科学特别相关（例如，气候情景制定）、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）的观点。拟议的项目提供了一个独特的机会，在气候变化和对北方自然资源的兴趣增加的背景下解决这些迫切需要。 将要发展的遥感科学将改进我们目前对亚北极和北极地区状况的了解，并将对决策者和北方利益攸关方具有重要意义。

The first and strongest signs of global climate variability and change have been observed in northern regions over the past 3 decades which has led to a variety of strong climate-related feedbacks. A direct consequence of warming temperatures in the North is the increased occurrence of winter extreme events (WEE) such as rain-on-snow, heat waves, blizzards and heavy snowfall that are expected to last longer. Hence, the overarching goal of the proposed research is to monitor WEE in subarctic and arctic environments using 30 years of satellite remote sensing data (microwave, multispectral) and modeling at various scales. In order for the proposed research to achieve its goals, my approach is twofold: 1) data field collection is planned to observe and characterize impacts of extreme events on surface properties and the associated electromagnetic responses in order to develop WEE detection algorithms using remote sensing. The WEE will then be monitored from space in order to identify trends in event occurrences; 2) the obtained results will be compared with snow model simulations to evaluate their performance in simulating WEE as well as identifying associated biases in climate scenarios. The novelty of the proposed research resides in the fact that the occurrence of WEE in arctic and subarctic regions has not been studied using remote sensing despite its significant impacts at various levels. This is mostly due to a lack of data and expertise given the harsh winter working conditions. Subarctic and arctic 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 project provides a unique opportunity to address these urgent needs in the context of climate change and increased interest in northern natural resources. The remote sensing science that would be developed will improve our current knowledge of the state of subarctic and arctic regions and will be of significant relevance to decision-makers and northern stakeholders.