A helicopter-borne radar system for Canadian glacier mass assessment

该项目将为购买定制的直升机雷达系统提供资金，以对厚度达1公里的冰川进行成像。由于普遍缺乏冰层厚度数据，目前对加拿大冰川质量的估计非常不准确，冰川对气候变暖的反应的建模受到有限的河床地形数据的严重阻碍。因此，我们预测加拿大冰川对海平面的贡献、冰川湖暴发洪水等快速变化的冰川的危害、下游水资源的可用性以及变化的冰川质量将对加拿大山地旅游产生的影响的能力是有限的。目前对冰层厚度和冰川床地形的估计主要是使用地面雷达系统进行的，这些雷达系统是徒步或由造雪机拖曳的，因此范围有限、非常耗时、后勤昂贵，而且在有裂缝的冰川地区作业是危险的或不可能的。拟议中的直升机雷达系统将缓解这些问题，首次允许在加拿大冰川环境中的冰块上进行大规模、安全的数据收集。这将有助于首次准确估计格陵兰和南极洲以外世界上最大的冰川区域的冰量。2021年夏天，飞行员直升机雷达系统在育空的圣埃利亚斯山脉进行了测试，成功的冰层穿透深度可达650米。拟议的系统将建立在这种设计的基础上，配备仪器以提高定位精度，改进平台空气动力学，更好的控制和采集软件，以及雷达开发，使温带(熔点)冰能够穿透1000米。后者是必要的，因为稀疏的地面测量表明，育空和加拿大北极高地的大多数冰川都比650米深得多。通过直升机雷达系统收集的数据将解决的主要研究问题是：1)加拿大冰川在地方、区域和国家尺度上的质量是多少？2)与冰川下地形和冰层厚度有关的加拿大冰川流速的驱动因素是什么？3)未来冰川质量和动态将如何变化？将在头五年在育空地区、加拿大北极高地和不列颠哥伦比亚省的主要冰川进行高分辨率直升机雷达调查，这些地区目前缺乏冰层厚度数据，以直接帮助目前资助的研究项目，并为小组成员指导的各种学生提供关键数据。从长远来看(5-10年)，调查将得出这三个地区的冰川总质量数据。收集的数据将使项目小组的直接成员以外的多个合作者受益，并提供世界冰川监测局(瑞士)和政府间气候变化专门委员会等组织所需的全球重要数据。

This project will fund the purchase of a custom-built helicopter radar system to image glacier ice up to 1km thick. Current mass estimates of Canadian glaciers are highly inaccurate due to widespread lack of ice thickness data, and modelling of glacier response to climate warming is significantly hindered by limited bed topography data. As such, our ability to predict sea-level contributions from Canadian glaciers, hazards from rapidly changing glaciers such as glacier lake outburst floods, downstream water resource availability, and the impact that changing glacier mass will have on Canadian mountain tourism, is limited. Current estimates of ice thickness and glacier bed topography have primarily been made using ground-based radar systems, which are towed on foot or by snowmachine and therefore limited in extent, highly time-consuming,  logistically expensive to obtain, and dangerous or impossible to operate in crevassed glacier regions. The proposed helicopter radar system will alleviate these problems, allowing for large-scale, safe data collection over ice masses in glacierized environments across Canada for the first time. This will facilitate the first accurate estimate of ice mass in the world's largest glaciated area outside of Greenland and Antarctica. A pilot helicopter radar system was tested in summer 2021 in the St. Elias Mountains, Yukon, with successful ice penetration depth up to 650m. The proposed system will build on this design with instrumentation to improve positioning accuracy, improved platform aerodynamics, better control and acquisition software, and radar developments to enable penetration of temperate (melting point) ice up to 1000m. The latter is necessary, as the sparse ground-based measurements suggest that most glaciers in the Yukon and Canadian High Arctic are considerably deeper than 650m. The primary research questions that will be addressed with data collected with the helicopter radar system are: 1) What is the mass of Canada's glaciers, on local, regional and national scales?; 2) What are the drivers of Canadian glacier flow rates in relation to subglacial topography and ice thickness?; 3) How will glacier mass and dynamics change in the future? High resolution helicopter radar surveys will be carried out in the first five years at major glaciers in the Yukon, Canadian High Arctic and British Columbia, where ice thickness data are currently lacking, to directly aid current funded research projects and provide crucial data for a wide variety of students supervised by team members. In the longer term (5-10 years), surveys will derive total glacial mass data for these three regions. The data gathered will benefit multiple collaborators, in addition to direct members of the project team, and provide globally important data required by organizations such as the World Glacier Monitoring Service (Switzerland), and the Intergovernmental Panel on Climate Change.