Investigating the boundaries of glaciology

地球上的冰川和冰盖是决定未来海平面上升的最重要变量。最容易发生快速变化的冰川是南极洲、格陵兰岛和北极部分地区与海洋相互作用的大型冰流。控制这些冰流快速流失的过程主要在冰流的边界处进行，包括冰-海界面和确定冰流边缘的剪切边缘。这些动态过程已经被数值模式观测和预测，但仍然知之甚少，部分原因是缺乏观测数据。 拟议的研究计划旨在通过分析遥感和实地数据，帮助了解这些过程。目标是：1.识别和理解导致冰架崩溃的机制，2。量化海洋热传输，渠道化的流动，并在冰流接地线，和崩解之间的相互作用。研究影响目标1和2中研究的冰-海边界的剪切边缘过程。这一跨学科的工作与当前的环境问题有关，需要使用灵活的定量工具，并强调外联和沟通，使其非常适合在所有学术层面培训HQP。南极工作将使用光学图像、激光测高和数字高程模型来调查冰架的变化过程。这项工作将通过与国际思韦茨冰川协作组织的其他成员密切协作来促进，这将使之能够与机载和地面雷达数据进行比较。南极洲的成果将扩大到格陵兰岛，那里的工作将侧重于接地线和剪切边缘过程，在格陵兰岛西部的乌佩尔纳维克伊斯特伦进行实地考察，这是Dorthe Dahl-Jensen博士的加拿大卓越研究主席关于巴芬湾海洋-淡水耦合的一个重点地点。格陵兰岛的分析将包括遥感数据，并利用海洋和冰上仪器来检查冰锋的融化和崩解模式。在我的发现计划中提出的工作将通过增加对埃尔斯米尔岛上的Sydkap冰川的关注来为CERC项目增加一个额外的维度。我的小组将利用在格陵兰获得的经验，与渥太华大学的卢克·科普兰博士的小组合作，对锡德卡普冰川上和冰川前的冰-海洋相互作用进行比较研究。从长远来看，这些补充性研究将有助于比较不同冰川几何形状、退缩阶段和海洋作用力的类似过程，从而有可能确定与冰川学背景相关的基本模式和过程。这些研究所产生的观测数据和对过程的进一步了解将为预测未来海平面上升所需的数值模型提供信息。由于加拿大的海岸线比其他任何国家都多，这些都是需要了解的重要问题。

Earth's glaciers and ice sheets comprise the most important variable in determining future sea-level rise. The glaciers that are most prone to rapid change are large ice streams in Antarctica, Greenland, and parts of the Arctic that interact with the ocean. Processes that govern the rapid loss of these ice streams operate largely at their boundaries, including at ice-ocean interfaces and the shear margins that define ice-stream edges. These dynamic processes have been observed and predicted by numerical models, but are still poorly understood, due in part to a lack of observational data. The proposed research program seeks to contribute to understanding of these processes through the analysis of remote sensing and field data. The objectives are to: 1. Identify and understand mechanisms that lead to ice-shelf collapse, 2. Quantify the interactions between ocean heat transport, channelized flow, and calving at ice-stream grounding lines, and 3. Investigate the shear-margin processes that influence the ice-ocean boundaries investigated in objectives 1 and 2. This interdisciplinary work is relevant to current environment issues, requires the use of flexible quantitative tools, and emphasizes outreach and communication, making it highly suitable for training HQP at all academic levels. Antarctic work will investigate ice-shelf processes using optical imagery, laser altimetry, and digital elevation models. This work will be facilitated by close collaboration with fellow members of the International Thwaites Glacier Collaboration, which will allow for comparison with airborne and ground-based radar data. Results in Antarctica will be extended to Greenland, where work will focus on grounding-line and shear-margin processes, with fieldwork on Upernavik Isstrom in western Greenland, a focus site in Dr. Dorthe Dahl-Jensen's Canada Excellence Research Chair (CERC) on marine-freshwater coupling in Baffin Bay. The Greenland analysis will include remote sensing data and also utilize ocean and on-ice instrumentation to examine melting and calving patterns at ice fronts. Work proposed in my Discovery program will add an extra dimension to the CERC project by adding a focus on Sydkap Glacier on Ellesmere Island. My group will use the experience gained in Greenland to carry out comparative studies of ice-ocean interaction on and in front of Sydkap Glacier, in collaboration with Dr. Luke Copland's group at the University of Ottawa. In the long-term, these complementary studies will allow for comparison of similar processes across varied glacier geometries, stages of retreat, and ocean forcing, which will make it possible to identify fundamental patterns and processes relevant across glaciological settings. The observational data and improved process understanding yielded by these studies will inform numerical models, which are needed to predict future sea-level rise. As Canada has more coastline than any other country, these are vital issues to understand.