Canadian Arctic fjords: The fate of floating ice in a changing environment

加拿大北极峡湾：不断变化的环境中浮冰的命运

• 批准号: RGPIN-2022-04875
• 负责人: Mueller, Derek
• 金额: $ 3.13万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754915
• 关键词: Canadian; Arctic; fjords; fate; floating

Major transformation is currently underway in terrestrial, marine and cryospheric environments in the Arctic. Coastal environments, such as fjords, where watersheds, glaciers, meltwater, floating ice and ocean interact, are particularly vulnerable and poorly understood. Climate warming has already altered the thick ice shelves that have existed at the mouth of fjords along Canada's northernmost coast for 5500 years. Over the last 2 decades, they have lost 57% of their areal extent in break-up events, including a recent calving of the Milne Ice Shelf. Meanwhile, seasonal landfast sea ice in other fjords near communities is also prone to episodes of break-off. These events are now more numerous, are coming earlier and are not easy to predict, putting those who use this ice at risk. My team of graduate students and collaborators will work at Milne Fiord in the Tuvaijuittuq Marine Protected Area (known as the "Last Ice Area") to examine the fjord as a coastal system. We will explore how runoff in the watershed has changed in the past and will evolve in the future. We will examine the large marine-terminating glacier at the head of this fjord to understand how and why its grounding line is shifting. This relates to oceanographic processes within the fjord, especially ice-ocean interaction. Fjord-scale processes will be represented by a state-of-the-art 3D model, which will be validated by data from our long-term mooring. We can then simulate the system response to the loss of the Milne Ice Shelf or understand the evolution of the freshwater layer between the glacier and the ice shelf. Milne Ice Shelf itself will be studied to better understand variation in ice thickness and the growth of melt ponds in summer. This information will be used to model stress and flexure across the ice and evaluate the contribution of ice morphology and meltwater to fracture. Fracture and break-off of landfast sea ice can be a hazard for Inuit and this process begins with the development of key flaws in the ice. At the mouth of Admiralty Inlet, in the Tallurutiup Imanga National Marine Conservation Area, the most important flaws are cross-fjord and along-shore leads. Cross-fjord leads appear in mid-winter due to mechanical stress, whereas along-shore leads grow in the spring and are influenced by heat from both the terrestrial and marine environment. Fieldwork will elucidate important processes at the shoreline, while cross-fjord leads will be followed using advanced remote sensing techniques. My research program will help determine the implications of the profound environmental transformation now underway in the Arctic. I will provide graduate training in glaciology, hydrology and oceanography using state-of-the-art modelling, remote sensing and field techniques in Nunavut. Our research explores topics of fundamental importance to Northerners and is critical for understanding processes of global significance, such as sea level rise and freshening of the Arctic Ocean.

北极的陆地、海洋和冰冻圈环境目前正在发生重大变化。峡湾等流域、冰川、融水、浮冰和海洋相互作用的沿海环境特别脆弱，人们对此知之甚少。气候变暖已经改变了加拿大最北部海岸沿着峡湾口5500年来的厚冰架。在过去的20年里，它们在分裂事件中失去了57%的面积，包括最近米尔恩冰架的崩解。与此同时，社区附近其他峡湾的季节性陆地固定海冰也容易发生断裂。这些事件现在越来越多，来得更早，而且不容易预测，使那些使用这种冰的人处于危险之中。我的研究生和合作者团队将在图瓦伊朱图克海洋保护区（被称为“最后的冰区”）的米尔恩峡湾工作，以研究峡湾作为一个沿海系统。我们将探讨流域径流在过去的变化和未来的演变。我们将检查这个峡湾头部的大型海洋终止冰川，以了解其接地线是如何以及为什么发生变化的。这与峡湾内的海洋学过程有关，特别是冰与海洋的相互作用。峡湾规模的过程将由最先进的3D模型表示，该模型将通过我们的长期系泊数据进行验证。然后，我们可以模拟系统对米尔恩冰架损失的反应，或者了解冰川和冰架之间淡水层的演变。米尔恩冰架本身将进行研究，以更好地了解冰厚度的变化和融化池在夏季的增长。这些信息将被用来模拟应力和弯曲的冰和冰形态和融水断裂的贡献进行评估。对因纽特人来说，固定在陆地上的海冰的断裂和脱落可能是一种危险，这一过程始于冰中关键缺陷的发展。在特鲁蒂普·伊曼加国家海洋保护区的金钟湾河口，最重要的缺陷是跨峡湾和沿岸的引线。由于机械应力，跨峡湾引线出现在仲冬，而沿岸引线在春季生长，并受到陆地和海洋环境热量的影响。实地工作将阐明海岸线的重要过程，同时将利用先进的遥感技术跟踪跨峡湾的线索。我的研究计划将有助于确定目前正在北极进行的深刻的环境变革的影响。我将在努纳武特利用最先进的建模、遥感和实地技术提供冰川学、水文学和海洋学方面的研究生培训。我们的研究探讨了对北方人至关重要的主题，对于理解具有全球意义的过程至关重要，例如海平面上升和北冰洋的清新。