Dynamics and Change of Canadian Arctic Glaciers

加拿大北极冰川的动态和变化

• 批准号: RGPIN-2015-05324
• 负责人: Sharp, Martin
• 金额: $ 3.64万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613486
• 关键词: Dynamics; Change; Canadian; Arctic; Glaciers

Over 600 million people live within 10m elevation of current sea level, and 270 million people and $13 trillion US of assets are exposed to the 1 in 100 year extreme sea level. Understanding how rapidly sea level will rise (and why) is critical for decision making about how/when/whether to respond to this threat, much of which results from melting of the world’s ice sheets and glaciers. Canada’s Queen Elizabeth Islands (QEI) contain 19% of the world’s glaciated area outside Greenland and Antarctica. If these glaciers and ice caps melted completely, global average sea level would rise by over 10 cm. Each year between 2003 and 2009, these glaciers added about 60 billion tons of water to the global ocean, equivalent to 0.16 mm of sea level rise. Glacier melt rates during this period were probably the highest in over 4000 years, and they approached rates last encountered during the Holocene thermal maximum ~9000 years ago. These high melt rates are attributable to strong summer warming after 2005, linked to unusually persistent high pressure systems over the region. My research program aims to document the recent history of glacier change in the QEI and its implications for global average sea level, to identify the processes by which this change is occurring and the factors that control the rate of change, and to develop the capability to predict what rates of change we might expect in future. Key questions I want to answer include: (i) How can we best measure how rapidly the total mass of ice in QEI glaciers has been changing in the recent past? (ii) How much have melting of snow and ice, and calving of icebergs into the ocean, contributed to past rates of mass loss? (iii) How will the relative contributions of these processes change in the future?, and (iv) How do feedbacks that come into play as the climate changes, such as the feedback associated with warming-induced decreases in the glacier surface albedo (the proportion of solar radiation arriving at a glacier surface that is reflected from it), affect the relationship between climate change and rates of glacier mass loss? As the QEI is a data-sparse region, I need to invest significant effort in building (and validating) the large, regional-scale datasets that are needed to support predictive modeling of future glacier changes. These include basic information on the surface topography, thickness and subglacial bedrock topography of the large ice caps, and the distribution of precipitation over the ice caps. As my research directly addresses an issue of concern to society, I try to make sure that, in addition to being published in the scientific literature, the results of my research find their way into major scientific assessments of climate change and its impacts. This ensures that they are available to decision makers confronting the challenges posed by future sea level rise.

超过6亿人居住在目前的海平面1000万人，2.7亿人和13万亿美元的资产暴露于100年的极端海平面。了解海平面的迅速上升（以及为什么）对于制定如何/何时/是否应对这种威胁至关重要，其中许多是由于世界冰盖和冰川的融化而导致的。加拿大皇后伊丽莎白群岛（QEI）包含格陵兰和南极洲以外的世界冰川地区的19％。如果这些冰川和冰盖完全融化，全球平均海平面将上升超过10厘米。每年2003年至2009年，这些冰川在全球海洋中增加了约600亿吨的水，相当于海平面上升的0.16毫米。在此期间，冰川熔体速率可能是4000多年来最高的，并且在全新世热最多〜9000年前遇到的最后一次遇到的速率。这些高熔体速率可归因​​于2005年以后的夏季变暖，这与该地区的高压系统很少持续。我的研究计划旨在记录QEI近期变化的历史及其对全球平均海平面的影响，以确定发生这种变化的过程以及控制变化速度的因素，并发展能力以预测我们将来可能期望的变化率。 我要回答的关键问题包括：（i）我们如何最好地衡量QEI冰川中冰的总质量在最近发生的变化？ （ii）雪和冰的融化以及冰山融化了多少，导致了过去的群众损失率？ （iii）这些过程的相对贡献将如何在未来发生变化？和（iv）随着气候变化的变化，例如与冰川表面反击的变暖引起的下降相关的反馈（例如，太阳辐射的比例在冰川表面上反射出来的冰川变化率和质量差异），如何发挥反馈？ 由于QEI是一个数据 - 帕斯斯地区，因此我需要投入大量的努力来构建（和验证）大型的区域尺度数据集，以支持未来冰川变化的预测建模。这些包括有关表面形貌，大冰盖的厚度和冰山下基岩地形的基本信息，以及在冰盖上的精度分布。 当我的研究直接解决了社会关注的问题时，我试图确保，除了发表在科学文献中，我的研究结果还将其进入对气候变化及其影响的重大科学评估。这确保了他们可以面对未来海平面上升所带来的挑战的决策者。