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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=664905
• 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6亿人生活在当前海平面海拔10米以内，2.7亿人和13万亿美元的资产将面临百年一遇的极端海平面。了解海平面上升的速度（以及原因）对于如何/何时/是否应对这一威胁的决策至关重要，其中大部分威胁是由世界冰盖和冰川融化造成的。加拿大的伊丽莎白女王群岛（QEI）包含了除格陵兰岛和南极洲外世界上19%的冰川面积。如果这些冰川和冰帽完全融化，全球平均海平面将上升10厘米以上。在2003年至2009年间，这些冰川每年向全球海洋增加约600亿吨水，相当于海平面上升0.16毫米。这一时期的冰川融化速率可能是4000多年来最高的，接近9000年前全新世热最大值时期的冰川融化速率。这些高融化率可归因于2005年之后夏季的强烈变暖，与该地区异常持续的高压系统有关。我的研究计划旨在记录QEI冰川变化的近期历史及其对全球平均海平面的影响，以确定这种变化正在发生的过程和控制变化率的因素，并发展预测我们未来可能预期的变化率的能力。******我想回答的关键问题包括：(I)我们如何才能最好地测量QEI冰川的总冰质量在最近的过去发生了多快的变化？（二）在过去的质量损失率中，冰雪的融化和冰山的崩解在多大程度上起到了促进作用？这些进程的相对贡献在未来将如何变化？（iv）随着气候变化而起作用的反馈，例如与变暖引起的冰川表面反照率（到达冰川表面的太阳辐射被冰川反射的比例）下降有关的反馈，如何影响气候变化与冰川质量损失率之间的关系？******由于QEI是一个数据稀疏的地区，我需要投入大量的精力来建立（和验证）大型的区域尺度数据集，这些数据集需要支持对未来冰川变化的预测建模。这些资料包括大冰盖的表面地形、厚度和冰下基岩地形的基本资料，以及冰盖上的降水分布。******由于我的研究直接涉及社会关注的问题，我努力确保，除了在科学文献中发表之外，我的研究结果还能用于对气候变化及其影响的主要科学评估。这确保决策者可以利用这些数据应对未来海平面上升带来的挑战。