Spatiotemporal characteristics of basal resistance to ice flow in the West Antarctic Ice Sheet from satellite observations and numerical modeling

Brent Minchew博士获得了美国国家科学基金会地球科学博士后奖学金，在英国南极调查局开展一项研究和教育计划。他的研究将集中在南极西部冰盖（WAIS）上，目的是量化床对冰川流动的阻力有多大，以及这种阻力在空间和时间上是如何变化的。WAIS是唯一一个床床明显低于海平面的大冰盖，这使得它在变暖的气候中可能不稳定。目前对冰川物理学的了解和地质证据表明，WAIS有能力迅速崩塌，在目前的结构下，这可能导致海平面上升几米。最近的研究提供的证据表明，崩溃可能正在进行中，但崩溃可能发生的合理时间尺度仍然不确定。这些时间尺度很大程度上是由床上发生的事情决定的，为了理解这些时间尺度，并阐明冰川床的显著力学特性，Minchew博士将结合观察到的冰流速度和数值冰流模型来推断几个WAIS冰川和冰流对冰流的基本阻力。在很长的时间跨度内，以前所未有的速度收集了观测数据，并对几个快速流动的冰区进行了完整的空间覆盖。当用于约束数值冰流模型时，这些观测结果允许估计基础阻力在空间和时间上的变异性，这将提供对冰川流如何与环境强迫耦合的更彻底的理解。这些结果将检验目前关于海床力学特性的假设，提供更详细的基础力学模型，并有助于开发WAIS的预测模型及其对海平面上升的影响。闵洲博士的研究将促进国际合作，更重要的是，将包括教育和公共宣传的组成部分。国际合作对于了解气候变化的近期潜在后果至关重要。通过这项奖学金，Minchew博士将有机会与英国南极调查局备受尊敬的冰川学家密切合作，积累经验，并在完成奖学金后返回美国。在研究期间，在国内外，Minchew博士将致力于提高公众对气候系统中WAIS作用的认识，气候变化对WAIS的影响，以及WAIS的变化如何影响世界各地的人们和社会。

Dr. Brent Minchew has been granted an NSF Earth Science postdoctoral fellowship to carry out a research and education plan at the British Antarctic Survey. His research will focus on the West Antarctic Ice Sheet (WAIS) with the goal of quantifying how much resistance to glacier flow the bed applies and how that resistance varies in space and time. WAIS is the only large ice sheet whose bed is significantly below sea level, making it potentially unstable in warming climates. Current knowledge of the physics of glaciers and geological evidence suggest that WAIS is capable of rapid collapse, which, in its current configuration, could lead to several meters of sea level rise. Recent studies provide evidence that a collapse may be underway but the plausible timescales over which a collapse can occur remain uncertain. In order to understand these timescales, which are largely governed by what happens at the bed, and to elucidate the salient mechanical properties of glacier beds, Dr. Minchew will use a combination of observed ice flow velocities and numerical ice flow models to infer the basal resistance to ice flow in several WAIS glaciers and ice streams. The observations were collected at an unprecedented rate over a long timespan and with complete spatial coverage of several areas of fast-flowing ice. When used to constrain numerical ice-flow models, these observations allow for estimates of the variability of basal resistance in space and time that will provide a more thorough understanding of how glacier flow is coupled to environmental forcing. These results will test current assumptions concerning the mechanical properties of the bed, inform more detailed models of basal mechanics, and contribute to the development of predictive models of WAIS and its influence on sea level rise. Dr. Minchew's research will foster international collaborations and, importantly, will include an education and public outreach component. International collaboration is essential for understanding the potential near-term consequences of climate change. Through this fellowship, Dr. Minchew will have the opportunity to work closely with esteemed glaciologists at the British Antarctic Survey, gaining experience that he will return to the US upon completion of the fellowship. Throughout the fellowship, while at home and abroad, Dr. Minchew will work to enhance the public's awareness of the role of WAIS in the climate system, the implications of climate change for WAIS, and how changes in WAIS affect people and societies around the world.