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

布伦特明丘博士已获得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研究和教育计划。他的研究将集中在西南极冰盖（WAIS），目标是量化冰川床对冰川流动的阻力以及这种阻力在空间和时间上的变化。WAIS是唯一一个大冰盖，其床明显低于海平面，使其在气候变暖时可能不稳定。目前对冰川物理学的了解和地质证据表明，WAIS能够迅速崩溃，以其目前的配置，可能导致海平面上升数米。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。为了理解这些时间尺度，这在很大程度上取决于在床上发生的事情，并阐明冰川床的突出机械特性，Minchew博士将使用观测到的冰流速度和数值冰流模型的组合来推断几个WAIS冰川和冰流的冰流的基础阻力。这些观测数据是在很长一段时间内以前所未有的速度收集的，并在空间上完全覆盖了几个快速流动的冰区。当用于约束数值冰流模型，这些观测允许估计的变化，空间和时间的基础阻力，将提供一个更彻底的了解冰川流动是如何耦合到环境强迫。这些结果将测试目前的假设有关的机械性能的床，通知更详细的模型的基础力学，并有助于发展预测模型的WAIS及其对海平面上升的影响。Minchew博士的研究将促进国际合作，重要的是，将包括教育和公共宣传部分。国际合作对于了解气候变化的潜在近期后果至关重要。通过这项奖学金，Minchew博士将有机会与英国南极调查局受人尊敬的冰川学家密切合作，获得经验，他将在完成奖学金后返回美国。在整个奖学金期间，在国内外，Minchew博士将致力于提高公众对WAIS在气候系统中的作用，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的认识。

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.