A multi-scale analysis of subglacial hydrology and ice dynamics

冰下环境的状态是上覆冰流动的一级控制因素。随着越来越多的水在变暖的世界中到达冰床界面，基础水文学的发展是气候变化对冰动态的影响与海平面上升之间的直接联系。进入冰下环境的困难阻碍了对基底过程的详细了解，关于水在南极和格陵兰冰盖底部以及在较小但非常脆弱的山谷冰川中的作用的重要问题仍然存在。随着代表有效和无效排水的复杂二维耦合模型的引入，使用数值模型越来越有利于检查基础水文。当这一方法与卫星遥感、地球物理勘测和现场数据收集的数据输入相结合时，它为处理目前缺乏知识的领域提供了一种强有力的方法。 这一研究方案将在各种空间和时间尺度上利用这种方法，从格陵兰和南极的条件到育空地区山谷冰川的较小尺度过程，并在全球气候范围内将较小和较大尺度的系统联系起来。研究计划的目标是短期的（1-5年），1）调查冰下水文对快速流动的南极冰流的控制，2）研究南极冰架和格陵兰岛冰川的冰-海洋相互作用，3）解决气候在育空地区冰川动态中的作用，（3-10年），利用目标1至3至4的产出）将基底过程和冰下水文学纳入大尺度冰盖和全球气候模型。 这些对冰下水文学和冰动力学在多个空间和时间尺度上的调查结果将使人们对世界各地冰块的基本状况有一个前所未有的了解。将最新的模型与包括遥感和现场收集在内的多种来源的数据相结合，将提供对这些脆弱系统的独特而详细的看法。改进冰盖模型和全球气候模型预测的长期目标将利用从各个研究目标中获得的结果和经验，并为政府间气候变化专门委员会（气专委）报告的下一次迭代做出贡献。除了这一全球方法外，各个项目还将阐明对气候变化最敏感的一些地区的冰动态的控制，包括格陵兰冰盖消融区、南极冰流、南极冰架和山谷冰川，这些冰川目前由于气温变暖而减少得最快。

The state of the subglacial environment is a first-order control on the flow of overlying ice. With greater volumes of water reaching the ice-bed interface in a warming world, basal hydrology development is a direct link between the impacts of climate change on ice dynamics and resulting sea-level rise. The difficulty of access to subglacial environments has hindered a detailed understanding of basal processes and vital questions remain about the role of water at the base of the Antarctic and Greenland ice sheets and in smaller but highly vulnerable valley glaciers. Use of numerical models is becoming increasingly beneficial for examining basal hydrology with the introduction of sophisticated 2D coupled models representing efficient and inefficient drainage. When this is combined with data inputs from satellite remote sensing, geophysical surveys and in situ data collection, it provides a powerful method for addressing areas where knowledge is currently lacking. This research program will utilize such methods on a variety of spatial and temporal scales ranging from conditions in Greenland and the Antarctic, to smaller scale processes at valley glaciers in the Yukon Territory and linking together the smaller and larger scale systems in the context of global climate. The research program objectives are in the short term (1-5 years) to 1) investigate the controls of subglacial hydrology on fast-flowing Antarctic ice streams, 2) examine ice-ocean interaction at Antarctic ice shelves and Greenland tidewater glaciers, 3) address the role of climate in glacier dynamics in the Yukon Territory and, in the longer term (3-10 years), utilize the outputs from objectives 1 through 3 to 4) incorporate basal processes and subglacial hydrology into large-scale ice sheet and global climate models. The outputs from these investigations into subglacial hydrology and ice dynamics over multiple spatial and temporal scales will give an unprecedented view of basal conditions of ice masses across the world. The combination of state-of-the-art models and data from multiple sources including remote sensing and in situ collection will provide a unique and detailed view of these vulnerable systems. The long-term goal to improve ice sheet models and global climate model predictions will utilize the results and experience gained from the individual research objectives and contribute to the next iterations of the Intergovernmental Panel on Climate Change (IPCC) report. In addition to this global approach, the individual projects will illuminate controls on ice dynamics for some of the regions most sensitive to climate-induced change, including the ablation area of the Greenland Ice Sheet, Antarctic ice streams, Antarctic ice shelves and valley glaciers that are currently diminishing the most rapidly due to warming temperatures.