Subglacial processes and their large-scale consequences

我们研究的主要目的是了解冰下过程的运作，并将这一理解应用于改进冰盖动力学和水文学的计算机模型。目前用于预测地球冰川未来的模型的一个主要缺陷是，对冰下过程的描述不充分。我们需要对极地冰盖未来的质量损失率和随之而来的全球海平面上升做出尽可能最好的估计。此外，我们需要好的模型来增加对过去突然气候变化事件的理解。我们的战略是在冰川内和冰川下安装仪器来观察过程及其相互作用，开发理论来封装这些测量的结果，并建立数值模型来模拟自然系统。我们的目标是扩展基于流经圆形冰墙管道的水的冰下排水系统的经典理论，以包括更真实的几何图形。应用这些结果，我们可以立即改进冰下和冰上暴发洪水的物理模型，并首次开发出适用于EKERS(一种景观特征)以及我们希望适用于其他冰下地貌的现实模型。在更大的范围内，我们将继续研究气候突然变化的机制，重点是大洪水的作用，如来自冰川湖的洪水，以及似乎涉及水和冰流动耦合不稳定的“海因里希事件”。为了补充我们对巨型洪水的研究，我们将启动一个适度的实地项目，研究育空地区阿尔塞克湖的暴发洪水和洪水河床。

The leading aim of our research is to understand the operation of subglacial processes and to apply this understanding to improve computer models of the dynamics and hydrology of ice sheets. Inadequate representation of subglacial processes is a major shortcoming of the models that are currently used to predict Earth's glacial future. We need the best possible estimates of future rates of mass loss from polar ice sheets and the consequent rise in global sea level. Additionally, we need good models to increase understanding of past abrupt climate change events. Our strategy is to install instruments within and beneath glaciers to observe processes and their interactions, develop theory to encapsulate the results of these measurements and build numerical models to simulate the natural systems. We aim to extend the classical theory of subglacial drainage systems, based on water flow through circular ice-walled conduits, to include more realistic geometries. Applying these results, we can immediately improve physical models of subglacial and supraglacial outburst floods and develop, for the first time, a realistic model for eskers (a landscape feature) and, we hope, for other subglacial landforms. At a larger scale, we will continue our research on mechanisms of abrupt climate change, focussing on the role of megafloods, such as that from glacial Lake Agassiz, and on "Heinrich events" which seem to involve a coupled instability of water and ice flow. To complement our research on megafloods we will launch a modest field program to study the outburst floods and flood bedforms of Neoglacial Lake Alsek, Yukon.