A Finite-Element Model of Basal Water Generated by Melting in an Ice Sheet Model

众所周知，当冰床的温度达到压力熔点时，水在冰床处产生。目前的冰盖模型，具有计算整个冰盖温度的能力，也能够计算冰层的融化速率。通过纳入一个基水流连续性方程模型，该项目将试图跟踪这一水在冰盖下从源区流向汇区时的运动。 预测湿基区域的能力对于理解滑动机制的发生是重要的，滑动机制被认为是控制冰流动力学的。 主要任务将是为基底水连续性方程的参数赋予物理意义。这将涉及从观测证据中提取冰下水流动的规律。 这些问题需要抓住基础物理学的本质，但仍然足够简单，可以在数值模拟提供的离散化和广义化的现实快照中处理。 主要工作将集中在汇编和分析现有的观测和理论上的冰盖水文限制。 这些数据将被用来评估冰下水流的模式是最重要的，什么样的参数值必须使用最好的结合到冰盖模型的冰下过程。

It is well known that water is produced at the bed of an ice sheet when the temperature of the bed reaches the pressure melting point. The current ice sheet model, with its ability to calculate temperaturesthroughout the ice sheet, is also able to calculate melt rates at the bed. By incorporating a model of the continuity equation for the basal-water flow, this project will attempt to follow the movement of this waterunder the ice sheet as it flows from source regions to sink regions. The ability to predict wet-based regions is important to the understanding of the occurrence of the sliding mechanism, which is thought to control ice stream dynamics. The primary task will be to ascribe physical meaning to the parameters of the basal-water continuity equation. This will involve extracting, from observational evidence, the laws governing the flow of subglacial water. These will need to capture the essence of the underlying physics and yet remain simple enough to be treatable within the discretized and generalized snapshot of reality provided bynumerical simulations. The primary effort will focus on compiling and analyzing the existing observational and theoretical constraints on ice-sheet hydrology. These data will be used to evaluate which modes of subglacial water flow are the most important and what values of parameters must be used to best incorporate the subglacial processes into the ice sheet model.