An experimental and theoretical study of the dynamics of grounding lines
An experimental and theoretical study of the dynamics of grounding lines
复制标题
接地线动力学的实验和理论研究
DOI：
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发表时间：
2013
影响因子：
3.7
通讯作者：
M. Worster
中科院分区：
文献类型：
--
作者：
S. Pegler;M. Worster
摘要我们提出了一个实验和理论研究的薄，粘性流体层，从一个点源到一个更密集的无粘流体层均匀的深度以上的刚性水平面上的重力径向流动。在近源处，粘性层与表面完全接触，形成垂直剪切为主的粘性重力流。在距源一定距离处，层与表面分离，形成浮流，其动力学由纵向延伸产生的粘性应力控制。我们描述的动态的接地和浮动组件使用不同的薄层理论。分离接地和浮动区域是自由移动的分离线，或接地线，其演变我们通过平衡两个区域之间的水平力来建模。使用数值和渐近分析，我们计算系统的演化从一个自相似的形式在早期到一个稳定的状态在后期的时间。我们用我们的解决方案来说明如何在海洋冰盖，如南极洲西部的三维应力，可以导致稳定的接地线。为了评估我们模型假设的有效性，我们将其预测与一系列实验室实验的数据进行了比较。
Abstract We present an experimental and theoretical study of a thin, viscous fluid layer that flows radially under gravity from a point source into a denser inviscid fluid layer of uniform depth above a rigid horizontal surface. Near the source, the viscous layer lies in full contact with the surface, forming a vertical-shear-dominated viscous gravity current. At a certain distance from the source, the layer detaches from the surface to form a floating current whose dynamics are controlled by the viscous stresses due to longitudinal extension. We describe the dynamics of the grounded and floating components using distinct thin-layer theories. Separating the grounded and floating regions is the freely moving line of detachment, or grounding line, whose evolution we model by balancing the horizontal forces between the two regions. Using numerical and asymptotic analysis, we calculate the evolution of the system from a self-similar form at early times towards a steady state at late times. We use our solutions to illustrate how three-dimensional stresses within marine ice sheets, such as that of West Antarctica, can lead to stabilization of the grounding line. To assess the validity of the assumptions underlying our model, we compare its predictions with data from a series of laboratory experiments.