Laboratory and Numerical Experiments on the Effects of Topography and the B-effect on Baroclinic Flows

本研究的目标是进行一系列的实验室和数值实验，以确定大尺度地形对热驱动旋转流体中斜压流动的影响。b效应将以径向倾斜的底部和顶部边界来模拟，而不考虑底部地形。从简单的2波底部地形开始，pi将利用北半球中纬度地区地球地形的主要模态的振幅和相位，发展到越来越复杂的地形。数值模型将被修改，以包括海底地形上的波浪，并将与实验室实验并行整合。这些模型将包含两个版本的b效应。在一个版本中，b效应将被纳入控制方程，就像它出现在大气流动方程中一样。在另一种情况下，它将被纳入边界条件中，假设在实验室实验中模拟的径向倾斜的底部和顶部边界。我们将比较两种形式的B的数值解，以评估实验中的倾斜边界在多大程度上反映了B对斜压流动的本质影响。地球物理流体动力学研究领域目前的主要兴趣是研究地形和旋转引起的行星波状态及其在平均纬向风波动中的作用。当前一批关于地形不稳定性的理论研究的一个问题是，很少有合适的观测来验证理论模型的预测。本项目的重要性在于，实验室环空实验为模拟各种边界条件下的流体行为和验证理论提供了有力的手段。Pfeffer博士及其同事提出的工作将通过一系列实验室环空和数值实验来研究大尺度地形对热驱动旋转流体的影响。

The goal of this research is to produce a series of laboratory and numerical experiments to determine the effects of large-scale topography on baroclinic flows in thermally-driven, rotating fluids. The B-effect will be simulated with radially sloping bottom and top boundaries without bottom topography. Starting with simple 2-wave bottom topography, the PIs will progress to increasingly more complex topography using the amplitudes and phases of the dominant modes of the earth's topography in the middle latitudes of the Northern Hemisphere. Numerical models will be modified to include waves over bottom topography and will be integrated in parallel with the laboratory experiments. These models will incorporate two versions of the B-effect. In one version, the B-effect will be incorporated in the governing equations as it appears in the equations for atmospheric flow. In the other, it will be incorporated in the boundary conditions by assuming radially sloping bottom and top boundaries as simulated in the laboratory experiments. The numerical solutions obtained with both forms of B will be compared in order to assess the degree to which the sloping boundaries in the experiment capture the essential influence of B on baroclinic flows. Much interest in the area of geophysical fluid dynamics research is currently focused on study of topography and rotation induced planetary wave regimes, and their role in the fluctuations of the mean zonal wind. One problem with the current batch of theoretical studies of topographic instability is that there is very little by the way of suitable observations for verifying predictions of theoretical models. The importance of this project is that laboratory annulus experiments provide a powerful means for simulating fluid behavior under various boundary conditions and validating theory. The work proposed by Dr. Pfeffer and colleagues will investigate through a series of laboratory annulus and numerical experiments the effects of large scale topography on thermally-driven rotating fluids.