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

地形影响和 B 效应对斜压流的实验室和数值实验

• 批准号: 8709410
• 负责人: Richard Pfeffer
• 金额: $ 50万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-15 至 1990-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8709410&HistoricalAwards=false
• 关键词: Laboratory; Numerical; Experiments; Effects; Topography

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.

这项研究的目标是进行一系列实验室和数值实验，以确定大尺度地形对热驱动旋转流体中斜压流的影响。 B 效应将通过径向倾斜的底部和顶部边界进行模拟，而无需底部地形。 从简单的 2 波底部地形开始，PI 将使用北半球中纬度地球地形主要模式的振幅和相位进展到越来越复杂的地形。 数值模型将被修改以包括底部地形上的波浪，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。 在一种版本中，B 效应将被纳入控制方程中，就像它出现在大气流动方程中一样。 另一方面，通过假设实验室实验中模拟的径向倾斜的底部和顶部边界，将其纳入边界条件中。 将比较使用两种形式的 B 获得的数值解，以评估实验中倾斜边界捕获 B 对斜压流的本质影响的程度。 目前，地球物理流体动力学研究领域的许多兴趣集中在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的研究。 当前一批地形不稳定性理论研究的一个问题是，很少有合适的观测手段来验证理论模型的预测。 该项目的重要性在于，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研究大规模地形对热驱动旋转流体的影响。