Dynamics of Rotating Stratified Fluids

Hart教授将对两层斜压旋转流体中各种有序和混沌状态之间的转换进行数值和理论建模，并进行进一步的实验室实验。数值模拟将处理大量的实验室数据集，这些数据集涉及由f平面以及极b平面上的斜压不稳定性引起的稳定、周期和混沌（非周期）运动类型之间的转换。特别令人感兴趣的是刚性侧壁边界条件在过渡过程中的作用。它的存在导致基本流的水平剪切，线性自由滑移问题的基本特征函数的修正，以及流动分离的可能性。理论和实验研究将集中在可能破坏实验室实验中观察到的简单稳定和振荡制度的过程上，这些过程是通过低阶（和/或弱非线性）准地转理论成功预测的。除了粘性侧壁的作用外，在大气和海洋科学中还有两种潜在的不稳定机制，即周期性强迫和地形强迫。这些物理效应对b面有限振幅斜压不稳定问题的作用将通过实验室和数值模型进行研究。//

Professor Hart will carry out numerical and theoretical modeling, as well as further laboratory experiments, on the transition between various ordered and chaotic states in a two- layer baroclinic rotating fluid. The numerical modeling will address the extensive laboratory data sets on transitions between steady, periodic, and chaotic (aperiodic) types of motion arising from baroclinic instability on the f-plane, as well as on the polar B-plane. Of particular interest is the role of the rigid sidewall boundary condition in the transition process. Its presence leads to a horizontal shear of the basic flow, a modification to the basic eigenfunctions of the linear free-slip problem, and the possibility of flow separation. Theoretical and experimental studies will focus on the processes that may destabilize the simple steady and vacillatory regimes that are observed in laboratory experiments, and which are successfully predicted by low-order (and/or weakly nonlinear) quasi-geostrophic theory. In addition to the role of the viscous sidewall, two potentially destabilizing mechanisms of interest in atmospheric and ocean sciences are periodic and topographic forcing. The action of these physical effects on the B-plane finite-amplitude baroclinic instability problem will be investigated through the use of laboratory and numerical models.//