Gravity Currents and Large-Amplitude Internal Waves

重力流和带困芯的非线性内波是沿海海洋的共同特征。重力流的传播可以产生振幅较大的非线性内波，而非线性内波的浅化可以形成圈闭流体的再循环岩心。该项目是一个重力流和非线性内波的动力学与困芯的合作研究，包括平行互补的实验室实验。波槽实验将侧重于稳定重力流和内波产生之间的过渡阶段，以及困芯波的理论和实验。该项目将调查：什么类型的岩心循环是可能的，它们如何依赖于波的产生机制，剪切不稳定性的发展，岩心流体被困多长时间，以及对远程质量输运的影响。实验结果将与高分辨率非流体静力数值计算结果进行比较。这项研究的结果可能会对沿海海洋环流、混合和近场河流羽流行为产生实质性的见解。实验和数值研究的一个主要重点是向合作者传播关键结果，以改进对实地观测和区域模式参数化的解释。作为幼虫扩散的一个关键未知因素，被困岩心的水平迁移可以用于生物学家模拟底栖生物种群连通性。该项目将支持两名研究生的博士论文工作，并涉及一名或多名GFD研究员。

Gravity currents and nonlinear internal waves with trapped cores are common features in the coastal ocean. Propagating gravity currents can generate large-amplitude nonlinear internal waves, while shoaling nonlinear internal waves can develop re-circulating cores of trapped fluid. The project is a collaborative study of the dynamics of gravity currents and nonlinear internal waves with trapped cores, including parallel complementary laboratory experiments. Wave tank experiments will focus on the stages of transition between steady gravity currents and internal wave generation,and theory and experiments for waves with trapped cores. The project will investigate: what types of core circulations are possible, how they depend on the wave generation mechanism, the development of shear instabilities, how long core fluid is trapped, and the implications for long-range mass transport. Experimental results will be compared with high-resolution non-hydrostatic numerical calculations.The results of this study could lead to substantial insights in coastal ocean circulation, mixing, and near-field river plume behavior. A major emphasis of the experimental and numerical studies is the dissemination of key results to collaborators to improve interpretation of field observations and parameterizations in regional models. As a key unknown in larval dispersal, horizontal transport by trapped cores can be of use to biologists modeling benthic population connectivity. The project will support the Ph.D. thesis work of two graduate graduate students, and involve one or more GFD fellows.