Gravity Currents and Large-Amplitude Internal Waves

重力流和大振幅内波

• 批准号: 1029672
• 负责人: Karl Helfrich
• 金额: $ 54.75万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029672&HistoricalAwards=false
• 关键词: Gravity; Currents; Large; Amplitude; Internal

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.

重力流和非线性内波是近岸海洋中常见的现象。变浅的重力流可以产生大振幅的非线性内波，而变浅的非线性内波可以形成捕获流体的再循环核。 该项目是一项关于重力流和非线性内波动力学的合作研究，包括平行的补充实验室实验。波浪水槽实验将侧重于稳定重力流和内波生成之间的过渡阶段，以及具有被困核心的波浪的理论和实验。该项目将调查：什么类型的核心环流是可能的，他们如何依赖于波的产生机制，发展的剪切不稳定性，多久核心流体被困，以及远程质量传输的影响。实验结果将与高分辨率非静力数值计算进行比较，这项研究的结果可能会导致沿海海洋环流，混合，近场河流羽流行为的实质性见解。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，以改进对实地观测的解释和区域模型的参数化。作为一个关键的未知的幼虫扩散，水平运输被困核心可以使用生物学家模拟底栖动物种群连接。 该项目将支持博士学位。两个研究生的论文工作，并涉及一个或多个GFD研究员。