Geophysical wave-vortex interactions and turbulence

地球物理波涡相互作用和湍流

基本信息

批准号：
2108225
负责人：
Oliver Buhler
金额：
$ 43.5万
依托单位：
New York University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2108225&HistoricalAwards=false
关键词：
Geophysical wave vortex interactions turbulence

项目摘要

This fluid dynamics study is aimed at improving the theoretical understanding of turbulent atmosphere ocean processes at small scales, which are unresolvable in today's global-scale computer models. The key components of the project are the improved understanding of turbulent energy transfers between large and small scales in the fluid. This involves vigorous interactions between current systems like the Gulf Stream and fast wave motions that cannot be seen by current global ocean computer models. Overall, the proposed work has broad impacts within fluid mechanics, physical oceanography, and its training aspects include both graduate and undergraduate students.The fluid dynamics of these complex systems is characterized by a nonlinear jigsaw puzzle of intermingling turbulent waves and vortices, especially at small scales, such as those relevant to submesoscale oceanography, for instance. Here classical wave-mean interaction theory fails, direct numerical simulation of the fluid motion with global computational models is not possible, and theoretical innovations for diagnostic and predictive models are needed. In this connection the present proposal seeks to break new ground with a multi-pronged approach that combines theory and numerical modelling. First, the long term evolution of turbulent internal wave spectra under refraction by the balanced mean flow is studied using a novel wave action advection-diffusion theory. Second, vigorous two-way interactions between internal waves and the balanced mean flow are studied using new wave-mean interaction equations derived from generalized Lagrangian-mean theory. These equations allow for strong interactions that cut both ways: the waves feel the mean flow and vice versa. This is an important but understudied regime for submesoscale oceanography.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项流体动力学研究旨在提高对小尺度湍流大气海洋过程的理论理解，这在当今的全球尺度计算机模型中是无法解决的。该项目的关键组成部分是加深对流体中大尺度和小尺度之间的湍流能量传递的理解。这涉及当前系统（如墨西哥湾流）与当前全球海洋计算机模型无法看到的快速波浪运动之间的剧烈相互作用。总体而言，所提出的工作在流体力学、物理海洋学领域具有广泛的影响，其培训方面包括研究生和本科生。这些复杂系统的流体动力学的特点是湍流波和涡流混合的非线性拼图，特别是在小例如，与亚尺度海洋学相关的尺度。在这里，经典的波均相互作用理论失败了，用全局计算模型直接数值模拟流体运动是不可能的，并且需要诊断和预测模型的理论创新。在这方面，本提案旨在通过结合理论和数值建模的多管齐下的方法开辟新天地。首先，利用一种新颖的波作用平流扩散理论研究了平衡平均流折射下湍流内波谱的长期演化。其次，使用从广义拉格朗日平均理论导出的新的波平均相互作用方程研究了内波和平衡平均流之间的剧烈双向相互作用。这些方程允许产生双向的强相互作用：波感受到平均流，反之亦然。这是亚尺度海洋学的一个重要但尚未得到充分研究的制度。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。