High-resolution modelling of near-inertial waves in the ocean

海洋中近惯性波的高分辨率建模

• 批准号: NE/J022012/1
• 负责人: Jacques Vanneste
• 金额: $ 37.34万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ022012%2F1
• 关键词: resolution; modelling; near; inertial; waves

The combination of the ocean's density stratification and the earth's rotation results in the existence of waves, termed inertia-gravity waves, which propagate through the whole depth of the ocean and make a large contribution to its energy. Most of the energy of inertia-gravity waves is in fact contained in the waves with the lowest frequencies: these are the inertial waves at the centre of this project. Inertial waves, which are generated by wind at the ocean's surface, are highly energetic and susceptible to instabilities which induce turbulence and mixing. Because they are the primary source of vertical mixing below the immediate top layer of the ocean, inertial waves are crucially important for the dispersion of pollutants and for biological activity. More surprisingly perhaps, they are also crucial in establishing the density stratification of the deep ocean. As a result, they have a strong influence on the large-scale circulation of the ocean and thereby on the earth's climate. It is therefore very important that the numerical models that are used for climate predictions take into account the effect of inertial waves. This is challenging, however. Because the scales of the inertial waves are much smaller than the typical scales of the ocean's circulation, it is not possible for climate models to describe fully (i.e., to resolve) the details of the motion associated with the waves. Instead, the models must represent the large-scale, global effect of the waves and relate this effect to the processes which they describe well, such as the surface winds and large-scale currents. This is the role of parameterisation schemes, which are one of the most important (and delicate) components of climate models. To be accurate and robust, these parameterisation schemes must be based on a sound understanding of the unresolved phenomena they represent. This project will build this understanding for wind-generated inertial waves. It will start by the development of a new numerical model specifically dedicated to the study of inertial waves. This model makes a number of simplifications tailored to inertial waves; thanks to these simplifications, its computational cost is much lower than that of traditional models. It will therefore provide a unique, highly efficient tool for the study of inertial waves. It will be benchmarked against the results of more costly models and against a series of measurements made by drifters floating near the ocean's surface. The propagation of inertial waves through the ocean will then be examined. Three specific aspects will be considered: the influence of currents with small vertical scales, the scattering and dissipation of the waves near the bottom topography, and the direct large-scale forcing induced by dissipating inertial waves. This will lead to a greatly improved understanding of the dynamics of inertial waves and pave the way for the design of parameterisation schemes to be implemented in climate models and in regional ocean models.

海洋的密度分层和地球自转的结合导致了波浪的存在，称为惯性重力波，它传播到整个海洋深度并对其能量做出了很大的贡献。事实上，惯性重力波的大部分能量都包含在频率最低的波中：这些是该项目中心的惯性波。由海洋表面的风产生的惯性波能量很高，容易受到不稳定因素的影响，从而引起湍流和混合。由于惯性波是海洋直接顶层以下垂直混合的主要来源，因此惯性波对于污染物的扩散和生物活动至关重要。也许更令人惊讶的是，它们对于建立深海的密度分层也至关重要。因此，它们对海洋的大规模环流以及地球的气候有很大的影响。因此，用于气候预测的数值模型考虑惯性波的影响非常重要。然而，这具有挑战性。由于惯性波的尺度远小于海洋环流的典型尺度，因此气候模型不可能完全描述（即解析）与波浪相关的运动细节。相反，模型必须代表波浪的大规模全球效应，并将这种效应与它们所描述的过程（例如表面风和大规模洋流）联系起来。这就是参数化方案的作用，它是气候模型最重要（也是最微妙）的组成部分之一。为了准确和稳健，这些参数化方案必须基于对其所代表的未解决现象的充分理解。该项目将建立对风力产生的惯性波的理解。它将首先开发专门用于惯性波研究的新数值模型。该模型针对惯性波进行了许多简化；由于这些简化，其计算成本远低于传统模型。因此，它将为惯性波的研究提供一种独特、高效的工具。它将以更昂贵的模型的结果以及漂浮在海洋表面附近的漂流者进行的一系列测量为基准。然后将检查惯性波在海洋中的传播。将考虑三个具体方面：小垂直尺度海流的影响、底部地形附近波的散射和耗散以及惯性波耗散引起的直接大尺度强迫。这将大大提高对惯性波动力学的理解，并为气候模型和区域海洋模型中实施的参数化方案的设计铺平道路。

项目成果

On the concentration of near-inertial waves in anticyclones

• DOI: 10.1017/jfm.2015.252
• 发表时间: 2015-03
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Eric Danioux;J. Vanneste;O. Bühler

Near-inertial wave scattering by random flows

随机流的近惯性波散射

• DOI: 10.48550/arxiv.1601.05456
• 发表时间: 2016
• 作者: Danioux E

Interaction between mountain waves and shear flow in an inertial layer

惯性层中山波与剪切流的相互作用

• DOI: 10.1017/jfm.2017.39
• 发表时间: 2017
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Xie J

A generalised-Lagrangian-mean model of the interactions between near-inertial waves and mean flow

• DOI: 10.1017/jfm.2015.251
• 发表时间: 2014-11
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Jin-Han Xie;J. Vanneste

Near-inertial-wave scattering by random flows

• DOI: 10.1103/physrevfluids.1.033701
• 发表时间: 2016-01
• 期刊: arXiv: Atmospheric and Oceanic Physics
• 作者: Eric Danioux;J. Vanneste