Multi-scale interactions between internal waves and rotationally modified vortices

内波和旋转修正涡之间的多尺度相互作用

基本信息

批准号：
EP/X028135/1
负责人：
Lois Baker
金额：
$ 47.71万
依托单位：
University of Edinburgh
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FX028135%2F1
关键词：
Multi scale interactions between internal

项目摘要

In rotating and density stratified fluids such as the ocean and atmosphere, dynamics can span a wide range of scales and dynamical regimes, from wave breaking on a beach, to circulation around entire ocean basins, and everything in-between. At large scales, the flow is dominated by rotational forces and the stabilising effect of density stratification, leading to slowly varying, rotationally constrained, horizontal flow - an example being atmospheric weather systems. This flow is in a state of near-balance between the Coriolis force due to the Earth's rotation and horizontal pressure gradients. However, at small scales, the effects of rotation and stratification are negligible, and the flow is characterised by 3D turbulence. In this project, I will study the interactions between two classes of fluid dynamical processes that occur at the intermediate scales between large-scale balanced motion and small-scale turbulence, and are therefore modified, but not constrained, by rotation: internal waves and rotationally modified vortices.Internal waves are ubiquitous in stratified flows, including the ocean and atmosphere. They overlap in scale with rotationally modified vortices for which both inertial forces and rotation are of comparable importance, termed 'submesoscale' in the ocean and 'mesoscale' in the atmosphere. Although internal waves and rotationally modified vortices have received considerable attention in recent years, their interactions are still not well understood. Here, I propose to study the way in which internal waves and rotationally modified vortices interact, including how energy is transferred between them, and how they might affect each other's generation, lifecycle, and eventual decay.These interactions will be investigated for three different flow scenarios using a theoretical framework and high-resolution numerical simulations. The modelling will be idealised and simplified, allowing me to isolate the key processes at play, whilst being motivated by real interactions that occur in the ocean and atmosphere. Oceanic observations will be used to verify results.This project is motivated by the growing consensus that internal waves and rotationally modified vortices couple large- and small- scale dynamics. Capturing this effect is a key challenge in developing the next generation of climate models, since small scales provide an essential sink of energy from the large scale flow. Whilst larger scale, balanced, flows will soon be fully resolved in climate models, rotationally modified vortices and internal waves are at the frontier of climate parameterisations, and will continue to be relevant to the UK's capability in the prediction of climate for decades to come.

在旋转和密度分层的流体（例如海洋和大气层）中，动力学可以跨越各种尺度和动态状态，从海滩上的波浪到围绕整个海洋盆地的循环以及两者之间的一切。在大尺度上，流动由旋转力和密度分层的稳定作用支配，导致缓慢变化，旋转约束，水平流动 - 一个例子是大气天气系统。由于地球的旋转和水平压力梯度，这种流量处于科里奥利力之间几乎平衡的状态。但是，在小尺度上，旋转和分层的影响可以忽略不计，流动的特征是3D湍流。在这个项目中，我将研究两类流体动力学过程之间在大规模平衡运动和小规模的湍流之间发生的两类流体动力学过程之间发生的相互作用，因此通过旋转进行了修改，但不受限制：内部波浪和旋转修饰的涡旋。内部波浪在包括海洋和大气在内的分层流中无处不在。它们与旋转修改的涡旋重叠，惯性力和旋转都具有相当的重要性，在大气中称为“ sbortsoscale”和“中尺度”。尽管近年来内部波浪和旋转修改的涡旋受到了很大的关注，但它们的相互作用仍然不太了解。在这里，我建议研究内部波和旋转修饰的涡流相互作用的方式，包括如何在它们之间传递能量，以及它们如何影响彼此的产生，生命周期和最终衰减。这些相互作用将使用理论框架和高分辨率的数字模拟来研究三种不同的流动场景。该建模将是理想化和简化的，使我能够隔离起作用的关键过程，同时是由于海洋和气氛中发生的实际相互作用而动机。海洋观察将用于验证结果。该项目的动机是越来越多的共识，即内部波和旋转修改的涡流将大量和小规模动态融为一体。捕获这种效果是开发下一代气候模型的关键挑战，因为小规模为大规模流量提供了必不可少的能量水槽。尽管气候模型将很快完全解决较大的规模，平衡，但旋转修改的涡旋和内部波浪处于气候参数的边界，并且将继续与英国在数十年来预测气候中的能力中继续相关。