Structure and transport properties of jets in the atmosphere and oceans

大气和海洋中喷流的结构和输运特性

• 批准号: NE/M014983/1
• 负责人: Richard Scott
• 金额: $ 36.06万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FM014983%2F1
• 关键词: Structure; transport; properties; jets; atmosphere

Over the last several years, the strongly inhomogeneous nature ofatmospheric and oceanic mixing in diverse situations has becomeincreasingly apparent, as high resolution numerical simulations andobservations begin to represent accurately the detailed spatialstructure of air and water masses and their constituents. Mixing isnow known to be confined to distinct latitudinal regions, oftenseparated by sharp gradients that indicate dynamical transportbarriers. Inhomogeneous mixing by waves and eddies in atmospheres andoceans is intrinsically linked to the presence of zonally alignedjets, which not only arise as a result of the eddy mixing, but alsoorganize the mixing in distinct latitudinal regions. The combinedeffect is a dynamical feedback that is now known to operate under verygeneral conditions. Inhomogeneous mixing is important for thetransport of constituents such as water vapour, carbon dioxide, ozone,heat, and salinity; their inhomogeneous re-distribution impacts bothglobal radiative balances and regional climate change.Despite recent advances, a complete understanding of the way zonaljets organize inhomogeneous mixing, in particular the verticalstructure of such mixing, remains elusive. Progress in understandingthe horizontal structure of jets and mixing has been made recently, inparticular by focusing on the potential vorticity, a key dynamicalquantity that contains information about both horizontal rotationalmotion and density stratification. The aim of this project is tobuild on that recent work to develop a complete theory for thevertical structure of jets and mixing. In doing so, it willcontribute to our understanding both of the structure of the dominantjet structures in the atmosphere and oceans, as well as providingpredictions of how they will reach dynamical equilibrium underdifferent forcing conditions, conditions that may change in a changingclimate. It is anticipated that the new theory will allow us toassess the robustness of predictions made by climate models, which arenow beginning to accurately represent the complexities inherent in jetstructures.As well as advancing our fundamental understanding of basic dynamicalprocesses, we will study four specific issues of current importance inclimate science: (i) systematic transport of trace chemicals withinthe stratosphere; (ii) the coupling of the stratospheric andtropospheric circulations; (iii) the consequences of a climatic shiftin the tropospheric jet stream; and (iv) inhomogeneous transport andmixing associated with jets in the Southern Ocean. The projecthighlights how advances in fundamental science can be effectivelycombined with directed goals driven by specific applications.

在过去的几年中，随着高分辨率数值模拟和观测开始准确地表示空气和水团及其成分的详细空间结构，不同情况下大气和海洋混合的强烈不均匀性变得越来越明显。现在已知混合仅限于不同的纬度区域，通常由表明动态传输障碍的锐梯度分隔。大气和海洋中波浪和涡流的不均匀混合本质上与纬向排列射流的存在有关，纬向排列射流不仅是涡流混合的结果，而且在不同的纬度区域组织混合。组合效应是一种动态反馈，目前已知它可以在非常一般的条件下运行。不均匀混合对于水蒸气、二氧化碳、臭氧、热量和盐分等成分的传输很重要；它们的不均匀重新分布会影响全球辐射平衡和区域气候变化。尽管最近取得了进展，但对区域喷气机组织不均匀混合的方式（特别是这种混合的垂直结构）的完整理解仍然难以捉摸。最近，在理解射流和混合的水平结构方面取得了进展，特别是通过关注位涡，这是一个包含水平旋转运动和密度分层信息的关键动态量。该项目的目的是在最近的工作基础上开发射流和混合垂直结构的完整理论。这样做，它将有助于我们了解大气和海洋中主要喷流结构的结构，并预测它们在不同的强迫条件下（可能随气候变化而变化的条件）如何达到动态平衡。预计新理论将使我们能够评估气候模型预测的稳健性，气候模型现在开始准确地表示喷流结构固有的复杂性。除了增进我们对基本动力过程的基本理解外，我们还将研究四个具体问题当前气候科学的重要性：(i) 平流层内痕量化学品的系统运输； (ii) 平流层和对流层环流的耦合； (iii) 对流层急流气候变化的后果； (iv) 与南大洋急流相关的不均匀输送和混合。该项目强调了如何将基础科学的进步与特定应用驱动的定向目标有效地结合起来。

项目成果

Scaling theory for vortices in the two-dimensional inverse energy cascade

• DOI: 10.1017/jfm.2016.756
• 发表时间: 2016-12
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: B. H. Burgess;R. K. Scott

Extended scale invariance in the vortices of freely evolving two-dimensional turbulence

• DOI: 10.1103/physrevfluids.2.114702
• 发表时间: 2017-11
• 作者: B. H. Burgess;D. Dritschel;R. K. Scott

On the spacing of meandering jets in the strong-stair limit

强楼梯极限下曲流射流间距的研究

• DOI: 10.1017/jfm.2021.898
• 发表时间: 2021
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Scott R

Vortex scaling ranges in two-dimensional turbulence

• DOI: 10.1063/1.4993144
• 发表时间: 2017-07
• 期刊: Physics of Fluids
• 影响因子: 4.6
• 作者: B. H. Burgess;D. Dritschel;R. K. Scott

Robustness of vortex populations in the two-dimensional inverse energy cascade

二维逆能量级联中涡群的鲁棒性

• DOI: 10.1017/jfm.2018.473
• 发表时间: 2018
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Burgess B