Consolidated Grant in Solar and Planetary Studies: Department of Applied Mathematics, University of Leeds

太阳和行星研究综合资助：利兹大学应用数学系

• 批准号: ST/N000765/1
• 负责人: David Hughes
• 金额: $ 130.57万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FN000765%2F1
• 关键词: Consolidated; Grant; Solar; Planetary; Studies

Many astrophysical phenomena involve the complex interaction between magnetic fields, rotation and turbulent fluid flows. We intend to undertake a systematic and integrated programme of research to investigate this interaction in a variety of contexts in solar system and planetary sciences. We shall utilise a combination of analytical and numerical techniques (including the application of cutting edge numerical algorithms optimised for use on massively parallel machines) to gain an understanding of such phenomena. Our unifying philosophy is to investigate and explain the underlying fundamental physical interactions in these astrophysical fluids whilst also providing a theoretical underpinning to the latest high-resolution observations. We propose to investigate the following specific problems:(1) The most exciting recent observational discovery in solar physics is the identification of the "solar tachocline", a thin region of strong velocity shear, deep in the Sun, sandwiched between the convective and radiative zones. This was entirely unexpected theoretically. We shall investigate the nature of the shear-dominated turbulent flow in the tachocline to investigate how quantities such as temperature, magnetic field and angular momentum are transported, and hence to understand why the tachocline does indeed exist.(2) On the Sun, magnetic field is observed to exist over a range of spatial and temporal scales, from the large and long-lived to the small and short-lived. Furthermore, the convection at the solar surface also has a range of scales, from supergranules (which are about 20,000 km across) down to granules (about 1000 km). We shall study the interaction between the convection and the magnetic fields to explain these observed ranges in scale.(3) The large-scale magnetic field erupts through the solar surface to cause sunspots in the photosphere and to trigger sometimes violent magnetic activity in the solar atmosphere. The velocity shear in the tachocline winds up the weak poloidal magnetic field into a strong toroidal field, which then escapes, to rise and eventually to appear at the surface. We have developed a new set of equations designed specifically to describe the magnetic field in the tachocline. We shall use these to explain the scale and morphology of the escaping magnetic field, and will then relate our findings to observations of emerging solar magnetic fields.(4) Most planets have magnetic fields, which vary widely in their strength and spatial form. By considering planet-specific computational models,we shall investigate the nature of the dynamo mechanism responsible for generating magnetic field in the gas giants, Jupiter and Saturn, and in the ice giants, Uranus and Neptune. Our results will be related to those of the JUNO mission to Jupiter.

许多天体物理现象涉及磁场、自转和湍流之间的复杂相互作用。我们打算开展一项系统和综合的研究方案，在太阳系和行星科学的各种背景下调查这种相互作用。我们将利用分析和数值技术的组合(包括优化用于大规模并行机器的尖端数值算法的应用)来获得对这些现象的理解。我们统一的哲学是调查和解释这些天体物理流体中潜在的基本物理相互作用，同时也为最新的高分辨率观测提供理论基础。我们打算研究以下具体问题：(1)最近太阳物理学中最令人兴奋的观测发现是“太阳跃层”的发现，这是一个夹在对流区和辐射区之间的太阳深处的薄薄的强速度切变区域。这在理论上完全出乎意料。我们将研究斜跃层中剪切主导的湍流的性质，以研究温度、磁场和角动量等量是如何传输的，从而理解为什么斜跃层确实存在。(2)在太阳上，观测到的磁场存在于一系列的时空尺度上，从大的和长的到小的和短的。此外，太阳表面的对流也有一系列尺度，从直径约20,000公里的超颗粒到颗粒(约1000公里)。我们将研究对流和磁场之间的相互作用，以解释这些尺度上的观测范围。(3)大规模磁场通过太阳表面爆发，在光球中产生太阳黑子，并在太阳大气中触发有时强烈的磁活动。角跃层中的速度切变将弱的极向磁场卷曲成强的环向磁场，然后环向磁场逃逸，然后上升，最终出现在地表。我们发展了一组新的方程，专门用来描述角跃层中的磁场。我们将用这些来解释逃逸磁场的规模和形态，然后将我们的发现与对新出现的太阳磁场的观测联系起来。(4)大多数行星都有磁场，其强度和空间形式差别很大。通过考虑行星特有的计算模型，我们将研究在气体巨星木星和土星以及在冰巨星天王星和海王星中产生磁场的发电机机制的性质。我们的结果将与朱诺前往木星的任务相关。

项目成果

Angular momentum transport by the GSF instability: nonlinear simulations at the equator

GSF 不稳定性引起的角动量传递：赤道处的非线性模拟

• DOI: 10.48550/arxiv.1905.06962
• 发表时间: 2019
• 作者: Barker A

Generalised quasilinear approximation of the helical magnetorotational instability

螺旋磁旋转不稳定性的广义拟线性近似

• DOI: 10.1017/s0022377816000556
• 发表时间: 2016
• 期刊: Journal of Plasma Physics
• 影响因子: 2.5
• 作者: Child A

Convection-driven kinematic dynamos with a self-consistent shear flow

• DOI: 10.1080/03091929.2018.1517210
• 发表时间: 2018-09
• 期刊: Geophysical & Astrophysical Fluid Dynamics
• 影响因子: 1.3
• 作者: Laura K. Currie;Steven M. Tobias

Convection-driven kinematic dynamos at low Rossby and magnetic Prandtl numbers: Single mode solutions.

低罗斯贝数和磁普朗特数的对流驱动运动发电机：单模解决方案。

• DOI: 10.1103/physreve.93.023115
• 发表时间: 2016
• 期刊: Physical review. E
• 作者: Calkins MA

Convection-driven kinematic dynamos at low Rossby and magnetic Prandtl numbers

• DOI: 10.1103/physrevfluids.1.083701
• 发表时间: 2016-07
• 期刊: arXiv: Geophysics
• 作者: M. Calkins;Louie Long;D. Nieves;K. Julien;S. Tobias