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/S00047X/1
• 负责人: Christopher Jones
• 金额: $ 51.28万
• 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: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FS00047X%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 will 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. We propose to investigate the following specific problems:(1) 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). A new anelastic code has been developed in Leeds, and we will use this to explore the interaction between the convection and the magnetic fields to explain these observed ranges in scale. We will address the important issue of whether the observed small-scale magnetic field is broken-down large-scale field, or whether it is generated afresh by a small-scale dynamo. We shall also explore the role of the near-surface shear layer to see how it affects the solar magnetic field just below the photosphere. (2) A key observational discovery in solar physics was the identification of the "solar tachocline", a thin region of strong velocity shear, deep in the Sun, sandwiched between the convective and radiative zones. Recent satellite observations of the Sun have revealed new short period activity cycles in addition to the 11 year activity cycle. Long term observations of bright points in the corona have revealed slow waves. These waves and activity cycles most likely arise in the tachocline. We will explore what types of waves the tachocline can support, and how they develop in the nonlinear regime. This will enable us to discover if these new observations can be understood in terms of tachocline dynamics, and how these signals in the deep interior are transmitted to the solar surface.(3) The nature and strength of the magnetic field in the radiative interior below the tachocline is a major unknown of solar research. We will explore a mechanism known as magnetic buoyancy, by which magnetic fields rise upwards. This is known to be important nearer the surface, but it might also play a role in the deepest regions of the Sun. There is an analogy between magnetic buoyancy and double diffusive convection, which occurs in our oceans. It has recently been discovered that by forming density layers, the transport of heat and salt in the ocean can be much enhanced. By studying three-dimensional, nonlinear models to investigate this layering process in the magnetic context, we will explore whether such layering can occur in the deep solar interior. This will provide important new constraints on the magnetic field in the solar radiative zone. (4) The Juno space mission has sent back stunning pictures of Jupiter's surface, and we now also have much more accurate data about Jupiter's magnetic field and its gravity field. The gravity field data has shown that the strong winds seen at the surface of Jupiter penetrate deep into the interior of the planet. We also have similar data for Saturn from the Cassini Grand Finale, when the Cassini probe dived into Saturn, recording close up data just before it was swallowed up. We now plan to assimilate this accurate data into our dynamo models for giant planets, and hence constrain interior models in a way that has hitherto not been possible. We aim to discover if Jupiter has a dense, compact core or a large, dilute core as recently suggested. We will also explore whether the deep winds predicted by our dynamo models are consistent with the observed winds.

许多天体物理现象涉及磁场，旋转和湍流流量之间的复杂相互作用。我们将采用系统和集成的研究计划，以在太阳系和行星科学的各种情况下研究这种相互作用。我们将利用分析和数值技术的组合（包括优化用于在大规模平行机上使用的尖端数值算法的应用）来了解这种现象。我们建议研究以下特定问题：（1）在太阳上，观察到磁场存在于一系列空间和时间尺度上，从大小寿命到长寿和短寿命。此外，太阳表面的对流也具有一系列尺度，从超级颗粒（约20,000 km）到颗粒（约1000公里）。利兹已开发了一种新的无弹性代码，我们将使用它来探索对流与磁场之间的相互作用，以在规模上解释这些观察到的范围。我们将解决一个重要的问题，即观察到的小规模磁场是否被打破了大规模磁场，还是通过小型发电机重新生成的大规模磁场。我们还将探索近表面剪切层的作用，以了解它如何影响光球下方的太阳磁场。 （2）太阳理物理学中的关键观察发现是“太阳速 /速loct”的鉴定，这是一个薄的速度剪切的薄区域，深处在太阳深处，夹在对流和辐射区域之间。最近对太阳的卫星观察结果揭示了除11年活动周期外，新的短期活动周期。对电晕中明亮点的长期观察显示了慢波。这些波和活性周期很可能是在转速素中出现的。我们将探索速粒可以支持哪些类型的波，以及它们在非线性方案中的发展方式。这将使我们能够发现这些新观察结果是否可以通过速粒动力学来理解，以及深层内部中的这些信号如何传递到太阳表面。（3）速粒内部辐射内部磁场的性质和强度是Solar Research的主要未知。我们将探索一种称为磁性浮力的机制，磁场上升。众所周知，这很重要，但它也可能在太阳的最深地区发挥作用。磁性浮力与双重扩散对流之间存在类比，这发生在我们的海洋中。最近发现，通过形成密度层，海洋中的热和盐的运输可以大大增强。通过研究三维非线性模型以在磁性环境中研究这种分层过程，我们将探讨在深太阳能内部是否可以发生这种分层。这将在太阳辐射区的磁场上提供重要的新约束。 （4）Juno太空任务已将木星表面的令人惊叹的图片发回了，我们现在还拥有有关木星磁场及其重力场的更准确的数据。重力场数据表明，在木星表面看到的强风深入地球内部。当卡西尼调查潜水到土星时，我们也有类似的土星数据的土星数据，在吞噬土星之前记录了近距离数据。现在，我们计划将这些准确的数据吸收到我们的巨型行星的发电机模型中，因此以迄今为止无法实现的方式来限制内部模型。我们旨在发现木星是最近建议的木星是否具有密集，紧凑的核心或大型稀释的核心。我们还将探索发电机模型预测的深风是否与观察到的风相一致。

项目成果

The deep winds of Jupiter

木星的深风

• DOI: 10.1038/s41550-023-02129-z
• 发表时间: 2023
• 期刊: Nature Astronomy
• 影响因子: 14.1
• 作者: Jones C

Convective turbulent viscosity acting on equilibrium tidal flows: new frequency scaling of the effective viscosity

作用于平衡潮汐流的对流湍流粘度：有效粘度的新频率缩放

• DOI: 10.1093/mnras/staa2216
• 发表时间: 2020
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Duguid C

Fully developed anelastic convection with no-slip boundaries

具有无滑移边界的完全发展的滞弹性对流

• DOI: 10.1017/jfm.2021.905
• 发表时间: 2021
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Jones C

Anelastic torsional oscillations in Jupiter's metallic hydrogen region

木星金属氢区域的滞弹性扭转振荡

• DOI: 10.1016/j.epsl.2019.04.042
• 发表时间: 2019
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Hori K

Solitary magnetostrophic Rossby waves in spherical shells

球壳中的孤立磁致罗斯贝波

• DOI: 10.1017/jfm.2020.743
• 发表时间: 2020
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Hori K