{"title":"The Sun’s Supergranulation","authors":"Michel Rieutord, François Rincon","doi":"10.12942/lrsp-2010-2","DOIUrl":null,"url":null,"abstract":"<p>The Sun’s supergranulation refers to a physical pattern covering the surface of the quiet Sun with a typical horizontal scale of approximately 30,000 km and a lifetime of around 1.8 d. Its most noticeable observable signature is as a fluctuating velocity field of 360 m s<sup>t-1</sup> rms whose components are mostly horizontal. Supergranulation was discovered more than fifty years ago, however explaining why and how it originates still represents one of the main challenges of modern solar physics.</p><p>A lot of work has been devoted to the subject over the years, but observational constraints, conceptual difficulties and numerical limitations have all concurred to prevent a detailed understanding of the supergranulation phenomenon so far. With the advent of 21st century supercomputing resources and the availability of unprecedented high-resolution observations of the Sun, a stage at which key progress can be made has now been reached. A unifying strategy between observations and modelling is more than ever required for this to be possible.</p><p>The primary aim of this review is therefore to provide readers with a detailed interdisciplinary description of past and current research on the problem, from the most elaborate observational strategies to recent theoretical and numerical modelling efforts that have all taken up the challenge of uncovering the origins of supergranulation. Throughout the text, we attempt to pick up the most robust findings so far, but we also outline the difficulties, limitations and open questions that the community has been confronted with over the years.</p><p>In the light of the current understanding of the multiscale dynamics of the quiet photosphere, we finally suggest a tentative picture of supergranulation as a dynamical feature of turbulent magnetohydrodynamic convection in an extended spatial domain, with the aim of stimulating future research and discussions.</p>","PeriodicalId":49147,"journal":{"name":"Living Reviews in Solar Physics","volume":"7 1","pages":""},"PeriodicalIF":20.9000,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrsp-2010-2","citationCount":"143","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Living Reviews in Solar Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.12942/lrsp-2010-2","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 143
Abstract
The Sun’s supergranulation refers to a physical pattern covering the surface of the quiet Sun with a typical horizontal scale of approximately 30,000 km and a lifetime of around 1.8 d. Its most noticeable observable signature is as a fluctuating velocity field of 360 m st-1 rms whose components are mostly horizontal. Supergranulation was discovered more than fifty years ago, however explaining why and how it originates still represents one of the main challenges of modern solar physics.
A lot of work has been devoted to the subject over the years, but observational constraints, conceptual difficulties and numerical limitations have all concurred to prevent a detailed understanding of the supergranulation phenomenon so far. With the advent of 21st century supercomputing resources and the availability of unprecedented high-resolution observations of the Sun, a stage at which key progress can be made has now been reached. A unifying strategy between observations and modelling is more than ever required for this to be possible.
The primary aim of this review is therefore to provide readers with a detailed interdisciplinary description of past and current research on the problem, from the most elaborate observational strategies to recent theoretical and numerical modelling efforts that have all taken up the challenge of uncovering the origins of supergranulation. Throughout the text, we attempt to pick up the most robust findings so far, but we also outline the difficulties, limitations and open questions that the community has been confronted with over the years.
In the light of the current understanding of the multiscale dynamics of the quiet photosphere, we finally suggest a tentative picture of supergranulation as a dynamical feature of turbulent magnetohydrodynamic convection in an extended spatial domain, with the aim of stimulating future research and discussions.
太阳的超粒是指覆盖在安静太阳表面的物理模式,其典型的水平尺度约为30,000公里,寿命约为1.8 d。其最显著的可观测特征是360 m st-1 rms的波动速度场,其组成部分主要是水平的。超粒现象早在50多年前就被发现了,然而解释它的起源和原因仍然是现代太阳物理学的主要挑战之一。多年来,人们对这个问题进行了大量的研究,但迄今为止,观测上的限制、概念上的困难和数值上的限制都阻碍了对超粒现象的详细理解。随着21世纪超级计算资源的出现和对太阳前所未有的高分辨率观测的可用性,现在已经达到了可以取得关键进展的阶段。观测和建模之间的统一策略比以往任何时候都更有可能实现。因此,本综述的主要目的是为读者提供过去和当前对该问题的研究的详细跨学科描述,从最详细的观察策略到最近的理论和数值模拟努力,这些努力都接受了揭示超颗粒起源的挑战。在整个文本中,我们试图挑选迄今为止最有力的发现,但我们也概述了困难,限制和开放的问题,该社区多年来一直面临。根据目前对安静光球的多尺度动力学的理解,我们最后提出了超颗粒作为湍流磁流体动力对流在扩展空间域中的动力学特征的初步图景,旨在促进未来的研究和讨论。
期刊介绍:
Living Reviews in Solar Physics, a platinum open-access journal, publishes invited reviews covering research across all areas of solar and heliospheric physics. It distinguishes itself by maintaining a collection of high-quality reviews regularly updated by the authors. Established in 2004, it was founded by the Max Planck Institute for Solar System Research (MPS). "Living Reviews®" is a registered trademark of Springer International Publishing AG.