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A history of solar activity over millennia 太阳活动几千年的历史
IF 20.9 1区 物理与天体物理 Pub Date : 2023-05-05 DOI: 10.1007/s41116-023-00036-z
Ilya G. Usoskin

Here we review present knowledge of the long-term behaviour of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the dedicated indices used to quantify different aspects of variable solar activity, with special emphasis on sunspot numbers. Over long timescales, quantitative information about past solar activity is historically obtained using a method based on indirect proxies, such as cosmogenic isotopes (^{14})C and (^{10})Be in natural stratified archives (e.g., tree rings or ice cores). We give a historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state of the art. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that the method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene (the past (sim )12 millennia). A separate section is devoted to reconstructions of extremely rare solar eruptive events in the past, based on both cosmogenic-proxy data in terrestrial and lunar natural archives, as well as statistics of sun-like stars. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.

在这里,我们回顾了目前关于太阳活动在几千年时间尺度上的长期行为的知识,这些知识是用间接代理方法重建的。讨论了太阳活动的概念,并概述了用于量化可变太阳活动不同方面的专用指数,特别强调了太阳黑子数。在较长的时间尺度上,过去太阳活动的定量信息是历史上使用基于间接代理的方法获得的,例如宇宙成因同位素(^{14}) C和(^{10}) Be在自然分层档案中(例如,树木年轮或冰芯)。我们对几千年来基于代理的太阳活动重建方法的发展进行了历史概述,并对现代技术状况进行了描述。特别注意重建的验证和交叉校准。有人认为,宇宙成因同位素的方法为研究全新世((sim )过去12000年)过去很长时间尺度(几百年到几千年)的太阳变化奠定了坚实的基础。一个单独的部分致力于重建过去极其罕见的太阳爆发事件,基于地球和月球自然档案中的宇宙成因代理数据,以及类太阳恒星的统计数据。最后,总结了太阳磁活动长期演变的主要特征,包括极大极小期和极大极小期的统计数据,并讨论了它们可能的意义,特别是对太阳/恒星发电机理论的意义。
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引用次数: 177
Surface and interior meridional circulation in the Sun 太阳的表面和内部经向环流
IF 23 1区 物理与天体物理 Pub Date : 2022-07-15 DOI: 10.1007/s41116-022-00034-7
Shravan M. Hanasoge

Solar meridional circulation is an axisymmetric flow system, extending from the equator to the poles ((sim )20 m/s at the surface, (approx )1% of the mean solar rotation rate), plunging inwards and subsequently completing the circuit in the interior through an equatorward return flow and a radially outward flow back up to the surface. This article reviews the profound role that meridional circulation plays in maintaining global dynamics and regulating large-scale solar magnetism. Because it is relatively weak in comparison to differential rotation ((sim )300 m/s, (approx )7% of the mean solar rotation rate) and owing to numerous systematical errors, accurate surface measurements were only first made in 1978 and initial inferences of interior meridional circulation were obtained using helioseismology two decades later. However, systematical biases have made it very challenging to reliably recover flow in the deep interior. Despite numerous advances that have served to improve the accuracy of inferences, the location of the return flow and the full extent of the circulation are still open problems. This article follows the historical developments and summarises contemporary advances that have led to modern inferences of surface and interior meridional flow.

太阳经向环流是一个轴对称的流动系统,从赤道向两极延伸((sim )地表20 m/s, (approx ) 1)% of the mean solar rotation rate), plunging inwards and subsequently completing the circuit in the interior through an equatorward return flow and a radially outward flow back up to the surface. This article reviews the profound role that meridional circulation plays in maintaining global dynamics and regulating large-scale solar magnetism. Because it is relatively weak in comparison to differential rotation ((sim )300 m/s, (approx )7% of the mean solar rotation rate) and owing to numerous systematical errors, accurate surface measurements were only first made in 1978 and initial inferences of interior meridional circulation were obtained using helioseismology two decades later. However, systematical biases have made it very challenging to reliably recover flow in the deep interior. Despite numerous advances that have served to improve the accuracy of inferences, the location of the return flow and the full extent of the circulation are still open problems. This article follows the historical developments and summarises contemporary advances that have led to modern inferences of surface and interior meridional flow.
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引用次数: 0
Magnetic fields in the solar convection zone 太阳对流区的磁场
IF 23 1区 物理与天体物理 Pub Date : 2021-11-03 DOI: 10.1007/s41116-021-00031-2
Yuhong Fan

It has been a prevailing picture that active regions on the solar surface originate from a strong toroidal magnetic field stored in the overshoot region at the base of the solar convection zone, generated by a deep seated solar dynamo mechanism. This article reviews the studies in regard to how the toroidal magnetic field can destabilize and rise through the convection zone to form the observed solar active regions at the surface. Furthermore, new results from the global simulations of the convective dynamos, and from the near-surface layer simulations of active region formation, together with helioseismic investigations of the pre-emergence active regions, are calling into question the picture of active regions as buoyantly rising flux tubes originating from the bottom of the convection zone. This article also gives a review on these new developments.

一种流行的观点认为,太阳表面的活动区域是由深层太阳发电机机制产生的,储存在太阳对流区底部超调区域的强环形磁场引起的。本文综述了环向磁场如何在对流区不稳定和上升,从而在地表形成观测到的太阳活动区的研究。此外,对对流发电机的全球模拟和对活动区域形成的近地表模拟的新结果,以及对出现前活动区域的日震调查,都对活动区域是源自对流区底部的浮力上升通量管的说法提出了质疑。本文还对这些新进展作了综述。
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引用次数: 0
Space weather: the solar perspective 太空天气:太阳的视角
IF 20.9 1区 物理与天体物理 Pub Date : 2021-06-29 DOI: 10.1007/s41116-021-00030-3
Manuela Temmer

The Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mission (launched in 2006), literally, new perspectives were provided that enabled for the first time to study coronal structures and the evolution of activity phenomena in three dimensions. New imaging capabilities, covering the entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their interplanetary counterparts measured in-situ (so called ICMEs). This vastly increased our knowledge and understanding of the dynamics of interplanetary space due to solar activity and fostered the development of Space Weather forecasting models. Moreover, we are facing challenging times gathering new data from two extraordinary missions, NASA’s Parker Solar Probe (launched in 2018) and ESA’s Solar Orbiter (launched in 2020), that will in the near future provide more detailed insight into the solar wind evolution and image CMEs from view points never approached before. The current review builds upon the Living Reviews article by Schwenn from 2006, updating on the Space Weather relevant CME-flare-SEP phenomena from the solar perspective, as observed from multiple viewpoints and their concomitant solar surface signatures.

太阳,作为一颗活跃的恒星,是构成行星际空间和影响行星大气的能量现象的驱动者。随着人类航天飞行为月球和火星任务做准备,空间天气对地球和太阳系的影响越来越重要。本文综述了太阳视角下的空间天气相关现象,包括日冕物质抛射(cme)、耀斑、太阳高能粒子(sep)和太阳风流相互作用区(SIR)。随着STEREO任务(2006年发射)的到来,从字面上讲,提供了新的视角,使我们第一次能够在三维空间上研究日冕结构和活动现象的演变。新的成像能力,覆盖整个太阳-地球距离范围,可以无缝连接日冕物质抛射和他们的行星际对应的原位测量(所谓的ICMEs)。这极大地增加了我们对太阳活动引起的行星际空间动力学的认识和理解,并促进了空间天气预报模型的发展。此外,我们正面临着从两个非凡的任务中收集新数据的挑战,美国宇航局的帕克太阳探测器(2018年发射)和欧洲航天局的太阳轨道飞行器(2020年发射),这将在不久的将来提供更详细的太阳风演化信息,并从从未接近过的视角拍摄cme图像。当前的评论建立在2006年Schwenn的生活评论文章的基础上,从太阳的角度更新了空间天气相关的日冕物质抛射-耀斑- sep现象,从多个角度观察到它们伴随的太阳表面特征。
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引用次数: 64
The evolution of the solar wind 太阳风的演变
IF 20.9 1区 物理与天体物理 Pub Date : 2021-04-26 DOI: 10.1007/s41116-021-00029-w
Aline A. Vidotto

How has the solar wind evolved to reach what it is today? In this review, I discuss the long-term evolution of the solar wind, including the evolution of observed properties that are intimately linked to the solar wind: rotation, magnetism and activity. Given that we cannot access data from the solar wind 4 billion years ago, this review relies on stellar data, in an effort to better place the Sun and the solar wind in a stellar context. I overview some clever detection methods of winds of solar-like stars, and derive from these an observed evolutionary sequence of solar wind mass-loss rates. I then link these observational properties (including, rotation, magnetism and activity) with stellar wind models. I conclude this review then by discussing implications of the evolution of the solar wind on the evolving Earth and other solar system planets. I argue that studying exoplanetary systems could open up new avenues for progress to be made in our understanding of the evolution of the solar wind.

太阳风是如何演变成今天的样子的?在这篇综述中,我讨论了太阳风的长期演变,包括与太阳风密切相关的观测性质的演变:旋转、磁性和活动。鉴于我们无法获得40亿年前太阳风的数据,这项研究依赖于恒星数据,以更好地将太阳和太阳风置于恒星背景下。本文概述了一些探测类太阳恒星风的巧妙方法,并由此推导出观测到的太阳风质量损失率的演化序列。然后,我将这些观测特性(包括旋转、磁性和活动)与恒星风模型联系起来。最后,我将讨论太阳风的演化对演化中的地球和其他太阳系行星的影响。我认为,研究系外行星系统可以为我们理解太阳风的演变开辟新的途径。
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引用次数: 36
Solar structure and evolution 太阳的结构和演化
IF 20.9 1区 物理与天体物理 Pub Date : 2021-04-26 DOI: 10.1007/s41116-020-00028-3
Jørgen Christensen-Dalsgaard

The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.

太阳为恒星结构和演化的一般研究提供了一个关键的基准。此外,关于太阳内部特性的知识对于理解太阳大气现象(包括太阳磁周期)也很重要。在这里,我简要概述了恒星结构和演化的理论,包括所涉及的物理过程和参数。接下来是对太阳演化的讨论,从诞生到最新阶段。作为解释与太阳内部有关的观测的背景,我对太阳模型对其计算所依据的假设的敏感性进行了相当广泛的分析。然后,我将讨论通过日震调查和太阳中微子探测获得的关于太阳内部的详细信息,以及观测到的最轻元素的丰度所提供的进一步限制。对太阳表面丰度测定的修正导致观测推断和太阳模式之间的差异增加,这在一些细节上已经讨论过。最后,我简要地介绍了太阳与其他类似恒星的关系,以及恒星结构和演化的星震研究的前景。
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引用次数: 6
Solar force-free magnetic fields 没有太阳力的磁场
IF 20.9 1区 物理与天体物理 Pub Date : 2021-01-11 DOI: 10.1007/s41116-020-00027-4
Thomas Wiegelmann, Takashi Sakurai

The structure and dynamics of the solar corona is dominated by the magnetic field. In most areas in the corona magnetic forces are so dominant that all non-magnetic forces such as plasma pressure gradients and gravity can be neglected in the lowest order. This model assumption is called the force-free field assumption, as the Lorentz force vanishes. This can be obtained by either vanishing electric currents (leading to potential fields) or the currents are co-aligned with the magnetic field lines. First we discuss a mathematically simpler approach that the magnetic field and currents are proportional with one global constant, the so-called linear force-free field approximation. In the generic case, however, the relationship between magnetic fields and electric currents is nonlinear and analytic solutions have been only found for special cases, like 1D or 2D configurations. For constructing realistic nonlinear force-free coronal magnetic field models in 3D, sophisticated numerical computations are required and boundary conditions must be obtained from measurements of the magnetic field vector in the solar photosphere. This approach is currently a large area of research, as accurate measurements of the photospheric field are available from ground-based observatories such as the Synoptic Optical Long-term Investigations of the Sun and the Daniel K. Inouye Solar Telescope (DKIST) and space-born, e.g., from Hinode and the Solar Dynamics Observatory. If we can obtain accurate force-free coronal magnetic field models we can calculate the free magnetic energy in the corona, a quantity which is important for the prediction of flares and coronal mass ejections. Knowledge of the 3D structure of magnetic field lines also help us to interpret other coronal observations, e.g., EUV images of the radiating coronal plasma.

日冕的结构和动力学是由磁场控制的。在日冕的大多数区域,磁力是如此的占主导地位,以至于所有的非磁力,如等离子体压力梯度和重力,在最低的顺序上可以忽略不计。这个模型假设被称为无力场假设,因为洛伦兹力消失了。这可以通过电流消失(导致势场)或电流与磁力线共向来获得。首先,我们讨论一种数学上更简单的方法,即磁场和电流与一个全局常数成正比,即所谓的线性无力场近似。然而,在一般情况下,磁场和电流之间的关系是非线性的,解析解只适用于特殊情况,如一维或二维构型。为了构建真实的三维非线性无力日冕磁场模型,需要进行复杂的数值计算,并且必须从太阳光球的磁场矢量测量中获得边界条件。这种方法目前是一个很大的研究领域,因为对光球场的精确测量可以从地面观测站获得,比如太阳综合光学长期研究和丹尼尔·k·井上太阳望远镜(DKIST),也可以从太空观测站获得,比如从日野和太阳动力学观测站。如果我们能得到精确的无力日冕磁场模型,我们就能计算出日冕中的自由磁能,这是预测耀斑和日冕物质抛射的重要量。对磁力线三维结构的了解也有助于我们解释其他日冕观测,例如辐射日冕等离子体的EUV图像。
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引用次数: 32
Radiation hydrodynamics in simulations of the solar atmosphere 太阳大气模拟中的辐射流体动力学
IF 20.9 1区 物理与天体物理 Pub Date : 2020-03-23 DOI: 10.1007/s41116-020-0024-x
Jorrit Leenaarts

Nearly all energy generated by fusion in the solar core is ultimately radiated away into space in the solar atmosphere, while the remaining energy is carried away in the form of neutrinos. The exchange of energy between the solar gas and the radiation field is thus an essential ingredient of atmospheric modeling. The equations describing these interactions are known, but their solution is so computationally expensive that they can only be solved in approximate form in multi-dimensional radiation-MHD modeling. In this review, I discuss the most commonly used approximations for energy exchange between gas and radiation in the photosphere, chromosphere, and corona.

太阳核心聚变产生的几乎所有能量最终都被辐射到太阳大气中的太空中,而剩余的能量则以中微子的形式被带走。因此,太阳气体和辐射场之间的能量交换是大气模拟的重要组成部分。描述这些相互作用的方程是已知的,但它们的解在计算上是如此昂贵,以至于它们只能在多维辐射mhd模型中以近似形式求解。在这篇综述中,我讨论了光球、色球和日冕中气体和辐射之间能量交换的最常用的近似。
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引用次数: 20
Solar structure and evolution 太阳的结构和演化
IF 20.9 1区 物理与天体物理 Pub Date : 2020-02-28 DOI: 10.1002/9783527412723.ch2
J. Christensen-Dalsgaard
The Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.
太阳为恒星结构和演化的一般研究提供了一个重要的基准。此外,了解太阳的内部性质对于理解太阳大气现象(包括太阳磁循环)也很重要。在这里,我简要介绍了恒星结构和演化理论,包括所涉及的物理过程和参数。接下来是关于太阳演化的讨论,从诞生一直延续到最新阶段。作为解释与太阳内部有关的观测结果的背景,我对太阳模型对其计算所依据的假设的敏感性进行了相当广泛的分析。然后,我讨论了通过太阳地震调查和太阳中微子探测获得的关于太阳内部的详细信息,以及观测到的最轻元素丰度所提供的进一步限制。对太阳表面丰度测定的修正导致观测推断和太阳模型之间的差异增加,对此进行了详细讨论。最后,我简要介绍了太阳与其他类似恒星的关系,以及恒星结构和演化的星震研究前景。
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引用次数: 26
Historical sunspot records 历史太阳黑子记录
IF 20.9 1区 物理与天体物理 Pub Date : 2020-02-26 DOI: 10.1007/s41116-020-0023-y
Rainer Arlt, José M. Vaquero

Sunspot observations are available in fairly good numbers since 1610, after the invention of the telescope. This review is concerned with those sunspot observations of which longer records and drawings in particular are available. Those records bear information beyond the classical sunspot numbers or group sunspot numbers. We begin with a brief summary on naked-eye sunspot observations, in particular those with drawings. They are followed by the records of drawings from 1610 to about 1900. The review is not a compilation of all known historical sunspot information. Some records contributing substantially to the sunspot number time series may therefore be absent. We also glance at the evolution of the understanding of what sunspots actually are, from 1610 to the 19th century. The final part of the review illuminates the physical quantities that can be derived from historical drawings.

自从1610年望远镜发明之后,太阳黑子的观测数据就相当可观了。这篇综述是关于太阳黑子观测的,特别是有更长的记录和图纸。这些记录包含的信息超出了经典的太阳黑子数或太阳黑子群数。我们首先简要总结一下裸眼观测太阳黑子,特别是那些有图纸的观测。其后是1610年至1900年左右的绘画记录。这篇综述并不是所有已知的历史太阳黑子信息的汇编。因此,一些对太阳黑子数时间序列有重大贡献的记录可能不存在。我们还回顾了从1610年到19世纪对太阳黑子的理解的演变。回顾的最后一部分阐明了可以从历史图纸中得出的物理量。
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引用次数: 72
期刊
Living Reviews in Solar Physics
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