Living Reviews in Solar Physics最新文献_第2页

Solar prominences: theory and models 太阳日珥:理论和模型

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2018-10-22 DOI: 10.1007/s41116-018-0016-2

Sarah E. Gibson

引用次数: 70

The Sun’s supergranulation 太阳的超颗粒

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2018-09-10 DOI: 10.1007/s41116-018-0013-5

François Rincon, Michel Rieutord

{"title":"The Sun’s supergranulation","authors":"François Rincon, Michel Rieutord","doi":"10.1007/s41116-018-0013-5","DOIUrl":"https://doi.org/10.1007/s41116-018-0013-5","url":null,"abstract":"Supergranulation is a fluid-dynamical phenomenon taking place in the solar photosphere, primarily detected in the form of a vigorous cellular flow pattern with a typical horizontal scale of approximately 30–35?Mm, a dynamical evolution time of 24–48?h, a strong 300–400?m/s (rms) horizontal flow component and a much weaker 20–30?m/s vertical component. Supergranulation was discovered more than 60?years ago, however, explaining its physical origin and most important observational characteristics has proven extremely challenging ever since, as a result of the intrinsic multiscale, nonlinear dynamical complexity of the problem concurring with strong observational and computational limitations. Key progress on this problem is now taking place with the advent of twenty-first-century supercomputing resources and the availability of global observations of the dynamics of the solar surface with high spatial and temporal resolutions. This article provides an exhaustive review of observational, numerical and theoretical research on supergranulation, and discusses the current status of our understanding of its origin and dynamics, most importantly in terms of large-scale nonlinear thermal convection, in the light of a selection of recent findings.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"15 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-018-0013-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4439547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 57

Space–time structure and wavevector anisotropy in space plasma turbulence 空间等离子体湍流中的时空结构和波矢量各向异性

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2018-02-21 DOI: 10.1007/s41116-017-0010-0

Yasuhito Narita

{"title":"Space–time structure and wavevector anisotropy in space plasma turbulence","authors":"Yasuhito Narita","doi":"10.1007/s41116-017-0010-0","DOIUrl":"https://doi.org/10.1007/s41116-017-0010-0","url":null,"abstract":"Space and astrophysical plasmas often develop into a turbulent state and exhibit nearly random and stochastic motions. While earlier studies emphasize more on understanding the energy spectrum of turbulence in the one-dimensional context (either in the frequency or the wavenumber domain), recent achievements in plasma turbulence studies provide an increasing amount of evidence that plasma turbulence is essentially a spatially and temporally evolving phenomenon. This review presents various models for the space–time structure and anisotropy of the turbulent fields in space plasmas, or equivalently the energy spectra in the wavenumber–frequency domain for the space–time structures and that in the wavevector domain for the anisotropies. The turbulence energy spectra are evaluated in different one-dimensional spectral domains; one speaks of the frequency spectra in the spacecraft observations and the wavenumber spectra in the numerical simulation studies. The notion of the wavenumber–frequency spectrum offers a more comprehensive picture of the turbulent fields, and good models can explain the one-dimensional spectra in the both domains at the same time. To achieve this goal, the Doppler shift, the Doppler broadening, linear-mode dispersion relations, and sideband waves are reviewed. The energy spectra are then extended to the wavevector domain spanning the directions parallel and perpendicular to the large-scale magnetic field. By doing so, the change in the spectral index at different projections onto the one-dimensional spectral domain can be explained in a simpler way.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"15 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2018-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-017-0010-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4815383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Coronal mass ejections and their sheath regions in interplanetary space 行星际空间的日冕物质抛射及其鞘层区域

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2017-11-24 DOI: 10.1007/s41116-017-0009-6

Emilia Kilpua, Hannu E. J. Koskinen, Tuija I. Pulkkinen

{"title":"Coronal mass ejections and their sheath regions in interplanetary space","authors":"Emilia Kilpua, Hannu E. J. Koskinen, Tuija I. Pulkkinen","doi":"10.1007/s41116-017-0009-6","DOIUrl":"https://doi.org/10.1007/s41116-017-0009-6","url":null,"abstract":"Interplanetary coronal mass ejections (ICMEs) are large-scale heliospheric transients that originate from the Sun. When an ICME is sufficiently faster than the preceding solar wind, a shock wave develops ahead of the ICME. The turbulent region between the shock and the ICME is called the sheath region. ICMEs and their sheaths and shocks are all interesting structures from the fundamental plasma physics viewpoint. They are also key drivers of space weather disturbances in the heliosphere and planetary environments. ICME-driven shock waves can accelerate charged particles to high energies. Sheaths and ICMEs drive practically all intense geospace storms at the Earth, and they can also affect dramatically the planetary radiation environments and atmospheres. This review focuses on the current understanding of observational signatures and properties of ICMEs and the associated sheath regions based on five decades of studies. In addition, we discuss modelling of ICMEs and many fundamental outstanding questions on their origin, evolution and effects, largely due to the limitations of single spacecraft observations of these macro-scale structures. We also present current understanding of space weather consequences of these large-scale solar wind structures, including effects at the other Solar System planets and exoplanets. We specially emphasize the different origin, properties and consequences of the sheaths and ICMEs.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"14 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2017-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-017-0009-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4951102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 234

Magnetism, dynamo action and the solar-stellar connection 磁力，发电机作用和太阳-恒星的联系

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2017-09-26 DOI: 10.1007/s41116-017-0007-8

Allan Sacha Brun, Matthew K. Browning

{"title":"Magnetism, dynamo action and the solar-stellar connection","authors":"Allan Sacha Brun, Matthew K. Browning","doi":"10.1007/s41116-017-0007-8","DOIUrl":"https://doi.org/10.1007/s41116-017-0007-8","url":null,"abstract":"The Sun and other stars are magnetic: magnetism pervades their interiors and affects their evolution in a variety of ways. In the Sun, both the fields themselves and their influence on other phenomena can be uncovered in exquisite detail, but these observations sample only a moment in a single star’s life. By turning to observations of other stars, and to theory and simulation, we may infer other aspects of the magnetism—e.g., its dependence on stellar age, mass, or rotation rate—that would be invisible from close study of the Sun alone. Here, we review observations and theory of magnetism in the Sun and other stars, with a partial focus on the “Solar-stellar connection”: i.e., ways in which studies of other stars have influenced our understanding of the Sun and vice versa. We briefly review techniques by which magnetic fields can be measured (or their presence otherwise inferred) in stars, and then highlight some key observational findings uncovered by such measurements, focusing (in many cases) on those that offer particularly direct constraints on theories of how the fields are built and maintained. We turn then to a discussion of how the fields arise in different objects: first, we summarize some essential elements of convection and dynamo theory, including a very brief discussion of mean-field theory and related concepts. Next we turn to simulations of convection and magnetism in stellar interiors, highlighting both some peculiarities of field generation in different types of stars and some unifying physical processes that likely influence dynamo action in general. We conclude with a brief summary of what we have learned, and a sampling of issues that remain uncertain or unsolved.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"14 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2017-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-017-0007-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5022765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 156

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

Living Reviews in Solar Physics Pub Date : 2017-03-04 DOI: 10.1007/s41116-017-0006-9

Ilya G. Usoskin

{"title":"A history of solar activity over millennia","authors":"Ilya G. Usoskin","doi":"10.1007/s41116-017-0006-9","DOIUrl":"https://doi.org/10.1007/s41116-017-0006-9","url":null,"abstract":"Presented here is a review of present knowledge of the long-term behavior 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 special indices used to quantify different aspects of variable solar activity, with special emphasis upon sunspot number. Over long timescales, quantitative information about past solar activity can only be obtained using a method based upon indirect proxies, such as the cosmogenic isotopes (^{14})C and (^{10})Be in natural stratified archives (e.g., tree rings or ice cores). We give an 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. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that this 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. A separate section is devoted to reconstructions of strong solar energetic-particle (SEP) events in the past, that suggest that the present-day average SEP flux is broadly consistent with estimates on longer timescales, and that the occurrence of extra-strong events is unlikely. 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.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"14 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2017-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-017-0006-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4175120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 210

Flare Observations 耀斑的观察

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2016-12-09 DOI: 10.1007/s41116-016-0004-3

Arnold O. Benz

{"title":"Flare Observations","authors":"Arnold O. Benz","doi":"10.1007/s41116-016-0004-3","DOIUrl":"https://doi.org/10.1007/s41116-016-0004-3","url":null,"abstract":"Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1?GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150?years since their discovery, remain a complex problem of astrophysics including major unsolved questions.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"14 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2016-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41116-016-0004-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4371241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 368

Solar Coronal Plumes 太阳日冕羽

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2015-12-01 DOI: 10.1007/lrsp-2015-7

Giannina Poletto

{"title":"Solar Coronal Plumes","authors":"Giannina Poletto","doi":"10.1007/lrsp-2015-7","DOIUrl":"https://doi.org/10.1007/lrsp-2015-7","url":null,"abstract":"Polar plumes are thin long ray-like structures that project beyond the limb of the Sun polar regions, maintaining their identity over distances of several solar radii. Plumes have been first observed in white-light (WL) images of the Sun, but, with the advent of the space era, they have been identified also in X-ray and UV wavelengths (XUV) and, possibly, even in in situ data. This review traces the history of plumes, from the time they have been first imaged, to the complex means by which nowadays we attempt to reconstruct their 3-D structure. Spectroscopic techniques allowed us also to infer the physical parameters of plumes and estimate their electron and kinetic temperatures and their densities. However, perhaps the most interesting problem we need to solve is the role they cover in the solar wind origin and acceleration: Does the solar wind emanate from plumes or from the ambient coronal hole wherein they are embedded? Do plumes have a role in solar wind acceleration and mass loading? Answers to these questions are still somewhat ambiguous and theoretical modeling does not provide definite answers either. Recent data, with an unprecedented high spatial and temporal resolution, provide new information on the fine structure of plumes, their temporal evolution and relationship with other transient phenomena that may shed further light on these elusive features.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"12 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/lrsp-2015-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4014297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 34

Solar Magnetism in the Polar Regions 极地地区的太阳磁性

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2015-11-05 DOI: 10.1007/lrsp-2015-5

Gordon J. D. Petrie

{"title":"Solar Magnetism in the Polar Regions","authors":"Gordon J. D. Petrie","doi":"10.1007/lrsp-2015-5","DOIUrl":"https://doi.org/10.1007/lrsp-2015-5","url":null,"abstract":"This review describes observations of the polar magnetic fields, models for the cyclical formation and decay of these fields, and evidence of their great influence in the solar atmosphere. The polar field distribution dominates the global structure of the corona over most of the solar cycle, supplies the bulk of the interplanetary magnetic field via the polar coronal holes, and is believed to provide the seed for the creation of the activity cycle that follows. A broad observational knowledge and theoretical understanding of the polar fields is therefore an essential step towards a global view of solar and heliospheric magnetic fields. Analyses of both high-resolution and long-term synoptic observations of the polar fields are summarized. Models of global flux transport are reviewed, from the initial phenomenological and kinematic models of Babcock and Leighton to present-day attempts to produce time-dependent maps of the surface magnetic field and to explain polar field variations, including the weakness of the cycle 23 polar fields. The relevance of the polar fields to solar physics extends far beyond the surface layers from which the magnetic field measurements usually derive. As well as discussing the polar fields’ role in the interior as seed fields for new solar cycles, the review follows their influence outward to the corona and heliosphere. The global coronal magnetic structure is determined by the surface magnetic flux distribution, and is dominated on large scales by the polar fields. We discuss the observed effects of the polar fields on the coronal hole structure, and the solar wind and ejections that travel through the atmosphere. The review concludes by identifying gaps in our knowledge, and by pointing out possible future sources of improved observational information and theoretical understanding of these fields.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"12 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2015-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/lrsp-2015-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4223839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 73

Large-scale Globally Propagating Coronal Waves 大规模全球传播的日冕波

IF 20.9 1区物理与天体物理

Living Reviews in Solar Physics Pub Date : 2015-09-18 DOI: 10.1007/lrsp-2015-3

Alexander Warmuth

{"title":"Large-scale Globally Propagating Coronal Waves","authors":"Alexander Warmuth","doi":"10.1007/lrsp-2015-3","DOIUrl":"https://doi.org/10.1007/lrsp-2015-3","url":null,"abstract":"Large-scale, globally propagating wave-like disturbances have been observed in the solar chromosphere and by inference in the corona since the 1960s. However, detailed analysis of these phenomena has only been conducted since the late 1990s. This was prompted by the availability of high-cadence coronal imaging data from numerous spaced-based instruments, which routinely show spectacular globally propagating bright fronts. Coronal waves, as these perturbations are usually referred to, have now been observed in a wide range of spectral channels, yielding a wealth of information. Many findings have supported the “classical” interpretation of the disturbances: fast-mode MHD waves or shocks that are propagating in the solar corona. However, observations that seemed inconsistent with this picture have stimulated the development of alternative models in which “pseudo waves” are generated by magnetic reconfiguration in the framework of an expanding coronal mass ejection. This has resulted in a vigorous debate on the physical nature of these disturbances. This review focuses on demonstrating how the numerous observational findings of the last one and a half decades can be used to constrain our models of large-scale coronal waves, and how a coherent physical understanding of these disturbances is finally emerging.","PeriodicalId":687,"journal":{"name":"Living Reviews in Solar Physics","volume":"12 1","pages":""},"PeriodicalIF":20.9,"publicationDate":"2015-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/lrsp-2015-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4735882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 132