Large-scale 3D MHD simulation on the solar flux emergence and the small-scale dynamic features in an active region

Toriumi, Shin; Yokoyama, T.

doi:10.1051/0004-6361/201118009

Cited by 23 publications

(14 citation statements)

References 21 publications

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“…Figure 3 shows the evolution of the magnetogram at z/H 0 = 0 and magnetic field lines for the Reference case (movie is attached to provide detailed evolution). The whole evolution is consistent with the previous 3D simulations by, e.g., Fan (2001), Archontis et al (2004), and Toriumi & Yokoyama (2012): the horizontal flux tube makes an Ω-shaped arcade, which rises through the convection zone and eventually penetrate the photosphere, creating a magnetic dome in the corona with bipolar spots in the photosphere.…”

Section: Numerical Conditions and The Reference Casesupporting

confidence: 90%

Numerical Simulations of Flare-productive Active Regions: δ-sunspots, Sheared Polarity Inversion Lines, Energy Storage, and Predictions

Toriumi

Takasao

2017

ApJ

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Solar active regions (ARs) that produce strong flares and coronal mass ejections (CMEs) are known to have a relatively high non-potentiality and are characterized by δ-sunspots and sheared magnetic structures. In this study, we conduct a series of flux emergence simulations from the convection zone to the corona and model four types of active regions that have been observationally suggested to cause strong flares, namely the Spot-Spot, Spot-Satellite, Quadrupole, and Inter-AR cases. As a result, we confirm that δ-spot formation is due to the complex geometry and interaction of emerging magnetic fields, with finding that the strong-field, high-gradient, highly-sheared polarity inversion line (PIL) is created by the combined effect of the advection, stretching, and compression of magnetic fields. We show that free magnetic energy builds up in the form of a current sheet above the PIL. It is also revealed that photospheric magnetic parameters that predict flare eruptions reflect the stored free energy with high accuracy, while CME-predicting parameters indicate the magnetic relationship between flaring zones and entire ARs.

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Section: Numerical Conditions and The Reference Casesupporting

confidence: 90%

Numerical Simulations of Flare-productive Active Regions: δ-sunspots, Sheared Polarity Inversion Lines, Energy Storage, and Predictions

Toriumi

Takasao

2017

ApJ

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“…Also, in the simulations, the final separation of two outer polarities reached 100H 0 = 17 Mm, which is one order of magnitude smaller than the 115 Mm observed in AR 11158. Toriumi and Yokoyama (2012;) may give us a suggestion for the situation when we expand the simulation box. They found that, even when the initial flux tube is located at −20 Mm, i.e.…”

Section: Discussionmentioning

confidence: 99%

Formation of a Flare-Productive Active Region: Observation and Numerical Simulation of NOAA AR 11158

et al. 2014

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We present a comparison of the Solar Dynamics Observatory (SDO) analysis of NOAA Active Region (AR) 11158 and numerical simulations of flux-tube emergence, aiming to investigate the formation process of the flareproductive AR. First, we use SDO/Helioseismic and Magnetic Imager (HMI) magnetograms to investigate the photospheric evolution and Atmospheric Imaging Assembly (AIA) data to analyze the relevant coronal structures. Key features of this quadrupolar region are a long sheared polarity inversion line (PIL) in the central δ-sunspots and a coronal arcade above the PIL. We find that these features are responsible for the production of intense flares including an X2.2-class event. Based on the observations, we then propose two possible models for the creation of AR 11158 and conduct flux emergence simulations of the two cases to reproduce this AR. Case 1 is the emergence of a single flux tube, which is split into two in the convection zone and emerges at two locations, while Case 2 is the emergence of two isolated but neighboring tubes. We find that, in Case 1, a sheared PIL and a coronal arcade are created in the middle of the region, which agrees with the AR 11158 observation. However, Case 2 never build a clear PIL, which deviates from the observation. Therefore, we conclude that the flare-productive AR 11158 is, between the two cases, more likely to be created from a single split emerging flux than two independent flux bundles.

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“…Note that the Parker instability has been seen in numerical simulations. 408,409 The above discussion identifies three major predictions for the photospheric signatures of poloidal flux injection: (1) the injected poloidal field emerges through the photosphere in the form of filamentary undular structures on small scales, (2) such serpentine field can reconnect in the photosphere and below, continually "shedding" the dense material as a magnetic structure rises, and (3) the induced current J p due to E h , Eq. (51), is essential in the magnetic flux budget and its measurement.…”

Section: -44mentioning

confidence: 99%

Physics of erupting solar flux ropes: Coronal mass ejections (CMEs)—Recent advances in theory and observation

Chen

2017

Physics of Plasmas

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Solar eruptions, observed as flares and coronal mass ejections (CMEs), are the most energetic visible plasma phenomena in the solar system. CMEs are the central component of solar eruptions and are detected as coherent magnetized plasma structures expanding in the solar wind (SW). If they reach the Earth, their magnetic fields can drive strong disturbances in the ionosphere, causing deleterious effects on terrestrial technological systems. The scientific and practical importance of CMEs has led to numerous satellite missions observing the Sun and SW. This has culminated in the ability to continuously observe CMEs expanding from the Sun to 1 AU, where the magnetic fields and plasma parameters of the evolved structures ("ejecta") can be measured in situ. Until recently, the physical mechanisms responsible for eruptions were major unanswered questions in solar and by extension stellar physics. New observations of CME dynamics and associated eruptive phenomena are now providing more stringent constraints on models, and quantitative theory-data comparisons are helping to establish the correct mechanism of solar eruptions, particularly the driving force of CMEs and the evolution of their magnetic fields in three dimensions. Recent work has demonstrated that theoretical results can simultaneously replicate the observed CME position-time data, temporal profiles of associated solar flare soft X-ray emissions, and the magnetic field and plasma parameters of CME ejecta measured at 1 AU. Thus, a new theoretical framework with testable predictions is emerging to model eruptions and the coupling of CME ejecta to geomagnetic disturbances. The key physics in CME dynamics is the Lorentz hoop force acting on toroidal "flux ropes," scalable from tokamaks and similar laboratory plasma structures. The present paper reviews the latest advances in observational and theoretical understanding of CMEs with the emphasis on quantitative comparisons of theory and observation. Published by AIP Publishing.

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Large-scale 3D MHD simulation on the solar flux emergence and the small-scale dynamic features in an active region

Cited by 23 publications

References 21 publications

Numerical Simulations of Flare-productive Active Regions: δ-sunspots, Sheared Polarity Inversion Lines, Energy Storage, and Predictions

Numerical Simulations of Flare-productive Active Regions: δ-sunspots, Sheared Polarity Inversion Lines, Energy Storage, and Predictions

Formation of a Flare-Productive Active Region: Observation and Numerical Simulation of NOAA AR 11158

Physics of erupting solar flux ropes: Coronal mass ejections (CMEs)—Recent advances in theory and observation

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