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Related papers: Electric Current Neutralization in Solar Active Re…

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The physical conditions that determine whether or not solar active regions (ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well understood. Here we investigate the association between electric-current…

Solar and Stellar Astrophysics · Physics 2017-09-06 Yang Liu , Xudong Sun , Tibor Török , Viacheslav S. Titov , James E. Leake

Solar flares are frequently accompanied by coronal mass ejections (CMEs) that release significant amount of energetic plasma into interplanetary space, potentially causing geomagnetic disturbances on Earth. However, many solar flares have…

Solar and Stellar Astrophysics · Physics 2025-03-28 Johan Muhamad , Kanya Kusano

Using time-sequence vector magnetic field observation from \textit{Helioseismic and Magnetic Imager}, we examined the connection of non-neutralized currents and the observed activity in 20 solar active-regions (ARs). The net current in a…

Solar and Stellar Astrophysics · Physics 2019-05-01 P. Vemareddy

Solar active regions (ARs) are the main sources of flares and coronal mass ejections (CMEs). NOAA AR 12089, which emerged on 2014 June 10, produced two C-class flares accompanied by CMEs within five hours after its emergence. When producing…

Solar and Stellar Astrophysics · Physics 2024-10-02 Hanzhao Yang , Lijuan Liu

There has been a long-lasting debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are…

Strong solar flares and coronal mass ejections (CMEs) are prone to originate within and near active regions (ARs) with a high magnetic complexity. Therefore, to better understand the generation mechanism of flares and the resultant CME…

Solar and Stellar Astrophysics · Physics 2024-09-26 Shin Toriumi

Solar active regions (ARs) are the major sources of two kinds of the most violent solar eruptions, namely flares and coronal mass ejections (CMEs). The largest AR in the past 24 years, NOAA AR 12192, crossed the visible disk from 2014…

Solar and Stellar Astrophysics · Physics 2016-07-28 Lijuan Liu , Yuming Wang , Jingxiu Wang , Chenglong Shen , Pinzhong Ye , Rui Liu , Jun Chen , Quanhao Zhang , S. Wang

Solar flares and coronal mass ejections (CMEs), especially the larger ones, emanate from active regions (ARs). With the aim to understand the magnetic properties that govern such flares and eruptions, we systematically survey all flare…

Solar and Stellar Astrophysics · Physics 2017-01-11 Shin Toriumi , Carolus J. Schrijver , Louise K. Harra , Hugh Hudson , Kaori Nagashima

We propose a new model for the initiation of a solar coronal mass ejection (CME). The model agrees with two properties of CMEs and eruptive flares that have proved to be very difficult to explain with previous models. a) Very low-lying…

Astrophysics · Physics 2009-10-30 S. K. Antiochos , C. R. DeVore , J. A. Klimchuk

There is a recurring question in solar physics about whether or not electric currents are neutralized in active regions (ARs). This question was recently revisited using three-dimensional (3D) magnetohydrodynamic (MHD) numerical simulations…

Solar and Stellar Astrophysics · Physics 2015-09-16 K. Dalmasse , G. Aulanier , P. Démoulin , B. Kliem , T. Török , E. Pariat

With the aim of understanding how the magnetic properties of active regions (ARs) control the eruptive character of solar flares, we analyze 719 flares of Geostationary Operational Environmental Satellite (GOES) class $\geq$C5.0 during…

Solar and Stellar Astrophysics · Physics 2021-09-01 Ting Li , Anqin Chen , Yijun Hou , Astrid M. Veronig , Shuhong Yang , Jun Zhang

Roles played by the currents in the impulsive phase of a solar flare and in a coronal mass ejection (CME) are reviewed. Solar flares are magnetic explosions: magnetic energy stored in unneutralized currents in coronal loops is released into…

Solar and Stellar Astrophysics · Physics 2017-08-16 D. B. Melrose

We explore the association of non-neutralized currents with solar flare occurrence in a sizable sample of observations, aiming to show the potential of such currents in solar flare prediction. We use the regularly produced high quality…

Solar and Stellar Astrophysics · Physics 2017-11-01 Ioannis Kontogiannis , Manolis K. Georgoulis , Sung-Hong Park , Jordan A. Guerra

The chapter "Solar Active Region Electric Currents Before and During Eruptive Flares" is a discussion on electric currents in the pre-eruption state and in the course of eruptions of solar magnetic structures, using information from solar…

Solar and Stellar Astrophysics · Physics 2019-03-13 Brigitte Schmieder , Guillaume Aulanier

We investigated how the magnetic field in solar active regions (ARs) controls flare activity, i.e., whether a confined or eruptive flare occurs. We analyzed 44 flares of GOES class M5.0 and larger that occurred during 2011--2015. We used 3D…

Solar and Stellar Astrophysics · Physics 2018-02-14 Christian Baumgartner , Julia K. Thalmann , Astrid M. Veronig

We establish the largest eruptive/confined flare database to date and analyze 322 flares of \emph{GOES} class M1.0 and larger that occurred during 2010$-$2019, i.e., almost spanning the entire solar cycle 24. We find that the total unsigned…

Solar and Stellar Astrophysics · Physics 2020-08-31 Ting Li , Yijun Hou , Shuhong Yang , Jun Zhang , Lijuan Liu , Astrid M. Veronig

Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio we perform a detailed study of electric current patterns in two solar active regions: a flaring/eruptive, and a flare-quiet one. We aim to…

Solar and Stellar Astrophysics · Physics 2015-06-11 Manolis K. Georgoulis , Viacheslav S. Titov , Zoran Mikic

Coronal mass ejections (CMEs) play a decisive role in driving space weather, especially, the fast ones (e.g., with speeds above $800$~km~s$^{-1}$). Understanding the trigger mechanisms of fast CMEs can help us gaining important information…

Solar and Stellar Astrophysics · Physics 2019-11-06 Peng Zou , Chaowei Jiang , Fengsi Wei , Pingbing Zuo , Yi Wang

Solar flares and coronal mass ejections (CMEs) cause immediate and adverse effects on the interplanetary space and geospace. The deeper understanding of the mechanisms that produce them and the construction of efficient prediction schemes…

Solar and Stellar Astrophysics · Physics 2022-10-12 Ioannis Kontogiannis

Solar eruptive events, like flares and coronal mass ejections, are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in…

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