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This work examines the relationship between solar eruptivity and the relative helicity that is contained around the polarity inversion line (PIL) of the magnetic field, along with its current-carrying component. To this end, we analyze the…

Solar and Stellar Astrophysics · Physics 2025-09-25 K. Moraitis , J. K. Thalmann

Based on a decomposition of the magnetic field into potential and nonpotential components, magnetic energy and relative helicity can both also be decomposed into two quantities: potential and free energies, and volume-threading and…

Solar and Stellar Astrophysics · Physics 2020-04-15 Luis Linan , Étienne Pariat , Guillaume Aulanier , Kostas Moraitis , Gherardo Valori

Identifying universal, topology-independent thresholds in the coronal magnetic fields at onset of solar eruptions is crucial for physics-based prediction of eruptions. To this end, we systematically analyze the evolution of magnetic energy…

Solar and Stellar Astrophysics · Physics 2026-05-13 Xinkai Bian , Chaowei Jiang , Qingjun Liu , Yang Wang , Peng Zou , Xueshang Feng , Pingbing Zuo , Yi Wang

The discovery of clear criteria that can deterministically describe the eruptive state of a solar active region would lead to major improvements on space weather predictions. Using series of numerical simulations of the emergence of a…

Solar and Stellar Astrophysics · Physics 2017-05-17 E. Pariat , J. E. Leake , G. Valori , M. G. Linton , F. P. Zuccarello , K. Dalmasse

While free/non-potential magnetic energy is a necessary element of any active phenomenon in the solar corona, its role as a marker of the trigger of eruptive process remains elusive. Based on the unique decomposition of the magnetic field…

Solar and Stellar Astrophysics · Physics 2023-01-04 E. Pariat , P. F. Wyper , L. Linan

Current helicity quantifies the location of twisted and sheared non-potential structures in a magnetic field. We simulate the evolution of magnetic fields in the solar atmosphere in response to flux emergence and shearing by photospheric…

Astrophysics · Physics 2009-11-13 A. R. Yeates , D. H. Mackay , A. A. van Ballegooijen

Magnetic helicity flux gives information about the topology of a magnetic field passing through a boundary. In solar physics applications, this boundary is the photosphere and magnetic helicity flux has become an important quantity in…

Solar and Stellar Astrophysics · Physics 2019-04-03 Chris Prior , David MacTaggart

Using photospheric vector magnetograms obtained by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and a magnetic connectivity-based method, we compute the magnetic helicity and free magnetic energy budgets of a…

Solar and Stellar Astrophysics · Physics 2024-09-06 A. Nindos , S. Patsourakos , K. Moraitis , V. Archontis , E. Liokati , M. K. Georgoulis , A. A. Norton

We recently proposed a method to calculate the relative magnetic helicity in a finite volume for a given magnetic field which however required the flux to be balanced separately on all the sides of the considered volume. In order to allow…

Solar and Stellar Astrophysics · Physics 2018-05-30 Shangbin Yang , Joerg Buechner , Jan Skala , Hongqi Zhang

We observed three recurrent blowout jets in an active regio with Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). Using Helioseismic Magnetic Imager (HMI) data. We found that the magnetic flux of an emerging…

Solar and Stellar Astrophysics · Physics 2025-04-16 Chang Zhou , Yang Guo , Guoyin Chen , Ye Qiu , M. D. Ding

Aims. Solar active regions (ARs), which are formed by flux emergence, serve as the primary sources of solar eruptions. However, the specific physical mechanism that governs the emergence process and its relationship with flare productivity…

Solar and Stellar Astrophysics · Physics 2024-03-28 Zheng Sun , Ting Li , Quan Wang , Shangbin Yang , Mei Zhang , Yajie Chen

Relative magnetic helicity is a gauge invariant quantity suitable for the study of the magnetic helicity content of heliospheric plasmas. Relative magnetic helicity can be decomposed uniquely into two gauge invariant quantities, the…

Solar and Stellar Astrophysics · Physics 2018-10-10 Luis Linan , Étienne Pariat , Kostas Moraitis , Gherardo Valori , James E. Leake

Magnetic helicity is a conserved quantity of ideal magneto-hydrodynamics characterized by an inverse turbulent cascade. Accordingly, it is often invoked as one of the basic physical quantities driving the generation and structuring of…

We search for signatures of magnetic flux cancellation in a 3D resistive MHD flux-emergence simulation of coronal jets and eruptions in a coronal-hole-like environment. To do this, we analysed the output from a 3D MHD simulation of an…

Solar and Stellar Astrophysics · Physics 2025-05-28 Spiros Patsourakos , Vasilis Archontis

We present a new methodology which can determine magnetic helicity transport by the passage of helical magnetic field lines from sub-photosphere and the shuffling motions of foot-points of preexisting coronal field lines separately. It is…

Solar and Stellar Astrophysics · Physics 2015-06-04 Y. Zhang , R. Kitai , K. Takizawa

{In order to understand the emergence of the active region, we investigate the emerging process and magnetic properties of a naked anti-Hale active region during the period between August 24 to 25, 2018.} {Using the data from Helioseismic…

Solar and Stellar Astrophysics · Physics 2021-08-11 Jincheng Wang , Xiaoli Yan , Defang Kong , Zhike Xue , Liheng Yang , Qiaoling Li , Yan Zhang , Hao Li

In helical hydromagnetic turbulence with an imposed magnetic field (which is constant in space and time) the magnetic helicity of the field within a periodic domain is no longer an invariant of the ideal equations. Alternatively, there is a…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , William H. Matthaeus

Using a 3D non-linear mean-field solar dynamo model, we investigate the magnetic helicity flux and magnetic twist, and tilt parameters of bipolar magnetic regions (BMRs) emerging from the solar convection zone due to the magnetic buoyancy…

Solar and Stellar Astrophysics · Physics 2025-08-04 V. V. Pipin , Shangbin Yang , A. G. Kosovichev

Magnetic helicity has the remarkable property of being a conserved quantity of ideal magnetohydrodynamics (MHD). Therefore, it could be used as an effective tracer of the magnetic field evolution of magnetized plasmas. Theoretical…

Solar and Stellar Astrophysics · Physics 2015-08-19 E. Pariat , G. Valori , P. Démoulin , K. Dalmasse

Coronal jets are the captivating eruptions which are often found in the solar atmosphere, and primarily formed due to magnetic reconnection. Despite their short-lived nature and lower energy compared to many other eruptive events, e.g.…

Solar and Stellar Astrophysics · Physics 2024-09-06 Sushree S Nayak , Samrat Sen , Arpit Kumar Shrivastav , R. Bhattacharyya , P. S. Athiray
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