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Related papers: Pre-Flare Dynamics of Sunspot Groups

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Observational pre-cursors of large solar flares provide a basis for future operational systems for forecasting. Here, we study the evolution of the normalized emergence (EM), shearing (SH) and total (T) magnetic helicity flux components for…

Solar and Stellar Astrophysics · Physics 2022-02-09 Sz. Soós , M. B. Korsós , H. Morgan , R. Erdélyi

Strong solar flares and coronal mass ejections, here defined not only as the bursts of electromagnetic radiation but as the entire process in which magnetic energy is released through magnetic reconnection and plasma instability, emanate…

Solar and Stellar Astrophysics · Physics 2019-05-29 Shin Toriumi , Haimin Wang

The extreme space weather conditions resulting from high energetic events likes solar flares and Coronal Mass Ejections (CMEs) demand for reliable space weather forecasting. The magnetic flux tubes while rising through the convection zone…

Solar and Stellar Astrophysics · Physics 2022-10-19 B Lekshmi , Kiran Jain , Rudolf W. Komm , Dibyendu Nandy

Since the launch of the Solar Dynamics Observatory (SDO) in 2010 and throughout the solar cycle 24, the Sun has produced few tens of xclass flares, which are the most energetic solar events. Those flares are produced in regions where the…

Solar and Stellar Astrophysics · Physics 2024-10-23 R. L. Edgar , S. Regnier

We developed a solar flare prediction model using a deep neural network (DNN), named Deep Flare Net (DeFN). The model can calculate the probability of flares occurring in the following 24 h in each active region, which is used to determine…

Solar and Stellar Astrophysics · Physics 2018-05-23 Naoto Nishizuka , Komei Sugiura , Yuki Kubo , Mitsue Den , Mamoru Ishii

In this article, we present the application of the weighted horizontal gradient of magnetic field (WGM) flare prediction method to 3-dimensional (3D) extrapolated magnetic configurations of 13 flaring solar active regions (ARs). The main…

Solar and Stellar Astrophysics · Physics 2020-06-24 M. B. Korsos , M. K. Georgoulis , N. Gyenge , S. K. Bisoi , S. Yu , S. Poedts , C. J. Nelson , J. Liu , Y. Yan , R. Erdelyi

Solar flares are caused by magnetic eruptions in active regions (ARs) on the surface of the sun. These events can have significant impacts on human activity, many of which can be mitigated with enough advance warning from good forecasts. To…

Solar and Stellar Astrophysics · Physics 2023-09-18 Varad Deshmukh , Thomas Berger , James Meiss , Elizabeth Bradley

We report a systematic strengthening of the local solar surface or fundamental $f$-mode $1$-$2$ days prior to the emergence of an active region (AR) in the same (corotating) location. Except for a possibly related increase in the kurtosis…

Solar and Stellar Astrophysics · Physics 2016-11-23 Nishant K. Singh , Harsha Raichur , Axel Brandenburg

Ways to give medium- and short-term predictions of solar flares are proposed according to the statistical analysis of events during solar cycle 23. On one hand, the time distribution of both C and M class flares shows two main periods of…

Astrophysics · Physics 2008-11-17 Z. Q. Qu

A question often arises as to why some solar flares are confined in the lower corona while others, termed eruptive flares, are associated with coronal mass ejections (CMEs). Here we intend to rank the importance of pre-flare magnetic…

Solar and Stellar Astrophysics · Physics 2025-11-10 Jinhui Pan , Rui Liu

We demonstrate that for weak flares the dependence on spottedness can be rather weak. The fact is that such flares can occur both in small and large active regions. At the same time, powerful large flares of classes M and X occur much more…

Solar and Stellar Astrophysics · Physics 2022-09-07 M. M. Katsova , V. N. Obridko , D. D. Sokoloff , I. M. Livshits

The twist of the magnetic field above a sunspot is an important quantity in solar physics. For example, magnetic twist plays a role in the initiation of flares and coronal mass ejections (CMEs). Various proxies for the twist above the…

Solar and Stellar Astrophysics · Physics 2022-08-31 C. Baumgartner , A. C. Birch , H. Schunker , R. H. Cameron , L. Gizon

Active regions (AR) appearing on the surface of the Sun are classified into $\alpha$, $\beta$, $\gamma$, and $\delta$ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the…

Solar and Stellar Astrophysics · Physics 2016-03-09 Piyali Chatterjee , Viggo Hansteen , Mats Carlsson

In this work, we have studied the temporal evolution of some properties of a sample of superactive regions with the aim to single out the most significant for flare activity forecasting. We have investigated properties of 14 superactive…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Criscuoli , P. Romano , F. Zuccarello , F. Giorgi

We present a study of multi-wavelength observations, of a C 2.3 solar flare in Active Region NOAA 12353, observed on 2015 May 23, which reveal new properties of acoustic waves in the flaring region. The space-, and ground-based data…

Solar and Stellar Astrophysics · Physics 2022-03-07 A. Wisniewska , E. Chmielewska , K. Radziszewski , M. Roth , J. Staiger

Solar flares - bursts of high-energy radiation responsible for severe space-weather effects - are a consequence of the occasional destabilization of magnetic fields rooted in active regions (ARs). The complexity of AR evolution is a barrier…

Solar and Stellar Astrophysics · Physics 2019-05-27 Dattaraj B. Dhuri , Shravan M. Hanasoge , Mark C. M. Cheung

Delta ($\delta$)-spots are active regions (ARs) in which positive and negative umbrae share a penumbra. They are known to be the source of strong flares. We introduce a new quantity, the degree of $\delta$ (Do$\delta$), to measure the…

Solar and Stellar Astrophysics · Physics 2022-10-26 A. A. Norton , P. J. Levens , K. J. Knizhnik , M. G. Linton , Y. Liu

Solar flares occur in complex sunspot groups, but it remains unclear how the probability of producing a flare of a given magnitude relates to the characteristics of the sunspot group. Here, we use Geostationary Operational Environmental…

Solar and Stellar Astrophysics · Physics 2012-02-28 D. Shaun Bloomfield , Paul A. Higgins , R. T. James McAteer , Peter T. Gallagher

We use helioseismic holography to study the association of shallow flows with solar flare activity in about 250 large sunspot groups observed between 2010 and 2014 with the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory.…

Solar and Stellar Astrophysics · Physics 2016-03-16 D. C. Braun

Solar flares are explosions on the Sun. They happen when energy stored in magnetic fields around solar active regions (ARs) is suddenly released. In this paper, we present a transformer-based framework, named SolarFlareNet, for predicting…

Solar and Stellar Astrophysics · Physics 2024-05-28 Yasser Abduallah , Jason T. L. Wang