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Related papers: Magnetic Energy Spectra in Active Regions

200 papers

To understand the physics of solar flares, including the local reorganisation of the magnetic field and the acceleration of energetic particles, we have first to estimate the free magnetic energy available for such phenomena, which can be…

Astrophysics · Physics 2008-05-16 S. Regnier , E. R. Priest

The excess broadening of high-temperature spectral lines, long observed near the tops of flare arcades, is widely considered to result from magnetohydrodynamic (MHD) turbulence. According to different theories, plasma turbulence is also…

Solar and Stellar Astrophysics · Physics 2024-07-18 William Ashfield , Vanessa Polito , Sijie Yu , Hannah Collier , Laura Hayes

Based on one-month long MMT time-series observations of the open cluster M37, we monitored light variations of nearly 2500 red dwarfs and successfully identified 420 flare events from 312 cluster M dwarf stars. For each flare light curve,…

Solar and Stellar Astrophysics · Physics 2015-10-16 S. -W. Chang , Y. -I. Byun , J. D. Hartman

In May 2024, the Sun exhibited intense magnetic activity, marked by numerous high-intensity flares resulting from the interaction and merging of NOAA ARs 13664 and 13668 in the southern hemisphere and AR 13663 in the northern hemisphere.…

Solar and Stellar Astrophysics · Physics 2025-07-04 B Lekshmi , Sushanta Tripathy , Kiran Jain , Alexei Pevtsov

Active regions (ARs) are the main sources of variety in solar dynamic events. Automated detection and identification tools need to be developed for solar features for a deeper understanding of the solar cycle. Of particular interest here…

Recent results of Singh et al. (2016) show that the emergence of an active region (AR) can be seen in a strengthening of the f-mode power up to two days prior of the region's formation. In the original work, ring diagram analysis was used…

Solar and Stellar Astrophysics · Physics 2023-03-15 Matthias Waidele , Markus Roth , Nishant Singh , Petri Käpylä

Solar active regions are driven dissipative dynamical systems. The turbulent convection zone forces new magnetic flux tubes to rise above the photosphere and shuffles the magnetic fields which are already above the photosphere. The driven…

Astrophysics · Physics 2009-09-29 Loukas Vlahos

We study structure and dynamics of the turbulent photospheric magnetic field in the active region NOAA 11158 by characterizing the spatial and temporal scaling properties of the line-of-sight (LOS) component. Using high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jordan A. Guerra , Antti A. Pulkkinen , Vadim M. Uritsky , Seiji Yashiro

Large scale solar eruptions significantly impact space weather and damages space-based human infrastructures. It is necessary to predict large scale solar eruptions, which will enable us to protect our vulnerable infrastructures of modern…

Solar and Stellar Astrophysics · Physics 2020-07-08 Soumitra Hazra , Gopal Sardar , Partha Choudhuri

Solar flares are complex phenomena driven by the release of magnetic energy, but a large energy reservoir is not sufficient to determine their eruptive potential; the magnetic topology and plasma dynamics play a key role. We investigate the…

Solar and Stellar Astrophysics · Physics 2026-03-04 C. J. Díaz Baso , J. de la Cruz Rodríguez , H. -P. Doerr , M. van Noort , A. Prasad , A. Feller , D. Kiselman

We present analysis of the magnetic field in seven solar flare regions accompanied by the pulsations of hard X-ray (HXR) emission. These flares were studied by Kuznetsov et al. (2016) (Paper~I), and chosen here because of the availability…

Solar and Stellar Astrophysics · Physics 2018-05-16 I. V. Zimovets , R. Wang , Y. D. Liu , C. C. Wang , S. A. Kuznetsov , I. N. Sharykin , A. B. Struminsky , V. M. Nakariakov

Active regions (ARs) appear in the solar atmosphere as a consequence of the emergence of magnetic flux ropes (FRs). Due to the presence of twist, the photospheric line-of-sight (LOS) magnetograms of emerging ARs show an elongation of the…

Solar and Stellar Astrophysics · Physics 2023-12-12 M. Poisson , M. López Fuentes , C. H. Mandrini , F. Grings , P. Démoulin

This work is a continuation of Paper I [Sharykin et al., 2018] devoted to analysis of nonthermal electron dynamics and plasma heating in the confined M1.2 class solar flare SOL2015-03-15T22:43 revealing energy release in the highly sheared…

Solar and Stellar Astrophysics · Physics 2020-05-06 I. N. Sharykin , I. V. Zimovets , I. I. Myshyakov

We present a combined analysis of the applications of the weighted horizontal magnetic gradient (denoted as WG_M in Korsos et al., ApJ, 802, L21, 2015) method and the magnetic helicity tool (Berger & Field, JFM, 147, 133, 1984) employed for…

Solar and Stellar Astrophysics · Physics 2018-01-03 Yudong Ye , M. B. Korsos , R. Erdelyi

Erupting magnetic flux ropes (MFRs) play a crucial role in producing solar flares. However, the formation of erupting MFRs in complex coronal magnetic configurations and their subsequent evolution in the flaring events are not fully…

Solar and Stellar Astrophysics · Physics 2023-08-30 Avijeet Prasad , Sanjay Kumar , Alphonse C. Sterling , Ronald L. Moore , Guillaume Aulanier , R. Bhattacharyya , Qiang Hu

Composed of shocked solar wind, the Earth's magnetosheath serves as a natural laboratory to study the transition of turbulence from low Alfv{\'e}n Mach number, $M_\mathrm{A}$, to high $M_\mathrm{A}$. The simultaneous observations of…

Space Physics · Physics 2020-08-05 Hui Li , Wence Jiang , Chi Wang , Daniel Verscharen , Chen Zeng , C. T. Russell , B. Giles , J. L. Burch

Context. The dynamics of the flaring loops in active region (AR) 11429 are studied. The observed dynamics consist of several evolution stages of the flaring loop system during both the ascending and descending phases of the registered…

We employ ring-diagram analysis to study the sub-surface thermal structure of active regions. We present results using a large number of active regions over the course of Solar Cycle 23. We present both traditional inversions of…

Solar and Stellar Astrophysics · Physics 2015-06-11 Charles S. Baldner , Richard S. Bogart , Sarbani Basu

This letter presents the first ab initio, fully electromagnetic, kinetic simulations of magnetized turbulence in a homogeneous, weakly collisional plasma at the scale of the ion Larmor radius (ion gyroscale). Magnetic and electric-field…

The presence of current sheet instabilities, such as the tearing mode instability, are needed to account for the observed rate of energy release in solar flares. Insights into these current sheet dynamics can be revealed by the behaviour of…

Solar and Stellar Astrophysics · Physics 2021-12-08 Ryan J. French , Sarah A. Matthews , I. Jonathan Rae , Andrew W. Smith