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Multiple recent investigations of solar magnetic field measurements have raised claims that the scale-free (fractal) or multiscale (multifractal) parameters inferred from the studied magnetograms may help assess the eruptive potential of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Manolis K. Georgoulis

Magnetograms acquired with the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) were used to calculate and analyze time variations of turbulence and multifractality in the photosphere during the…

Solar and Stellar Astrophysics · Physics 2025-06-04 Valentina Abramenko

Intermittent magnetohydrodynamical turbulence is most likely at work in the magnetized solar atmosphere. As a result, an array of scaling and multi-scaling image-processing techniques can be used to measure the expected self-organization of…

Astrophysics · Physics 2007-05-23 Manolis K. Georgoulis

Solar flares are intense bursts of electromagnetic radiation, which occur due to a rapid destabilization and reconnection of the magnetic field. While pre-flare signatures and trends have been investigated from magnetic observations prior…

Solar and Stellar Astrophysics · Physics 2025-06-18 Kara L. Kniezewski , Emily I. Mason , Daniel J. Emmons , Kyle E. Fitch , Seth H. Garland

Recent studies indicate that measurements of fractal and multifractal parameters of active regions (ARs) are not efficient tools to discriminate ARs on the basis of the flare activity, as well as to predict flare events. Attempting…

Solar and Stellar Astrophysics · Physics 2017-05-19 F. Giorgi , I. Ermolli , P. Romano , M. Stangalini , F. Zuccarello , S. Criscuoli

Aims. Although the temporal evolution of active regions (ARs) is relatively well understood, the processes involved continue to be the subject of investigation. We study how the magnetic field of a series of ARs evolves with time to better…

A solar active region (AR) that produces at least one M- or X-class major flare tends to produce multiple flares during its passage across the solar disk. It will be interesting if we can estimate how flare-productive a given major flaring…

Solar and Stellar Astrophysics · Physics 2018-12-12 Eo-Jin Lee , Sung-Hong Park , Yong-Jae Moon

We analyze high-cadence vector magnetograms (135~s) and flare-ribbon observations of 37 flares from the Solar Dynamics Observatory to understand the spatial and temporal properties of changes in the photospheric vector magnetic field and…

Solar and Stellar Astrophysics · Physics 2023-03-08 Rahul Yadav , Maria D. Kazachenko

The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay et al. A time sequence of cleaned photospheric…

Solar and Stellar Astrophysics · Physics 2021-01-13 Stephanie L. Yardley , Duncan H. Mackay , Lucie M. Green

Sequences of line-of-sight (LOS) magnetograms recorded by the Michelson-Doppler Imager are used to quantitatively characterize photospheric magnetic structure and evolution in three active regions that rotated across the Sun's disk during…

Solar and Stellar Astrophysics · Physics 2015-05-27 B. T. Welsch , S. Christe , J. M. McTiernan

Time series of photospheric magnetic parameters of solar active regions (ARs) are used to answer whether scaling properties of fluctuations embedded in such time series help to distinguish between flare-quiet and flaring ARs. We examine a…

Solar and Stellar Astrophysics · Physics 2020-10-21 Eo-Jin Lee , Sung-Hong Park , Yong-Jae Moon

The abrupt and permanent changes of photospheric magnetic field in the localized regions of active regions during solar flares called magnetic imprints (MIs), have been observed for the past nearly three decades. The well known "coronal…

Solar and Stellar Astrophysics · Physics 2022-03-14 N. Vasantharaju , P. Vemareddy , B. Ravindra , V. H. Doddamani

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

This work examines the relation between the fractal properties of the photospheric magnetic patterns and those of the coronal magnetic fields in solar active regions.Our results show no correlation between the fractal dimensions of the…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. Dimitropoulou , M. Georgoulis , H. Isliker , L. Vlahos , A. Anastasiadis , D. Strintzi , X. Moussas

We estimated photospheric velocities by separately applying the Fourier Local Correlation Tracking (FLCT) and Differential Affine Velocity Estimator (DAVE) methods to 2708 co-registered pairs of SOHO/MDI magnetograms, with nominal 96-minute…

Solar and Stellar Astrophysics · Physics 2009-11-13 B. T. Welsch , Y. Li , P. W. Schuck , G. H. Fisher

Sunspots are regions of decreased brightness on the visible surface of the Sun (photosphere) that are associated with strong magnetic fields. They have been found to be locations associated with solar flares, which occur when energy stored…

Solar and Stellar Astrophysics · Physics 2013-01-24 Sophie A. Murray

We present results of a study of intermittency and multifractality of magnetic structures in solar active regions (ARs). Line-of-sight magnetograms for 214 ARs of different flare productivity observed at the center of the solar disk from…

Solar and Stellar Astrophysics · Physics 2010-12-08 Valentyna Abramenko , Vasyl Yurchyshyn

Long-term evolution characteristics of the solar transition region have been unclear. In this study, daily images of the solar full disk derived from the observations by the Solar Dynamics Observatory/Atmospheric Imaging Assembly at 304 A…

Solar and Stellar Astrophysics · Physics 2024-12-13 W. Q. Chen , K. J. Li , J. C. Xu

A statistical study is carried out on the photospheric magnetic nonpotentiality in solar active regions and its relationship with associated flares. We select 2173 photospheric vector magnetograms from 1106 active regions observed by the…

Solar and Stellar Astrophysics · Physics 2012-08-10 Xiao Yang , HongQi Zhang , Yu Gao , Juan Guo , GangHua Lin

Unstable states of the solar coronal magnetic field structure result in various flare behaviors. In this study, we compared the confined and eruptive flares that occurred under similar magnetic circumstances in the active region 12673, on…

Solar and Stellar Astrophysics · Physics 2025-03-24 Kouhei Teraoka , Daiki Yamasaki , Yusuke Kawabata , Shinsuke Imada , Toshifumi Shimizu
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