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Related papers: Intermittency spectra of current helicity in solar…

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In the solar corona, magnetic helicity slowly and continuously accumulates in response to plasma flows tangential to the photosphere and magnetic flux emergence through it. Analyzing this transfer of magnetic helicity is key for identifying…

Solar and Stellar Astrophysics · Physics 2018-01-31 K. Dalmasse , E. Pariat , G. Valori , J. Jing , P. Démoulin

Results from initial helioseismic observations by Solar Optical Telescope onboard Hinode are reported. It has been demonstrated that intensity oscillation data from Broadband Filter Imager can be used for various helioseismic analyses. The…

We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2019-03-20 D. C. Braun

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

We employ time sequences of images observed with a G-band filter (4305{\AA}) by the Solar Optical Telescope (SOT) on board of Hinode spacecraft at different latitude along solar central me-ridian to study vorticity of granular flows in…

Solar and Stellar Astrophysics · Physics 2017-02-02 A. A. Pevtsov

Identifying solar active regions (ARs), which consist of one or more pairs of magnetic patches with opposite polarities, is essential due to their significant role in dynamic solar atmospheric phenomena. In this study, we analyze ARs during…

Solar and Stellar Astrophysics · Physics 2025-09-16 Zahra Tajik , Hasan Rezaei , Mehdi Simiari , Hossien Safari

The solar wind is highly turbulent, and intermittency effects are observed for fluctuations within the inertial range. By analyzing magnetic field spectra and fourth-order moments, we perform a comparative study of turbulence and…

Space Physics · Physics 2025-02-11 Shiladittya Mondal , Supratik Banerjee , Luca Sorriso-Valvo

A statistical relationship between magnetic reconnection, current sheets and intermittent turbulence in the solar wind is reported for the first time using in-situ measurements from the Wind spacecraft at 1 AU. We identify intermittency as…

Space Physics · Physics 2015-06-19 K. T. Osman , W. H. Matthaeus , J. T. Gosling , A. Greco , S. Servidio , B. Hnat , S. C. Chapman , T. D. Phan

Investigating the properties of magnetic flux emergence is one of the most important problems of solar physics. In this study we present a newly developed deep-focus time-distance measurement scheme which is able to detect strong emerging…

Solar and Stellar Astrophysics · Physics 2012-03-13 Stathis Ilonidis , Junwei Zhao , Alexander G. Kosovichev

The Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO/HMI) provides continuous full-disk observations of solar oscillations. We develop a data-analysis pipeline based on the time-distance helioseismology method to…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. Zhao , S. Couvidat , R. S. Bogart , K. V. Parchevsky , A. C. Birch , T. L. Duvall , J. G. Beck , A. G. Kosovichev , P. H. Scherrer

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

In the present work we study evolution of magnetic helicity in the solar corona. We compare the rate of change of a quantity related to the magnetic helicity in the corona to the flux of magnetic helicity through the photosphere and find…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , M. H. Yusuf , D. W. Longcope

We compare the coronal magnetic energy and helicity of two solar active regions (ARs), prolific in major eruptive (AR~11158) and confined (AR~12192) flaring, and analyze the potential of deduced proxies to forecast upcoming flares. Based on…

Solar and Stellar Astrophysics · Physics 2020-01-08 J. K. Thalmann , K. Moraitis , L. Linan , E. Pariat , G. Valori , K. Dalmasse

We present an automated system for detecting, tracking, and cataloging emerging active regions throughout their evolution and decay using SOHO Michelson Doppler Interferometer (MDI) magnetograms. The SolarMonitor Active Region Tracking…

Solar and Stellar Astrophysics · Physics 2010-07-01 Paul A. Higgins , Peter T. Gallagher , R. T. James McAteer , D. Shaun Bloomfield

The recently released spacecraft potential measured by the RPW instrument on-board Solar Orbiter has been used to estimate the solar wind electron density in the inner heliosphere. Solar-wind electron density measured during June 2020 has…

We study a simple model for the solar dynamo in the framework of the Parker migratory dynamo, with a nonlinear dynamo saturation mechanism based on magnetic helicity conservation arguments. We find a parameter range in which the model…

Astrophysics · Physics 2009-11-07 N. Kleeorin , K. Kuzanyan , D. Moss , I. Rogachevskii , D. Sokoloff , H. Zhang

Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun and the outer layers. We…

Solar and Stellar Astrophysics · Physics 2021-03-05 T. Roudier , M. Švanda , J. M. Malherbe , J. Ballot , D. Korda , Z. Frank

Recently discovered inertial waves, observed on the solar surface, likely extend to the deeper layers of the Sun. Utilizing helioseismic techniques, we explore these motions, allowing us to discern inertial-mode eigenfunctions in both…

Solar and Stellar Astrophysics · Physics 2024-03-14 Krishnendu Mandal , Shravan M. Hanasoge

Helioseismology is the study of the variations in the internal structure and properties of the dynamics of the Sun from measurements of its surface oscillations. With the 2010 launch of the Solar Dynamics Observatory (SDO) we are…

Solar and Stellar Astrophysics · Physics 2015-06-11 Hamed Moradi

We examine statistics of magnetic field vector components to explore how intermittency evolves from near sun plasma to radial distances as large as 10 au. Statistics entering the analysis include auto-correlation, magnetic structure…