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We present a comprehensive radiative magnetohydrodynamic simulation of the quiet Sun and large solar active regions. The 197 Mm wide simulation domain spans from 18 (10) Mm beneath the photosphere to 113 Mm in the solar corona. Radiative…

Solar and Stellar Astrophysics · Physics 2022-10-12 Feng Chen , Matthias Rempel , Yuhong Fan

We present in this Letter the first global comparison between traditional line-tied steady state magnetohydrodynamic models and a new, fully time-dependent thermodynamic magnetohydrodynamic simulation of the global corona. The maps are…

Solar and Stellar Astrophysics · Physics 2023-06-22 Emily I. Mason , Roberto Lionello , Cooper Downs , Jon A. Linker , Ronald M. Caplan

We study the coupling of the force-free magnetosphere to the long-term internal evolution of a magnetar. We allow the relation between the poloidal and toroidal stream functions - that characterizes the magnetosphere - to evolve freely…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Taner Akgün , Pablo Cerdá-Durán , Juan Antonio Miralles , José A. Pons

Starting from a realistically sheared magnetic arcade connecting chromospheric, transition region to coronal plasma, we simulate the in-situ formation and sustained growth of a quiescent prominence in the solar corona. Contrary to previous…

Solar and Stellar Astrophysics · Physics 2015-06-04 Chun Xia , P. F. Chen , Rony Keppens

Using magnetographic data provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we analyzed the structure of magnetic fields and vertical electric currents in six active regions (ARs) with different level…

Solar and Stellar Astrophysics · Physics 2020-02-19 Yuriy A. Fursyak , Alexander S. Kutsenko , Valentina I. Abramenko

A proxy for horizontal electric currents in the solar photosphere was suggested. For a set of evolving active regions (ARs) observed with {\it Solar and Heliospheric Observatory (SOHO)} Michelson Doppler Imager (MDI) in the high resolution…

Astrophysics · Physics 2008-06-11 Valentyna Abramenko

We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope on Hinode. Consistent with previous studies, we find that the moss is unipolar,…

Solar and Stellar Astrophysics · Physics 2015-05-19 David H. Brooks , Harry P. Warren , Amy R. Winebarger

The energy release and build-up processes in the solar corona have significant implications in particular for the case of large recurrent flares, which pose challenging questions about the conditions that lead to the episodic energy release…

Solar and Stellar Astrophysics · Physics 2019-11-20 Ranadeep Sarkar , Nandita Srivastava , Astrid M. Veronig

Coronal magnetic fields evolve quasi statically over long time scales and dynamically over short time scales. As of now there exists no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field…

Solar and Stellar Astrophysics · Physics 2023-12-20 P. Vemareddy , Jörn Warnecke , Ph. A. Bourdin

The coronal magnetic field above a particular photospheric region will vanish at a certain number of points, called null points. These points can be found directly in a potential field extrapolation or their density can be estimated from…

Astrophysics · Physics 2009-11-13 D. W. Longcope , C. E. Parnell

We discuss the evolution of solar coronal element abundances over an active region lifetime. Magneto-convection drives the complexity of magnetic fields that emerge above the photosphere. This complexity is dissipated, together with that of…

Solar and Stellar Astrophysics · Physics 2025-12-16 David H. Brooks , Deborah Baker , David M. Long. Paola Testa , Harry P. Warren

Nonlinear force-free solutions for the magnetic field in the solar corona constructed using photospheric vector magnetic field boundary data suffer from a basic problem: the observed boundary data are inconsistent with the nonlinear…

Solar and Stellar Astrophysics · Physics 2009-07-22 M. S. Wheatland , S. Regnier

Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…

Solar and Stellar Astrophysics · Physics 2025-07-25 Gottfried Mann , Frédéric Schuller

The large-scale structure of the magnetic field in the solar corona provides the energy to power large-scale solar eruptive events. Our physical understanding of this structure, and hence our ability to predict these events, is limited by…

Solar and Stellar Astrophysics · Physics 2015-08-06 R. T. James McAteer

This paper is the second in a series of studies working towards constructing a realistic, evolving, non-potential coronal model for the solar magnetic carpet. In the present study, the interaction of two magnetic elements is considered. Our…

Solar and Stellar Astrophysics · Physics 2012-11-19 K. A. Meyer , D. H. Mackay , A. A. van Ballegooijen

The compression or expansion of a magnetic field that is initially potential is considered. It was recently suggested by Janse & Low [2009, ApJ, 690, 1089] that, following the volumetric deformation, the relevant lowest energy state for the…

Solar and Stellar Astrophysics · Physics 2015-06-05 D. I. Pontin , Y. -M. Huang

We examine a simulation of flux emergence and cancellation, which shows a complex sequence of processes that accumulate free magnetic energy in the solar corona essential for the eruptive events such as coronal mass ejections (CMEs),…

Solar and Stellar Astrophysics · Physics 2015-06-05 Fang Fang , Ward Manchester , William P. Abbett , Bart van der Holst

Force-free current sheets are local plasma structures with field-aligned electric currents and approximately uniform plasma pressures. Such structures, widely found throughout the heliosphere, are sites for plasma instabilities and magnetic…

Plasma Physics · Physics 2023-07-20 Xin An , Anton Artemyev , Vassilis Angelopoulos , Andrei Runov , Sergey Kamaletdinov

The physical processes in the solar corona that shape the solar wind remain an active research topic. Modeling efforts have shown that energy and plasma exchanges near the transition region plays a crucial role in modulating solar wind…

The dynamics of magnetic fields in the Sun's active regions plays a key role in triggering solar eruptions. Studies have shown that changes in the photosphere's magnetic field can destabilize large-scale structure of the corona, leading to…

Solar and Stellar Astrophysics · Physics 2025-03-25 Partha Chowdhury , Belur Ravindra , Sanjiv Kumar Tiwari