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Related papers: A Method for Data-Driven Simulations of Evolving S…

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Data-driven time-dependent magnetofrictional modelling (TMFM) of active region magnetic fields has been proven to be a useful tool to study the corona. The input to the model is the photospheric electric field that is inverted from a time…

Solar and Stellar Astrophysics · Physics 2023-07-05 A. Kumari , D. J. Price , F. Daei , J. Pomoell , E. K. J. Kilpua

We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field…

Solar and Stellar Astrophysics · Physics 2014-06-18 Yuhong Fan , Fang Fang

We present an analysis of the formation of atmospheric flux ropes in a magnetohydrodynamic (MHD) solar flux emergence simulation. The simulation domain ranges from the top of the solar interior to the low corona. A twisted magnetic flux…

Solar and Stellar Astrophysics · Physics 2015-06-17 David MacTaggart , Andrew Haynes

We use observations of line-of-sight magnetograms from Helioseismic and Magnetic Imager (HMI) on board of Solar Dynamics Observatory (SDO) to investigate polarity separation, magnetic flux, flux emergence rate, twist and tilt of solar…

Solar and Stellar Astrophysics · Physics 2019-02-20 A. S. Kutsenko , V. I. Abramenko , A. A. Pevtsov

We have performed a three-dimensional magnetohydrodynamic simulation to study the emergence of a twisted magnetic flux tube from -20,000 km of the solar convection zone to the corona through the photosphere and the chromosphere. The middle…

Solar and Stellar Astrophysics · Physics 2015-06-03 S. Toriumi , T. Yokoyama

$\delta$-sunspots, with highly complex magnetic structures, are very productive in energetic eruptive events, such as X-class flares and homologous eruptions. We here study the formation of such complex magnetic structures by numerical…

Solar and Stellar Astrophysics · Physics 2015-06-17 Fang Fang , Yuhong Fan

The Coronal Global Evolutionary Model (CGEM) provides data-driven simulations of the magnetic field in the solar corona to better understand the build-up of magnetic energy that leads to eruptive events. The CGEM project has developed six…

We develop a general description of how information propagates through a magnetohydrodynamic (MHD) system based on the method of characteristics and use that to formulate numerical boundary conditions (BCs) that are intrinsically consistent…

Solar and Stellar Astrophysics · Physics 2023-11-07 Lucas A. Tarr , N. Dylan Kee , Mark G. Linton , Peter W. Schuck , James E. Leake

We use SDO/HMI and SOLIS/VSM photospheric magnetic field measurements to model the force-free coronal field above a solar active region, assuming magnetic forces to dominate. We take measurement uncertainties caused by, e.g., noise and the…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. K. Thalmann , A. Pietarila , X. Sun , T. Wiegelmann

Estimates of the photospheric magnetic, electric and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and by using…

Solar and Stellar Astrophysics · Physics 2017-12-18 E. Lumme , J. Pomoell , E. K. J. Kilpua

The energy that heats the magnetically closed solar corona originates in the complex motions of the massive photosphere. Turbulent photospheric convection slowly displaces the footpoints of coronal field lines, causing them to become…

This work analyzes the Hall magnetohydrodynamics (HMHD) and magnetohydrodynamics (MHD) numerical simulations of a flaring solar active region as a testbed while idealizing the coronal Alfv\'en speed to be of two orders of magnitude lesser.…

Solar and Stellar Astrophysics · Physics 2022-02-16 Kamlesh Bora , Ramit Bhattacharyya , Avijeet Prasad , Bhuwan Joshi , Qiang Hu

Context. The solar chromosphere is the interface between the solar surface and the solar corona. Modelling of this region is difficult because it represents the transition from optically thick to thin radiation escape, from gas-pressure…

Solar and Stellar Astrophysics · Physics 2015-12-09 Mats Carlsson , Viggo H. Hansteen , Boris V. Gudiksen , Jorrit Leenaarts , Bart De Pontieu

Magnetic flux ropes are a bundle of twisted magnetic field lines produced by internal electric currents, which are responsible for solar eruptions and are the major drivers of geomagnetic storms. As such, it is crucial to develop a…

Solar and Stellar Astrophysics · Physics 2023-10-31 J. H. Guo , Y. W. Ni , Y. Guo , C. Xia , B. Schmieder , S. Poedts , Z. Zhong , Y. H. Zhou , F. Yu , P. F. Chen

The magnetic fields in the solar atmosphere structure the plasma, store free magnetic energy and produce a wide variety of active solar phenomena, like flare and coronal mass ejections(CMEs). The distribution and strength of magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-12 Tilaye Tadesse , T. Wiegelmann , K. Olson , P. J. MacNeice

Time-dependent three-dimensional magnetohydrodynamics (MHD) simulation modules are implemented at the Joint Science Operation Center (JSOC) of Solar Dynamics Observatory (SDO). The modules regularly produce three-dimensional data of the…

Solar and Stellar Astrophysics · Physics 2015-04-22 Keiji Hayashi , J. Todd Hoeksema , Yang Liu , Monica G. Bobra , Xudong D. Sun , Aimee A. Norton

We study the formation of coronal jets through numerical simulation of the emergence of a twisted magnetic flux rope into a pre-existing open magnetic field. Reconnection inside the emerging flux rope in addition to that between the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Fang Fang , Yuhong Fan , Scott W. McIntosh

The formation and evolution of active regions is an inherently complex phenomenon. Magnetic fields generated at the base of the convection zone follow a chaotic evolution before reaching the solar surface. In this article, we use a 2-D…

Astrophysics · Physics 2009-11-07 L. Vlahos , T. Fragos , H. Isliker , M. Georgoulis

Coronal mass ejections (CMEs) are the primary drivers of adverse space-weather events, yet their initiation and onset prediction remain insufficiently understood due to the complexity of the magnetic topology and physical processes in real…

Solar and Stellar Astrophysics · Physics 2026-02-13 J. H. Guo , S. Poedts , B. Schmieder , Y. Guo , C. Zhou , H. Wu , Y. W. Ni , Z. Zhong , Y. H. Zhou , S. H. Li , P. F. Chen

An overview is given about recent developments and results of comprehensive simulations of magneto-convective processes in the near-surface layers and photosphere of the Sun. Simulations now cover a wide range of phenomena, from whole…

Solar and Stellar Astrophysics · Physics 2015-06-12 Manfred Schüssler