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Time-evolving magnetohydrodynamic (MHD) coronal modeling, driven by a series of time-dependent photospheric magnetograms, represents a new generation of coronal simulations. This approach offers greater realism compared to traditional…

The photospheric magnetic field vector is continuously derived from measurements, while reconstruction of the three-dimensional (3D) coronal magnetic field requires modelling with photospheric measurements as a boundary condition. For…

Solar and Stellar Astrophysics · Physics 2022-03-23 I. Chifu , B. Inhester , T. Wiegelmann

Space weather modelling has been gaining importance due to our increasing dependency on technology sensitive to space weather effects, such as satellite services, air traffic and power grids. Improving the reliability, accuracy and…

Space Physics · Physics 2024-12-17 Michaela Brchnelova , Boris Gudiksen , Mats Carlsson , Andrea Lani , Stefaan Poedts

With the development of new instrumentation providing measurements of solar photospheric vector magnetic fields, we need to develop our understanding of the effects of current density on coronal magnetic field configurations. The object is…

Astrophysics · Physics 2009-11-13 S. Regnier , E. R. Priest

Accurate prediction of solar activity calls for precise calibration of solar cycle models. Consequently we aim to find optimal parameters for models which describe the physical processes on the solar surface, which in turn act as proxies…

Solar and Stellar Astrophysics · Physics 2017-11-22 T. Whitbread , A. R. Yeates , A. Muñoz-Jaramillo , G. J. D. Petrie

Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties. The effect of…

Solar and Stellar Astrophysics · Physics 2019-08-21 D. Y. Kolotkov , V. M. Nakariakov , D. I. Zavershinskii

We study the physical properties and behavior of the solar atmosphere during the GOES X1.6 solar flare on 2014 September 10. The steady plasma flows and the fast sausage MHD waves were analysed with the wavelet separation method. The…

Solar and Stellar Astrophysics · Physics 2020-11-18 Hana Meszarosova , Peter Gomory

Accurate estimates of the horizontal electric field on the Sun's visible surface are important not only for estimating the Poynting flux of magnetic energy into the corona but also for driving time-dependent magnetohydrodynamic models of…

Solar and Stellar Astrophysics · Physics 2017-02-22 A. R. Yeates

We aim to reproduce the structure of the corona above a solar active region as seen in the extreme ultraviolet (EUV) using a three-dimensional magnetohydrodynamic (3D MHD) model. The 3D MHD data-driven model solves the induction equation…

Solar and Stellar Astrophysics · Physics 2019-04-30 Jörn Warnecke , Hardi Peter

Extrapolation codes in Cartesian geometry for modelling the magnetic field in the corona do not take the curvature of the Sun's surface into account and can only be applied to relatively small areas, e.g., a single active region. We compare…

Solar and Stellar Astrophysics · Physics 2015-06-11 Tilaye Tadesse , T. Wiegelmann , B. Inhester , P. MacNeice , A. Pevtsov , X. Sun

Predictions of the solar wind at Earth are a central aspect of space weather prediction. The outcome of such a prediction, however, is highly sensitive to the method used for computing the magnetic field in the corona. We analyze the impact…

Solar and Stellar Astrophysics · Physics 2017-09-07 Marion Weinzierl , Francois-X. Bocquet , Anthony R. Yeates

We describe the construction of stepped-pressure equilibria as extrema of a multi-region, relaxed magnetohydrodynamic (MHD) energy functional that combines elements of ideal MHD and Taylor relaxation, and which we call MRXMHD. The model is…

Plasma Physics · Physics 2015-06-12 S. R. Hudson , R. L. Dewar , G. Dennis , M. J. Hole , M. McGann , G. von Nessi , S. Lazerson

Nonlinear force-free field (NLFFF) models are thought to be viable tools for investigating the structure, dynamics and evolution of the coronae of solar active regions. In a series of NLFFF modeling studies, we have found that NLFFF models…

We describe a magnetohydrodynamic (MHD) constrained energy functional for equilibrium calculations that combines the topological constraints of ideal MHD with elements of Taylor relaxation. Extremizing states allow for partially chaotic…

Plasma Physics · Physics 2012-04-03 S. R. Hudson , R. L. Dewar , M. J. Hole , M. McGann

Non-linear force-free extrapolations are a common approach to estimate the 3D topology of coronal magnetic fields based on photospheric vector magnetograms. The force-free assumption is a valid approximation at coronal heights, but for the…

We present a new 3D MHD heliospheric model for space-weather forecasting driven by boundary conditions defined from white-light observations of the solar corona. The model is based on the MHD code PLUTO, constrained by an empirical…

In this paper, single-stage stellarator optimization is combined with stochastic coil optimization to improve the robustness of the stellarator as compared to deterministic methods. The plasma boundary, solved with an MHD solver in…

Plasma Physics · Physics 2026-03-13 Pedro F. Gil , Jason Smoniewski , Rogerio Jorge , Paul Huslage , Eve V. Stenson

We investigate the propagation of MHD waves in a homogenous, magnetized plasma in a weakly stratified atmosphere, representing hot coronal loops. In most of earlier studies a time-independent equilibrium is considered. Here we abandon this…

Solar and Stellar Astrophysics · Physics 2015-05-20 R. Erdelyi , K. S. Al-Ghafri , R. J. Morton

Expanding on an earlier work that relied on linear force-free magnetic fields, we self-consistently derive the instantaneous free magnetic energy and relative magnetic helicity budgets of an unknown three-dimensional nonlinear force-free…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. K. Georgoulis , K. Tziotziou , N. -E. Raouafi

We study stationary free boundary configurations of an ideal incompressible magnetohydrodynamic fluid possessing nested flux surfaces. In 2D simply connected domains, we prove that if the magnetic field and velocity field are never…

Analysis of PDEs · Mathematics 2022-06-22 Peter Constantin , Theodore D. Drivas , Daniel Ginsberg