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Photospheric electric fields, estimated from sequences of vector magnetic field and Doppler measurements, can be used to estimate the flux of magnetic energy (the Poynting flux) into the corona and as time-dependent boundary conditions for…

Solar and Stellar Astrophysics · Physics 2014-10-13 Maria D. Kazachenko , George H. Fisher , Brian T. Welsch

The Phase-Field Method (PFM) is employed to simulate two-phase flows with the fully-coupled Cahn-Hilliard-Navier-Stokes (CHNS) equations governing the temporal evolution. The methodology minimizes the total energy functional, accounting for…

We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…

Solar and Stellar Astrophysics · Physics 2017-12-05 Jörn Warnecke , Feng Chen , Sven Bingert , Hardi Peter

Using a potential field source surface (PFSS) model, we recently analyzed the global topology of the background coronal magnetic field for a sequence of coronal mass ejections (CMEs) that occurred on 2010 August 1-2. Here we repeat this…

Solar and Stellar Astrophysics · Physics 2017-08-30 Viacheslav S. Titov , Zoran Mikic , Tibor Torok , Jon A. Linker , Olga Panasenco

Synthesizing extrapolated views from recorded driving logs is critical for simulating driving scenes for autonomous driving vehicles, yet it remains a challenging task. Recent methods leverage generative priors as pseudo ground truth, but…

Computer Vision and Pattern Recognition · Computer Science 2025-08-26 Kaiyuan Tan , Yingying Shen , Haohui Zhu , Zhiwei Zhan , Shan Zhao , Mingfei Tu , Hongcheng Luo , Haiyang Sun , Bing Wang , Guang Chen , Hangjun Ye

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

Extrapolations of solar photospheric vector magnetograms into three-dimensional magnetic fields in the chromosphere and corona are usually done under the assumption that the fields are force-free. The field calculations can be improved by…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Fuhrmann , N. Seehafer , G. Valori , T. Wiegelmann

The multi-scale structure of the solar surface magnetic field is essential for understanding both the Sun's internal dynamo processes and its external magnetic activity. The surface flux transport (SFT) model has been successful in…

Solar and Stellar Astrophysics · Physics 2025-09-09 Yukun Luo , Jie Jiang , Ruihui Wang

By comparing a magneto-frictional model of the low coronal magnetic field to a potential-field source-surface model, we investigate the possible impact of non-potential magnetic structure on empirical solar-wind models. These empirical…

Solar and Stellar Astrophysics · Physics 2015-12-09 S. J. Edwards , A. R. Yeates , F. -X. Bocquet , D. H. Mackay

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

We investigate the recently quantified misalignment of $\alpha_{mis} \approx 20^\circ-40^\circ$ between the 3-D geometry of stereoscopically triangulated coronal loops observed with STEREO/EUVI (in four active regions) and theoretical…

Solar and Stellar Astrophysics · Physics 2015-05-18 Markus J. Aschwanden , Anne W. Sandman

For a better understanding of magnetic field in the solar corona and dynamic activities such as flares and coronal mass ejections, it is crucial to measure the time-evolving coronal field and accurately estimate the magnetic energy.…

Solar and Stellar Astrophysics · Physics 2020-02-26 Shin Toriumi , Shinsuke Takasao , Mark C. M. Cheung , Chaowei Jiang , Yang Guo , Keiji Hayashi , Satoshi Inoue

Context. High resolution magnetic field measurements are routinely done only in the solar photosphere. Higher layers like the chromosphere and corona can be modeled by extrapolating the photospheric magnetic field upward. In the solar…

Solar and Stellar Astrophysics · Physics 2020-08-26 Xiaoshuai Zhu , Thomas Wiegelmann , Sami Solanki

Based on a second-order approximation of nonlinear force-free magnetic field solutions in terms of uniformly twisted field lines derived in Paper I, we develop here a numeric code that is capable to forward-fit such analytical solutions to…

Solar and Stellar Astrophysics · Physics 2015-06-05 Markus J. Aschwanden , Anna Malanushenko

The solar magnetic field is key to understanding the physical processes in the solar atmosphere. Nonlinear force-free codes have been shown to be useful in extrapolating the coronal field from underlying vector boundary data [see Schrijver…

Astrophysics · Physics 2008-01-21 T. Wiegelmann , J. K. Thalmann , C. J. Schrijver , M. L. DeRosa , T. R. Metcalf

This paper introduces an innovative end-to-end model-based deep learning approach for efficient electromagnetic analysis of high-dimensional frequency selective surfaces (FSS). Unlike traditional data-driven methods that require large…

Machine Learning · Computer Science 2024-10-23 Cheima Hammami , Lucas Polo-López , Luc Le Magoarou

Knowledge of electric fields in the photosphere is required to calculate the electromagnetic energy flux through the photosphere and set up boundary conditions for data-driven magnetohydrodynamic (MHD) simulations of solar eruptions.…

Solar and Stellar Astrophysics · Physics 2021-09-22 Andrey N. Afanasyev , Maria D. Kazachenko , Yuhong Fan , George H. Fisher , Benoit Tremblay

Forbush decreases (FDs) are short-term depressions in the galactic cosmic ray flux and one of the common signatures of coronal mass ejections (CMEs) in the heliosphere. They often show a two-step profile, the second one associated with the…

Solar and Stellar Astrophysics · Physics 2024-01-18 M. Dumbovic , L. Kramaric , I. Benko , B. Heber , B. Vrsnak

This work employs a new approach to analyze coupled-resonator circuits to design and manufacture a fully metallic dual polarization frequency selective surface (FSS). The proposed filtering structure is composed of a series of unit cells…

Context: Faraday rotation measurements of extragalactic radio sources during coronal occultation allow assessment of both the electron density distribution and the three-dimensional magnetic field topology in the outer solar corona. Aims:…

Astrophysics · Physics 2008-11-26 S. Mancuso , M. V. Garzelli
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