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Related papers: Comparison of Coronal Extrapolation Methods for Cy…

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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

We estimated the coronal magnetic field strength ($B$) during the 23 July 2016 coronal mass ejection (CME) event using i) the flux rope structure of the CME in the whitelight coronagraph images and ii) the band splitting in the associated…

Solar and Stellar Astrophysics · Physics 2017-11-08 Anshu Kumari , R. Ramesh , C. Kathiravan , T. J. Wang

Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…

Solar and Stellar Astrophysics · Physics 2024-11-20 L. P. Chitta , M. van Noort , H. N. Smitha , E. R. Priest , L. H. M. Rouppe van der Voort

The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…

Solar and Stellar Astrophysics · Physics 2021-08-09 Samarth G Kashyap , Shravan M Hanasoge

Context: Hard X-ray emission of coronal sources in solar flares has been observed and studied since its discovery in Yohkoh observations. Several models have been proposed to explain the physical mechanisms causing this emission and the…

Astrophysics · Physics 2009-11-13 Marina Battaglia , Arnold O. Benz

Solar Orbiter provides unique capabilities to understand the heliosphere. In particular, it has made observations of the far-side of the Sun and provides unique information to improve space weather monitoring. We aim to quantify how…

Solar and Stellar Astrophysics · Physics 2024-04-11 Barbara Perri , Adam Finley , Victor Réville , Susanna Parenti , Allan Sacha Brun , Antoine Strugarek , Éric Buchlin

The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than…

Solar and Stellar Astrophysics · Physics 2014-08-18 Nat Gopalswamy , Sachiko Akiyama , Seiji Yashiro , Hong Xie , Pertti Mäkelä , Grzegorz Michalek

Three-dimensional global magnetohydrodynamic simulations of the solar wind - magnetosphere - ionosphere system are carried out to explore the dependence of the magnetospheric reconnection voltage, the ionospheric transpolar potential, and…

Solar and Stellar Astrophysics · Physics 2009-04-07 XIONG Ming , PENG Zhong , HU Youqiu , ZHENG Huinan

Previous ambient solar wind (SW) validation studies have reported on discrepancies between modeled and observed SW conditions at L1. They indicated that a major source of discrepancies stems from how we model the solar corona. Thus,…

Solar and Stellar Astrophysics · Physics 2025-06-12 Satabdwa Majumdar , Martin Reiss , Karin Muglach , Charles N. Arge

Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (February 5, 1999 to February 10, 2003) of the Large Angle…

Astrophysics · Physics 2009-11-10 Y. -Q. Lou , Y. -M. Wang , Z. Fan , S. Wang , J. Wang

Magnetic field in the solar corona is usually extrapolated from photospheric vector magnetogram using a nonlinear force-free field (NLFFF) model. NLFFF extrapolation needs a considerable effort to be devoted for its numerical realization.…

Solar and Stellar Astrophysics · Physics 2015-06-04 Chaowei Jiang , Xueshang Feng

In this work we describe our implementation of a thermodynamic energy equation into the global corona model of the Space Weather Modeling Framework (SWMF), and its development into the new Lower Corona (LC) model. This work includes the…

Solar and Stellar Astrophysics · Physics 2014-11-20 Cooper Downs , Ilia I. Roussev , Bart van der Holst , Noé Lugaz , Igor V. Sokolov , Tamas I. Gombosi

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are…

Solar and Stellar Astrophysics · Physics 2024-11-27 Rafael A. Garcia , Sylvain N. Breton , David Salabert , Sushant C. Tripathy , Kiran Jain , Savita Mathur , Eva Panetier

The magnetic field in the Sun's corona stores energy that can be released to heat the coronal plasma and drive solar eruptions. Measurements of the global coronal magnetic field have been limited to a few snapshots. We present observations…

Solar and Stellar Astrophysics · Physics 2024-10-23 Zihao Yang , Hui Tian , Steven Tomczyk , Xianyu Liu , Sarah Gibson , Richard J. Morton , Cooper Downs

We compare photospheric line-of-sight magnetograms from the Synoptic Long-term Investigations of the Sun (SOLIS) vector spectromagnetograph (VSM) instrument with observations from the 150-foot Solar Tower at Mt. Wilson (MWO), Helioseismic…

Solar and Stellar Astrophysics · Physics 2012-10-01 A. Pietarila , L. Bertello , J. W. Harvey , A. A. Pevtsov

Recent models of variations of the Sun's structure with the 11-year activity cycle by Sofia et al (2005) predict strong non-homologous changes of the radius of subsurface layers, due to subsurface magnetic fields and field-modulated…

Astrophysics · Physics 2009-11-13 S. Lefebvre , A. G. Kosovichev , J. P. Rozelot

We present a magnetic flux rope (FR) extraction tool for solar coronal magnetic field modelling data, which builds upon the methodology from Wagner et al. (2023). We apply the scheme to magnetic field simulations of active regions AR12473…

The origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists…

Solar and Stellar Astrophysics · Physics 2015-06-05 Bo Li , Xing Li , Hui Yu

It was recently proposed that the intensity ratios of several extreme ultraviolet spectral lines from the Fe X ion can be used to measure the solar coronal magnetic field based on the magnetic-field-inducedtransition (MIT) theory. To verify…

Solar and Stellar Astrophysics · Physics 2021-10-27 Yajie Chen , Wenxian Li , Hui Tian , Feng Chen , Xianyong Bai , Yang Yang , Zihao Yang , Xianyu Liu , Yuanyong Deng

The solar atmosphere being magnetic in nature, the understanding of the structure and evolution of the magnetic field in different regions of the solar atmosphere has been an important task over the past decades. This task has been made…

Solar and Stellar Astrophysics · Physics 2015-06-16 S. Regnier
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