English
Related papers

Related papers: Modeling Coronal Response in Decaying Active Regio…

200 papers

With multiple vantage points around the Sun, STEREO and SDO imaging observations provide a unique opportunity to view the solar surface continuously. We use He II 304 A data from these observatories to isolate and track ten active regions…

Solar and Stellar Astrophysics · Physics 2015-12-16 Ignacio Ugarte-Urra , Lisa Upton , Harry P. Warren , David H. Hathaway

Understanding the relationship between the magnetic field and coronal heating is one of the central problems of solar physics. However, studies of the magnetic properties of impulsively heated loops have been rare. We present results from a…

Solar and Stellar Astrophysics · Physics 2019-06-12 Ignacio Ugarte-Urra , Nicholas A. Crump , Harry P. Warren , Thomas Wiegelmann

Magnetic flux emergence and decay in the Sun span from days to months. However, their tracking is typically limited to about half a solar rotation when relying on single-vantage-point observations. Combining observations from both the…

Solar and Stellar Astrophysics · Physics 2026-01-14 I. Kontogiannis , Y. Zhu , K. Barczynski , M. Z. Stiefel , H. Collier , J. McKevitt , J. S. Castellanos Durán , S. Berdyugina , L. K. Harra

We investigate the evolution of coronal loop emission in the context of the coronal magnetic field topology. New modeling techniques allow us to investigate the magnetic field structure and energy release in active regions. Using these…

Solar and Stellar Astrophysics · Physics 2015-05-19 J. -Y. Lee , Graham Barnes , K. D. Leka , Katharine K. Reeves , K. E. Korreck , L. Golub , E. E. DeLuca

Many studies of the solar corona have shown that the observed X-ray luminosity is well correlated with the total unsigned magnetic flux. In this paper we present results from the extensive numerical modeling of active regions observed with…

Astrophysics · Physics 2016-08-30 Harry P. Warren , Amy R. Winebarger

The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay et al. A time sequence of cleaned photospheric…

Solar and Stellar Astrophysics · Physics 2021-01-13 Stephanie L. Yardley , Duncan H. Mackay , Lucie M. Green

When magnetic flux emerges from beneath the photosphere it displaces the preexisting field in the corona, and a current sheet generally forms at the boundary between the old and new magnetic domains. Reconnection in the current sheet…

Solar and Stellar Astrophysics · Physics 2015-06-17 Lucas A. Tarr , Dana W. Longcope , David E. McKenzie , Keiji Yoshimura

Coronal heating through the explosive release of magnetic energy remains an open problem in solar physics. Recent hydrodynamical models attempt an investigation by placing swarms of 'nanoflares' at random sites and times in modeled…

Solar and Stellar Astrophysics · Physics 2016-11-30 K. Moraitis , A. Toutountzi , H. Isliker , M. Georgoulis , L. Vlahos , G. Chintzoglou

We investigate the thermal, kinematic and magnetic structure of small-scale heating events in an emerging flux region (EFR). We use high-resolution multi-line observations (including Ca II 8542~\AA, Ca II K, and Fe I 6301~\AA line pair) of…

Solar and Stellar Astrophysics · Physics 2023-09-14 Rahul Yadav , Maria D. Kazachenko , Andrey N. Afanasyev , Jaime de la Cruz Rodríguez , Jorrit Leenaarts

Coupled flux transport and magneto-frictional simulations are extended to simulate the continuous magnetic field evolution in the global solar corona for over 15 years, from the start of Solar Cycle 23 in 1996. By simplifying the dynamics,…

Solar and Stellar Astrophysics · Physics 2015-06-15 A. R. Yeates

Recent observations suggest that magnetic flux cancellation may play a crucial role in heating the Sun's upper atmosphere (chromosphere, transition region, corona). Here, we intended to validate an analytic model for magnetic reconnection…

Solar and Stellar Astrophysics · Physics 2020-07-08 Sung-Hong Park

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

A detailed study is presented of the decaying solar active region NOAA 10103 observed with the Coronal Diagnostic Spectrometer (CDS), the Michelson Doppler Imager (MDI) and the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar…

Astrophysics · Physics 2007-05-23 R. O. Milligan , P. T. Gallagher , M. Mathioudakis , F. P. Keenan , D. S. Bloomfield

To adequately constrain the frequency of energy deposition in active region cores in the solar corona, systematic comparisons between detailed models and observational data are needed. In this paper, we describe a pipeline for forward…

Solar and Stellar Astrophysics · Physics 2019-07-31 W. T. Barnes , S. J. Bradshaw , N. M. Viall

Observations the Sun's photospheric magnetic field are often confined to the Sun-Earth line. Surface flux transport (SFT) models, such as the Advective Flux Transport (AFT) model, simulate the evolution of the photospheric magnetic field to…

Solar and Stellar Astrophysics · Physics 2024-04-09 Lisa A. Upton , Ignacio Ugarte-Urra , Harry P. Warren , David H. Hathaway

The recent analysis of observations taken with the EIS instrument on Hinode suggests that well constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for…

Solar and Stellar Astrophysics · Physics 2015-06-04 Harry P. Warren , Amy R. Winebarger , David H. Brooks

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

We present the application of the data-driven branch of the MURaM code, which follows the evolution of the active region 11640 over 4 days starting from 2012 December 30 at 12:00 UT and reproduces many key coronal extreme-ultraviolet (EUV)…

Solar and Stellar Astrophysics · Physics 2026-05-14 Feng Chen

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

Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic…

Solar and Stellar Astrophysics · Physics 2025-06-24 Gregory D. Fleishman , Alexey A. Kuznetsov , Gelu M. Nita
‹ Prev 1 2 3 10 Next ›