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Related papers: Coronal loops above an Active Region - observation…

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Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated…

Astrophysics · Physics 2009-11-13 J. A. Klimchuk , S. Patsourakos , P. J. Cargill

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…

We report preliminary results from a series of numerical simulations of the reduced magnetohydrodynamic equations, used to describe the dynamics of magnetic loops in active regions of the solar corona. A stationary velocity field is applied…

Astrophysics · Physics 2009-10-31 Pablo Dmitruk , Daniel Gomez

We present observations of high temperature emission in the core of a solar active region using instruments on Hinode and SDO. These multi-instrument observations allow us to determine the distribution of plasma temperatures and follow the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Harry P. Warren , David H. Brooks , Amy R. Winebarger

We aim to study the influence of radiative cooling on the standing kink oscillations of a coronal loop. Using the FLASH code, we solved the 3D ideal magnetohydrodynamic equations. Our model consists of a straight, density enhanced and…

Solar and Stellar Astrophysics · Physics 2015-10-30 N. Magyar , T. Van Doorsselaere , A. Marcu

A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and…

Solar and Stellar Astrophysics · Physics 2018-03-14 Takuma Matsumoto

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

We perform a number of numerical simulations of the solar corona with the aim to understand how it responds to different conditions in the photosphere. By changing parameters which govern the motion of the plasma at the photosphere we study…

Solar and Stellar Astrophysics · Physics 2014-11-20 Leandro F. Gomes de Jesus , Boris V. Gudiksen

A forward model is described in which we synthesize spectra from an ab-initio 3D MHD simulation of an outer stellar atmosphere, where the coronal heating is based on braiding of magnetic flux due to photospheric footpoint motions. We…

Astrophysics · Physics 2009-11-10 H. Peter , B. V. Gudiksen , A. Nordlund

The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross sectional area of the loops is expected to depend on the temperature and pressure, and might be…

Solar and Stellar Astrophysics · Physics 2015-06-18 M. Guarrasi , F. Reale , S. Orlando , A. Mignone , J. A. Klimchuk

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…

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

In this paper we seek to understand the timescale on which the photospheric motions on the Sun braid coronal magnetic field lines. This is a crucial ingredient for determining the viability of the braiding mechanism for explaining the high…

Solar and Stellar Astrophysics · Physics 2018-09-19 Simon Candelaresi , David Pontin , Anthony Yeates , Paul Bushby , Gunnar Hornig

The corona is a layer of hot plasma that surrounds the Sun, traces out its complex magnetic field, and ultimately expands into interplanetary space as the supersonic solar wind. Although much has been learned in recent decades from advances…

Solar and Stellar Astrophysics · Physics 2019-09-11 Steven R. Cranmer , Amy R. Winebarger

The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that…

Solar and Stellar Astrophysics · Physics 2015-05-28 Amy Winebarger , Joan Schmelz , Harry Warren , Steve Saar , Vinay Kashyap

The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that coronal loops in the core of an active region are not seen cooling through lower temperatures and therefore are…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ignacio Ugarte-Urra , Harry P. Warren , David H. Brooks

The present study provides statistical information on the coronal magnetic field and intensity properties of small-scale bright and faint loops in the quiet Sun. We aim to quantitatively investigate the morphological and topological…

Solar and Stellar Astrophysics · Physics 2024-10-16 Maria S. Madjarska , Thomas Wiegelmann , Pascal Démoulin , Klaus Galsgaard

The heating of coronal loops is investigated to understand the observational consequences in terms of the thermodynamics and radiative losses from the Sun as well as the magnetized coronae of stars with an outer convective envelope. The…

Solar and Stellar Astrophysics · Physics 2018-07-02 A. F. Rappazzo , R. B. Dahlburg , G. Einaudi , M. Velli

Images of the solar corona by extreme-ultraviolet (EUV) telescopes reveal elegant arches of glowing plasma that trace the corona's magnetic field. Typically, these loops are preferentially illuminated segments of an arcade of vaulted field…

Solar and Stellar Astrophysics · Physics 2021-11-17 Bradley W. Hindman , Rekha Jain

Long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out, within the framework of reduced magnetohydrodynamics (RMHD), to understand coronal heating driven by motion of field lines…

Astrophysics · Physics 2008-11-26 A. F. Rappazzo , M. Velli , G. Einaudi , R. B. Dahlburg
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