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The Parker or field line tangling model of coronal heating is investigated through long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics (RMHD).…

Solar and Stellar Astrophysics · Physics 2010-02-15 A. F. Rappazzo , M. Velli , G. Einaudi

Transverse magnetohydrodynamic (MHD) waves have been shown to be ubiquitous in the solar atmosphere and can in principle carry sufficient energy to generate and maintain the Sun's million-degree outer atmosphere or corona. However, direct…

Solar and Stellar Astrophysics · Physics 2015-08-19 Takenori J. Okamoto , Patrick Antolin , Bart De Pontieu , Han Uitenbroek , Tom Van Doorsselaere , Takaaki Yokoyama

Propagating transverse waves are thought to be a key transporter of Poynting flux throughout the Sun's atmosphere. Recent studies have shown that these transverse motions, interpreted as the magnetohydrodynamic kink mode, are prevalent…

Solar and Stellar Astrophysics · Physics 2022-01-05 Richard J. Morton , Ajay K. Tiwari , Tom Van Doorsselaere , James A. McLaughlin

There is considerable observational evidence of implosion of magnetic loop systems inside solar coronal active regions following high energy events like solar flares. In this work, we propose that such collapse can be modeled in three…

Solar and Stellar Astrophysics · Physics 2017-12-27 Aveek Sarkar , Bhargav Vaidya , Soumitra Hazra , Jishnu Bhattacharyya

Plasma in the Sun's hot corona expands into the heliosphere as a supersonic and highly magnetized solar wind. This paper provides an overview of our current understanding of how the corona is heated and how the solar wind is accelerated.…

Solar and Stellar Astrophysics · Physics 2015-08-19 S. R. Cranmer , M. Asgari-Targhi , M. P. Miralles , J. C. Raymond , L. Strachan , H. Tian , L. N. Woolsey

High-resolution observations show the fine structure of the global equilibrium magnetic field configuration in solar atmosphere to be essentially different from that assumed in the traditional 'potential + force-free' field scenarios. The…

Solar and Stellar Astrophysics · Physics 2012-05-01 L. A. Pustil'nik , N. R. Ikhsanov , N. G. Beskrovnaya

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

A model is presented for generation of fast solar wind in coronal holes, relying on heating that is dominated by turbulent dissipation of MHD fluctuations transported upwards in the solar atmosphere. Scale-separated transport equations…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Verdini , M. Velli , W. H. Matthaeus , S. Oughton , P. Dmitruk

Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…

Solar and Stellar Astrophysics · Physics 2010-05-18 George H. Fisher

A hot corona is suggested to be above the standard thin disk. The anisotropy of hard X-ray emission in radio-quiet active galactic nuclei implies that the corona is not static and probably moves outwards like winds. We perform…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Xiao-Hong Yang , De-Fu Bu , Qi-Xiu Li

We present results revealing microwave pulsations produced in a model of a flaring twisted solar coronal loop, without any external oscillatory driver. Two types of oscillations are identified: slowly-decaying oscillations with a period of…

Solar and Stellar Astrophysics · Physics 2022-02-09 C. Smith , M. Gordovskyy , P. K. Browning

One of the mechanisms proposed for heating the corona above solar active regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on previous work, we provide observational evidence for the existence of high-frequency MHD waves…

Fast-mode magnetohydrodynamic (MHD) waves in the solar corona are often known to be produced by solar flares and eruptive prominences. We here simulate the effect of the interaction of an external perturbation on a magnetic null in the…

Solar and Stellar Astrophysics · Physics 2024-11-05 Sripan Mondal , A. K. Srivastava , David I. Pontin , Eric R. Priest , R. Kwon , Ding Yuan

Recent observations with the Atmospheric Imaging Assembly (AIA) instrument on the SDO spacecraft have revealed the existence of decayless coronal kink oscillations. These transverse oscillations are not connected to any external phenomena…

Solar and Stellar Astrophysics · Physics 2019-06-06 K. Karampelas , T. Van Doorsselaere , D. J. Pascoe , M. Guo , P. Antolin

The standing MHD modes in a zero-$\beta$ cylindrical magnetic flux tube modelled as a straight core surrounded by a magnetically twisted annulus, both embedded in a straight ambient external field is considered. The dispersion relation for…

Astrophysics · Physics 2009-11-13 K. Karami , M. Barin

Low-frequency turbulence in the solar chromosphere remains poorly understood. We address 1) the sources of low-frequency turbulence that potentially heat the chromosphere, and 2) how turbulence is transported and dissipated throughout the…

From the the solar photosphere to the outer heliosphere, the Sun's plasma properties are fluctuating with a broad range of temporal and spatial scales. In fact, a turbulent cascade of energy from large to small scales is a frequently…

Solar and Stellar Astrophysics · Physics 2018-08-30 Steven R. Cranmer

Solar flares and coronal mass ejections, the primary space weather disturbances affecting the entire heliosphere and near-Earth environment, mainly emanate from sunspot regions harbouring high degrees of magnetic twist. However, it is not…

Solar and Stellar Astrophysics · Physics 2023-06-01 Shin Toriumi , Hideyuki Hotta , Kanya Kusano

We propose a novel one-dimensional model that includes both shock and turbulence heating and qualify how these processes contribute to heating the corona and driving the solar wind. Compressible MHD simulations allow us to automatically…

Solar and Stellar Astrophysics · Physics 2018-02-21 Munehito Shoda , Takaaki Yokoyama , Takeru K. Suzuki

A single open magnetic flux tube spanning the solar photosphere (solar radius R) and the lower corona (R + 10 Mm) is modelled in magnetohydrostatic equilibrium within a realistic stratified atmosphere subject to solar gravity. Such flux…

Solar and Stellar Astrophysics · Physics 2014-06-16 Frederick Armstrong Gent , Viktor Fedun , Stuart John Mumford , Robertus Erdelyi