English
Related papers

Related papers: The coronal power spectrum from MHD mode conversio…

200 papers

It is well known that magnetic fields dominate the dynamics in the solar corona, and new generation of numerical modelling of the evolution of coronal magnetic fields, as featured with boundary conditions driven directly by observation…

Solar and Stellar Astrophysics · Physics 2021-04-16 Chaowei Jiang , Xinkai Bian , Tingting Sun , Xueshang Feng

Although the mechanisms responsible for heating the Sun's corona and accelerating the solar wind are still being actively investigated, it is largely accepted that photospheric motions provide the energy source and that the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-18 Roberto Lionello , Marco Velli , Cooper Downs , Jon A. Linker , Zoran Mikić , Andrea Verdini

The sunspot penumbra is a transition zone between the strong vertical magnetic field area (sunspot umbra) and the quiet Sun. The penumbra has a fine filamentary structure that is characterized by magnetic field lines inclined toward the…

Solar and Stellar Astrophysics · Physics 2010-12-02 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

Alfv\'enic waves are thought to play an important role in coronal heating and acceleration of solar wind. Here we investigated the statistical properties of Alfv\'enic waves along spicules (jets that protrude into the corona) in a polar…

Solar and Stellar Astrophysics · Physics 2015-05-28 Takenori J. Okamoto , Bart De Pontieu

We describe the presence of wavefront dislocations in magnetohydrodynamic waves in stratified stellar atmospheres. Scalar dislocations such as edges and vortices can appear in Alfv\'en waves, as well as in general magneto-acoustic waves. We…

Solar and Stellar Astrophysics · Physics 2015-06-16 A. López Ariste , M. Collados , E. Khomenko

Aims. We investigate the transfer of energy between a standing kink mode and azimuthal Alfven waves within an expanding flux tube. We consider the process of resonant absorption in a loop with a non-uniform Alfven frequency profile but in…

Solar and Stellar Astrophysics · Physics 2019-11-06 Thomas Howson , Ineke De Moortel , Patrick Antolin , Tom Van Doorsselaere , Andrew Wright

Alfv\'en-wave turbulence has emerged as an important heating mechanism to accelerate the solar wind. The generation of this turbulent heating is dependent on the presence and subsequent interaction of counter-propagating alfv\'en waves.…

Solar and Stellar Astrophysics · Physics 2022-05-04 Chaitanya Prasad Sishtla , Jens Pomoell , Emilia Kilpua , Simon Good , Farhad Daei , Minna Palmroth

Sunspots are known to be strong absorbers of solar oscillation modal power. The most convincing way to demonstrate this is done via Fourier-Hankel decomposition (FHD), where the local oscillation field is separated into in- and outgoing…

Solar and Stellar Astrophysics · Physics 2021-06-04 Matthias Waidele , Markus Roth , Gangadharan Vigeesh , Kolja Glogowski

We investigate the difference in the spatial distribution of the energy input for parametrizations of different mechanisms to heat the corona of the Sun and possible impacts on the coronal emission. We use a 3D MHD model of a solar active…

Solar and Stellar Astrophysics · Physics 2015-06-15 T. van Wettum , S. Bingert , H. Peter

Alfv\'en waves, considered one of the primary candidates for heating and accelerating the fast solar wind, are ubiquitous in spacecraft observations, yet their origin remains elusive. In this study, we analyze data from the first 19…

A simplified non-linear numerical model for the development of incompressible magnetohydrodynamics (MHD) in the presence of a strong magnetic field B0 and stratification, nicknamed Shell-Atm, is presented. In planes orthogonal to the mean…

Astrophysics · Physics 2011-02-11 E. Buchlin , M. Velli

Magnetohydrodynamic (MHD) simulations of the solar atmosphere are often performed under the assumption that the plasma is fully ionized. However, in the lower solar atmosphere a reduced temperature often results in only the partial…

Solar and Stellar Astrophysics · Physics 2022-11-09 Conor D. MacBride , David B. Jess , Elena Khomenko , Samuel D. T. Grant

Magnetic reconnection in the solar corona is thought to be unstable to the formation of multiple interacting plasmoids, and previous studies have shown that plasmoid dynamics can trigger MHD waves of different modes propagating outward from…

Solar and Stellar Astrophysics · Physics 2018-10-25 Elena Provornikova , J. Martin Laming , Vyacheslav S. Lukin

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

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

We report analysis of sub-Alfv\'enic magnetohydrodynamic (MHD) perturbations in the low-\b{eta} radial-field solar wind using the Parker Solar Probe spacecraft data from 31 October to 12 November 2018. We calculate wave vectors using the…

Solar and Stellar Astrophysics · Physics 2022-01-05 S. Q. Zhao , Huirong Yan , Terry Z. Liu , Mingzhe Liu , Mijie Shi

Recent observations of coronal-loop waves by TRACE and within the corona as a whole by CoMP clearly indicate that the dominant oscillation period is 5 minutes, thus implicating the solar p modes as a possible source. We investigate the…

Astrophysics · Physics 2010-11-11 Bradley W. Hindman , Rekha Jain

Alfv\'en waves may be difficult to excite at the photosphere due to low ionization fraction and suffer near-total reflection at the transition region (TR). Yet they are ubiquitous in the corona and heliosphere. To overcome these…

Solar and Stellar Astrophysics · Physics 2015-06-04 Shelley C. Hansen , Paul S. Cally

We review our recent results of Alfven wave-driven winds. First, we present the result of a self-consistent 1D MHD simulations for solar winds from the photosphere to interplanetary region. Here, we emphasize the importance of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Takeru K. Suzuki

Understanding the evolution of the complex magnetic fields found in solar active regions is an active area of research. There are numerous models for such fields which range in their complexity due to the number of known physical effects…

Solar and Stellar Astrophysics · Physics 2025-02-26 Oliver Rice , Christopher Prior