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Related papers: Wave transformations near a coronal magnetic null-…

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Context: Supersonic nonthermal motions in molecular clouds are often interpreted as long-lived magnetohydrodynamic (MHD) waves. The propagation and amplitude of these waves is affected by local physical characteristics, most importantly the…

Astrophysics of Galaxies · Physics 2015-06-05 C. Pinto , A. Verdini , D. Galli , M. Velli

Recently it was found that helical magnetized flows efficiently amplify Alfv\'en waves (Rogava et al. 2003, A&A, v.399, p.421). This robust and manifold nonmodal effect was found to involve regimes of transient algebraic growth (for purely…

Astrophysics · Physics 2009-11-07 Andria Rogava , Gianluigi Bodo , Silvano Massalgia , Zaza Osmanov

Measurements and simulations of inertial compressive turbulence in the solar wind are characterized by anti-correlated magnetic fluctuations parallel to the mean field and density structures. This signature has been interpreted as…

Space Physics · Physics 2018-03-14 Trevor A. Bowen , Samuel Badman , Petr Hellinger , Stuart D. Bale

We used long duration, high quality, unresolved (Sun-as-a star) observations collected by the ground based network BiSON and by the instruments GOLF and VIRGO on board the ESA/NASA SOHO satellite to search for solar-cycle-related changes in…

Solar and Stellar Astrophysics · Physics 2010-04-21 R. Simoniello , W. Finsterle , R. A. Garcia , D. Salabert , A. Jimenez , Y. Elsworth , H. Schunker

Phase mixing of Alfv\'en waves has been studied extensively as a possible coronal heating mechanism but without the full thermodynamic consequences considered self-consistently. It has been argued that in some cases, the thermodynamic…

Solar and Stellar Astrophysics · Physics 2020-04-01 H. J. Van Damme , I. De Moortel , P. Pagano , C. D. Johnston

Non-uniformity plays an important role for MHD waves. For a uniform plasma of infinite extent the MHD waves can be subdivided in two classes with distinct properties. The first class contains the Alfv\'en waves. The Alfv\'en waves are…

Solar and Stellar Astrophysics · Physics 2025-11-19 Marcel Goossens , Iñigo Arregui , Roberto Soler , Jaume Terradas , Tom Van Doorsselaere

Two-dimensional ideal incompressible magnetohydrodynamic (MHD) linear waves at the surface of a rotating sphere are studied as a model to imitate the outermost layer of the Earth's core or the solar tachocline. This thin conducting layer is…

Fluid Dynamics · Physics 2024-12-23 Ryosuke Nakashima , Shigeo Yoshida

We perform global unstratified 3D magnetohydrodynamic simulations of an astrophysical boundary layer (BL) -- an interface region between an accretion disk and a weakly magnetized accreting object such as a white dwarf -- with the goal of…

Solar and Stellar Astrophysics · Physics 2015-06-12 Mikhail A. Belyaev , Roman R. Rafikov , James. M. Stone

Using radiation magnetohydrodynamic simulations of the solar atmospheric layers from the upper convection zone to the lower corona, we investigate the self-consistent excitation of slow magneto-acoustic body waves (slow modes) in a magnetic…

Solar and Stellar Astrophysics · Physics 2016-08-17 Yoshiaki Kato , Osker Steiner , Viggo Hansteen , Boris Gudiksen , Sven Wedemeyer , Mats Carlsson

We aim to understand the formation of dense cores by magnetosonic waves in regions where the thermal to magnetic pressure ratio is small. Because of the low-ionisation fraction in molecular clouds, neutral and charged particles are weakly…

Astrophysics · Physics 2009-11-13 S. Van Loo , S. A. E. G. Falle , T. W. Hartquist , A. J. Barker

We investigate the behaviour of nonlinear, nonideal Alfv\'en wave propagation within an inhomogeneous magnetic environment. The governing MHD equations are solved in 1D and 2D using both analytical techniques and numerical simulations. We…

Solar and Stellar Astrophysics · Physics 2015-03-18 J. A. McLaughlin , I. De Moortel , A. W. Hood

Magnetohydrodynamic (MHD) waves are candidates for heating the solar chromosphere, although it is still unclear which mode of the wave is dominant in heating. We perform two-dimensional radiative MHD simulation to investigate the…

Solar and Stellar Astrophysics · Physics 2021-08-04 Yikang Wang , Takaaki Yokoyama , Haruhisa Iijima

We investigate the effect of a strong large scale magnetic field on the reflection of high frequency acoustic modes in rapidly oscillating Ap stars. To that end we consider a toy model composed of an isothermal atmosphere matched onto a…

Astrophysics · Physics 2009-11-13 S. G. Sousa , M. S. Cunha

Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised. The lower chromosphere contains neutral atoms, the existence of which greatly increases the efficiency of the damping of waves due to…

Astrophysics · Physics 2009-11-11 J. E. leake , T. D. Arber , M. L. Khodachenko

With the ultimate aim of using the fundamental or $f$-mode to study helioseismic aspects of turbulence-generated magnetic flux concentrations, we use randomly forced hydromagnetic simulations of a piecewise isothermal layer in two…

Solar and Stellar Astrophysics · Physics 2015-06-19 Nishant K. Singh , Axel Brandenburg , S. M. Chitre , Matthias Rheinhardt

We carry out two-dimensional magnetohydrodynamic (MHD) simulations of an ensemble of Alfv\'enic fluctuations propagating in a structured, expanding solar wind including the presence of fast and slow solar wind streams. Using an appropriate…

Solar and Stellar Astrophysics · Physics 2020-01-15 Chen Shi , Marco Velli , Anna Tenerani , Franco Rappazzo , Victor Réville

One view of the solar-wind turbulence is that the observed highly anisotropic fluctuations at spatial scales near the proton inertial length $d_p$ may be considered as Kinetic Alfv\'en waves (KAWs). In the present paper, we show how…

Solar and Stellar Astrophysics · Physics 2015-12-09 C. L. Vasconez , F. Pucci , F. Valentini , S. Servidio , W. H. Matthaeus , F. Malara

In this Letter we establish clear evidence for the resonant absorption damping mechanism by analyzing observational data from the novel Coronal Multi-Channel Polarimeter (CoMP). This instrument has established that in the solar corona there…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Verth , M. Goossens , J. Terradas

In the approximation of linear dissipative magnetohydrodynamics (MHD) it can be shown that driven MHD waves in magnetic plasmas with high Reynolds number exhibit a near resonant behaviour if the frequency of the wave becomes equal to the…

Astrophysics · Physics 2010-06-18 C. T. M. Clack , I. Ballai , M. S. Ruderman

We study the role the the p-mode-like vertical oscillation on the photosphere in driving solar winds in the framework of Alfven-wave-driven winds. By performing one-dimensional magnetohydrodynamical numerical simulations from the…

Solar and Stellar Astrophysics · Physics 2022-11-10 Kimihiko Shimizu , Munehito Shoda , Takeru K. Suzuki