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Related papers: Reflection and dissipation of Alfv\'en waves in in…

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Two dimensional compressible magneto-hydrodynamical (MHD) simulations run for 20 crossing times on a 800x640 grid with two stable thermal states show persistent hierarchical density structures and Kolmogorov turbulent motions in the…

Astrophysics · Physics 2009-10-31 Bruce G. Elmegreen

We have performed MHD simulations of Alfven wave propagation along an open flux tube in the solar atmosphere. In our numerical model, Alfven waves are generated by the photospheric granular motion. As the wave generator, we used a derived…

Solar and Stellar Astrophysics · Physics 2015-05-18 Takuma Matsumoto , Kazunari Shibata

System-scale magnetohydrodynamic (MHD) waves within Earth's magnetosphere are often understood theoretically using box models. While these have been highly instructive in understanding many fundamental features of the various wave modes…

Space Physics · Physics 2022-02-01 M. O. Archer , D. J. Southwood , M. D. Hartinger , L. Rastaetter , A. N. Wright

We investigate dispersive and kinetic effects on the evolution of a two-dimensional kinked Alfv\'en wave packet by comparing results from MHD, Hall-MHD and hybrid simulations of a low-$\beta$ plasma. We find that the Hall term determines…

Solar and Stellar Astrophysics · Physics 2026-05-07 Anna Tenerani , Carlos González , Nikos Sioulas , Chen Shi , Marco Velli

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Carlos Rijs , Hamed Moradi , Damien Przybylski , Paul S. Cally

We (Li et al. 2009; Paper-I) compared the magnetic field directions inferred from polarimetry data obtained from 100-pc scale inter-cloud media (ICM) and from sub-pc scale molecular cloud cores. The highly correlated result led us to…

Astrophysics of Galaxies · Physics 2019-08-10 Y. Zhang , Z. Guo , H. H. Wang , H-b Li

Counterpropagating Alfv\'en waves are ubiquitously observed in many astrophysical environments, such as a star surface and a planetary foreshock. We discuss an efficient particle acceleration mechanism in two counterpropagating circularly…

High Energy Astrophysical Phenomena · Physics 2023-04-06 S. Isayama , K. Takahashi , S. Matsukiyo , T. Sano

We study the scattering of low-energy Cosmic Rays (CRs) in a turbulent, compressive MHD fluid. We show that compressible MHD modes -- fast or slow waves with wave lengths smaller than CR mean free paths induce cyclotron instability in CRs.…

Astrophysics · Physics 2009-11-11 Alex Lazarian , Andrey Beresnyak

Rockets and satellites have previously observed small-scale Alfv\'en waves inside large-scale downward field-aligned currents and numerical simulations have associated their formation with self-consistent magnetosphere-ionosphere coupling.…

Space Physics · Physics 2013-04-05 Alexander J. B. Russell , Andrew N. Wright

We present numerical studies of compressible, decaying turbulence, with and without magnetic fields, with initial rms Alfven and Mach numbers ranging up to five, and apply the results to the question of the support of star-forming…

Astrophysics · Physics 2009-10-30 Mordecai-Mark Mac Low , Ralf S. Klessen , Andreas Burkert , Michael D. Smith

Cool stars at giant and supergiant evolutionary phases present low velocity and high density winds, responsible for the observed high mass-loss rates. Although presenting high luminosities, radiation pressure on dust particles is not…

Astrophysics · Physics 2009-11-11 D. Falceta-Goncalves , A. A. Vidotto , V. Jatenco-Pereira

Nonlinear energy transfer and dissipation in Alfv\'en wave turbulence are analyzed in the first gyrokinetic simulation spanning all scales from the tail of the MHD range to the electron gyroradius scale. For typical solar wind parameters at…

Plasma Physics · Physics 2015-07-10 D. Told , F. Jenko , J. M. TenBarge , G. G. Howes , G. W. Hammett

We consider the ideal magnetohydrodynamics (MHD) subjected to a strong magnetic field along $x_1$ direction in three-dimensional thin domains $\Omega_\delta=\mathbb{R}^2\times(-\delta,\delta)$ with slip boundary conditions. It is well-known…

Analysis of PDEs · Mathematics 2018-04-02 Li Xu

Observations of magnetic field strengths imply that molecular cloud fragments are individually close to being in a magnetically critical state, even though both magnetic field and column density measurements range over two orders of…

Astrophysics · Physics 2007-05-23 Shantanu Basu

The subject of this study is oscillations in the lower atmosphere in coronal-hole regions, where the conditions are favorable for propagation between the atmospheric layers. Based on spectroscopic observations in photospheric and…

Solar and Stellar Astrophysics · Physics 2021-12-22 Andrei Chelpanov , Nikolai Kobanov , Maksim Chelpanov , Aleksandr Kiselev

We study theoretically mode conversion and resonant overreflection of magnetohydrodynamic waves in an inhomogeneous plane-stratified plasma in the presence of a nonuniform shear flow, using precise numerical calculations of the reflection…

Plasma Physics · Physics 2022-12-21 Seulong Kim , Kihong Kim

A three-dimensional MHD model for the propagation and dissipation of Alfven waves in a coronal loop is developed. The model includes the lower atmospheres at the two ends of the loop. The waves originate on small spatial scales (less than…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. A. van Ballegooijen , M. Asgari-Targhi , S. R. Cranmer , E. E. DeLuca

We describe how analytic solutions for linear hydromagnetic waves can be used for testing cosmological magnetohydrodynamic (MHD) codes. We start from the comoving MHD equations and derive analytic solutions for the amplitude evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-03 Thomas Berlok

Turbulence in an accretion disk launches Alfv\'en waves (AWs) that propagate away from the disk along magnetic field lines. Because the Alfv\'en speed varies with distance from the disk, the AWs undergo partial non-WKB reflection, and…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Benjamin D. G. Chandran , Francois Foucart , Alexander Tchekhovskoy

Context: MHD waves and magnetic null points are both prevalent in many astrophysical plasmas, including the solar atmosphere. Interaction between waves and null points has been implicated as a possible mechanism for localised heating…

Solar and Stellar Astrophysics · Physics 2015-06-16 J. O. Thurgood , J. A. McLaughlin