English
Related papers

Related papers: MHD Mode Conversion around a 2D Magnetic Null Poin…

200 papers

A fast-wave pulse in a simple, cold, inhomogeneous MHD model plasma is constructed by Fourier superposition over frequency of harmonic waves that are singular at their respective Alfven resonances. The pulse partially reflects before…

Solar and Stellar Astrophysics · Physics 2010-11-17 C S Hanson , P S Cally

The solar atmosphere is known to contain many different types of wavelike oscillation. Waves and other fluctuations (e.g., turbulent eddies) are believed to be responsible for at least some of the energy transport and dissipation that heats…

Solar and Stellar Astrophysics · Physics 2023-08-09 Steven R. Cranmer , Momchil E. Molnar

We study the coupling of magneto-acoustic waves to Alven waves using 2.5D numerical simulations. In our experiment, a fast magnetoacoustic wave of a given frequency and wavenumber is generated below the surface. The magnetic field in the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Elena Khomenko , Paul Cally

Null collapse is an implosive process whereby MHD waves focus their energy in the vicinity of a null point, forming a current sheet and initiating magnetic reconnection. We consider, for the first time, the case of collapsing 3D magnetic…

Solar and Stellar Astrophysics · Physics 2018-03-21 J. O. Thurgood , D. I. Pontin , J. A. McLaughlin

A ray-theoretic phase space description of linear waves in a two-fluid (charges and neutrals) magnetized plasma is used to calculate analytic decay rates and mode transmission and conversion coefficients between fast and slow waves in two…

Solar and Stellar Astrophysics · Physics 2023-04-12 Paul S Cally , M. M. Gomez-Miguez

Three-dimensional numerical simulations of magnetoacoustic wave propagation are performed in a sunspot atmosphere with a computational domain covering from the photosphere to the chromosphere. The wave source, with properties resembling the…

Solar and Stellar Astrophysics · Physics 2010-05-21 T. Felipe , E. Khomenko , M. Collados

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

Waves observed in the photosphere and chromosphere of sunspots show complex dynamics and spatial patterns. The interpretation of high-resolution sunspot wave observations requires modeling of three-dimensional non-linear wave propagation…

Solar and Stellar Astrophysics · Physics 2015-05-19 T. Felipe , E. Khomenko , M. Collados

We numerically investigate the excitation and temporal evolution of oscillations in a two-dimensional coronal arcade by including the three-dimensional propagation of perturbations. The time evolution of impulsively generated perturbations…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. Rial , I. Arregui , J. Terradas , R. Oliver , J. L. Ballester

The aim of this work is to study the energy transport by means of MHD waves propagating in quiet Sun magnetic topology from layers below the surface to the corona. Upward propagating waves find obstacles, such as the equipartition layer…

Solar and Stellar Astrophysics · Physics 2015-05-13 Irantzu C. Santamaria , Elena Khomenko , Manuel Collados

Planar acoustically dominated magneto\-hydro\-dynamic waves are initiated at the high-$\beta$ base of a simulated 2D isothermal stratified atmosphere with potential magnetic field exhibiting both open and closed field regions as well as…

Solar and Stellar Astrophysics · Physics 2021-06-23 Jamon D. Pennicott , Paul S. Cally

The highly dynamical, complex nature of the solar atmosphere naturally implies the presence of waves in a topologically varied magnetic environment. Here, the interaction of waves with topological features such as null points is inevitable…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. W. Threlfall , C. E. Parnell , I. De Moortel , K. G. McClements , T. D. Arber

Sunspots are intense regions of magnetic flux that are rooted deep below the photosphere. It is well established that sunspots host magnetohydrodynamic waves, with numerous observations showing a connection to the internal acoustic (or…

Solar and Stellar Astrophysics · Physics 2025-01-07 Hemanthi Miriyala , Richard J. Morton , Elena Khomenko , Patrick Antolin , Gert J. J. Botha

A 2.5D numerical model of magnetoacoustic-Alfv\'en linear mode conversions in the partially ionised low solar atmosphere induced by the Hall effect is surveyed, varying magnetic field strength and inclination, and wave frequency and…

Solar and Stellar Astrophysics · Physics 2021-08-06 Abbas Raboonik , Paul Cally

The interaction of a fast magnetoacoustic wave with a magnetic null point is studied in the context of the sympathetic flare phenomenon. Attention is paid to steepening the wave caused by the finite-amplitude effects in a non-uniform plasma…

Solar and Stellar Astrophysics · Physics 2026-05-07 Yu Zhong , Valery M. Nakariakov , Mariana Cécere , Andrea Costa

We performed 2.5D magnetohydrodynamic (MHD) simulations showing the propagation of fast-mode MHD waves of different initial amplitudes and their interaction with a coronal hole (CH), using our newly developed numerical code. We find that…

In spherical tokamaks, the electron plasma frequency is greater than the electron cyclotron frequency. Electromagnetic waves in the electron cyclotron range of frequencies are unsuitable for directly heating such plasmas due to their…

Plasma Physics · Physics 2018-11-14 N. A. Lopez , A. K. Ram

Certain types of electro-magnetic waves propagating in a plasma can undergo a mode conversion process. In magnetic confinement fusion, this phenomenon is very useful to heat the plasma, since it permits to transfer the heat at or near the…

Plasma Physics · Physics 2019-08-16 Lise-Marie Imbert-Gérard

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 present a new global model of the solar corona, including the low corona, the transition region and the top of chromosphere. The realistic 3D magnetic field is simulated using the data from the photospheric magnetic field measurements.…