scholarly journals Numerical simulations and simplified models of nonlinear electron inertial Alfvén waves

1998 ◽  
Vol 103 (A9) ◽  
pp. 20419-20433 ◽  
Author(s):  
R. Rankin ◽  
V. T. Tikhonchuk
Keyword(s):  
Numerical Simulations ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Simplified Models ◽  
Inertial Alfvén Waves

scholarly journals Numerical simulations of the lower solar atmosphere heating by two-fluid nonlinear Alfvén waves

2020 ◽  
Vol 639 ◽  
pp. A45
Author(s):  
B. Kuźma ◽  
D. Wójcik ◽  
K. Murawski ◽  
D. Yuan ◽  
S. Poedts
Keyword(s):  
Magnetic Flux ◽  
Numerical Simulations ◽  
Solar Atmosphere ◽  
Flux Tube ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Magnetic Flux Tube ◽  
Alfvén Waves ◽  
Two Fluid ◽  
Lower Solar Atmosphere

Context. We present new insight into the long-standing problem of plasma heating in the lower solar atmosphere in terms of collisional dissipation caused by two-fluid Alfvén waves. Aims. Using numerical simulations, we study Alfvén wave propagation and dissipation in a magnetic flux tube and their heating effect. Methods. We set up 2.5-dimensional numerical simulations with a semi-empirical model of a stratified solar atmosphere and a force-free magnetic field mimicking a magnetic flux tube. We consider a partially ionized plasma consisting of ion + electron and neutral fluids, which are coupled by ion-neutral collisions. Results. We find that Alfvén waves, which are directly generated by a monochromatic driver at the bottom of the photosphere, experience strong damping. Low-amplitude waves do not thermalize sufficient wave energy to heat the solar atmospheric plasma. However, Alfvén waves with amplitudes greater than 0.1 km s−1 drive through ponderomotive force magneto-acoustic waves in higher atmospheric layers. These waves are damped by ion-neutral collisions, and the thermal energy released in this process leads to heating of the upper photosphere and the chromosphere. Conclusions. We infer that, as a result of ion-neutral collisions, the energy carried initially by Alfvén waves is thermalized in the upper photosphere and the chromosphere, and the corresponding heating rate is large enough to compensate radiative and thermal-conduction energy losses therein.

Solar coronal heating by Alfvén waves in bi-kappa distributed plasma

2019 ◽  
Vol 491 (2) ◽  
pp. 2403-2412 ◽  
Author(s):  
Imran A Khan ◽  
Z Iqbal ◽  
G Murtaza
Keyword(s):  
Distribution Function ◽  
Velocity Distribution ◽  
Particle Interaction ◽  
Velocity Distribution Function ◽  
Alfven Waves ◽  
Coronal Heating ◽  
Alfvén Waves ◽  
Heating Process ◽  
Thermal Features ◽  
Inertial Alfvén Waves

ABSTRACT In solar physics, there is a decades-old conundrum that is still unsolved. Why is the temperature of the corona so much larger than that of the surface of the Sun? To solve this, various approaches have been adopted so far, but they have certain limitations. In the present analysis, we invoke the standard Vlasov model and the steady-state Poynting theorem to unlock the mysterious coronal heating mechanism in terms of inertial and kinetic Alfvén waves whose electromagnetic energies turn into heat during wave–particle interaction. The coronal plasmas that support these waves are modelled by a non-thermal bi-kappa velocity distribution function. The non-thermal distribution function, which is assumed to pre-exist in the system, strongly influences the wave-heating process. Particularly, during heating by the waves in the inertial limit, the non-thermal features of the distribution function give rise to a unique competition (which is entirely absent in the usual Maxwellian plasmas) between waves of different perpendicular wavenumbers (kx). For small kx, when either the non-thermal parameter κ or the electron parallel temperature T||e increases, the inertial Alfvén waves can efficiently heat the plasma in their immediate vicinity. However, for relatively large kx, an increase in either κ or T||e enables the inertial Alfvén waves to effectively heat the plasma in remote regions in the corona. Although such competition is not seen in the kinetic limit, the non-thermal features still seem to control the heating process. The possible explanations behind the above-mentioned cases are provided by the bi-kappa velocity distribution function, which holds vital clues as to how the non-thermal features, together with kx, dictate the resonance conditions that play a crucial role in the heating process.

On the dispersion and damping of kinetic and inertial Alfvén waves in Cairns distributed plasmas

2019 ◽  
Vol 26 (6) ◽  
pp. 062101
Author(s):  
S. Ayaz ◽  
Imran A. Khan ◽  
G. Murtaza
Keyword(s):  
Alfven Waves ◽  
Alfvén Waves ◽  
Inertial Alfvén Waves

scholarly journals Nonlinear interactions between three inertial Alfvén waves

2007 ◽  
Vol 73 (1) ◽  
pp. 9-13 ◽  
Author(s):  
G. BRODIN ◽  
L. STENFLO ◽  
P. K. SHUKLA
Keyword(s):  
Temperature Effects ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Nonlinear Interactions ◽  
Resonant Coupling ◽  
Inertial Alfvén Waves

Abstract.The resonant coupling between Alfvén waves is reconsidered. New results are found for cold magnetoplasmas where temperature effects are negligible.

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