Longitudinal Plasma Motions Generated by Shear Alfvén Waves in Plasma with Thermal Misbalance

Белов, С. А.; Farahani, S. Vasheghani; Molevich, N. E.; Zavershinskii, D. I.

doi:10.1007/s11207-021-01850-0

Cited by 9 publications

(18 citation statements)

References 42 publications

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“…In case of nonlinear shear Alfvén waves, only the ponderomotive force features in the equation analogues to Eq. (30), see (Belov et al 2021b).…”

Section: Longitudinal Velocitymentioning

confidence: 99%

“…The solution expressed by Eq. ( 32) for torsional waves has the same form as the solution for shear waves (Belov et al 2021b):…”

Section: Longitudinal Velocitymentioning

confidence: 99%

“…However they can generate compressional plasma motions in the nonlinear regime (Hollweg 1971;Vasheghani Farahani et al 2011). Belov et al (2021b) showed that compressional plasma motions generated by shear Alfvén waves could be affected by the thermal misbalance. This is reflected by the term which is exponentially dependent on the coordinate along the magnetic field appearing in the expression for the induced longitudinal motions.…”

Section: Introductionmentioning

confidence: 99%

“…In the present paper, a further step is taken to study the nonlinearly induced longitudinal motions due to Alfvén waves when thermal misbalance is associated with the solar plasma magnetic structure. Belov et al (2021b) studied the nonlinear effects connected with shear Alfvén waves in the presence of thermal misbalance, in particular, the deviations of phase shifts and amplitudes of the induced longitudinal motions. Therefore, the aim here is to compare the phase shifts and amplitudes of the longitudinal motions induced by the torsional Alfvén wave with the analogous longitudinal motions induced by the shear Alfvén wave, as well as, to check the efficiency of this generation due to various environmental effects like plasma-β, which is directly related to the magnetic field in the solar atmospheric conditions.…”

Section: Introductionmentioning

confidence: 99%

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Propagating torsional Alfvén waves in thermally active solar plasma

Белов

Farahani

Molevich

2022

Monthly Notices of the Royal Astronomical Society

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The aim of this study is to shed light on the effects connected with thermal misbalance due to non-equal cooling and heating rates induced by density and temperature perturbations in solar active regions hosting either propagating torsional or shear Alfvén waves. A description for the non-linear forces connected with Alfvén waves in non-ideal conditions is provided, based on the second-order thin flux tube approximation. This provides insight into the effects of Alfvén-induced motions on the boundary of thin magnetic structures in thermally active plasmas. The equations describing the process of generating longitudinal velocity perturbations, together with density perturbations by non-linear torsional Alfvén waves, are obtained and solved analytically. It is shown that the phase shift (compared with the ideal case) and the amplitude of the induced longitudinal plasma motions against the period of the mother Alfvén wave are greater for shear Alfvén waves compared with torsional Alfvén waves, although following the same pattern. The difference in the influence of thermal misbalance on the induced velocity perturbations is governed by the plasma-β although its effect is stronger for shear waves. It is deduced that for a harmonic Alfvén driver the induced density perturbations are left uninfluenced by the thermal misbalance.

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“…In case of nonlinear shear Alfvén waves, only the ponderomotive force features in the equation analogues to Eq. (30), see (Belov et al 2021b).…”

Section: Longitudinal Velocitymentioning

confidence: 99%

“…The solution expressed by Eq. ( 32) for torsional waves has the same form as the solution for shear waves (Belov et al 2021b):…”

Section: Longitudinal Velocitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Propagating torsional Alfvén waves in thermally active solar plasma

Белов

Farahani

Molevich

2022

Monthly Notices of the Royal Astronomical Society

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“…• Revealing the effects and implications of TM on other MHD eigenmodes of coronal plasma structures, such as fast MA waves and torsional Alfvén waves. The ground for this has been recently seeded in, for example, [62], where nonlinear shear Alfvén waves in a plasma with TM were considered. • Development and applications of the theory of TM, accounting for the effects of parallel non-uniformity of the coronal plasma, i.e.…”

Section: Summary and Prospectsmentioning

confidence: 99%

The solar corona as an active medium for magnetoacoustic waves

Kolotkov

Zavershinskii

Nakariakov

2021

Plasma Phys. Control. Fusion

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The presence and interplay of continuous cooling and heating processes maintaining the corona of the Sun at the observed one million K temperature were recently understood to have crucial effects on the dynamics and stability of magnetoacoustic (MA) waves. These essentially compressive waves perturb the coronal thermal equilibrium, leading to the phenomenon of a wave-induced thermal misbalance (TM). Representing an additional natural mechanism for the exchange of energy between the plasma and the wave, TM makes the corona an active medium for MA waves, so that the wave can not only lose but also gain energy from the coronal heating source (similarly to burning gases, lasers and masers). We review recent achievements in this newly emerging research field, focussing on the effects that slow-mode MA waves experience as a back-reaction of this perturbed coronal thermal equilibrium. The new effects include enhanced frequency-dependent damping or amplification of slow waves, and effective, not associated with the coronal plasma non-uniformity, dispersion. We also discuss the possibility to probe the unknown coronal heating function by observations of slow waves and linear theory of thermal instabilities. The manifold of the new properties that slow waves acquire from a thermodynamically active nature of the solar corona indicate a clear need for accounting for the effects of combined coronal heating/cooling processes not only for traditional problems of the formation and evolution of prominences and coronal rain, but also for an adequate modelling and interpretation of magnetohydrodynamic waves.

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Alfvén Waves in the Solar Atmosphere

Magyar

2024

Alfvén Waves Across Heliophysics

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Longitudinal Plasma Motions Generated by Shear Alfvén Waves in Plasma with Thermal Misbalance

Cited by 9 publications

References 42 publications

Propagating torsional Alfvén waves in thermally active solar plasma

Propagating torsional Alfvén waves in thermally active solar plasma

The solar corona as an active medium for magnetoacoustic waves

Alfvén Waves in the Solar Atmosphere

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