Evidence of Traveling Waves in Filament Threads

Lin, Yong; Engvold, O.; Voort, L. H. M. Rouppe van der; Noort, M. van

doi:10.1007/s11207-007-0402-8

Cited by 134 publications

(181 citation statements)

References 18 publications

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“…Recent observations of Alfvénic transverse waves in spicules have been reported by, e.g, De Pontieu et al (2007), Zaqarashvili et al (2007), Kim et al (2008), He et al (2009a,b), Okamoto & De Pontieu (2011). In addition, propagating transverse waves in thin threads of solar prominences have been observed (e.g., Lin et al 2007Lin et al , 2009) and Alfvénic waves in bright points have been reported (Jess et al 2009). The role and implications of the observed Alfvénic waves for the heating of the solar atmosphere have been discussed by, e.g., Erdélyi & Fedun (2007); De Pontieu et al (2007); McIntosh et al (2011);Cargill & De Moortel (2011).…”

Section: Introductionmentioning

confidence: 90%

Resonant Alfvén waves in partially ionized plasmas of the solar atmosphere

Soler

Andries

Goossens

2012

A&A

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Context. Magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere. In magnetic waveguides resonant absorption due to plasma inhomogeneity naturally transfers wave energy from large-scale motions to small-scale motions. In the cooler parts of the solar atmosphere as, e.g., the chromosphere, effects due to partial ionization may be relevant for wave dynamics and heating. Aims. We study resonant Alfvén waves in partially ionized plasmas. Methods. We use the multifluid equations in the cold plasma approximation. We investigate propagating resonant MHD waves in partially ionized flux tubes. We use approximate analytical theory based on normal modes in the thin tube and thin boundary approximations along with numerical eigenvalue computations. Results. We find that the jumps of the wave perturbations across the resonant layer are the same as in fully ionized plasmas. The damping length due to resonant absorption is inversely proportional to the frequency, while that due to ion-neutral collisions is inversely proportional to the square of the frequency. For observed frequencies in the solar atmosphere, the amplitude of MHD kink waves is more efficiently damped by resonant absorption than by ion-neutral collisions. Conclusions. Most of the energy carried by chromospheric kink waves is converted into localized azimuthal Alfvén waves that can deposit energy in the coronal medium. The dissipation of wave energy in the chromosphere due to ion-neutral collisions is only effective for high-frequency waves. The chromosphere acts as a filter for kink waves with periods shorter than 10 s.

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Section: Introductionmentioning

confidence: 90%

Resonant Alfvén waves in partially ionized plasmas of the solar atmosphere

Soler

Andries

Goossens

2012

A&A

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“…For instance, observations of filaments made by Lin et al (2005a,b) suggest that the thickness of thin threads forming the filaments is ≤ 250 km, that only a small portion of filament threads are filled with cool plasma, and that this absorbing plasma is continuously flowing along the thread structure with velocities 15 ± 10 km s −1 . Lin (2004) Lin et al (2007) have found evidence for traveling waves in the threaded structure of a filament and, in some cases it seems that the propagating waves move in the same direction as mass flows. They also have determined the wavelength of a propagating wave, obtaining a value of around 3,000 km.…”

Section: Referencementioning

confidence: 99%

Physics of Solar Prominences: II—Magnetic Structure and Dynamics

et al. 2010

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Observations and models of solar prominences are reviewed. We focus on non-eruptive prominences, and describe recent progress in four areas of prominence research: (1) magnetic structure deduced from observations and models, (2) the dynamics of prominence plasmas (formation and flows), (3) Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and large-scale patterns of the filament channels in which prominences are located. Finally, several outstanding issues in prominence research are discussed, along with observations and models required to resolve them.

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“…Small-amplitude magnetohydrodynamic (MHD) waves and oscillations are frequently observed in solar prominence threads Lin et al 2005Lin et al , 2007Lin et al , 2009Mackay et al 2010;Arregui et al 2012). MHD oscillations in prominences are well studied by both slab and tube approximations (Roberts 1991;Joarder & Roberts 1992a, 1992bOliver et al 1993;Joarder et al 1997;Díaz et al 2002Díaz et al , 2005Dymova & Ruderman 2005;Terradas et al 2008;Oliver 2009;Arregui et al 2011Arregui et al , 2012.…”

Section: Introductionmentioning

confidence: 99%

Fast magnetohydrodynamic oscillation of longitudinally inhomogeneous prominence threads: an analogue with quantum harmonic oscillator

Lomineishvili

Zaqarashvili

Zhelyazkov

et al. 2014

A&A

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Context. Previous works indicate that the frequency ratio of second and first harmonics of kink oscillations tends towards 3 in the case of prominence threads. This is not a straightforward result, so it requires adequate explanation. Aims. We aim to study the magnetohydrodynamic oscillations of longitudinally inhomogeneous prominence threads and to shed light on the problem of the frequency ratio. Methods. The classical Sturm-Liouville problem is used for the threads with longitudinally inhomogeneous plasma density. We show that the spatial variation of total pressure perturbations along the thread is governed by the stationary Schrödinger equation, where the longitudinal inhomogeneity of plasma density stands for the potential energy. The Schrödinger equation appears as the equation of quantum harmonic oscillator for a parabolic profile of plasma density. Consequently, the equation has bounded solutions in terms of Hermite polynomials. Results. Boundary conditions at the thread surface lead to a transcendental dispersion equation with Bessel functions. The thin flux tube approximation of the dispersion equation shows that the frequency of kink waves is proportional to the expression α(2n + 1), where α is the density inhomogeneity parameter, and n the longitudinal mode number. Consequently, the ratio of the frequencies of second and first harmonics tends to 3 in prominence threads. The numerical solution of the dispersion equation shows that the ratio decreases only slightly for thicker tubes in the case of less longitudinal inhomogeneity of the external density, therefore the thin flux tube limit is a good approximation for prominence oscillations. However, stronger longitudinal inhomogeneity of external density may lead to the significant shift in the frequency ratio for wider tubes, and therefore the thin tube approximation may fail. Conclusions. The tendency of frequency ratio of second and first harmonics towards 3 in prominence threads is explained by the analogy of the oscillations with quantum harmonic oscillator, where the density inhomogeneity of the threads plays a role as the potential energy.

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Evidence of Traveling Waves in Filament Threads

Cited by 134 publications

References 18 publications

Resonant Alfvén waves in partially ionized plasmas of the solar atmosphere

Resonant Alfvén waves in partially ionized plasmas of the solar atmosphere

Physics of Solar Prominences: II—Magnetic Structure and Dynamics

Fast magnetohydrodynamic oscillation of longitudinally inhomogeneous prominence threads: an analogue with quantum harmonic oscillator

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