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Lin, Yong; Engvold, O.; Wiik, J. E.

doi:10.1023/a:1026150809598

Cited by 138 publications

(152 citation statements)

References 2 publications

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“…Deng et al (2002) found counter-streaming in an active region filament. Lin et al (2003) and observed such flows in large polar crown filaments two days before filament eruptions, so the counterstreaming may be a signature of the slow rise of a filament before eruption. With new high-resolution observations such as those by Hinode, many more examples of counterstreaming are expected to be found.…”

Section: Filament Barbsmentioning

confidence: 94%

“…2. Prominence plasma is predominantly dynamic, exhibiting horizontal and/or vertical motions of order 10-70 km s −1 (Kubota and Uesugi, 1986;Zirker et al, 1998a;Kucera et al, 2003;Lin et al, 2003;Okamoto et al, 2007;Chae et al, 2008). Quiescent filaments can go through phases of enhanced internal motion and activity (Martin, 1973;Tandberg-Hanssen, 1995;Kucera et al, 2006), altering the amount of cool material in the filament (Kilper et al, 2009).…”

Section: Plasma Structure and Dynamicsmentioning

confidence: 99%

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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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Section: Filament Barbsmentioning

confidence: 94%

Section: Plasma Structure and Dynamicsmentioning

confidence: 99%

Physics of Solar Prominences: II—Magnetic Structure and Dynamics

et al. 2010

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“…These models indicate that the plasma in prominences should have significant dynamical motion and static models may be obsolete. Observations performed by the Swedish Solar Telescope (SST) show highly dynamic plasma in filament threads (Lin et al 2003(Lin et al , 2005 and were also used in a first attempt to compute the velocity vectors of the filament threads. The authors conclude that the threads' inclinations from the horizontal were about 16 degrees with a net flow in both directions of 8 km s −1 .…”

Section: Introductionmentioning

confidence: 99%

Velocity vectors of a quiescent prominence observed byHinode/SOT and the MSDP (Meudon)

Schmieder¹,

Chandra²,

Berlicki

et al. 2010

A&A

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Context. The dynamics of prominence fine structures present a challenge to our understanding of the formation of cool plasma prominence embedded in the hot corona. Aims. Observations performed by the high resolution Hinode/SOT telescope allow us to compute velocities perpendicular to the lineof-sight or transverse velocities. Combining simultaneous observations obtained in Hα with Hinode/SOT and the MSDP spectrograph operating in the Meudon solar tower, we derive the velocity vectors of a quiescent prominence. Methods. The velocities perpendicular to the line-of-sight are measured using a time-slice technique and the Doppler shifts velocity using the bisector method.Results. The Doppler shifts of bright threads derived from the MSDP show counterstreaming of the order of 5 km s −1 in the prominence and reaching 15 km s −1 at the edges of the prominence. Even though they are minimum values because of seeing effects, they are of the same order as the transverse velocities. Conclusions. These measurements are very important because they suggest that the vertical structures detected by SOT may not be true vertical magnetic structures in the sky plane. The vertical structures could be a pile up of dips in more or less horizontal magnetic field lines in a 3D perspective, as proposed by many MHD modelers. In our analysis, we also calibrate the Hinode Hα data using MSDP observations obtained simultaneously.

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“…In Hα quiescent filaments, the observed velocities range from 5 to 20 km s −1 (Zirker et al 1998;Lin et al 2003Lin et al , 2005Lin et al , 2007Schmieder et al 2008;Chae et al 2006;Labrosse et al 2010) and, because of the physical conditions in filament plasma, they seem to be field-aligned. Also, the presence in filaments of oscillating absorbing features which, at the same time, move along the filament axis has been reported (Lin 2004).…”

Section: Introductionmentioning

confidence: 99%

Time damping of non-adiabatic magnetohydrodynamic waves in a partially ionised prominence medium: Effect of a background flow

Barceló

Carbonell

Ballester

2010

A&A

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Context. The simultaneous occurrence of flows and time damped small-amplitude oscillations in solar prominences is a common phenomenon. These oscillations are mostly interpreted in terms of magnetohydrodynamic (MHD) waves. Aims. We study the time damping of linear non-adiabatic MHD waves in a flowing partially ionised plasma with prominence-like physical conditions. Methods. Considering non-adiabatic single fluid equations for a partially ionised hydrogen plasma, we have solved our dispersion relations for the complex frequency, ω, and we have analysed the behavior of the period, damping time and the ratio of the damping time to the period, versus the real wavenumber k, for Alfvén, fast, slow, and thermal waves. Results. While in the case without flow there is a critical wavenumber at which the period of Alfvén and fast waves goes to infinite, when a flow is present two different critical wavenumbers appear. The smaller wavenumber depends on the flow speed and causes the period of the high-period branch to go to infinite. When the second critical wavenumber is attained the period of both branches become equal. In general, the time damping of Alfvén and fast waves is dominated by resistive effects, and its damping ratio is very inefficient when compared to observations. The damping of slow and thermal waves is basically dominated by non-adiabatic effects, and for slow waves it is possible to obtain a damping ratio close to observations, although it would correspond to long period oscillations with large damping times not often observed. The consideration of a structured medium produces new features such as the apparition of four critical wavenumbers for Alfvén waves, and one critical wavenumber for slow waves. For fast waves, constrained propagation substantially improves, within the range of observed wavelengths, the ratio of the damping time to period. Conclusions. The presence of a background flow in a partially ionised plasma gives place to new interesting features when the time damping of MHD waves is studied. In general, the results point out that ion-neutral collisions are an inefficient mechanism to explain the observed time damping of prominence oscillations if they are produced by Alfvén and fast waves. If the oscillations are produced by slow waves, only long period oscillations with large damping times produce damping ratios in agreement with observations.

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Cited by 138 publications

References 2 publications

Physics of Solar Prominences: II—Magnetic Structure and Dynamics

Physics of Solar Prominences: II—Magnetic Structure and Dynamics

Velocity vectors of a quiescent prominence observed byHinode/SOT and the MSDP (Meudon)

Time damping of non-adiabatic magnetohydrodynamic waves in a partially ionised prominence medium: Effect of a background flow

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