Transition region counterpart of a moving magnetic feature

Lin, Chia Hsien; Banerjee, D.; O’Shea, E.; Doyle, J. G.

doi:10.1051/0004-6361:20065688

Cited by 8 publications

(6 citation statements)

References 16 publications

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“…Chromospheric LOS velocity derived from the Ca ii core shift also shows variations on various time scales from upflows to downflows. This fact, together with the variable intensity enhancement observed in Ca ii frames, might suggest the presence of traveling waves (Lin et al 2006). This issue will be investigated in a subsequent study.…”

Section: Type N Featuresmentioning

confidence: 84%

High cadence spectropolarimetry of moving magnetic features observed around a pore

Criscuoli

Moro

Giannattasio

et al. 2012

A&A

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Context. Moving magnetic features (MMFs) are small-size magnetic elements that are seen to stream out from sunspots, generally during their decay phase. Several observational results presented in the literature suggest them to be closely related to magnetic filaments that extend from the penumbra of the parent spot. Nevertheless, few observations of MMFs streaming out from spots without penumbra have been reported. The literature still lacks analyses of the physical properties of these features. Aims. We investigate physical properties of monopolar MMFs observed around a small pore that had developed penumbra in the days preceding our observations and compare our results with those reported in the literature for features observed around sunspots.Methods. We analyzed NOAA 11005 during its decay phase with data acquired at the Dunn Solar Telescope in the Fe i 617.3 nm and the Ca ii 854.2 nm spectral lines with IBIS, and in the G-band. The field of view showed monopolar MMFs of both polarities streaming out from the leading negative polarity pore of the observed active region. Combining different analyses of the data, we investigated the temporal evolution of the relevant physical quantities associated with the MMFs as well as the photospheric and chromospheric signatures of these features. Results. We show that the characteristics of the investigated MMFs agree with those reported in the literature for MMFs that stream out from spots with penumbrae. Moreover, observations of at least two of the observed features suggest them to be manifestations of emerging magnetic arches.

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Section: Type N Featuresmentioning

confidence: 84%

High cadence spectropolarimetry of moving magnetic features observed around a pore

Criscuoli

Moro

Giannattasio

et al. 2012

A&A

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“…Thus, currently it is difficult to validate the existence of these strong internetwork magnetic elements above the photosphere. However, in an active region Lin et al (2006) found a correlation between localized emission enhancement above the photosphere (in the chromosphere and TR) and a moving magnetic feature, which followed the boundary of a supergranulation cell. Zhang & Zhang (2000) analyzed quiet-Sun photospheric and chromospheric magnetograms observed by the vector video magnetograph at Huairou Solar Observing Station, and found that all visible variations in the photosphere had corresponding variations in the chromosphere, although the Hβ line, which they used to derive the chromospheric magnetogram, are complicated and may include signals from both the photosphere and chromosphere.…”

Section: Magneto-convection In the Chromospherementioning

confidence: 88%

Horizontal supergranule-scale motions inferred from TRACE ultraviolet observations of the chromosphere

Potts

Marsch

Attié

et al. 2010

A&A

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Aims. We study horizontal supergranule-scale motions revealed by TRACE observation of the chromospheric emission, and investigate the coupling between the chromosphere and the underlying photosphere. Methods. A highly efficient feature-tracking technique called balltracking has been applied for the first time to the image sequences obtained by TRACE (transition region and coronal explorer) in the passband of white light and the three ultraviolet passbands centered at 1700 Å, 1600 Å, and 1550 Å. The resulting velocity fields have been spatially smoothed and temporally averaged in order to reveal horizontal supergranule-scale motions that may exist at the emission heights of these passbands. Results. We find indeed a high correlation between the horizontal velocities derived in the white-light and ultraviolet passbands. The horizontal velocities derived from the chromospheric and photospheric emission are comparable in magnitude. Conclusions. The horizontal motions derived in the UV passbands might indicate the existence of a supergranule-scale magnetoconvection in the chromosphere, which may shed new light on the study of mass and energy supply to the corona and solar wind at the height of the chromosphere. However, it is also possible that the apparent motions reflect the chromospheric brightness evolution as produced by acoustic shocks which might be modulated by the photospheric granular motions in their excitation process, or advected partly by the supergranule-scale flow towards the network while propagating upward from the photosphere. To reach a firm conclusion, it is necessary to investigate the role of granular motions in the excitation of shocks through numerical modeling, and future high-cadence chromospheric magnetograms must be scrutinized.

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“…Nye et al (1984) reported a case in which the MMF is clearly associated with a bright feature in the Ca II K line wing but is undetectable in the K line core, implying that the erupting magnetic flux loop associated with this MMF must lie in the low chromosphere. However, Lin et al (2006) found an MMF associated with a bright patch both in the chromosphere and the transition region. Concerning the association between the MMF and the chromospheric jet, Morita et al (2010) identified a case showing that a chromospheric anemone jet may be caused by anMMF colliding with the preexisting magnetic flux.…”

Section: Introductionmentioning

confidence: 91%

Observational Evidence for the Causes and Consequences of Chromospheric Reconnection

Yan

Xia

et al. 2015

ApJ

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The chromospheric anemone jets with an inverse "Y" shape are ubiquitous, as revealed by the Solar Optical Telescope observations. These jets are considered to be consequences of chromospheric magnetic reconnections. Although these jets have been studied intensively, the dynamics and their driving causes remain unclear observationally. In this work, we report a case of a chromospheric jet showing complete observational evidencefor the cause and consequence of chromospheric intermittent reconnection. The intermittent eruption of this jet shows two distinct quasi-periods, 50-60 s and 600-700 s. The short-period eruptions may be related to the plasmoidinduced reconnection, and the long-period ones may be interpreted as sequences of cycles of energy storage and release during magnetic reconnections. The observations also reveal Alfvénic waves with a mean period around 88 s and a maximum transverse displacement around 0″ .26. The jet is hosted by a loop moving smoothly with a horizontal speed of ∼0.4 km s −1 . Our results provide observational evidence supporting the magnetic reconnection model of the formation of the chromospheric jets with related products, in which the loop advection drives intermittent magnetic reconnections, and the reconnection outflows carrying plasmoids collide further with the ambient field linesand finally excitewaves and jets.

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Transition region counterpart of a moving magnetic feature

Cited by 8 publications

References 16 publications

High cadence spectropolarimetry of moving magnetic features observed around a pore

High cadence spectropolarimetry of moving magnetic features observed around a pore

Horizontal supergranule-scale motions inferred from TRACE ultraviolet observations of the chromosphere

Observational Evidence for the Causes and Consequences of Chromospheric Reconnection

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