Polarization Calibration of the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO)

Schou, J.; Borrero, J. M.; Norton, A. A.; Tomczyk, S.; Elmore, D.; Card, G.

doi:10.1007/s11207-010-9639-8

Cited by 153 publications

(112 citation statements)

References 9 publications

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“…The CME resulting from this eruption was observed by the Large Angle and Spectrometric Coronagraph (LASCO; Brueckner et al 1995) on board the Solar and Heliospheric Observatory (SOHO). Magnetograms obtained by the Helioseismic and Magnetic Imager (HMI; Schou et al 2012bSchou et al , 2012a on board SDO provide the magnetic context of the eruption's source region.…”

Section: Instrumentsmentioning

confidence: 99%

A Prominence Eruption Driven by Flux Feeding From Chromospheric Fibrils

Zhang

Wang

et al. 2014

ApJ

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We present multi-wavelength observations of a prominence eruption originating from a quadrupolar field configuration, in which the prominence was embedded in a side arcade. Within the two-day period prior to its eruption on 2012 October 22, the prominence was perturbed three times by chromospheric fibrils underneath, which rose upward, became brightened, and merged into the prominence, resulting in horizontal flows along the prominence axis, suggesting that the fluxes carried by the fibrils were incorporated into the magnetic field of the prominence. These perturbations caused the prominence to oscillate and to rise faster than before. The absence of intense heating within the first two hours after the onset of the prominence eruption, which followed an exponential increase in height, indicates that ideal instability played a crucial role. The eruption involved interactions with the other side arcade, leading up to a twin coronal mass ejection, which was accompanied by transient surface brightenings in the central arcade, followed by transient dimmings and brightenings in the two side arcades. We suggest that flux feeding from chromospheric fibrils might be an important mechanism to trigger coronal eruptions.

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Section: Instrumentsmentioning

confidence: 99%

A Prominence Eruption Driven by Flux Feeding From Chromospheric Fibrils

Zhang

Wang

et al. 2014

ApJ

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“…To compensate for this, each AIA frame was normalised to its respective exposure time, resulting in a time series where true changes in intensity could clearly be observed. The magnetic topology of the observed active region was studied with SDO Helioseismic and Magnetic Imager (HMI; Schou et al 2012) line-of-sight magnetograms.…”

Section: Instruments and Datamentioning

confidence: 99%

Failed filament eruption inside a coronal mass ejection in active region 11121

Kuridze

Mathioudakis

Kowalski

et al. 2013

A&A

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Aims. We study the formation and evolution of a failed filament eruption observed in NOAA active region 11121 near the southeast limb on November 6, 2010. Methods. We used a time series of SDO/AIA 304, 171, 131, 193, 335, and 94 Å images, SDO/HMI magnetograms, as well as ROSA and ISOON Hα images to study the erupting active region. Results. We identify coronal loop arcades associated with a quadrupolar magnetic configuration, and show that the expansion and cancellation of the central loop arcade system over the filament is followed by the eruption of the filament. The erupting filament reveals a clear helical twist and develops the same sign of writhe in the form of inverse γ-shape. Conclusions. The observations support the "magnetic breakout" process in which the eruption is triggered by quadrupolar reconnection in the corona. We propose that the formation mechanism of the inverse γ-shape flux rope is the magnetohydrodynamic helical kink instability. The eruption has failed because of the large-scale, closed, overlying magnetic loop arcade that encloses the active region.

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“…The discussion of the temporal evolution and morphology of the active region NOAA 11126 is based on full-disk images and line-of-sight (LOS) magnetograms obtained with the Helioseismic and Magnetic Imager (HMI, Schou et al 2012;Couvidat et al 2012;Wachter et al 2012) on board the Solar Dynamics Observatory (SDO). Since the Hinode FOV is too small to cover the entire active region and provide an overview of the magnetic field topology, we show in Fig.…”

Section: Sdo/hmi Full-disk Imagesmentioning

confidence: 99%

Horizontal flow fields observed in Hinode G-band images

Verma

Balthasar

Deng

et al. 2012

A&A

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Context. Generation and dissipation of magnetic fields is a fundamental physical process on the Sun. In comparison to flux emergence and the initial stages of sunspot formation, the demise of sunspots still lacks a comprehensive description. Aims. The evolution of sunspots is most commonly discussed in terms of their intensity and magnetic field. Here, we present additional information about the three-dimensional flow field in the vicinity of sunspots towards the end of their existence. Methods. We present a subset of multi-wavelengths observations obtained with the Japanese Hinode mission, the Solar Dynamics Observatory (SDO), and the Vacuum Tower Telescope (VTT) at Observatorio del Teide, Tenerife, Spain during the time period 2010 November 18−23. Horizontal proper motions were derived from G-band and Ca ii H images, whereas line-of-sight velocities were extracted from VTT echelle Hα λ656.28 nm spectra and Fe i λ630.25 nm spectral data of the Hinode/Spectro-Polarimeter, which also provided three-dimensional magnetic field information. The Helioseismic and Magnetic Imager on board SDO provided continuum images and line-of-sight magnetograms, in addition to the high-resolution observations for the entire disk passage of the active region. Results. We perform a quantitative study of photospheric and chromospheric flow fields in and around decaying sunspots. In one of the trailing sunspots of active region NOAA 11126, we observe moat flow and moving magnetic features (MMFs), even after its penumbra had decayed. We also detect a superpenumbral structure around this pore. We find that MMFs follow well-defined, radial paths from the spot all the way to the border of a supergranular cell surrounding the spot. In contrast, flux emergence near the other sunspot prevents the establishment of similar well ordered flow patterns, which could be discerned around a tiny pore of merely 2 Mm diameter. After the disappearance of the sunspots/pores, a coherent patch of abnormal granulation remained at their location, which was characterized by more uniform horizontal proper motions, low divergence values, and smaller photospheric Doppler velocities. This region, thus, differs significantly from granulation and other areas covered by G-band bright points. We conclude that this peculiar flow pattern is a signature of sunspot decay and the dispersal of magnetic flux.

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Polarization Calibration of the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO)

Cited by 153 publications

References 9 publications

A Prominence Eruption Driven by Flux Feeding From Chromospheric Fibrils

A Prominence Eruption Driven by Flux Feeding From Chromospheric Fibrils

Failed filament eruption inside a coronal mass ejection in active region 11121

Horizontal flow fields observed in Hinode G-band images

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