High-Frequency Dynamics of Active Region Moss as Observed by IRIS

Narang, Nancy; Pant, Vaibhav; Banerjee, D.; Doorsselaere, Tom Van

doi:10.3389/fspas.2019.00036

Cited by 4 publications

(2 citation statements)

References 37 publications

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“…Shock waves have also been studied (using coordinated data from DST or Hinode) in sunspot light bridges, with their provenance tied to magnetic reconnection and leakage of photospheric waves (Tian et al, 2018a;Bai et al, 2019). Similar processes have been invoked to explain the presence of high-frequency signals discovered in active-region plage (Narang et al, 2019). To determine whether these phenomena play a significant role in the local energy balance, novel techniques such as the IRIS 2 database and new methods to accurately determine shock-wave properties (Ruan et al, 2018), in combination with coordinated observations, will be very useful.…”

Section: Observationsmentioning

confidence: 99%

A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)

et al. 2021

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The Interface Region Imaging Spectrograph (IRIS) has been obtaining near- and far-ultraviolet images and spectra of the solar atmosphere since July 2013. IRIS is the highest resolution observatory to provide seamless coverage of spectra and images from the photosphere into the low corona. The unique combination of near- and far-ultraviolet spectra and images at sub-arcsecond resolution and high cadence allows the tracing of mass and energy through the critical interface between the surface and the corona or solar wind. IRIS has enabled research into the fundamental physical processes thought to play a role in the low solar atmosphere such as ion–neutral interactions, magnetic reconnection, the generation, propagation, and dissipation of waves, the acceleration of non-thermal particles, and various small-scale instabilities. IRIS has provided insights into a wide range of phenomena including the discovery of non-thermal particles in coronal nano-flares, the formation and impact of spicules and other jets, resonant absorption and dissipation of Alfvénic waves, energy release and jet-like dynamics associated with braiding of magnetic-field lines, the role of turbulence and the tearing-mode instability in reconnection, the contribution of waves, turbulence, and non-thermal particles in the energy deposition during flares and smaller-scale events such as UV bursts, and the role of flux ropes and various other mechanisms in triggering and driving CMEs. IRIS observations have also been used to elucidate the physical mechanisms driving the solar irradiance that impacts Earth’s upper atmosphere, and the connections between solar and stellar physics. Advances in numerical modeling, inversion codes, and machine-learning techniques have played a key role. With the advent of exciting new instrumentation both on the ground, e.g. the Daniel K. Inouye Solar Telescope (DKIST) and the Atacama Large Millimeter/submillimeter Array (ALMA), and space-based, e.g. the Parker Solar Probe and the Solar Orbiter, we aim to review new insights based on IRIS observations or related modeling, and highlight some of the outstanding challenges.

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Section: Observationsmentioning

confidence: 99%

A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)

et al. 2021

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“…Cho et al, 2016). The use of EMD has also allowed for an advancement of our understanding of MHD waves and oscillations in solar coronal loops (Terradas et al, 2004) and at chromospheric and transition region heights (Narang et al, 2019) with typical periods of a few minutes, and for identification of quasi-periodic oscillatory modes in long-lived solar facular regions with periods ranging from several minutes to a few hours (Kolotkov et al, 2017;Strekalova et al, 2018). Oscillatory variabilities in the longer-term solar proxies with periods from about a month up to the entire solar cycle were found with EMD in 10.7 cm solar radio flux and sunspot records (Zolotova and Ponyavin, 2007;Mei et al, 2018), coronal Fe XIV emission (Deng et al, 2015), flare activity index and occurrence rate of coronal mass ejections (Deng et al, 2019;Gao et al, 2012), total and surface solar irradiance (Li et al, 2012;Lee et al, 2015;Bengulescu et al, 2018), helioseismic frequency shift (Kolotkov et al, 2015a), spatio-temporal dynamics of the solar magnetic field (Vecchio et al, 2012) and in the Sun-as-a-star observations of the solar mean magnetic field (Xiang and Qu, 2016), solar radius data (Qu et al, 2015), and also in direct numerical simulations of convection-driven dynamos (Käpylä et al, 2016).…”

Section: Empirical Mode Decomposition For Analysis Of Oscillatory Pro...mentioning

confidence: 99%

Novel Data Analysis Techniques in Coronal Seismology

et al. 2022

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A New Type of Jet in a Polar Limb of the Solar Coronal Hole

Cho

Moon

Cho

et al. 2019

ApJL

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A new type of chromospheric jet in a polar limb of a coronal hole is discovered in the Ca ii filtergram of the Solar Optical Telescope on board the Hinode. We identify 30 jets in a filtered Ca ii movie with a duration of 53 minutes. The average speed at their maximum heights is found to be 132 ± 44 km s−1 ranging from 57 to 264 km s−1 along the propagation direction. The average lifetime is 20 ± 6 ranging from 11 to 36 s. The speed and lifetime of the jets are located at end-tails of those parameters determined for type II spicules, hence implying a new type of jets. To confirm whether these jets are different from conventional spicules, we construct a time–height image averaged over a horizontal region of 1″, and calculate lagged cross-correlations of intensity profiles at each height with the intensity at 2 Mm. From this, we obtain a cross-correlation map as a function of lag and height. We find that the correlation curve as a function of lag time is well fitted into three different Gaussian functions whose standard deviations of the lag time are 193, 42, and 17 s. The corresponding propagation speeds are calculated to be 9 km s−1, 67 km s−1, and 121 km s−1, respectively. The kinematic properties of the former two components seem to correspond to the 3-minute oscillations and type II spicules, while the latter component to the jets is addressed in this study.

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High-Frequency Dynamics of Active Region Moss as Observed by IRIS

Cited by 4 publications

References 37 publications

A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)

A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)

Novel Data Analysis Techniques in Coronal Seismology

A New Type of Jet in a Polar Limb of the Solar Coronal Hole

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