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Plasmoids, Flows, and Jets during Magnetic Reconnection in a Failed Solar Eruption
Antiochos, Spiro K.; Kumar, Pankaj; Cho, Kyung-Suk +3 more
We report a detailed analysis of a failed eruption and flare in active region 12018 on 2014 April 3 using multiwavelength observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly, IRIS, STEREO, and Hinode/Solar Optical Telescope. At least four jets were observed to emanate from the cusp of this small active region (large brigh…
Spatial and Temporal Analysis of Quiescent Coronal Rain over an Active Region
Antolin, Patrick; Schad, Thomas A.; Froment, Clara +1 more
The solar corona produces coronal rain, hundreds of times colder and denser material than the surroundings. Coronal rain is known to be deeply linked to coronal heating, but its origin, dynamics, and morphology are still not well understood. The leading theory for its origin is thermal instability (TI) occurring in coronal loops in a state of ther…
Solar Flare Ribbon Fronts. I. Constraining Flare Energy Deposition with IRIS Spectroscopy
Polito, Vanessa; Xu, Yan; Kerr, Graham S. +2 more
Spectral lines formed at lower atmospheric layers show peculiar profiles at the "leading edge" of ribbons during solar flares. In particular, increased absorption of the BBSO/GST He I λ10830 line, as well as broad and centrally reversed profiles in the spectra of the Mg II and C II lines observed by the IRIS satellite, has been reported. In this w…
Numerical Study on Excitation of Turbulence and Oscillation in Above-the-loop-top Region of a Solar Flare
Reeves, Katharine K.; Takasao, Shinsuke; Shibata, Kengo
Extreme-ultraviolet imaging spectroscopic observations often show an increase in line width around the loop-top or above-the-loop-top (ALT) region of solar flares, suggestive of turbulence. In addition, recent spectroscopic observations found the oscillation in the Doppler velocity around the ALT region. We performed 3D magnetohydrodynamic (MHD) s…
Numerical Simulations and Observations of Mg II in the Solar Chromosphere
De Pontieu, Bart; Carlsson, Mats; Hansteen, Viggo H. +3 more
The Mg II h and k lines are among the best diagnostic tools of the upper solar chromosphere. This region of the atmosphere is of particular interest, as it is the lowest region of the Sun's atmosphere where the magnetic field is dominant in the energetics and dynamics, defining its structure. While highly successful in the photosphere and lower to…
Multithermal Jet Formation Triggered by Flux Emergence
Li, Xiaohong; Keppens, Rony; Zhou, Yuhao
Flux emergence is responsible for various solar eruptions. Combining observation and simulations, we investigate the influence of flux emergence at one footpoint of an arcade on coronal rain as well as induced eruptions. The emergence changes the pressure in the loops, and the internal coronal rain all moves to the other side. The emerging flux re…
Chromospheric Heating from Local Magnetic Growth and Ambipolar Diffusion under Nonequilibrium Conditions
Martínez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo H. +3 more
The heating of the chromosphere in internetwork regions remains one of the foremost open questions in solar physics. In the present study, we tackle this old problem by using a very-high-spatial-resolution simulation of quiet-Sun conditions performed with radiative MHD numerical models and interface region imaging spectrograph (IRIS) observations.…
Observational Signatures of Electron-driven Chromospheric Evaporation in a White-light Flare
Warmuth, Alexander; Li, Dong; Ning, Zongjun +7 more
We investigate observational signatures of explosive chromospheric evaporation during a white-light flare (WLF) that occurred on 2022 August 27. Using the moment analysis, bisector techniques, and the Gaussian fitting method, redshifted velocities of less than 20 km s‑1 are detected in low-temperature spectral lines of Hα, C I, and Si I…
Macrospicules and Their Connection to Magnetic Reconnection in the Lower Solar Atmosphere
Shen, Yuandeng; Zhou, Xinping; Duan, Yadan +4 more
Solar macrospicules are beam-like cool plasma ejections of size in between spicules and coronal jets, which can elucidate potential connections between plasma jetting activity at different scales. With high-resolution observations from the New Vacuum Solar Telescope and Solar Dynamics Observatory, we investigate the origin of five groups of recurr…
Reconnection-generated Plasma Flows in the Quasi-separatrix Layer in Localized Solar Corona
Srivastava, Abhishek K.; Kayshap, Pradeep; Pontin, David I. +8 more
Multiwavelength observations of the propagating disturbances (PDs), discovered by Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory (SDO), are analyzed to determine their driving mechanism and physical nature. Two magnetic strands in the localized corona are observed to approach and merge with each other, followed by the gener…