Search Publications
Quasiperiodic Super-Alfvénic Slippage along Flare Ribbons Observed by the Interface Region Imaging Spectrograph
Hou, Yijun; Li, Ting; Zhou, Guiping +3 more
The apparent slipping motion of flare loops is regarded as a key feature of the 3D magnetic reconnection in the solar flares. The slippage with a super-Alfvénic speed could be defined as slipping–running reconnection, while the slippage with a sub-Alfvénic speed is called slipping reconnection. Due to the limitation of the observational instrument…
Temporal Evolution of a Network Jet's Physical Properties Inferred from FISS/GST and IRIS Observations
Yurchyshyn, Vasyl; Chae, Jongchul; Cho, Kyuhyoun +6 more
Small-scale jets, such as chromospheric and transition region (TR) network jets, are of great interest regarding coronal heating and solar wind acceleration. Spectroscopic analysis based on multiple spectral lines with different formation temperatures is essential for understanding the physical properties and driving mechanisms of jets. Here, we c…
ALMA Observations of Solar Spicules in a Polar Coronal Hole
Nindos, A.; White, S. M.; Shimojo, M. +2 more
We report observations of solar spicules at millimeter wavelengths (mm-λ) using the Atacama Large Millimeter/submillimeter Array (ALMA). These are supplemented by observations in optical, ultraviolet (UV), and extreme ultraviolet (EUV) wavelengths. The observations were made on 2018 December 25 of the northern polar coronal hole. ALMA obtained tim…
Solar Variability in the Mg II h and k Lines
Solanki, S. K.; Shapiro, A. I.; Krivova, N. A. +3 more
Solar irradiance and its variations in the ultraviolet (UV) control the photochemistry in Earth's atmosphere and influence Earth's climate. The variability in the Mg II h and k core-to-wing ratio, also known as the Mg II index, is highly correlated with the solar UV irradiance variability. Because of this, the Mg II index is routinely used as a pr…
Simultaneous Existence of Oscillations, Counterstreaming Flows, and Mass Injections in Solar Quiescent Prominences
Xu, Zhe; Xue, Zhike; Yan, Xiaoli +8 more
Solar prominences are very spectacular structures embedded in the tenuous and hot solar corona. Counterstreaming flows, a common feature in solar quiescent prominences, have been discovered for more than 20 yr. However, the mechanism driving the counterstreaming flows is still elusive. To unveil the nature of this phenomenon, we analyzed data of a…
On the Magnetic and Thermodynamic Properties of Dark Fibrils in the Chromosphere
Kriginsky, Matheus; Oliver, Ramon
Fibrillar structures are ubiquitous in the solar chromosphere. An accurate determination of their properties requires the use of advanced high-resolution observations, which are now becoming broadly available from different observatories. We exploit the capabilities of multi-atom, multiline spectropolarimetric inversions using the Stockholm Invers…
CHIANTI—An Atomic Database for Emission Lines—Paper. XVIII. Version 11, Advanced Ionization Equilibrium Models: Density and Charge Transfer Effects
Young, P. R.; Del Zanna, G.; Dere, K. P. +4 more
Version 11 of the CHIANTI database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si, and S), and represent a significant improvement especially when modeling the solar transition region. The models include the effects of higher electron density an…
Inferring Fundamental Properties of the Flare Current Sheet Using Flare Ribbons: Oscillations in the Reconnection Flux Rates
Kazachenko, Maria D.; Lynch, Benjamin J.; Corchado Albelo, Marcel F.
Magnetic reconnection is understood to be the main physical process that facilitates the transformation of magnetic energy into heat, motion, and particle acceleration during solar eruptions. Yet, observational constraints on reconnection region properties and dynamics are limited due to a lack of high-cadence and high-spatial-resolution observati…
Magnetic Fields and Plasma Heating in the Sun's Atmosphere
Kleint, L.; de Wijn, A. G.; Tritschler, A. +3 more
We use the first publicly available data from the Daniel K. Inouye Solar Telescope to track magnetic connections from the solar photosphere into the corona. We scrutinize relationships between chromospheric magnetism and bright chromospheric, transition region, and coronal plasmas. In 2022 June, the Visible Spectro-Polarimeter (ViSP) instrument ta…
Solar Flare Ribbon Fronts. II. Evolution of Heating Rates in Individual Flare Footpoints
Polito, Vanessa; Xu, Yan; Kerr, Graham S. +1 more
Solar flare ribbon fronts appear ahead of the bright structures that normally characterize solar flares, and can persist for an extended period of time in spatially localized patches before transitioning to "regular" bright ribbons. They likely represent the initial onset of flare energy deposition into the chromosphere. Chromospheric spectra (e.g…