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CHIANTI—An Atomic Database for Emission Lines. XVI. Version 10, Further Extensions
Young, P. R.; Del Zanna, G.; Dere, K. P. +1 more
We present version 10 of the CHIANTI package. In this release, we provide updated atomic models for several helium-like ions and for all the ions of the beryllium, carbon, and magnesium isoelectronic sequences that are abundant in astrophysical plasmas. We include rates from large-scale atomic structure and scattering calculations that are in many…
Coronal Hole Detection and Open Magnetic Flux
Temmer, Manuela; Vršnak, Bojan; Pinto, Rui F. +14 more
Many scientists use coronal hole (CH) detections to infer open magnetic flux. Detection techniques differ in the areas that they assign as open, and may obtain different values for the open magnetic flux. We characterize the uncertainties of these methods, by applying six different detection methods to deduce the area and open flux of a near-disk …
From Pseudostreamer Jets to Coronal Mass Ejections: Observations of the Breakout Continuum
Antiochos, Spiro K.; Lynch, Benjamin J.; Kumar, Pankaj +3 more
The magnetic breakout model, in which reconnection in the corona leads to destabilization of a filament channel, explains numerous features of eruptive solar events, from small-scale jets to global-scale coronal mass ejections (CMEs). The underlying multipolar topology, pre-eruption activities, and sequence of magnetic-reconnection onsets (first b…
First Simultaneous In Situ Measurements of a Coronal Mass Ejection by Parker Solar Probe and STEREO-A
Lugaz, Noé; Scolini, Camilla; Galvin, Antoinette B. +1 more
We present the first Parker Solar Probe mission (PSP)-observed coronal mass ejection (CME) that hits a second spacecraft before the end of the PSP encounter, providing an excellent opportunity to study short-term CME evolution. The CME was launched from the Sun on 2019 October 10 and was measured in situ at PSP on 2019 October 13 and at STEREO-A o…
Coronal Conditions for the Occurrence of Type II Radio Bursts
Monstein, Christian; Kouloumvakos, Athanasios; Warmuth, Alexander +5 more
Type II radio bursts are generally observed in association with flare-generated or coronal-mass-ejection-driven shock waves. The exact shock and coronal conditions necessary for the production of type II radio emission are still under debate. Shock waves are important for the acceleration of electrons necessary for the generation of the radio emis…
Magnetic Flux and Magnetic Nonpotentiality of Active Regions in Eruptive and Confined Solar Flares
Veronig, Astrid M.; Hou, Yijun; Li, Ting +3 more
With the aim of understanding how the magnetic properties of active regions (ARs) control the eruptive character of solar flares, we analyze 719 flares of Geostationary Operational Environmental Satellite (GOES) class ≥C5.0 during 2010-2019. We carry out the first statistical study that investigates the flare-coronal mass ejection (CME) associatio…
The Effect of Stream Interaction Regions on ICME Structures Observed in Longitudinal Conjunction
Lugaz, Noé; Scolini, Camilla; Galvin, Antoinette B. +1 more
We study two interplanetary coronal mass ejections (ICMEs) observed at Mercury and at 1 au by spacecraft in longitudinal conjunction, investigating the question: what causes the drastic alterations observed in some ICMEs during propagation, while other ICMEs remain relatively unchanged? Of the two ICMEs, the first one propagated relatively self-si…
Modeling the 2012 May 17 Solar Energetic Particle Event Using the AWSoM and iPATH Models
Lario, D.; Li, Gang; de Nolfo, G. A. +6 more
We model the 2012 May 17 solar energetic particle event by combining the AWSoM and iPATH codes. Using this combined approach, we investigate particle acceleration when the parent coronal mass ejection (CME) is still close to the Sun. We have obtained reasonable agreements between our simulation and observations made by multiple spacecraft. We foll…
Nonequilibrium Flux Rope Formation by Confined Flares Preceding a Solar Coronal Mass Ejection
Masuda, Satoshi; Liu, Chang; Liu, Rui +3 more
We present evidence that a magnetic flux rope was formed before a coronal mass ejection (CME) and its associated long-duration flare during a pair of preceding confined eruptions and associated impulsive flares in a compound event in NOAA Active Region 12371. Extreme-ultraviolet images and the extrapolated nonlinear force-free field show that the …
Visual Explanation of a Deep Learning Solar Flare Forecast Model and Its Relationship to Physical Parameters
Moon, Yong-Jae; Lim, Daye; Lee, Harim +2 more
In this study, we present a visual explanation of a deep learning solar flare forecast model and its relationship to physical parameters of solar active regions (ARs). For this, we use full-disk magnetograms at 00:00 UT from the Solar and Heliospheric Observatory/Michelson Doppler Imager and the Solar Dynamics Observatory/Helioseismic and Magnetic…