Search Publications
Probing Velocity Dispersion Inside Coronal Mass Ejections: New Insights on Their Initiation
Mierla, Marilena; Reiss, Martin A.; Banerjee, Dipankar +4 more
This work studies the kinematics of the leading edge and the core of six coronal mass ejections (CMEs) in the combined field of view of Sun Watcher using Active Pixel System detector and Image Processing (SWAP) on board PRoject for On-Board Autonomy (PROBA-2) and the ground-based K-Cor coronagraph of the Mauna Loa Solar Observatory. We report, for…
Simultaneous High Dynamic Range Algorithm, Testing, and Instrument Simulation
Chamberlin, Phillip C.; Jin, Meng; Woods, Thomas N. +4 more
Within an imaging instrument's field of view, there may be many observational targets of interest. Similarly, within a spectrograph's bandpass, there may be many emission lines of interest. The brightness of these targets and lines can be orders of magnitude different, which poses a challenge to instrument and mission design. A single exposure can…
Formation of Coronal Mass Ejection and Posteruption Flow of Solar Wind on 2010 August 18 Event
Slemzin, Vladimir; Goryaev, Farid; Rodkin, Denis
The state of the space environment plays a significant role in the forecasting of geomagnetic storms produced by disturbances of the solar wind (SW). Coronal mass ejections (CMEs) passing through the heliosphere often have a prolonged (up to several days) trail with declining speed, which affects propagation of the subsequent SW streams. We studie…
Turbulent Generation of Magnetic Switchbacks in the Alfvénic Solar Wind
Cranmer, Steven R.; Shoda, Munehito; Chandran, Benjamin D. G.
One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensional direct numerical simulation of the equations of compressible magnetohydrodynamics from the corona to 40 solar radii, we investigate whether magnetic switchbacks emerge…
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 …
Detection of Flare Multiperiodic Pulsations in Mid-ultraviolet Balmer Continuum, Lyα, Hard X-Ray, and Radio Emissions Simultaneously
Li, Gang; Gan, Weiqun; Li, Xiaobo +7 more
Quasi-periodic pulsations (QPPs), which usually appear as temporal pulsations of the total flux, are frequently detected in the light curves of solar/stellar flares. In this study, we present the investigation of nonstationary QPPs with multiple periods during the impulsive phase of a powerful flare on 2017 September 6, which were simultaneously m…
A Model for the Coupled Eruption of a Pseudostreamer and Helmet Streamer
Lynch, B. J.; Antiochos, S. K.; Kumar, P. +3 more
A highly important aspect of solar activity is the coupling between eruptions and the surrounding coronal magnetic field topology, which determines the trajectory and morphology of the event and can even lead to sympathetic eruptions from multiple sources. In this paper, we report on a numerical simulation of a new type of coupled eruption, in whi…
LOFAR Observations of a Jet-driven Piston Shock in the Low Solar Corona
Gallagher, Peter T.; Zucca, Pietro; Carley, Eoin P. +2 more
The Sun produces highly dynamic and eruptive events that can drive shocks through the corona. These shocks can accelerate electrons, which result in plasma emission in the form of a type II radio burst. Despite the large number of type II radio burst observations, the precise origin of coronal shocks is still subject to investigation. Here, we pre…
A Comparison of Flare Forecasting Methods. IV. Evaluating Consecutive-day Forecasting Patterns
Leka, K. D.; Gallagher, Peter T.; Murray, Sophie A. +21 more
A crucial challenge to successful flare prediction is forecasting periods that transition between "flare-quiet" and "flare-active." Building on earlier studies in this series in which we describe the methodology, details, and results of flare forecasting comparison efforts, we focus here on patterns of forecast outcomes (success and failure) over …
Multipoint Study of Successive Coronal Mass Ejections Driving Moderate Disturbances at 1 au
Poedts, Stefaan; Scolini, Camilla; West, Matthew J. +10 more
We analyze in this work the propagation and geoeffectiveness of four successive coronal mass ejections (CMEs) that erupted from the Sun during 2013 May 21-23 and were detected in interplanetary space by the Wind and/or STEREO-A spacecraft. All these CMEs featured critical aspects for understanding so-called “problem space weather storms” at Earth.…