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How Many CMEs Have Flux Ropes? Deciphering the Signatures of Shocks, Flux Ropes, and Prominences in Coronagraph Observations of CMEs
Li, Y.; Lynch, B. J.; Howard, R. A. +1 more
We intend to provide a comprehensive answer to the question on whether all Coronal Mass Ejections (CMEs) have flux rope structure. To achieve this, we present a synthesis of the LASCO CME observations over the last 16 years, assisted by 3D MHD simulations of the breakout model, EUV and coronagraphic observations from STEREO and SDO, and statistics…
Propagation of Interplanetary Coronal Mass Ejections: The Drag-Based Model
Möstl, C.; Temmer, M.; Rollett, T. +9 more
We present the "Drag-Based Model" (DBM) of heliospheric propagation of interplanetary coronal mass ejections (ICMEs). The DBM is based on the hypothesis that the driving Lorentz force, which launches a CME, ceases in the upper corona and that beyond a certain distance the dynamics becomes governed solely by the interaction of the ICME and the ambi…
Solar Flare Prediction Using Advanced Feature Extraction, Machine Learning, and Feature Selection
Gallagher, Peter T.; Bloomfield, D. Shaun; Colak, Tufan +3 more
Novel machine-learning and feature-selection algorithms have been developed to study: i) the flare-prediction-capability of magnetic feature (MF) properties generated by the recently developed Solar Monitor Active Region Tracker (SMART); ii) SMART's MF properties that are most significantly related to flare occurrence. Spatiotemporal association a…
On-Orbit Degradation of Solar Instruments
Schmutz, W.; Berghmans, D.; Auchère, F. +38 more
We present the lessons learned about the degradation observed in several space solar missions, based on contributions at the Workshop about On-Orbit Degradation of Solar and Space Weather Instruments that took place at the Solar Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on 3 May 2012. The aim of this workshop was …
Origins of Rolling, Twisting, and Non-radial Propagation of Eruptive Solar Events
Vourlidas, Angelos; Velli, Marco; Panasenco, Olga +1 more
We demonstrate that major asymmetries in erupting filaments and CMEs, namely major twists and non-radial motions are typically related to the larger-scale ambient environment around eruptive events. Our analysis of prominence eruptions observed by the STEREO, SDO, and SOHO spacecraft shows that prominence spines retain, during the initial phases, …
Stealth Coronal Mass Ejections: A Perspective
Howard, Timothy A.; Harrison, Richard A.
"Stealth CME" has become a commonly used term in recent studies of solar activity. It refers to a coronal mass ejection (CME) with no apparent solar surface association, and therefore has no easily identifiable signature to locate the region on the Sun from which the CME erupted. We review the literature and express caution in categorising CMEs in…
Three-Dimensional Evolution of Erupted Flux Ropes from the Sun (2 - 20 R ⊙) to 1 AU
Kilpua, E. K. J.; Vourlidas, A.; Isavnin, A.
Studying the evolution of magnetic clouds entrained in coronal mass ejections using in-situ data is a difficult task, since only a limited number of observational points is available at large heliocentric distances. Remote sensing observations can, however, provide important information for events close to the Sun. In this work we estimate the flu…
Initiation of Coronal Mass Ejections by Sunspot Rotation
van Driel-Gesztelyi, L.; Temmer, M.; Veronig, A. M. +3 more
We study a filament eruption, two-ribbon flare, and coronal mass ejection (CME) that occurred in NOAA Active Region 10898 on 6 July 2006. The filament was located South of a strong sunspot that dominated the region. In the evolution leading up to the eruption, and for some time after it, a counter-clockwise rotation of the sunspot of about 30 degr…
Ensemble Modeling of CME Propagation
Arge, C. N.; Henney, C. J.; Pizzo, V. +4 more
The current progression toward solar maximum provides a unique opportunity to use multi-perspective spacecraft observations together with numerical models to better understand the evolution and propagation of coronal mass ejections (CMEs). Of interest to both the scientific and forecasting communities are the Earth-directed "halo" CMEs, since they…
Coronal Hole Influence on the Observed Structure of Interplanetary CMEs
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We report on the coronal hole (CH) influence on the 54 magnetic cloud (MC) and non-MC associated coronal mass ejections (CMEs) selected for studies during the Coordinated Data Analysis Workshops (CDAWs) focusing on the question if all CMEs are flux ropes. All selected CMEs originated from source regions located between longitudes 15E - 15W. Xie, G…