Search Publications
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…
The SWAP EUV Imaging Telescope. Part II: In-flight Performance and Calibration
Mierla, M.; Berghmans, D.; Seaton, D. B. +6 more
The Sun Watcher with Active Pixel System detector and Image Processing (SWAP) telescope was launched on 2 November 2009 onboard the ESA PROBA2 technological mission and has acquired images of the solar corona every one to two minutes for more than two years. The most important technological developments included in SWAP are a radiation-resistant C…
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…
The LYRA Instrument Onboard PROBA2: Description and In-Flight Performance
Schmutz, W.; Shapiro, A. I.; Zhukov, A. N. +7 more
The Large Yield Radiometer (LYRA) is an XUV-EUV-MUV (soft X-ray to mid-ultraviolet) solar radiometer onboard the European Space Agency Project for On-Board Autonomy 2 (PROBA2) mission, which was launched in November 2009. LYRA acquires solar-irradiance measurements at a high cadence (nominally 20 Hz) in four broad spectral channels, from soft X-ra…
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…
The Solar Connection of Enhanced Heavy Ion Charge States in the Interplanetary Medium: Implications for the Flux-Rope Structure of CMEs
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We investigated a set of 54 interplanetary coronal mass ejection (ICME) events whose solar sources are very close to the disk center (within ± 15∘ from the central meridian). The ICMEs consisted of 23 magnetic-cloud (MC) events and 31 non-MC events. Our analyses suggest that the MC and non-MC ICMEs have more or less the same eruption ch…
PROBA2: Mission and Spacecraft Overview
Zender, J.; Schwehm, G.; de Groof, A. +9 more
Within the European Space Agency's (ESA) General Support and Technology Programme (GSTP), the Project for On-Board Autonomy (PROBA) missions provide a platform for in-orbit technology demonstration. Besides the technology demonstration goal, the satellites allow to provide services to, e.g., scientific communities. PROBA1 has been providing multi-…
Solar Energetic Particle Events in the 23rd Solar Cycle: Interplanetary Magnetic Field Configuration and Statistical Relationship with Flares and CMEs
Klein, K. -L.; Malandraki, O.; Miteva, R. +1 more
We study the influence of the large-scale interplanetary magnetic field configuration on the solar energetic particles (SEPs) as detected at different satellites near Earth and on the correlation of their peak intensities with the parent solar activity. We selected SEP events associated with X- and M-class flares at western longitudes, in order to…
Near-Sun Flux-Rope Structure of CMEs
St. Cyr, O. C.; Gopalswamy, N.; Xie, H.
We have used the Krall flux-rope model (Krall and St. Cyr, Astrophys. J.2006, 657, 1740) (KFR) to fit 23 magnetic cloud (MC)-CMEs and 30 non-cloud ejecta (EJ)-CMEs in the Living With a Star (LWS) Coordinated Data Analysis Workshop (CDAW) 2011 list. The KFR-fit results shows that the CMEs associated with MCs (EJs) have been deflected closer to (awa…