Search Publications
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…
Comparison of Ground-Based and Space-Based Longitudinal Magnetograms
Bertello, L.; Pevtsov, A. A.; Pietarila, A. +1 more
We compare photospheric line-of-sight magnetograms from the Synoptic Optical Long-term Investigations of the Sun (SOLIS) Vector Spectro-Magnetograph (VSM) instrument with observations from the 150-foot Solar Tower at Mt. Wilson Observatory (MWO), the Helioseismic and Magnetic Imager (HMI) on the Solar Dynamics Observatory (SDO), and the Michelson …
Solar TErrestrial Relations Observatory-A (STEREO-A) and PRoject for On-Board Autonomy 2 (PROBA2) Quadrature Observations of Reflections of Three EUV Waves from a Coronal Hole
Berghmans, D.; Seaton, D. B.; Temmer, M. +5 more
We investigate the interaction of three consecutive large-scale coronal waves with a polar coronal hole, simultaneously observed on-disk by the Solar TErrestrial Relations Observatory (STEREO)-A spacecraft and on the limb by the PRoject for On-Board Autonomy 2 (PROBA2) spacecraft on 27 January 2011. All three extreme ultraviolet (EUV) waves origin…
Heliospheric Imaging of 3D Density Structures During the Multiple Coronal Mass Ejections of Late July to Early August 2010
Liu, Y.; Webb, D. F.; Möstl, C. +16 more
It is usually difficult to gain a consistent global understanding of a coronal mass ejection (CME) eruption and its propagation when only near-Sun imagery and the local measurements derived from single-spacecraft observations are available. Three-dimensional (3D) density reconstructions based on heliospheric imaging allow us to "fill in" the tempo…
Propagation Characteristics of CMEs Associated with Magnetic Clouds and Ejecta
Cho, K. -S.; Moon, Y. -J.; Gopalswamy, N. +2 more
We have investigated the characteristics of magnetic cloud (MC) and ejecta (EJ) associated coronal mass ejections (CMEs) based on the assumption that all CMEs have a flux rope structure. For this, we used 54 CMEs and their interplanetary counterparts (interplanetary CMEs: ICMEs) that constitute the list of events used by the NASA/LWS Coordinated D…
Observations of Coronal Mass Ejections with the Coronal Multichannel Polarimeter
de Toma, G.; Tian, H.; Bethge, C. +3 more
The Coronal Multichannel Polarimeter (CoMP) measures not only the polarization of coronal emission, but also the full radiance profiles of coronal emission lines. For the first time, CoMP observations provide high-cadence image sequences of the coronal line intensity, Doppler shift, and line width simultaneously over a large field of view. By stud…
Comparisons of CME Morphological Characteristics Derived from Five 3D Reconstruction Methods
Mierla, M.; Feng, L.; Inhester, B.
We compare different methods to reconstruct three-dimensional (3D) coronal mass ejection (CME) morphology. The explored methods include geometric localisation, mask fitting, forward modelling, polarisation ratio, and local correlation tracking plus triangulation. These five methods are applied to the same CME event that occurred on 7 August 2010. …
Initial Fe/O Enhancements in Large, Gradual, Solar Energetic Particle Events: Observations from Wind and Ulysses
Marsden, Richard G.; Ko, Yuan-Kuen; Malandraki, Olga E. +4 more
Shocks driven by fast coronal mass ejections (CMEs) are the dominant particle accelerators in large, "gradual" solar energetic particle (SEP) events. In these events, the event-integrated value of the iron-to-oxygen ratio (Fe/O) is typically ∼ 0.1, at least at energies of a few MeV/nucleon. However, at the start of some gradual events, when intens…
Measuring the Magnetic-Field Strength of the Quiet Solar Corona Using "EIT Waves"
Long, D. M.; Régnier, S.; Harra, L. K. +1 more
Variations in the propagation of globally propagating disturbances (commonly called "EIT waves") through the low solar corona offer a unique opportunity to probe the plasma parameters of the solar atmosphere. Here, high-cadence observations of two "EIT wave" events taken using the Atmospheric Imaging Assembly (AIA) instrument onboard the Solar Dyn…