Association of Impulsive Solar Energetic Particle Events With Large-Scale Coronal Waves
Abstract
Impulsive or 3He-rich solar energetic particle (SEP) events have been commonly associated with EUV jets and narrow CMEs which are believed to be the signatures of magnetic reconnection involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In addition to their anomalous abundances, 3He-rich SEPs show puzzling energy spectral shapes varying from rounded forms to power laws where the later are characteristics of shock acceleration. In this study we identify 32 impulsive SEP events observed by the ACE near the Earth during the solar minimum period 2007-2010 and examine their solar sources with the high resolution STEREO EUV images. Leading the Earth, STEREO-A provided for the first time a direct view on impulsive SEP event sources, which are generally located on the Sun's western hemisphere. Surprisingly, we find that about half of the impulsive SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation and the coronal magnetic field connections suggests that the EUV waves may affect the injection of 3He-rich SEPs into interplanetary space. We found the events with jets tend to be associated with rounded spectra and the events with coronal waves with power laws. This suggests that coronal waves may be related to the unknown second stage mechanism commonly used to interpret spectral forms of 3He-rich SEPs. R. Bucik is supported by the Deutsche Forschungsgemeinschaft under grant BU 3115/2-1.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSH41D..07B
- Keywords:
-
- 2114 Energetic particles;
- INTERPLANETARY PHYSICSDE: 7513 Coronal mass ejections;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMYDE: 7519 Flares;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMYDE: 7845 Particle acceleration;
- SPACE PLASMA PHYSICS