Constraining the Origin of CIR-associated Energetic Particles at 1 AU That Arrive From a Non-Local Source
Abstract
Corotating interaction regions (CIRs) are a major producer of 10s of keV to several MeV particle enhancements at 1 AU, especially during periods of low solar activity. The long-standing interpretation is that these energetic particles are accelerated at CIR-driven shocks between ~3-5 AU and are transported to 1 AU along the interplanetary magnetic field. This paradigm has begun to shift with evidence that CIRs can accelerate energetic particles at 1 AU in events with a reverse shock or a well-formed compression region trailing edge (e.g. Ebert et al. 2012a,b). However, there are a significant number of events where the CIR does not appear to play a role in the acceleration process, especially where the compression region is not well formed. While many studies point to the source of these particles being beyond 1 AU, exactly how far beyond is still under debate. In this study, we will use multi-spacecraft observations of CIR energetic particles from STEREO-A/B and ACE in conjunction with the theory of Fisk & Lee (1980) to constrain the distance from which these non-local particles may originate. We discuss the results obtained using this approach and their implication for the origin of CIR energetic particles at 1 AU whose source is not observed in situ.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMSH31C..08E
- Keywords:
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- 2102 INTERPLANETARY PHYSICS Corotating streams;
- 2114 INTERPLANETARY PHYSICS Energetic particles