Observations of Energetic Particles between a Pair of Corotating Interaction Regions
Abstract
We report observations of the acceleration and trapping of energetic ions and electrons between a pair of corotating interaction regions (CIRs). The event occurred in Carrington Rotation 2060. Observed by the STEREO-B spacecraft, the two CIRs were separated by less than 5 days. In contrast to other CIR events, the fluxes of the energetic ions and electrons in this event reached their maxima between the trailing edge of the first CIR and the leading edge of the second CIR. The radial magnetic field (Br ) reversed its sense and the anisotropy of the flux also changed from Sunward to anti-Sunward between the two CIRs. Furthermore, there was an extended period of counterstreaming suprathermal electrons between the two CIRs. Similar observations for this event were also obtained with the Advanced Composition Explorer and STEREO-A. We conjecture that these observations were due to a U-shaped, large-scale magnetic field topology connecting the reverse shock of the first CIR and the forward shock of the second CIR. Such a disconnected U-shaped magnetic field topology may have formed due to magnetic reconnection in the upper corona.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2014
- DOI:
- 10.1088/0004-637X/781/1/17
- arXiv:
- arXiv:1401.2214
- Bibcode:
- 2014ApJ...781...17W
- Keywords:
-
- acceleration of particles;
- magnetohydrodynamics: MHD;
- shock waves;
- solar wind;
- Sun: rotation;
- Astrophysics - Solar and Stellar Astrophysics;
- Physics - Space Physics
- E-Print:
- doi:10.1088/0004-637X/781/1/17