White-light and radio observations of CME interaction during the 2013 May 22 solar energetic particle event
Abstract
On 2013 May 22, the SOHO/LASCO coronagraph observed two coronal mass ejections (CMEs) in close sequence at 08:48 UT and 13:25 UT originating from the same NOAA AR11745 located at N15W70. The CMEs were associated with a large increase of proton flux with a peak intensity of 1660 protons cm^-2 sr^-1 s^-1 in the GOES >10 MeV integral channel. During the event, the following, faster CME with a sky-plane speed of 1466 km/s overtook and interacted with the preceding, slower CME with a sky-plane speed of 687 km/s. The LASCO white-light images clearly revealed that during the interaction the preceding CME accelerated while the following CME decelerated. The CME interaction also caused an enhancement of type II radio emission detected at the decameter-hectometric wavelengths by radio instruments on the Wind and STEREO spacecraft. The source location of the type II enhancement estimated by direction finding technique confirmed that the radio emission was coming from the interaction region. The drift rate of the type II radio burst was also seen to be different after the merger of the CMEs.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2015)
- Pub Date:
- July 2015
- Bibcode:
- 2015shin.confE..96M