The Radio–Coronal Mass Ejection Event on 2001 April 15

Abstract

On 2001 April 15, the Nançay radioheliograph observed fast-moving, expanding loops in images taken in the wavelength range between 164 and 432 MHz. We were able to follow the progression of the radio loops, starting from a few tenths to more than 1 Rsolar above the solar limb, with a time cadence of order seconds. The loops seen in radio agree very well with the features of the coronal mass ejection (CME) seen later, more than 2.5 Rsolar above the limb, in white-light images by the Large Angle Spectrometric Coronagraph (LASCO) experiment on board the Solar and Heliospheric Observatory (SOHO) spacecraft. The event is well associated with an energetic electron event seen by the Electron, Proton, and Alpha Monitor (EPAM) experiment on board the Advanced Composition Explorer (ACE) spacecraft. A detailed transport model for the electrons shows that, not only the inferred onset at the Sun, but also the duration of the particle release, are similar for the radio loop and the in situ electron event detected near the Earth.