A new approach in the observation of two successiveCoronal Mass Ejections

Abstract

On 2000 February 17-19 and 2000 April 04-06 ,the Energetic and Relativistic Nuclei and Electron (ERNE) instrument onboard Solar and Heliospheric Observatory (SOHO) observed gradual solar energetic particle events(SEPs). These events associated with two solar eruptions. The event 2000 February 17-19, is association with two solar flares (M1.3,C1.1) and halo Coronal Mass Ejections (CMEs) separated by ~ 13hours, while on 2000 April 04-06, the event was associated with two CMEs separated by ~8hours .The observational data make a proposal that the second acceleration of various protons energy occurred behind the first CME and it was not an obstaclefor the new particles to reach 1AU in both events. The magnetic field and plasma measurements show that the shock wave of the first CME was an efficient, decelerate, soften, and become transparent for the protons produced by the second eruption.