Coronal Mass Ejections Associated with Impulsive Solar Energetic Particle Events

Abstract

An impulsive solar energetic particle (SEP) event observed on the Wind spacecraft on 2000 May 1 was associated with an impulsive solar active region M1 X-ray flare. The timing and position of a fast (v = 960 km s^-1), narrow CME observed in the LASCO coronagraph on SOHO make clear the connection between the CME and the flare and SEP event. Impulsive SEP events have long been associated with impulsive flares, but only gradual SEP events have thus far been found to be associated with CMEs. A comparison of impulsive SEP events with CME observations from the Solwind and LASCO coronagraphs revealed further good cases of narrow (10°-40°) CMEs associated with impulsive SEP events. A recent model of impulsive flares includes jets or plasmoids that are ejected upward from magnetic reconnection sites over active regions and might therefore be expected to appear in exceptional cases as faint and narrow CMEs in coronagraphs. We suggest that this model allows us to understand better SEP production and propagation in impulsive flares.