Variations in Abundance Enhancements in Impulsive Solar Energetic-Particle Events and Related CMEs and Flares

We study event-to-event variations in the abundance enhancements of the elements He through Pb for Fe-rich impulsive solar energetic-particle (SEP) events, and their relationship with properties of associated coronal mass ejections (CMEs) and solar flares. Using a least-squares procedure we fit the power-law enhancement of element abundances as a function of their mass-to-charge ratio A/Q to determine both the power and the coronal temperature (which determines Q) in each of 111 impulsive SEP events identified previously. Individual SEP events with the steepest element enhancements, e.g. similar to aEuro parts per thousand(A/Q)(6), tend to be smaller, lower-fluence events with steeper energy spectra that are associated with B- and C-class X-ray flares, with cooler (similar to aEuro parts per thousand 2.5 MK) coronal plasma, and with narrow (< 100(a similar to)), slower (< 700 km s(-1)) CMEs. On the other hand, higher-fluence SEP events have flatter energy spectra, less-dramatic heavy-element enhancements, e.g. similar to aEuro parts per thousand(A/Q)(3), and come from somewhat hotter coronal plasma (similar to aEuro parts per thousand 3.2 MK) associated with C-, M-, and even X-class X-ray flares and with wider CMEs. Enhancements in He-3/He-4 are uncorrelated with those in heavy elements. However, events with He-3/(4)Hea parts per thousand yen0.1 are even more strongly associated with narrow, slow CMEs, with cooler coronal plasma, and with B- and C-class X-ray flares than are other Fe-rich impulsive SEP events with smaller enhancements of He-3.