Low coronal signatures of large solar energetic particle events

We report on the low coronal signatures of major solar energetic particle (SEP) events. Because large SEP events are highly associated with both flares and coronal mass ejections, we focused on flare-associated motions in soft X-rays. In a sample of a half-dozen well-observed flares associated with SEP events, we identified two basic types of motions or ejections. For one class of events including those of 2001 November 4 and 1998 April 20, the ejections occur on active region or larger scales. They have an extended "preeruption" phase in which the involved structures slowly rise or expand on timescales of tens of minutes. For the second class of events, including those on 1997 November 6 and 2001 April 15, the large-scale preeruption phase is absent. In these events, ejecta appear explosively at the onset of the flare impulsive phase. The observed differences in ejections appear to correlate with spectral/compositional/charge state characteristics of large SEP events, suggesting that flare ejecta are diagnostic of shock properties/environment.