American Institute of Physics, AIP Conference Proceedings, 2010
DOI: 10.1063/1.3395960
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Around 350 solar energetic proton events with energies >20 MeV were detected by near‐Earth spacecraft during solar cycle 23. Focusing on the 280 events with ∼25 MeV intensity >2×10−4particles/(cm23 sr s MeV), we examine the early stages (∼first 12 hours) of these events including their intensity and composition and the properties of the related solar phenomena such as CMEs, flares and radio bursts. Although we divide the events into 5 representative groups based on particle profiles and relative abundances, we find no single, or set of variables that divides the particle events into clear cut “classes” for example associated with shock and flare acceleration. In particular, there is a continuum of event properties from the smallest, flare‐accelerated events, to the largest events dominated by shock acceleration. This suggests that both flare and shock acceleration can contribute in individual events.