Solar proton events during solar cycles 19, 20, and 21

摘要: Solar proton events have been studied for over thirty years and a great deal of lore has grown around them. It is the purpose this paper to test some against actual data. Data on solar now exist period from 1956 1985 during which time 140 took place in event integrated fluxes protons energy > 30 MeV was larger than 105 particles cm-2. We statistical properties with 10 MeV. Earlier studies based single cycle had resulted sharp division into ‘ordinary’ ‘anomalously large’ events.Two such entirely separate distributions imply two acceleration mechanisms, one common other very rare. find that neither required nor justified by sample. Instead intensity forms smooth distribution intensities up largest observed implying any second mechanism cannot be also relation sizes sunspot number phase. clear bimodal variation annual flux phase but no statistically significant tendency large avoid maximum. show there almost between maximum flux. numbers greater 35 (i.e., non-minimum conditions) whatsoever