Relationship between Solar Energetic Particles and Properties of Flares and CMEs: Statistical Analysis of Solar Cycle 23 Events

摘要

A statistical analysis of the relationship between solar energetic particles(SEPs) and properties of solar flares and coronal mass ejections (CMEs) ispresented. SEP events during solar cycle 23 are selected which are associatedwith solar flares originating on the visible hemisphere of the Sun and at leastof magnitude M1. Taking into account all flares and CMEs that occurred duringthis period, the probability for the occurrence of an SEP event near Earth isdetermined. A strong rise of this probability is observed for increasing flareintensities, more western locations, larger CME speeds and halo CMEs. Thecorrelations between the proton peak flux and these solar parameters arederived for a low (>10 MeV) and high (>60 MeV) energy range excluding any fluxenhancement due to the passage of fast interplanetary shocks. The obtainedcorrelation coefficients are: 0.55+-0.07 (0.63+-0.06) with flare intensity and0.56+-0.08 (0.40+-0.09) with the CME speed for E>10 MeV (E>60 MeV). For bothenergy ranges, the correlations with flare longitude and CME width are verysmall or non-existent. Furthermore, the occurrence probabilities, correlationcoefficients and mean peak fluxes are derived in multi-dimensional binscombining the aforementioned solar parameters. The correlation coefficients arealso determined in different proton energy channels ranging from 5 to 200 MeV.The results show that the correlation between the proton peak flux and the CMEspeed decreases with energy, while the correlation with the flare intensityshows the opposite behavior. Furthermore, the correlation with the CME speed isstronger than the correlation with the flare intensity below 15 MeV and becomesweaker above 20 MeV. Excluding the flux enhancements due to interplanetaryshocks, only a small but not very significant change is observed in thecorrelation between the peak flux below 7 MeV and the CME speed.