To the problem on the regularities of solar energetic particle events occurrence Original Research Article

The occurrence of solar energetic particle (SEP) events over a long-term time scale is described by the probability theory using some regularities inherent in sets of SEP events. The first regularity states that the mean rate of SEP events occurrence is proportional to the solar activity level presented as a smoothed monthly mean sunspot (Wolf) numbers (W). The second regularity states that the SEP events distribution functions, recorded during various solar activity levels (the “active” or “quiet” Sun) or phases (maximum or minimum, ascending or declining), being divided by the sums of smoothed monthly mean sunspot numbers (∑W) during the time of observation, are identical within the limits of statistical errors.