Recurrence of flare energy releases in solar active regions (Cycle 23)

Abstract

The following results have been achieved in this work. The distribution of the recurrence times of solar flare events is generally lognormal. The typical flare recurrence times at the cycle 23 minimum and maximum are different: the average times (100–200 min) are most typical of the maximum; at the same time, the minimum is simultaneously characterized by short (several tens of seconds) and long (from several hundreds to a thousand of minutes). The minimal flare recurrence time tends to decrease in an active region with increasing sunspot group area in this region. The average flare recurrence times in an active region have typical values of 120m, 210m, 300m, 400m, and 530m, which is close to the typical periods of long-period sunspot oscillations. The total number of flares in an active region depends on the sunspot area in this region and the flare energy release rate.