Large Flares (M1–X7) in Solar Activity Cycle 24

Abstract

The large (X-ray class > M1) and very large (X-ray class > X1) flares (according to the observations of GOES-15 and Preliminary data from Current Catalog of Flare Events) in solar activity cycle 24 were analyzed. The monthly average values of optical Flare Index for 2010–2016 were calculated. The values of the total energy of the flare E (J m^–2) in the 0.1–0.8 nm range at the level of the earth’s atmosphere were estimated. The energy spectrum (the dependence of the number of flares with the full energy E from the value of this full energy) for 115 flares of M5–X7 classes was built. The comparative study of monthly average values of several indices of solar activity in current cycle 24–the relative sunspot numbers (SSN), the 10.7 cm radio flux (F_10.7), the radiation flux in the Lyman-alpha line (F_Ly-α), the solar constant (TSI) and the Flare Index (FI)–was made.