# Large flares (M1 - X7) in solar cycle 24

## TL;DR

This study analyzes large solar flares in cycle 24, estimating their energies, constructing energy spectra, and comparing various solar activity indices to understand flare characteristics and their relation to solar activity.

## Contribution

It provides new estimates of flare energies, constructs energy spectra for large flares, and compares multiple solar activity indicators in cycle 24.

## Key findings

- Energy spectrum of large flares was established.
- Correlations between flare activity and other solar indices were analyzed.
- Quantitative estimates of flare energies in the Earth's atmosphere were obtained.

## 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 averaged values of several indices of solar activity in current cycle 24: the relative sunspot numbers (SSN), the 10.7 cm radio flux, the radiation flux in the Lyman-alpha line, the solar constant (TSI) and the Flare Index (FI) was made.