Physical Mechanism of a Solar Flare Based on the Accumulation of the Energy in the Magnetic Field of the Current Sheet in the Solar Corona

Abstract

During a solar flare, the magnetic energy of ~10³² erg is released in a few dozens of minutes. The invariability of the magnetic field on the solar surface during flares proves the appearance of a flare in the corona. An analysis of the dynamics of the electron temperature of the solar atmosphere provides independent evidence of the coronal origin of the flare. The appearance of the flare in the corona is explained by the release of the energy accumulated in the magnetic field of the current sheet. To study the flare situation, numerical MHD simulation was performed for a real active region. The simulation results showed the appearance of a current sheet, which position coincides with the position of the observed source of thermal X-ray emission. A methodology for calculations in real time scale has been developed. Based on the mechanism of energy release in the current sheet, an electrodynamic model of a solar flare is proposed, which explains its main observed manifestations. Sources of hard X-ray emission appear due to deceleration in the lower dense layers of the solar atmosphere of electron beams accelerated in field-aligned currents. The acceleration of solar cosmic rays occurs in the current sheet by the electric field E = –V × B/c, and not in shock waves.