Heliophysics: from observations to models and applications

Study of the physical phenomena and processes on the Sun and in the heliosphere, a natural plasma laboratory, is based on near-earth and space-based observations and building models which help to obtain a general view of how the Sun was made and how it works, while allowing one to address the practical problems of solar activity influencing space weather and its impact on various areas of human activity. In this paper a brief outline is given of the models of trigger mechanisms driving the most powerful manifestations of solar activity—solar flares and mass ejections, the wave mechanism of solar corona heating. Also, analytical solutions are presented for MHD shock waves in solar wind collisionless plasma with heat fluxes.