Investigation of Shock Wave Dynamics in An Inhomogeneous Solar Atmosphere

The shock front (SF) propagation in the solar atmosphere with a power-law decrease of density is studied in the Kompaneets approximation. It is shown that the SF part moving from the Sun in the radial direction speeds up at the exponent n > 3 and slows down at n < 3. When passing from the lower corona with n = 6 to the solar wind with n = 2, the acceleration in the front part changes into deceleration. This result allows us to understand the kinematics of the SF obtained from the observational data on type II bursts at low frequencies. Besides, in the region of solar wind, new analytical solutions of the Kompaneets equation (KE) for SF have been obtained. One of them describes SF as an expanding sphere with the center moving from the Sun (plain case). Another solution has been obtained for the case of the inverse near-square law density depending on radius with the singularity at a given levelR.