About the magnetic barrier of Venus

Abstract

The magnetized supersonic solar wind, when flowing around planets, forms a magnetic barrier near the streamlined surface. The main feature of the magnetic barrier is that the magnetic pressure prevails over the plasma pressure. The Hall-MHD model is used to simulate the magnetic barrier in the case of solar wind flow around the atmosphere of Venus. The obtained numerical results are compared with an analytical approximation of the magnetic barrier thickness, which expresses the dependence of the magnetic barrier on solar wind parameters. Particular attention is paid to the physical reasons for the asymmetry of the magnetic barrier caused by the Hall effects, which are mainly concentrated in the boundary layer near the ionopause, where the electric current has a maximum strength. An additional source of asymmetry is also considered, which acts in the same direction and is associated with the influence of the normal component of the electric field on the specific behavior of new atmospheric ions. It is shown that solar wind protons are loaded by new atmospheric ions mainly in the E+ hemisphere. In the case of more intense loading, the boundary of the magnetic barrier and the shock wave are located farther from the ionopause.