Two-dimensional stationary configurations of the current-carrying plasma sheet and their usage in describing physical effects of disturbance development in the nightside magnetosphere

Abstract

It has been indicated that the previously proposed two-dimensional model of collisionless isotropic current-carrying plasma sheet makes it possible to reproduce and physically clearly describe many phenomena in the observed process of disturbance development in the nighttime magnetosphere. The formation of thin current sheets in the near zone, the characteristic scale of these sheets (the current sheet thickness and a change in this scale along the magnetotail), and the formation of the configuration with a neutral point in the near zone have been considered in the work. The latter is possible since the solution of the model problem includes the solution with a change in the magnetic field topology. The initial stage of the disturbance development in the magnetotail in the case when the electric field is switched on at the northern and southern boundaries has been considered within the scope of the MHD description where the Ohm’s law has been used in the generalized form (∂/∂ ≠ 0) in the inertial term. The problem of current sheet intensification is analyzed (approximately) by considering two competitive processes: an increase in the current velocity in the plasma sheet and a development of convection.