Аннотация: This article deals with a two-dimensional MHD model of a viscous-like plasma convection in the plasma sheet of the terrestrial magnetotail. In this model the role of viscous forces is mostly important inside the boundary layers adjacent to the magnetopause where the plasma sheet contacts with the solar wind how. A selfsimilar solution was obtained to describe the profiles of velocity and electric potential in the viscous boundary layers. This solution determines the boundary conditions for large scale electric potential and plasma convection in the plasma sheet. For zero IMF the plasma is convecting to the Earth in the central part of the sheet. The electric potential difference across the magnetotail in the equatorial plane depends on the effective viscous Reynolds number. A value of the Reynolds parameter of about 100 corresponds to the assumption that the distance between two effective collisions of ions is similar to the Larmor radius. This condition corresponds to a case of turbulent diffusion of ions in a magnetized plasma. For a nonzero IMF an additional electric field appears which is caused by reconnection of magnetic fields. In this case the resulting electric field in the tail is the sum of viscous-like and of reconnection fields. The plasma convection to the Earth increases for a southward IMF and decreases (or disappears) for a northward IMF.
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Pudovkin, M.I. \ed.\; Besser, B.P. \ed.\; Riedler, W. \ed.\; Riedler, . \ed.\