The corotation field in collisionless magnetospheric plasma and its influence on average electric field in the lower atmosphere Original Research Article

The aim of the present paper is to describe a self-consistent model of formation of the corotation field in the strongly-anisotropic collisionless magnetospheric plasma (as distinct from the most of studies, where this field was either taken a priori as an electric field of rigid-body corotation or derived from the magnetohydrodynamic equations for isotropic medium). The basic assumption of our model is infinite conductivity of plasma along the magnetic field lines and zero in two perpendicular directions, which agrees well with the actual magnetospheric conditions. An interesting consequence of this model is that superposition of the corotation fields inside the solid Earth and in the magnetosphere leads to an appreciable change of the electric potential in polar regions of the lower atmosphere, resulting in the decrease of average atmospheric electric field by 10–20%. Such effect was really known since the International geophysical Year (1957–1958) but had no adequate theoretical interpretation by now.