The polarization electric field and its effects in an anisotropic rotating magnetospheric plasma

Abstract

Spatial variations of density and temperature along a magnetic field line are evaluated for a plasma undergoing adiabatic motion in a rotating magnetosphere. The effects of centrifugal and gravitational forces are accounted for, as is anisotropy in the pitch angle distribution functions of individual species. A polarization electric field is invoked to eliminate the net electric charge density resulting from the aforementioned mass dependent forces and different anisotropies. The position of maximum density in a two‐component, electron‐ion plasma is determined both in the absence and in the presence of the polarization effect and compared. A scale height, generalized to include anisotropies, is derived for the density fall‐off. The polarization electric field is also included in the parallel guiding center equation; equilibrium points are determined and compared in both individual and average senses with the position of density maximum. Finally a transverse (to magnetic field lines) electric component is deduced as a consequence of dissimilar charge neutralization on adjacent field lines. The E × B velocity resultant from such a “fringing” electric field is calculated and compared with the magnitude of other drifts.