Kinetic theory of E0×B0 instabilities in the ionosphere

Abstract

A self‐consistent kinetic theory of the E0×B0 instabilities in partially ionized, inhomogeneous plasmas with arbitrary values of να/Ωα, where να represents the electron (ion)‐neutral collision frequency and Ωα is the electron (ion) gyrofrequency, is presented. The theory is based on the kinetic equation with a particle number conserving collision term, which allows the particle distribution function to relax toward a local Maxwellian distribution at rest. The method consists of first solving the zero‐order kinetic equation to determine the self‐consistent equilibrium distribution function. The distribution function is shown to accurately represent the plasma equilibrium state, with appropriate Hall and Pedersen drifts that occur in a collisional plasma in the presence of crossed ambient electric and magnetic fields. The linear dispersion relation is then derived from the first‐order kinetic equation, and it can be used to study the E0×B0 instabilities in all altitude regions of the ionosphere in a unified manner, without the need for any a priori knowledge of the different types of particle drifts (Hall and Pedersen drifts) that are responsible for the instabilities in different altitude regions. The present theory therefore provides a more rigorous kinetic description of the E0×B0 instabilities than that obtained from the previously studied kinetic model in which the zero‐order particle drifts are not determined self‐consistently but have to be specified extraneously.