Ion Kinetics in the Lower Ionosphere

Abstract

Various positive and negative ionic processes of importance in controlling the electron density in the lower ionosphere are discussed. In particular, models of the effective dissociative recombination coefficient based on laboratory and ionospheric experiments are constructed. Rate constants for charge transfer and ion-atom interchange in this region are determined from various in situ measurements, and the results are compared with the corresponding laboratory data. Processes involving negative ions are treated next, and suggestions that O2? is not the dominant negative ion are shown to be entirely reasonable. Finally we discuss the diffusion of electrons to dust and show that it cannot constitute an important mode of electron removal.