Statistics and Mapping of Auroral Features

Abstract

Statistical studies of the large-scale convection electric field, field-aligned currents, auroral luminosity, accelerated electron and ion distributions, small-scale electric field structures (‘electrostatic shocks’), plasma density, and waves, such as auroral kilometric radiation, can provide important constraints on interpretations of both the drivers and the mechanisms of auroral acceleration. The microphysics of acceleration and wave processes has been discussed in Chapter 4. In the first section of this chapter, we describe statistical properties of these phenomena and their dependence on solar wind conditions, the IMF, magnetic activity, solar illumination (‘season’), and solar cycle, as well as altitude, magnetic local time and magnetic latitude. In the second section we discuss the mapping of the low altitude auroral features to their source region in the magnetosphere.