Equatorial Ionospheric Electrodynamics

The low-latitude ionosphere is one of the most dynamic regions of the Earth's upper atmosphere. The morphology of this region is controlled by radiative and coupled chemical, neutral, and plasma transport processes. Equatorial electrodynamics plays a fundamental role on the low-latitude plasma density, total electron content (TEC), and plasma structures and waves extending from the E-region to the protonosphere. Ground-based and satellite measurements over the last six decades determined the climatology of quiet- and storm-time equatorial electrodynamic processes. Extensive theoretical and numerical simulations, particularly in the last two decades, investigated the main electrodynamic driving mechanisms. These combined studies have led tomajor advances in the understanding of the short-term variability of equatorial electrodynamics, which is essential for the accurate forecast of low-latitude ionospheric weather, and its effects on ground- and space-based technological systems. In this work, we review the main properties of low-latitude electrodynamics, focusing on recent results of the equatorial ambient plasma drifts, which are the main drivers of low-latitude ionospheric weather. We also briefly mention some outstanding questions and suggest possible future directions for their more complete understanding.