Modeling Equatorial and Low Latitude Ionospheric Plasma Drifts by Habtamu Marew, Doctor of Philosophy Bahir Dar University, 2020 Major Professor: Melessew Nigussie, Ph.D. Department: Physics One of the important generators of the ionospheric current is the ionospheric wind dynamo, which operates as upper-atmospheric winds move the electrically conducting medium through the Earth's magnetic eld, creating an electromotive force that drives currents and causes electric polarization elds to develop. Ionospheric electrodynamics depends mainly on the conductivity of the ionosphere and on the strength of thermospheric winds which in-turn depend on the ux of solar ultraviolet radiation absorbed in the upper atmosphere. The E-region dynamo which is driven by tidal winds is the main source of the electric elds in the equatorial ionosphere. It is the electric elds that play an important role in shaping the electron distribution in the equatorial F region. The daytime eastward electric eld drives intense current in the E-region known as equatorial electrojet (EEJ) and also maps along the equipotential geomagnetic eld lines and produces plasma vertical drift E B at F-region of the ionosphere. The east-west neutral winds drag plasma along with them in the east-west direction, which creates the vertical electric eld (a source for zonal plasma drift) which plays an important role in the distribution of plasma in nighttime low-latitude F-region and to the generation of post sunset irregularities. Both Vertical and zonal plasma drifts have been studied since the discovery of remote sensing instruments like ionosondes