A brief review of recent computational studies of the E-region equatorial electrojet is presented. Agreement and discrepancies between numerical simulation studies and both theory and experiment are given. Some outstanding problems are identified and new experiments suggested.

This is the first book to review all the fields of equatorial electrojet phenomena and their relevant theories in one volume. In certain relevant sections, the book discusses both the equatorial electrojet and the world-wide parts of the Sq current systems. Onwumwchili is an internationally known and highly respected expert in the equatorial electrojet field- a brand of geomagnetism.

A computer program which calculates electron and ion densities, ionospheric conductivities, electric fields and currents, and magnetic variations in regions near the magnetic equator is described in detail. It is also explained how this numerical model can be used to deduce F-region vertical plasma drifts in the equatorial ionosphere from observed magnetic variations at ground level. (Author).

This dissertation describes a theoretical, experimental, and modeling investigation of the equatorial electrojet. We review low latitude ionospheric current models, synthesizing developments from the early times until the present. We then show how to utilize equatorial electrojet irregularities to infer E region electron density and wind profiles from coherent scatter radar experiments. The procedure involves a numerical model of the equatorial ionosphere that relates the vector electric field and current density to the winds. We present electron densities inferred in the equatorial electrojet inferred using a new bistatic radar system installed between Paracas and Jicamarca, Peru. The radar system monitors density profiles using a coherent scatter radar technique that utilizes the Faraday rotation of the scattered signal. Radar measured density profiles are validated by comparing with other electron density measures. A three dimensional electrostatic potential model of the equatorial ionosphere in a magnetic dipole coordinate system is described. The model incorporates realistic ionospheric conductivities, electric fields, winds, and includes anamalous collision effects. The model utilizes bistatic radar measured densities, coherent scatter spectral measurements made at large zenith angles, and electric fields derived from 150 km echo drifts. The model is also constrained by magnetometer records. We next present a technique for extracting zonal winds in the equatorial electrojet from the Doppler shifts of type II radar echoes measured by a narrow beam, obliquely oriented antenna at the Jicamarca Radio Observatory. The wind profiles were retrieved by combining the 3-D model with theory and measurements of type II echo Doppler shifts. The amplitude and phasing of the calculated wind profiles are in general agreement with satellite and rocket-borne wind measurements. We have used height varying type I radar echoes and large-scale electrojet irregularities inferred from interferometric imaging to validate wind profiles estimates derived from type II echoes. (Abstract).