The Earth's ionosphere is the weakly ionized region of the upper atmosphere extending from about 90 km to 800 km. Electrodynamic processes driven by ionospheric electric fields can significantly affect the propagation of radiowaves used in communication, navigation and space based positioning systems, especially in the equatorial region. These processes can be highly variable over space and time and can introduce errors in the transmitted information. One of the ways to understand this equatorial ionospheric electrodynamics is to monitor the vertical and zonal drifts of the plasma in the ionosphere. Traditionally, these drifts were studied in a height averaged sense or a single altitude satellite data neglecting the altitudinal variations in the drifts/electric fields. Also neglecting these gradients contradicts with the irrotational condition of the electric field in the ionosphere. We present results on the climatology and local time variations of equatorial electric field height gradients with emphasis on evening time variations when these gradients change rapidly.
Available at: http://works.bepress.com/debruphui/1/