DISTORTIONS IN THE HEIGHT STRUCTURE OF THE EQUATORIAL ELECTROJET DURING COUNTER ELECTROJET EVENTS

This paper presents simultaneous observations made near the magnetic equator during counter electrojet events using a coherent VHF backscatter radar, magnetometer and digital ionosonde to understand the physical processes that generate the counter electrojet conditions. The VHF backscatter radar gives the height structure of the drift velocity of the ionization irregularities, the equatorial electrojet current variations are obtained from the magnetometer and the digital ionosonde provides the presence of blanketing E(s)-layers at the E-region heights which give rise to the backscatter signals. These observations have provided direct experimental evidence for the theoretically predicted distortions in the height structure of the polarization electric field in the equatorial electrojet due to the local effects of shearing zonal neutral winds.