HEIGHT STRUCTURE OF THE EQUATORIAL ELECTROJET AS OBSERVED WITH THE VHF BACKSCATTER RADAR

Doppler frequency measurements with VHF backscatter radar at Thumba give the drift velocity of the ionization irregularities, which can be used to deduce the electron drift velocity. By measuring the frequency shifts at different altitudes within the electrojet, the height structure of the electron drift velocity in the E-W direction is obtained. The study shows that on some days, deviations from a simple structure in the altitude profile take place. Also westward currents flowing at lower heights (below 100 km.) along with the normal eastward currents above 100 km are also observed on some days.