VHF backscatter radar observations of the equatorial electrojet irregularities - diurnal, seasonal and solar cycle variations

Abstract

VHF backscatter radar observations at Thumba, for the period 1974-1982, are used to study the diurnal, seasonal and solar cycle variations of the Doppler frequency of the Doppler frequency of the backscatter echoes from the 2.7 m scale size ionization iregularities in the equatorial electrojet. The study shows that the Doppler frequency exhibits strong diurnal, seasonal and solar activity dependences. Also, it is seen that the average characteristics of the Doppler frequency variations are in broad agreement with the observed Delta-H variations at Trivandrum. A discussion is given on the constraints under which the observed Doppler frequency variations can be regarded as representing the corresponding variations in the electric fields of the equatorial electrojet