Untitled

Abstract

The variation of drift and anisotropy parameters of Ionospheric irregularities in the E-region at Waltair (dip 17.7 o N; 83.3 o E) during 3 geomagnetic storms has been studied mainly to resolve the controversy that has been reported in the literature about the effect of magnetic activity on the drift and anisotropy parameters. E-region spaced antenna drift records taken on frequency 2.4 MHz during the period September 1983-May 1984 at Waltair are used in the present study. In the E-region, the true drift velocity during storm period appears to be larger than the control day values. The ratio of V a /V shows a gradual decrease during storm period and random velocity during storm time is quiet less compared to the control day values. No significant variation is observed in the apparent drift direction and structure size on storm days with respect to the control days. The orientation of the semi-major axis mostly lies in the range of 120 o -150 o N of E, both on storm days as well as on control days but the average value of the axial ratio shows a higher value compared to the average on control days.