Effect of sunspot activity on F-region drift speed at Waltair

Briggs has reported the variation of the night-time north-south component of F-region drift at Cambridge (52° N., 0° E.) from a southward direction during a sunspot maximum to the northward direction during a minimum. This result highlights the importance of a study of long-term variations of drift parameters with a view to studying the effect of solar activity and verifying existing theories. Morriss and Lyon at Ibadan (7° N., 4° E.) reported a general decrease in wind speed with decreasing solar activity and showed that there was no marked change from the International Geophysical Year (IGY) to the International Year of the Quiet Sun (IQSY) in the diurnal variation of the east-west component. Results from Waltair show a decrease in the wind speed with decreasing solar activity. All the investigations mentioned were carried out using similar fades analysis