Study of “winds” in the F-region of the ionosphere during the unusual days in the IGY-calendar

Abstract

The three-spaced-receiver fading records were taken at Banaras with vertical pulsed transmission at 3.8–4.2 Mc/s during the regular world days, world meteorological intervals following the IGY-calendar and also during the SWI's. The records gave information about the movements of the F-region of the ionosphere during these unusual days. The velocity and the direction of the “wind” were obtained by the method of similar fades and the cross-correlation method. The experimental arrangements and the methods of measurements have been described. Usually the velocity of the F-region “winds” was found to have high values during the world meteorological intervals. The sudden reversal in the direction of the F-region “wind” round the midnight hour was confirmed by the observations taken during the regular world days. The sudden reversal in the direction of the “wind” was found to be followed usually by extremely rapid random fading, indicating turbulence in the ionosphere. The fading records on the unusual days in the IGY-calendar have been classified and fully discussed with reference to the random and steady movements of the irregularities which exist for a short time in the F-region.