Mullard Space Science Laboratory, Department of Physics and Astronomy, University College London, Holmbury St. Mary, Dorking, Surrey, England
Abstract:
The total ion-density probe on the satellite ESRO-4 has been used to monitor the position of the boundary of the high-latitude ionospheric irregularity zone. The diurnal behaviour of this boundary suggests the appearance of a distinct night-time sub-auroral irregularity zone. Possible irregularity production mechanisms are discussed.