A Relation Between Ionospheric Drifts and Atmospheric Dynamo Current Systems

Abstract

Travelling ionospheric disturbances have been studied at this laboratory over a considerable period using fixed frequency observations on 5·8 Mc/s. They are observed as anomalies in height on ionospheric records at three stations, spaced approximately 40 km apart. Munro (1950) has used normal triangulation techniques to determine speeds and directions and has shown (Munro 1958) that their average speed is 7 km/min with median directions 30° east of north during the winter and 120° east of north by day, during the summer months. In both seasons there is a marked easterly component. However, in recent sunspot maximum years during summer, a predominant westerly component is evident on certain days.