Fast Plasma Drifts in the High Latitude Ionosphere

We have identified over 200 fast plasma drift events (>5 km/s) in the high-latitude ionosphere, as measured by electric field double probe on Dynamics Explorer-2 satellite during its 18 months lifetime from August 1981 to February 1983. Although these drifts can appear at all local time sectors, they are most common dawnside and pre-midnight sector. The generally occur between 64° 82° inv.lat. although sometimes below 55° sector, which case associated with a phenomenon often referred sub-auroral ion drifts. For increasing Auroral Electrojet index, their occurrence rate increases latitudinal locations move equatorward. observed last 0.1 60 s, corresponding (north-south) widths of 1–500 km along trajectory. observations show seasonal dependence such that faster tend dark (winter) hemisphere.