Auroral current systems and ARC formation: Observations and theory

It is a common misconception that the aurora is caused by solar wind electrons “captured by earth's magnetic field” and directed toward the magnetic poles. While the aurora is powered by the solar wind, some - and perhaps most - auroral electrons are recycled from plasma originating in the terrestrial ionosphere itself. The aurora is in fact the visible manifestation of massive current systems which, while powered by the solar wind-magnetosphere dynamo, close within the ionosphere/magnetosphere system.