Plasmaspheric Trough Discovered During Storm.

The IMAGE EUV imager observed a plasmaspheric density trough in association with a geomagnetically active period on 24 May 2000. In EUV, this density trough appears as an Archimedes spiral extending from Earth's shadow to approximately 1800 MLT

(2001: M.L. Adrian and D.L. Gallagher)