IONOSPHERE/MAGNETOSPHERE DYNAMICS
A magnetic storm is a large-scale disturbance of the magnetosphere, often initiated by the arrival of an interplanetary shock originating at the Sun. A magnetic storm is marked by the injection of an appreciable number of ions from the magnetotail into the ring current, a process accompanied by increased auroral displays. The strengthened ring current causes a world-wide drop in the equatorial magnetic field, taking perhaps 12 hours to reach its greatest intensity, followed by a more gradual recovery.
MAGNETIC STORMS