The October 1989 Solar Storms

What happened

A distinct storm cluster from the March 1989 Quebec Blackout event, triggered by an X13-class flare that produced a sudden storm commencement on October 20, 1989. The resulting geomagnetic storm unfolded in two separate peaks of activity over the following two days, driving low-latitude aurora sightings in both hemispheres and significant, well-studied disruption to the global ionosphere, measured across a worldwide network of 40 ionosonde stations.