Most Powerful Northern Lights for Decades ‘Exposed Weaknesses’

In May 2024, the Gannon geomagnetic storm—the strongest in more than two decades—compressed Earth’s plasmasphere to roughly one-fifth its previous radial extent, while the same disturbance pushed auroras unusually close to the equator, bringing the northern lights to Mexico and Japan and the southern lights across Australia.

Arase measurements show exactly how the May 2024 Gannon storm drove the plasmapause from L=7 to L=1.5 in nine hours while auroral ovals expanded towards low latitudes worldwide. The post In May 2024, the Gannon geomagnetic storm—the strongest in more than two decades—compressed Earth’s plasmasphere to roughly one-fifth its previous radial extent, while the same disturbance pushed auroras unusually close to the equator, bringing the northern ligh…