Two things happen in a Coronal Mass Ejection (CME). Electromagnetic (EM) radiation travels at the speed of light and interacts with our ionosphere. This causes radio blackouts. I'm a ham radio operator, and a lot of us have apps for solar flare alerts because it pretty much shuts things down, and you can time it pretty good if the alert service is on top of it. Alert -> 8-9 minutes later -> tons of noise (static) that you can't punch a signal through. Secondly, actual particles of matter are ejected from the sun, these travel significantly slower - when they end up hitting the atmosphere, they collide with other atoms and create the aurora.
Two things happen in a Coronal Mass Ejection (CME). Electromagnetic (EM) radiation travels at the speed of light and interacts with our ionosphere. This causes radio blackouts. I'm a ham radio operator, and a lot of us have apps for solar flare alerts because it pretty much shuts things down, and you can time it pretty good if the alert service is on top of it. Alert -> 8-9 minutes later -> tons of noise (static) that you can't punch a signal through. Secondly, actual particles of matter are ejected from the sun, these travel significantly slower - when they end up hitting the atmosphere, they collide with other atoms and create the aurora.