Pulsating Aurora
Definition
Patches of aurora that blink on and off every few seconds, common late at night after big displays.
In plain language
After the dramatic curtains fade, the sky often fills with soft patches that pulse like slow heartbeats. Easy to dismiss as the show ending โ but it is a distinct phenomenon, and more activity often follows.
The science
Pulsating aurora is driven by modulated electron precipitation from the magnetosphere, where chorus waves scatter trapped electrons into the loss cone at 2โ20 second periods, typically during substorm recovery phases.
Why it matters for aurora viewing
Seeing pulsation means you are in the recovery phase โ rest your eyes, keep the camera running, and expect possible re-intensification.
See this in action on tonight's data.