Why do some auroras pulsate?
No one is sure.
Although this unusual behavior has been known for a long time, the cause remains an active topic of research.
Featured here is a dramatic video that captured some impressive pulsating auroras in mid-March over Sv�nafellsj�kull Glacier in Iceland.
The 48-second video shown is not time-lapse.
The real-time pulsations are exemplified by sequences where the astrophotographer is visible moving about in the foreground.
A close inspection of the enigmatic flickering sky colors reveals that some structures appear to repeat, while others do not.
The quick rapidity of the pulsations seen here is somewhat unusual -- more common are aurora with pulsations that last several seconds.
Recent research shows that pulsations are more common in electron-generated aurora, rather than proton aurora, and that the Earth's local magnetic field may fluctuate in unison.
Media Credits & Attribution
** Video Credit & Copyright: ** [Stéphane Vetter](mailto: stephane dot vetter at wanadoo dot fr) (Nuits sacrées);
- Music: * Eric Aron