Auroral Oval
An elliptical ring-shaped belt around Earth's magnetic poles where energetic magnetospheric electrons precipitate into the upper atmosphere to create auroras.
Governing formula
Excitation: e⁻ + O → O* → O + h ν (557.7 nm Green Light)
SI unit
Degrees Latitude (~60°–70° Geomagnetic Latitude)
In depth
Precipitating electrons collide with atmospheric oxygen and nitrogen atoms at 100–300 km altitude. De-excitation emits atomic oxygen green (557.7 nm) and red (630.0 nm) light (Aurora Borealis / Australis).
Examples in the real world
Bright green curtain displays of the Aurora Borealis observed across High-latitude regions like Scandinavia and Alaska.