transient luminous event

plural transient luminous events

1. aeronauticsAny of a variety of upper atmospheric optical phenomena associated with thunderstorms.

   Transient luminous events can be another source of ionization in the upper atmosphere.

   2010, Rafael Escribano Torres, Isabel Tanarro Onrubiay, Spectroscopy of the atmospheres, CSIC, page 34

   2 more examples

   During World War II (and probably before), high flying pilots were reported to have observed unexplained aerial phenomena (UAP), often now called transient luminous events (TLE’s), particularly in the vicinity of thunderstorms.

   2012, Don Lipman, “Red sprites, blue jets, and elves What are these mysterious, elusive phenomena?”, in The Washington Post

   Known as Transient Luminous Events (TLEs), these unusual features were first spotted by accident in 1989.

   2018, Mary Halton, “Hunting mystery giant lightning from space”, in BBC News