Transient luminous event
From Glossary of Meteorology
transient luminous event
(Abbreviated TLE.) The collective name for a family of lightning-related phenomena induced above thunderstorms and/or emerging from convective storm cloud tops.
TLEs include a growing family of optical phenomena occurring in the stratosphere or mesosphere, or at the base of the ionosphere, including sprites, green ghosts, halos, elves, blue starters and jets, gigantic jets, and pixies. Their durations range from submillisecond (elves) and several to tens of milliseconds (sprites) to almost a second (gigantic jets). Their optical brightness varies considerably, with gigantic jets being easily detected with the naked eye. While the brightest sprites are visible, most remain below the range of visual perception (brightness levels are comparable to aurora.) Elves and halos can be brighter but are so brief as to be rendered imperceptible to humans. In addition to visible light, some TLEs emit in the near infrared and perhaps the ultraviolet.
TLEs can be grouped into two major categories: 1) those that are induced in the middle atmosphere by energetic lightning discharges within their parent thunderstorms below (sprites, halos, green ghosts, elves) and 2) those that occur within and/or emerge from convective storm tops (pixies, blue starters and jets, gigantic jets).
Term edited 10 November 2022.
