Transient luminous event

Transient luminous events (TLEs) are electrical phenomena that occur above storm clouds. TLEs are not well understood.

There are several types of TLEs, the most common being the Sprite. Sprites are flashes of bright red light that occur above storm systems. C-sprites is the name given to single vertical columns of red light. C-Sprites exhibiting tendrils are sometimes called carrot sprites. Other types of TLEs include Gnomes, Blue Jets, Blue Starters, and Elves.

TLEs seem to occur near lightning both chronologically and spatially. However, the nature of the relationship between TLEs and lightning is still unclear. Current theory holds that TLEs are similar to lightning, the basic difference being that they strike upwards and are conducted by the ionosphere, as opposed to striking downwards and conducted by the Earth. TLEs also vary greatly in appearance from traditional lightning, ranging from bright red flashes of with yellow halos to blue flames firing into the sky.

TLEs generally last anywhere from less than a millisecond to more than 2 seconds, making their documentation a challenge. The first TLE wasn’t captured on film until 1989. University of Minnesota researchers were waiting to record a rocket launch and pointed the camera at a distant thunderstorm. A TLE was later identified, appearing in only two frames of the film. Currently the number of videos documenting TLEs is estimated to be around 1000.

ee also

* Aurora (astronomy)
* St. Elmo's fire

External links

* http://www.nssl.noaa.gov/primer/lightning/ltg_tle.html
* http://elf.gi.alaska.edu/