Transient Optical Emissions in the Upper Atmosphere Monday 17 June 2002 Silverthorne 01:00-03:00 pm

This workshop will discuss various questions related to the physical nature and energetics of sprites and related optical phenomena formed as a result of strong electrodynamic coupling of tropospheric thunderstorms to the mesospheric and lower ionospheric regions.

Sprites are spectacular luminous glows which occupy volumes in excess of thousands of cubic kilometers in clear air above thunderstorms in the altitude range ~40-90 km. Sprites often exhibit an amorphous non structured glow at their tops, which gradually converts to highly (predominantly vertically) structured breakdown regions at lower altitudes. Sprites are transient in nature and last only a small fraction of a second following intense positive or negative lightning discharges (more than 90% of sprites are associated with positive lightning discharges). It appears from space shuttle observations that sprites occur over most regions of the globe (in temperate and tropical areas, over the oceans, and over the land). To date sprites have been successfully detected from ground and airborne platforms in North, Central and South America, in Europe, in Australia and over winter storms in Japan.

Please see the following web sites for more information on sprites and related atmospheric optical effects:

http://elf.gi.alaska.edu/
http://www-star.stanford.edu/~vlf/
http://www.FMA-Research.com/
http://ibis.nmt.edu/sprites/
http://sprg.ssl.berkeley.edu/atmos/isual.html