Volcanic lightning
A dirty thunderstorm is a weather phenomenon that occurs when lightning is produced in a volcanic plume.[1]
Geography
The most famous image of the phenomenon was photographed by Carlos Gutierrez and occurred in Chile above the Chaiten Volcano.[2] It circulated widely on the internet.[3] Other instances have been reported above Alaska's Mount Augustine volcano.[4]
Causes
A study in the journal Science indicated that electrical charges are generated when rock fragments, ash, and ice particles in a volcanic plume collide and produce static charges, just as ice particles collide in regular thunderstorms.
As the plume started going downwind, it seemed to have a life of its own and produced some 300 more or less normal [lightning bolts] ... The implication is that it has produced more charge than it started with. Otherwise [the plume] couldn't continue to make lightning.
—Martin Uman, co-director of the University of Florida Lightning Research program
Volcanic eruptions also release large amounts of water, which may help fuel these thunderstorms.
References
- ^ Simons, Paul (May 8, 2008). "Dirty thunderstorm shoots lightning from volcano". London: Times Online. Retrieved 2009-01-09.
- ^ "Chile Volcano Erupts with Ash and Lightning". National Geographic. May 6, 2008. Retrieved 2009-01-09.
- ^ http://www.cracked.com/blog/7-images-too-badass-to-be-real-that-totally-are/
- ^ Handwerk, Brian (February 22, 2007). "Volcanic Lightning Sparked by "Dirty Thunderstorms"". National Geographic. Retrieved 2009-01-09.