Quirks & Quarks

Superbolts and megaflashes — scientists study souped up lightning

Extra intense bolts can be 100 to 1000 times as bright and powerful as normal lightning

Extra intense bolts can be 100 to 1000 times as bright and powerful as normal lightning

Lightning strikes behind a home in the community of Cold Creek, Nevada. Superbolt lightning strikes can be 100 to 1000 times more electrically powerful and optically brighter than an ordinary lightning bolt. (Ethan Miller / Getty Images)

Years of satellite observations of millions of lightning strikes has provided new insight into extra powerful lightning strikes called 'superbolts' and an associated phenomenon called 'megaflashes.'

Micheal Peterson, a scientist from the U.S. Los Alamos National Laboratory in New Mexico, has been crunching data from two Earth observing satellites. One study used data from the FORTE satellite the the other used images from the Geostationary Lightning Mapper instrument on the GEOS-R satellite

In all, he was able to spot two million 'superbolt' lightning strikes, which are 100 to 1000 times more electrically powerful and optically brighter than an ordinary lightning bolt. They are, however, relatively rare, representing only about 0.3 per cent of all lightning strikes picked up by the satellites.

The superbolts were most often associated with large winter storms over water, which created conditions in which unusually large amounts of electrical charge were able to accumulate, making the eventual discharge of energy a powerful superbolt.

Peterson says superbolts were also associated with long chains of electrical discharge horizontally through storm systems and the clouds associated with them called 'megaflashes.' These extended chains of flashes have been observed to occur over more than 700 kilometres, lasting up to 16 seconds.  

Peterson says that because of their power and the distance they propagate, it's likely that some of these megaflash / superbolt events cause dangerous "blue sky" lightning strikes well in front and behind storm systems.  

Superbolts were first identified in the 1970s when their intense flashes were picked up by satellites designed to detect nuclear weapon detonations.

Produced and written by Jim Lebans

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