The rare “superbolt” flashes are 1000 times brighter than normal lightning

LOS ALAMOS, NM, November 12, 2020: Two new studies of the brightest lightning events on Earth, called “superbolt”, have found that they are distinct from normal lightning and can be over 1,000 times brighter. The new findings could help scientists better understand these mysterious strikes and inform safety efforts, such as public warnings and engineering guidelines. The two studies analyzed lightning events seen by orbiting satellites and provide a better picture of how these energetic lightning strikes originate.

“A lightning strike even exceeded 3 terawatts of power, thousands of times stronger than normal lightning detected from space,” said Michael Peterson, remote sensing scientist at Los Alamos National Laboratory and lead author of the studies, published today in Journal of Geophysical Research: Atmospheres of the American Geophysical Union. “Understanding these extreme events is important because it tells us what lightning is capable of.”

The research addresses an ongoing debate among scientists about how these energetic lightnings originate. The new studies propose that superbolts typically result from rare positively charged cloud-to-ground events, rather than the more common negatively charged cloud-to-ground events characteristic of most lightning strikes.

Superbolt, first reported in 1977 based on optical brightness measurements made by the Vela satellite, were initially described as flashes 100 times brighter than typical lightning. Since then, however, scientists have debated whether these observations represented phenomena distinct from ordinary lightning. The viewing angle of a satellite, for example, could affect the observed brightness of a lightning bolt.

“When you see a flash from space, it will look much fainter than if you saw it from ground level because the clouds block some of the light,” Peterson said.

The new studies complement the 1977 report. One study used data acquired by the Geostationary Lightning Mapper, a detector on a satellite that remains centered on the Americas, from January 2018 to January 2020. The authors summed the signals detected on the sensor similar to a camera to calculate the total brightness for lightning.

This work was supported by the Department of Energy, National Nuclear Security Administration.

Links to documents (available for free download until December 15):

Geostationary Lightning Mapper (GLM) Observations of the Brightest Lightning in the Americas, Michael Peterson, Erin Lay: Los Alamos National Laboratory, Los Alamos, New Mexico, United States.

Review of Superbolt Detection by Optical Lightning, Michael Peterson, Matt W. Kirkland: Los Alamos National Laboratory, Los Alamos, New Mexico, United States.