Recovering Record-Setting Lightning Strikes Obscured by a Software Glitch

Back in 2016, NASA built its Geostationary Lightning Mapper (GLM), a single-channel, near-infrared optical transient detector, then put it on the GOES-16 satellite in a geostationary orbit. The device can monitor the entire U.S. and record lightning strikes that happen all across the continent. But NASA software engineers didn’t want the device to be overloaded with data, so they programmed it to record no events longer than three seconds. The unintended consequence of that decision was that some megastrikes were ignored or chopped into three-second bites

To see if there was more information that could be pulled from GLM’s sliced and diced images, Los Alamos National Laboratory had one of its software experts, Michael Peterson, develop a software program to repair the data.

Once Peterson got it running and he stitched several large flash events together, he discovered two “megaflashes” that were declared world records—one for flash distance and the other for flash duration—by the World Meteorological organization.

The world record for flash distance went to a single horizontal megaflash that happened over southern Brazil on Oct. 31, 2018. The flash spanned 440 miles, more than doubling the previous record of 199 miles. Rather than moving in just one direction, the flash started centrally and extended simultaneously both northwest and southeast. The flash was finished in 11.3 sec.

The other world record was set for a lightning flash duration. It occurred over northern Argentina on March 4, 2019. Although smaller than the Brazil flash, the Argentina flash lasted more than 16.7 sec., more than twice the duration of the previous record of 7.74 sec.

With this new analysis technique and modern satellite technology, more discoveries are sure to follow, including national security-relevant discoveries.