The biggest lightning flash on record has been identified. More than twice the size of the previous record, it spanned 709 kilometres 鈥� about the distance from London to Geneva.
A second flash has set a world record for longest duration. It went on for 16.7 seconds, also doubling the previous record.聽鈥淲e identified two new lightning flashes that are substantially bigger than anything we鈥檝e ever seen before,鈥� says Randall Cerveny at Arizona State University.
Until recently, lightning was primarily tracked using ground-based sensors that detect radio waves from these flashes. In 2017, the UN鈥檚 World Meteorological Organization (WMO) used this data to certify two world records. A lightning flash over Oklahoma in 2007 spanned 321 kilometres, while a 2012 flash over France lasted 7.74 seconds.
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However, in 2016, the US launched the world鈥檚 first lightning-mapping satellite. This gives much more comprehensive coverage of Earth鈥檚 surface. Two flashes detected from space have now been certified by the WMO as covering the longest distance and having the longest duration respectively.
The 709-kilometre flash occurred on 31 October 2018 over southern Brazil and part of north-east Argentina. The satellite image revealed dozens of branches from the core flash.
On 4 March 2019, the 16.7-second flash occurred over northern Argentina. Both were cloud-to-cloud flashes and so聽didn鈥檛 hit the ground.
The flashes were so huge because of the powerful 鈥渕esoscale convective systems鈥� that develop over the plains of South America, says Cerveny. 鈥淭hey鈥檙e aggregate individual superstorms that merge together into massive big storms,鈥� he says.
Similar huge storms form over North America鈥檚 Great Plains. Within the storm clouds, enormous electrical charges can build up, ultimately discharging over huge distances through the air.
鈥淵ou are forcing lots of energy through a space that is about the diameter of a pencil,鈥� says Cerveny. 鈥淢other Nature [discharges this voltage] pretty quick, but it still takes some time, and apparently 16.7 seconds is our new record for how long that takes.鈥�
Given that the satellite data has only been collected for a few years, Cerveny doesn鈥檛 expect the records to stand for long.
Geophysical Research Letters
