Using satellites and ground stations, researchers have documented an epic lightning strike from 2017 that zipped across three states in the US southwest. Incredibly, researchers say that discoveries of even larger “megaflash” are likely.
We usually think of lighting as something that moves along the vertical domain, but lightning can also move horizontally, especially at high altitudes. New research published last week in the Bulletin of the American Meteorological Society confirms that lightning strikes are “more common” than is usually estimated. These superbolts often extend over 100 miles long, including a record-breaking 2017 megaflash that spanned 500 miles across Texas, Oklahoma and Kansas.
The length of vertical flashes usually flashes between 6 and 10 kilometers (3.7 to 6 miles), with the highest up to 20 kilometers (12 miles). However, the “horizontal extent of a flash in the cloud can be much longer, reaching” mesoscale “dimensions in large storm systems,” wrote the authors of the new study, led by Walter Lyons of FMA Research at Fort Collins, Colorado. By “mesoscale”, the authors refer to lightning strikes longer than 100 kilometers. As for the total possible length that horizontal lightning strikes can extend, it is still a scientific unknown.
Scientists first became aware of mesoscale lightning strikes in the 1950s, but it was not until the discovery of spirits – the upper atmosphere flash in 1989 that meteorologists began to appreciate the nature of the phenomenon. Sprites are light electric flashes that occur in clusters at altitudes reaching 50 to 90 kilometers (31 to 56 miles) above the Earth’s surface. These flashes occur within an organized collection of individual thunderstorms called mesoscale convective systems. Under the right circumstances, these flashes can trigger a chain reaction that extends over large distances. In 2007, for example, researchers used 3D lightning strike mapping to chronicle a 321-kilometer (200-mile) lightning strike above Oklahoma, a record-breaker at that time.
For the new study, the researchers sought to better understand and characterize the largest of these mega-bottles. To this end, Lyons and his colleagues looked at data collected by Geostationary Lightning Mapper (GLM) aboard the National Oceanic and Atmospheric Administration’s GOES 16 and GOES 17 satellites, which were launched in 2017 and 2018, respectively. GLM gives researchers an outstanding ability to track large storms from high above the earth.
Using GOES data and ground-based flash mounting stations, the researchers found that mega bottles that extend over 100 kilometers or more are actually quite common. However, as the new document shows, the largest of these mega bottles is larger than the researchers thought.
On the morning of October 22, 2017, a squall line appeared, that is, a severe thunderstorm that formed in front of a cold front, in the southwestern United States. At 1:13 a.m. local time, a lightning bolt appeared over northern Texas, and it quickly spread in a north-northeast direction across Oklahoma, eventually ending in southeast Kansas. In total, the megaflash traveled over 500 kilometers (310 miles), lighting up an area of 67,845 square miles (26,195 square miles).
This megaflash has not been confirmed by the World Meteorological Organization (WMO), so it is technically not an official world record. Lyons and his colleagues wrote in the paper, saying it is a “point” point given the strong likelihood of even longer megaflash in the specific storm system and other storms since then. In addition, unpublished GOES data has already hinted at an even longer megaflash – a 673-kilometer (418-mile) behemoth from Brazil, recorded earlier this year.
So how big can a mega bottle get? Apparently large, according to research.
“A megaflash, once initiated, seems to be able to disperse almost indefinitely as long as there are adequate continuous charge reservoirs in the [storm system],” the authors wrote. “Is it possible that a future megaflash can reach a length of 1,000 km? We wouldn’t bet on that. Let the search begin. “