When the Hunga Tonga-Hunga Ha’apai volcano erupted in January 2022, it sent shockwaves around the world. Not only did it trigger widespread tsunami waves, but it also belched an enormous amount of climate-warming water vapor into the Earth’s stratosphere.
Now scientists in a new report have revealed something else: the eruption set off more than 25,500 lightning strikes in just five minutes. In just six hours, the volcano unleashed nearly 400,000 lightning bolts. Half of all the lightning in the world was concentrated around this volcano at the peak of the eruption.
The “cataclysmic eruption” broke “all records,” according to the report by Vaisala, an environmental monitoring company that tracks lightning around the world.
“It’s the most extreme concentration of lightning that we’ve ever seen,” Chris Vagasky, a meteorologist and lightning expert at Vaisala, told CNN. “We’ve been detecting lightning for 40 years now, and this is truly an extreme event.”
Vaisala’s annual report found 2022 to be a year of extremes for lightning. Lightning increased in the US in 2022, with more than 198 million lightning strikes – 4 million more than observed in 2021, and 28 million more than 2020.
“We continue an upward trend in lightning,” Vagasky said.
The World-Wide Lightning Location Network, another lightning monitoring network led by the University of Washington, which is not involved in the report, said Vaisala’s findings about global lightning as well as the Hunga volcano are consistent with their own observations.
“We can do this because the stronger bursts generate lightning, and lightning sends detectable radio signals around the world,” Robert Holzworth, director of the network, told CNN. “The Hunga eruption was absolutely stunning in its lightning activity.”
Scientists have used lightning as a key indicator of the climate crisis, since the phenomenon typically signals warmer temperatures. Lightning occurs in energetic storms associated with an unstable atmosphere, which requires relatively warm and moist air, which is why they occur primarily in tropical latitudes and elsewhere during the summer months.
But in 2022, Vaisala’s National Lightning Detection Network found more than 1,100 lightning strikes in Buffalo, New York, during a devastating lake-effect blizzard that dumped more than 30 inches of snow on the city but accumulated historic totals of more than 6 feet in the surrounding suburbs along Lake Erie . Snow effect occurs when cold air blows over warm lake water, in this case from the Great Lakes. The large temperature difference can cause extreme instability in the atmosphere and lead to thunder-like lightning even in snowstorms.
The report noted that many of those lightning events occurred near wind turbines south of Buffalo, which Vagasky said was significant. He explained that the ice crystal-filled clouds were lower to the ground than usual, scraping just above the blades of the turbines.
“That can cause what’s known as self-initiated upward lightning,” Vagasky said. “So the lightning occurs because you have charge on the tip of this wind turbine blade which is very close to the base of the cloud, and it’s very easy to get a connection of the electrical charge.”
This is an area of ongoing research, he said, as the country turns to more clean energy options.
“We’re seeing bigger and bigger wind turbines, and as we put in more and more wind energy and renewable energy, lightning is going to play a role in that,” he said.
The report comes after an unusual year in 2021, when they found that lightning strikes increased significantly in the typically frozen Arctic region, which the researchers say is a clear sign of how the climate crisis is changing global weather.
“Lightning in polar regions was not mentioned [in this year’s Vaisala report]but our global lightning network shows a trend for much more lightning in the northern polar regions,” Michael McCarthy, research lecturer and associate professor of the World Wide Lightning Location Network, told CNN. “This trend closely follows the observed average temperature changes over the Northern Hemisphere.
“This close tracking suggests, but does not prove, a climate change effect,” McCarthy added.
Vagasky said lightning in colder areas will only intensify as the planet warms, noting that meteorologists and climatologists have been collecting more data to not only make the climate connections clear, but also keep people safe.
“That’s why they’ve called lightning an important climate variable,” he said, “because it’s important to know where it’s happening, how much is happening, and so you can see how thunderstorms are trending as a result of changing climate.”