Lightning in ‘catastrophic’ Tonga eruption breaks ‘all records’



CNN

When the Hunga Tonga-Hunga Ha’apai volcano erupted in January 2022, it sent shockwaves across the world. Not only did it generate widespread tsunamis, but it also spewed massive amounts of climate-warming water vapor into Earth’s stratosphere.

Now, researchers have revealed something else in a new report: The eruption triggered more than 25,500 lightning events in just five minutes. In just six hours, the volcano triggered nearly 400,000 lightning events. Half of the world’s lightning strikes are concentrated around the peak of this volcano’s eruption.

The “catastrophic eruption” broke “all records,” according to a report by environmental monitoring firm Vaisala, which tracks lightning around the world.

“This is the most extreme concentration of lightning that we’ve ever detected,” Chris Vajski, a meteorologist and lightning expert at Vaisala, told CNN. “We’ve been detecting lightning for 40 years, and this is truly an extreme event.”

A one-minute snapshot of lightning during the January 15 eruption in Tonga.lightning around the volcano

Vaisala’s annual report finds that 2022 is the year lightning extremes occur. The number of lightning strikes in the United States increased in 2022, with more than 198 million lightning strikes — 4 million more than observed in 2021 and 28 million more than in 2020.

“We’re continuing the upward trend in lightning,” Vagasky said.

Another lightning monitoring network led by the University of Washington, the Global Lightning Location Network, which was not involved in the report, said Vaisala’s findings on global lightning and Hunga were consistent with their own observations.

“We can do this because more intense eruptions would produce lightning that would send detectable radio signals around the globe,” Robert Holdsworth, the network’s director, told CNN . “The lightning activity from the Huga eruption was absolutely impressive.”

Researchers are targeting lightning as a key indicator of the climate crisis because the phenomenon often heralds rising temperatures. Lightning occurs during high-energy storms associated with an unstable atmosphere and requires relatively warm and humid air, which is why they occur mainly in tropical latitudes and elsewhere during the summer.

But in 2022, Vaisala’s National Lightning Detection Network detected more than 1,100 lightning strikes in Buffalo, New York, during a devastating lake-effect snowstorm that dumped more than 30 inches of snow on the city, but history Snowpack totals were more than 6 feet on surrounding suburbs along the shores of Lake Erie. Lake-effect snow occurs when cold air blows over warm lake water, in this case from the Great Lakes. Huge temperature differences can lead to extreme instability in the atmosphere, and even blizzards can lead to thunderstorm-like lightning.

More than 1,100 lightning strikes in Buffalo, N.Y., during a devastating lake-effect snowstorm that brought more than 30 inches of snow to the city but more than 6 feet to surrounding suburbs along the shores of Lake Erie .

The report noted that many lightning events occurred near wind turbines south of Buffalo, which Vagasky said is significant. He explained that the ice crystal-laden clouds were lower than usual to the ground, scraping just above the turbine blades.

“This could lead to what’s called spontaneous upward lightning,” Vagasky said. “So the lightning happens because you’re charging at the tip of the wind turbine blade this very close to the cloud base, and there’s an easy connection to the charge.”

This is an ongoing area of ​​research, he said, as the country turns to more clean energy alternatives.

“We’re seeing bigger and bigger wind turbines, and of course lightning will play a role in that as we put more and more wind and renewable energy into it,” he said.

The report comes after an unusual year in 2021, when they found a significant increase in lightning strikes in the normally frozen Arctic, in what scientists say is a stark sign of how the climate crisis is changing the world’s weather.

“No mention of lightning in polar regions [in this year’s Vaisala report]but our Global Lightning Network shows a trend towards more lightning in the Arctic,” Michael McCarthy, associate professor of research and associate director of research at the Global Lightning Location Network, told CNN. .

“This close tracking shows, but doesn’t prove, the effects of climate change,” McCarthy added.

Lightning in cold regions will only intensify as the planet warms, Vagasky said, noting that meteorologists and climatologists have been collecting more data not only to understand the link between climates but also to keep people safe.

“That’s why they named lightning an important climate variable,” he said, “because it’s important to know where lightning is happening, how much it’s happening, so you can see trends in climate change leading to thunderstorms.”

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