By Yereth Rosen
ANCHORAGE, Alaska (Reuters) – Forecasters were shocked this week when three successive storms hit the icy Arctic from Siberia to northern Alaska, setting off lightning bolts in an unusual phenomenon that scientists say will be less rare with global warming.
“Forecasters haven’t seen anything like it before,” said Ed Plumb, a meteorologist with the National Weather Service in Fairbanks, speaking about the storms that began Saturday.
Normally, the air over the Arctic Ocean, especially when the water is covered in ice, lacks the convective heat necessary to generate thunderstorms.
But as climate change warms the Arctic faster than the rest of the world, that is changing, scientists say.
Summer lightning episodes within the Arctic Circle have tripled since 2010, a trend directly related to climate change and increasing loss of sea ice in the far north, scientists reported in a March study published in the journal Geophysical. Research Letters. As the sea ice disappears, more water can evaporate, adding moisture to the warming atmosphere.
“It’s going to go with the temperatures,” said co-author Robert Holzworth, an atmospheric physicist at the University of Washington in Seattle.
These thunderstorms threaten the boreal forests that border the Arctic, starting fires in remote regions that are already baking in the summer sun 24 hours a day. Russia’s boreal Siberia receives more lightning than any other Arctic region, Holzworth said.
The paper also documented more frequent lightning strikes over the treeless tundra regions of the Arctic, as well as over the Arctic Ocean and ice. In August 2019, lightning even reached 60 miles (100 kilometers) from the North Pole, the researchers found.
In Alaska alone, thunderstorm activity is on track to triple by the end of the century if current weather trends continue, according to two studies by scientists at the National Center for Atmospheric Research in Boulder, Colorado, published last year in the Climate Dynamics magazine.
“What used to be very weird is now just weird,” said Rick Thoman, a climate scientist at the University of Alaska Fairbanks. As this week’s parade of Arctic storms demonstrated, lightning is already showing up in unexpected places, he said. “I have no recollection of three consecutive days of this kind of thing” in the Arctic.
With the sharp increase in lightning, Siberia has seen increasingly fierce forest fires in recent years. This week, the Russian military deployed planes that dumped water to put out the flames that burned around 2 million acres (800,000 hectares) of forest, while the worst-affected region of Yakutia has been in a state of emergency for weeks.
Meanwhile, in mid-June lightning sparked one of the largest fires in Alaska this summer, burning more than 18,000 acres of tundra about 125 miles (200 km) north of the Arctic Circle in the Noatak National Reserve in the northwest corner of the state.
Warming in the Arctic is also encouraging vegetation growth in the northern Alaskan tundra, adding more fuel for fires, the scientists said.
By the end of the century, the Alaskan tundra could burn twice as often as usual, and fires were occurring four times as frequently, according to researchers at the International Arctic Research Center in Fairbanks.
On the water, lightning is an increasing danger to sailors and boat traffic increases as the sea ice retreats, Holzworth said.
People can become lightning rods and usually try to duck for safety. That’s hard to do on flat tundra or sprawling ocean.
“What you really need is to pay more attention to lightning forecasts,” he said.