Lightning Rises Sharply in the Arctic

Warmer temperatures and higher humidity may be key factors

Lightning is relatively uncommon in the Arctic—the air is usually not warm enough for thunderstorms. Now that might be changing, new data suggests.

A study recently published in the journal Geophysical Research Letters finds that Arctic lightning has tripled in the last decade alone.

The researchers, led by Bob Holzworth of the University of Washington, analyzed data collected by the World Wide Lightning Location Network between 2010 and 2020. The network, operated by the University of Washington, has lightning sensors all over the world.

The new study focused on summer lightning flashes, or “strokes,” detected above 65 degrees latitude—that includes parts of northern Canada, Alaska and Russia, as well as Greenland and the central Arctic Ocean.

The data suggests that the total number of Arctic lightning strokes has risen sharply since 2010.

Still, the scientists wanted to be sure. The World Wide Lightning Location Network has added a number of sensors over the last 10 years, and the increase in strokes could have been the simple product of better detection. So the team adjusted their data to account for the new equipment.

The increase still held up.

Next, the researchers compared the rate of Arctic lightning strokes with lightning around the rest of the world. They found that the fraction of Arctic lightning compared with global lightning tripled between 2010 and 2020.

The study points out that summer temperatures in the Arctic have risen by about a half-degree Fahrenheit over the last decade.

While scientists know there’s a connection between air temperature and thunderstorms, the study doesn’t actually prove that warming has caused the lightning. It simply suggests there could be a link. More research would be needed to demonstrate the connection.

Still, other studies have suggested that continued climate change may cause an increase in Arctic thunderstorms. One recent paper, published in September in Climate Dynamics, projects that thunderstorms would triple in Alaska by the end of the century under a severe climate change scenario.

A follow-up study published last month in the same journal suggests that increased humidity, driven by warming and melting sea ice, is the driver.

More research may still be needed to determine exactly what’s going on with Arctic storms. Nature recently reported that at least one other global lightning detection network has not recorded the same increase in Arctic lightning, although its records only extend back to 2012.