Climate change strikes again - literally. New findings from a study published in the journal Nature Climate Change report an increase of lightning strikes in the Arctic Circle. Lightning strikes in this region of the world are uncommon, but 2019 came in as the year that saw a rise in lightning within 300 miles of the North Pole, according to the National Weather Service in Alaska. The study, conducted by researchers at the University of California, Irvine, says that this trend is likely to continue.
"We projected how lightning in high-latitude boreal forests and Arctic tundra regions will change across North America and Eurasia," said lead researcher Yang Chen, of the UCI Department of Earth System Science. "The size of the lightning response surprised us because expected changes at mid-latitudes are much smaller."
Although the connection between lightning and climate change may not be immediately clear, the two are most definitely related. As CO2 increases in the atmosphere and land temperatures rise, we are seeing more frequent and stronger storms, which bring with them lighting. But the lightning-climate change relationship isn’t only unidirectional, lighting also affects climate by the nitrogen oxides it releases which act as strong greenhouse gases. Watch the video below to learn more.
Co-author of the study James Randerson is a professor in UCI's Department of Earth System Science. Randerson took part in investigations about the 2015 Alaskan wildfires, which he says spurred interest in the research on lightning. "2015 was an exceptional fire year because of a record number of fire starts," Randerson said. "One thing that got us thinking was that lightning was responsible for the record-breaking number of fires."
With this in mind, the team used climate projection models to determine a relationship between the flash rate and climatic factors in the Arctic. They found that increases in atmospheric convection and more intense thunderstorms resulted in a significant increase in lightning strikes.
But what, you may ask, is the harm of a little more lightning? Randerson explains that the harm comes from the dangerous consequences of wildfires, which greatly alter Arctic ecosystems, modifying them from tundra to forest. This produces a positive feedback mechanism because forests absorb more solar heat than tundra (due to the albedo effect), thus increasing land surface temperatures. Additionally, higher temperatures melt permafrost, which in turn releases methane and carbon dioxide, which warms the climate even more.
The authors hope that their findings will urge the public to call for more investigation into this topic. "This phenomenon is very sporadic, and it's very difficult to measure accurately over long time periods," concludes Randerson. "It's so rare to have lightning above the Arctic Circle."