Effects of a Flash

“ALL-NATURAL” IS OFTEN used as a synonym for “pure,” but nature’s fury can get pretty dirty—think volcanoes. Recent UMD research shows how even lightning can release the same pollution—nitrogen oxide—as your car when it’s idling in traffic.

For the first time, scientists from the University of Maryland were able to detect lightning’s impact on air quality using high-frequency satellite observations that revealed how storms produce both pollution and other critical chemicals that help cleanse Earth’s atmosphere.

Over the course of a few days last summer, atmospheric and oceanic science Research Professor Kenneth Pickering and Associate Research Scientist Dale Allen used data from NASA’s orbiting TEMPO instrument to monitor the evolution of Eastern U.S. thunderstorms, with readings taken at 10-minute intervals.

A lightning flash’s extremely hot temperatures break apart nitrogen and oxygen molecules, resulting in up to 15% of all nitrogen oxides released into the atmosphere, contributing to ozone pollution that can trigger asthma and other respiratory conditions.

“Human pollution is much greater, but what’s important to consider is that lightning releases nitrogen oxides at much higher altitudes, where it can be more efficient at catalyzing the production of ozone,” Pickering says.

Luckily, lightning doesn’t just create pollution—it also triggers the formation of hydroxyl radicals, important molecules that help clean Earth’s atmosphere by breaking down gases like methane, an important contributor to global warming and ozone pollution.