You may think of flooding or power outages when storms roll in. But each lightning strike also emits nitrogen oxides, gases more commonly linked to vehicle exhaust.
For the first time, researchers have captured how lightning impacts air quality in real time, using NASA’s TEMPO satellite.
A team from the University of Maryland tracked June 2025 thunderstorms with rapid 10-minute satellite readings. The experiment offered a rare glimpse into how lightning pollutes and simultaneously helps cleanse the air.
UMD professors Kenneth Pickering and Dale Allen used the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument, which usually scans hourly.
By switching to high-frequency mode, they captured the gases linked to lightning as storms moved across the eastern United States.
“This is the first time this kind of research has been conducted at such a temporal frequency,” Pickering said. “Thunderstorms evolve on a rapid basis. They often build up, intensify and die within an hour’s time.”
The team combined TEMPO readings with data from NOAA’s Geostationary Lightning Mapper to count flashes.
“With this experiment, we’re able to count the number of lightning flashes as they occur… and in turn, get a more accurate idea of how much nitrogen dioxide each flash of lightning produces during a storm and how long it sticks around afterward,” Allen said. “This information will help researchers improve existing climate models and enhance our understanding of how lightning can affect the air we breathe.”
Pollution high above Earth
Lightning creates extreme heat that breaks apart nitrogen and oxygen molecules, producing nitrogen oxides. Pickering said, “Lightning globally makes up 10 to 15 percent of total nitrogen oxides released into the atmosphere.”
While car engines emit pollution at ground level, lightning injects gases high above Earth. There, they more effectively drive ozone formation, which warms the atmosphere.
Allen noted that summer heat worsens the effect. “Lightning’s effects on climate during the summer season are comparable to anthropogenically created nitrogen oxides, which is why we wanted to study storms during June,” he explained.
Lightning also sparks hydroxyl radicals, which help cleanse the air by breaking down methane and other gases. Allen said earlier studies suggest each flash produces about 250 moles of nitrogen oxides.
But the figure varies widely. “We believe that when storms get more intense, lightning flashes get shorter and produce less nitrogen oxide per flash. This study will give us a chance to prove that.”
Impacts on health and forecasting
The gases created aloft often travel long distances on moving air currents. Sometimes they mix down to ground level and worsen smog, posing health risks.
“For people living in mountainous areas like Colorado, this information can be very important as lightning does make a significant contribution to surface ozone at higher terrain altitudes,” Pickering said.
The researchers believe their data will sharpen the ability to distinguish natural versus human-made pollution.
Allen said, “We want to use this high-frequency data to narrow the major uncertainties in our current climate models. With better data comes better predictions, and potentially better ways to protect our health and environment from both natural and human-made pollution.”