When a thunderstorm begins, lightning discharges change the physical and chemical state of the air, and this is not always good for us and our equipment. Recently, an American satellite managed to track this.
Observation using the TEMPO satellite
You probably never thought about the fact that every flash of lightning streaking across the sky also releases a gas — nitrogen oxide (NO) — which is an air pollutant and is found, for example, in your car’s exhaust fumes.
However, this is exactly what happens during a thunderstorm. For the first time, scientists at the University of Maryland were able to detect lightning and its impact on air quality using high-frequency satellite observations, gaining valuable insights into how storms produce both pollutants and critical chemical compounds that help clean the Earth’s atmosphere.
Over several days in late June 2025, Professor Kenneth Pickering of Atmospheric and Oceanic Sciences at the University of Maryland and Associate Research Scientist Dale Allen used data obtained from NASA’s Tropospheric Emissions: Monitoring of POllution (TEMPO) instrument to carefully monitor the eastern United States. Launched in 2023, TEMPO typically tracks air pollutants in North America hourly from 22,000 miles above Earth, but Pickering and Allen’s experiment allowed them to take rapid measurements of nitrogen dioxide associated with each storm. Finally, they could study complex processes as they occurred in the air, rather than piecing together clues after the fact.
Role of lightning in nature
When lightning strikes, extremely high temperatures are generated, which break apart nitrogen and oxygen molecules in the air. This produces nitrogen oxides, pollutants similar to those emitted by cars and other sources of fuel combustion, which contribute to ozone pollution.
While car exhaust pollutes the air near the ground, lightning causes pollution high in the atmosphere, where the ozone formed is particularly effective in contributing to global warming. Sometimes this pollution and the ozone it produces can travel to the surface, worsening air quality hundreds of miles from the storm. Allen notes that this effect is amplified in summer due to higher temperatures and accelerated ozone formation.
But lightning doesn’t just create pollution — it also causes the formation of hydroxyl radicals, important molecules that help clean the Earth’s atmosphere by breaking down gases such as methane, which is a major contributor to global warming, and background ozone levels. The lightning experiment provided researchers with critical insights into this chain reaction triggered by lightning, linking the production of nitrogen oxides to hydroxyl radicals, which helped them map the atmospheric composition and complex molecular dynamics occurring during thunderstorms.
“From past studies by our group and others we believe that each flash of lightning creates about 250 moles of nitrogen oxides in the sky on average,” Allen said. “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. Understanding how the footprint of lightning will change in a world of intensifying weather extremes is essential to formulate climate models for the future.”
Improving air quality forecasting with TEMPO
Pickering and Allen consider that their TEMPO experiment has the potential to have a real impact on everyday life. Gas formed during thunderstorms can travel on large “moving air conveyors” and affect air quality far from where the storms occurred, Allen noted. Sometimes thunderstorms also contribute to the formation of ground-level ozone, which is a major component of smog and can cause asthma and other respiratory problems in humans.
“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. “It could make a difference in how meteorologists predict air quality during and after storms in such regions.”
Although Pickering and Allen are still analyzing their early TEMPO findings, they believe their experiment will help scientists assess how much of the Earth’s atmospheric pollutants can be attributed to human activity versus natural processes. Currently, scientists studying the atmosphere are uncertain about the amount of pollution generated by each lightning flash, but the TEMPO experiment provides raw data that lays the foundation for understanding how different levels of lightning intensity can affect local and global air quality. The experiment also provides insight into the atmosphere’s ability to naturally break down pollutants such as methane and other harmful hydrocarbons.
Scientists want to use the experimental data to narrow down the main uncertainties in current climate models. This will contribute to better forecasting and better ways to protect our health and the environment from natural and man-made pollution.
According to phys.org
