Air pollution increases thunderstorm danger

• Air pollution is making thunderstorms more lightning-prone, according to researchers at James Madison University.
• Tiny particles of pollution act as cloud nuclei. That’s part of the process by which, ultimately, more pollution particles increase the number of lightning strikes.
• Scientists studied 500,000 thunderstorms in the U.S. over three years to be able to drawn these conclusions. Now they are studying storms over Bangkok and getting similar results, suggesting this is a global phenomenon.

James Madison University originally posted this story on August 19, 2024. Edits by EarthSky.

Researchers at James Madison University in Harrisonburg, Virginia, reported on August 19, 2024, that air pollution is increasing the severity of summertime thunderstorms. That’s according to their new study, which examined a correlation between air pollution and thunderstorms in two large U.S. cities. The study is published in the peer-reviewed journal Atmospheric Research.

JMU geography professor Mace Bentley is lead author of the study. He explained:

Pollution acts as cloud nuclei. It’s brought into the cloud through the updraft. The updraft and downdraft then separate the pollution particles, which divides the electrical charges in the cloud and leads to more lightning production.

The three-year study, funded by the National Science Foundation, examined nearly 200,000 thunderstorms in the Washington, D.C., area and more than 300,000 in the Kansas City area.

Air pollution data from 2 cities

The scientists used 12 years of lightning data from the National Lightning Detection Network, combined with data from hundreds of air pollution stations in the two cities. They were able to determine that – in environments with high instability – adding more pollution increases cloud-to-ground lightning strikes, Bentley said.

Bentley is now doing similar research on Bangkok, the capital of Thailand. It’s a megacity with more pollution than Washington, D.C. or Kansas City. Bangkok is also located in a hot, tropical climate. His results so far are similar, albeit with lightning rates even higher in those storms than in the two U.S. cities studied. Bentley commented:

It looks like no matter where you go in the world, urban pollution is capable of enhancing thunderstorms and lightning.

Bottom line: Researchers studying thunderstorms in urban areas found that air pollution leads to more cloud-to-ground lightning strikes.

Source: Toward untangling thunderstorm-aerosol relationships: An observational study of regions centered on Washington, DC and Kansas City, MO

Via JMU