Over the course of a three-year project, the authors studied about 200,000 thunderstorms in the Washington, D.C., area and more than 300,000 thunderstorms in Kansas.

Using lightning data from the National Lightning Detection Network and information from air pollution monitoring stations, the researchers determined that under conditions of high instability, increased atmospheric aerosol concentrations lead to more lightning strikes.

Scientists say airborne pollutants enter clouds via updrafts, where the particles separate electrical charges, increasing the number of lightning strikes.

The researchers also conducted a similar study in Bangkok, a metropolis with high levels of air pollution in a tropical climate. The analysis showed a similar picture, adjusted for hotter and more humid conditions.