Lightning strikes in the upper layers of the atmosphere cause local outbreaks of hydroxyl radicals, which contribute to the natural cleaning of the air. Scientists have observed that this leads to an increased breakdown of pollutants. In a recent study published in the journal Science, researchers have shown that electrical discharges and lightning are responsible for the direct generation of hydroxyl radicals, which contribute to the cleaning of the atmosphere.
During thunderstorms, strong increases in atmospheric concentrations of hydroxyl radicals were measured, acting as an important cleaning mechanism in the atmosphere. Nine years ago, William Brune from Pennsylvania State University and his colleagues flew in a NASA research aircraft through thunderstorms in Colorado. On board were sensitive sensors that could precisely detect various substances in the atmosphere. They found that the hydroxyl concentration increased significantly near lightning strikes due to the discharge in electric fields with up to 80,000 volts per meter. This was enough energy to directly generate hydroperoxyl and hydroxyl radicals from water molecules. The radical concentrations increased to values hundreds to thousands of times higher than previously assumed.
Based on these measurements, the researchers estimated the amounts of radicals that could be generated globally during thunderstorms. They assumed that lightning strikes in approximately 1,800 thunderstorms around the world at any given time, accounting for up to 12% of the hydroxyl radicals in the atmosphere. This contributes significantly more to the cleaning of the atmosphere than previously thought.
In conclusion, the study highlights the important role that lightning strikes play in the natural cleaning of the atmosphere. The findings could have implications for future research on air pollution and climate change.
