Lightning could play an important role in flushing pollutants out of the atmosphere.Oxidants help clear the air by reacting with contaminants like methane to form molecules that are more water soluble or stickier, allowing them to more easily rain out of Earth’s atmosphere or stick to its surface.
Researchers knew lightning produces nitric oxide, which can lead to the formation of oxidants such as hydroxyl radicals. But no one had seen lightning directly create lots of these oxidants.
In May and June 2012, a NASA jet measured two oxidants in storm clouds over Colorado, Oklahoma and Texas. One was the hydroxyl radical, OH. The other was a similar oxidant called the hydroperoxyl radical, HO2. The combined concentration of OH and HO2 molecules, generated by lightning and other electrified regions of air, reached up to thousands of parts per trillion in some parts of these clouds. The highest concentration of OH previously observed in the atmosphere was a few parts per trillion. The most HO2 observed was about 150 parts per trillion.
“We didn’t expect to see any of this,” says William Brune, an
Researchers knew lightning produces nitric oxide, which can lead to the formation of oxidants such as hydroxyl radicals. But no one had seen lightning directly create lots of these oxidants.
In May and June 2012, a NASA jet measured two oxidants in storm clouds over Colorado, Oklahoma and Texas. One was the hydroxyl radical, OH. The other was a similar oxidant called the hydroperoxyl radical, HO2. The combined concentration of OH and HO2 molecules, generated by lightning and other electrified regions of air, reached up to thousands of parts per trillion in some parts of these clouds. The highest concentration of OH previously observed in the atmosphere was a few parts per trillion. The most HO2 observed was about 150 parts per trillion.
“We didn’t expect to see any of this,” says William Brune, an
