Can lightning clean up the atmosphere?

American scientists have discovered that lightning has released large amounts of hydroxyl radicals and hydroperoxyl radicals that are invisible to the camera or the naked eye.

Lightning can produce from 2 – 16% of the amount of hydroxyl. The hydroxyl radical is important in the atmosphere because it triggers chemical reactions and breaks down air pollutant molecules like methane. Decomposition of atmospheric pollutants Lightning may play a bigger role than we thought in a fundamental process that helps clean our air of pollutants, according to the results of a new study. Lightning strikes during storms produce large amounts of molecules called oxidizing radicals, which can break down gases such as carbon monoxide and methane in the atmosphere. These are atmospheric pollutants that can contribute to global warming and damage to the ozone layer. Carbon monoxide and methane enter the atmosphere from both natural and industrial sources. Methane is produced by the decomposition of plants, but is also released by oil and gas development and agriculture. Carbon monoxide and other polluting hydrocarbons can be generated by industries and wildfires. However, natural processes in the atmosphere, driven mainly by sunlight, have produced molecules called radicals, the most important of which are hydroxyls. These molecules are very chemically active (meaning that they are more likely to react with other molecules) and can react with pollutants to form new compounds that are harmless or potentially harmful. can be easily attached to water and released into the air. New research led by Pennsylvania State University meteorology professor William Brune has found that lightning produces far more hydroxyl molecules than previously known. His work shows that more than 10% of the supply of these scavenging radicals in the atmosphere can be generated by lightning storms. Use an airplane to fly through the storm Lightning’s ability to clean the atmosphere. The work involved flying NASA’s DC-8 research plane through deep convection thunderstorms to collect data. According to Professor Brune, this is not as dangerous as one might think. “Very interesting indeed. The pilots are phenomenal. They know what they’re doing. They know how to keep planes safe. But it’s really interesting because you can see deep convection and this is very close and personal,” said Prof. Brune. “We did this study in 2012, flying over central China. America and try to see what’s going into the storm chemically, what’s going to come up above. And to our surprise, we saw a very large amount of OHs (hydroxyl molecules). At first, we did not believe the signals received. They are huge, a thousand times larger than the largest mass we have ever seen.” The data collected from the aircraft was compared with data collected from radio receivers on the ground that track lightning flashes in the clouds. Both data sets confirmed the production of high amounts of hydroxyl radicals due to lightning strikes. Hydroxyl radicals are produced when the energy of lightning strikes breaks down water vapor in the atmosphere. “You can think of it like water that has removed the hydrogen atom and then wants to get that hydrogen back. So it becomes very active as it goes and tries to get the hydrogen back,” he said. That means the hydroxyl radical is very reactive with methane or carbon monoxide molecules. Climate change models need to be updated According to the scientists, about 1,800 lightning storms circulate around the planet, which leads the researchers to estimate that this phenomenon produces between 2% and 16% of the amount of hydroxyl present in the atmosphere.

A single lightning bolt can release up to a billion volts, tens of thousands of amps, travel at more than 434,000 km/h and in just a few millionths of a second reach 30,000 degrees Celsius – hotter than the surface of the Sun. Professor Brune admits that it is difficult to gauge the effectiveness of this process on a global scale. The results of this study were based on a limited number of flights over a small portion of the United States. There is still a lot of information that needs to be gathered to create a global picture. However, Professor Brune believes that the hydroxyl generated by lightning has a significant worldwide impact. Previous models suggested that lightning was not a significant contributor to the clean-up of the atmosphere. “Our best estimate right now is from 2%, which is quite important, to more than 10%, which is very important, for the total cleanup of the atmosphere. These estimates may change as our planet warms. Some climate change models show an increase in thunderstorm activity, which means more hydroxyl production and more cleaning of the atmosphere in the future. Other climate models suggest that there may not be much lightning, but lightning strikes will be more intense and may also alter the numbers. In any case, future models of climate change and global pollution will have to take into account this new information about the cleaning of the atmosphere, according to Professor Brune. Existing models may need updating.