NEW ORLEANS, Louisiana — As the coronavirus spread across the globe and countries imposed lockdown restrictions in spring 2020, air and water quality increased, people traveled less and now scientists say lightning activity decreased across the globe.
Last month, scientists gathered in New Orleans for the American Geophysical Union meeting to present findings on this recent study involving the amount of pollution and lightning activity. Scientists discovered that as large populations of people were placed under restrictions during spring 2020, fewer aerosols (or pollutants) were released into the atmosphere, due in part to less travel.
Aerosols are tiny particles in the atmosphere that are produced both naturally and artificially. Mist, fog and dust are examples of natural aerosols while pollutants are examples of humanmade aerosols.
Some of these aerosols can collect water vapor that later goes on to create cloud droplets. When more of these aerosols are present, the droplets become smaller and can help produce small hail and ice crystals. As these objects collide within the cloud, charges are formed and the difference between these charges creates lightning.
Working with data from the same time periods during pre-COVID-19 years, including the period of 2002-2019, scientists were able to confirm the lack of aerosols produced by human activities led to an overall decrease in lightning activity across the globe by an astounding 19%.
Earle Williams, a physical meteorologist at the Massachusetts Institute of Technology who presented the research, said his team used three different methods to measure lightning.
"All results showed the same trend, that is, diminished lightning activity associated with diminished aerosol concentration," Williams said.
As large populations began locking down in early 2020, humans emitted fewer aerosols into the atmosphere. Pollution from air travel also declined significantly.
"Automobile traffic has a big impact on surface aerosol production," said Williams.
Results also showed that regions with more dramatic drops in aerosol concentration also tended to have the largest reduction in lightning activity.