Over the years, as global warming has started showing its effects around the world, studies have suggested that extreme weathers will be one of them. A recent report has shown that the reason why weathers, especially thunderstorms and desert storms, are increasingly rapidly is because of pollution created by humans, including production of aerosols.
Scientists from the Massachusetts Institute of Technology (MIT) have found that lightning flashes are more frequent at the shipping routes, where freighters emit particles into the air, compared to the surrounding ocean. The study also observed that the most intense thunderstorms in the tropics occurred over land, where aerosols are released by both natural sources and human activities.
Aerosols are any collection of very fine particles that are suspended in air. They are generated by humans through various activities like burning of organic material, pollutants released by ships, factories, and vehicles. Aerosol is also produced through natural processes like volcanic eruptions, sea spray, and dust storms.
The study is led by Tim Cronin, who is designated as the assistant professor of atmospheric science at MIT. The co-author of this study is Tristan Abbott, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences.
According to MIT News, the two scientists devised a new mechanism by which aerosols escalate thunderstorms in tropical regions. For the study, MIT scientists used idealized simulations of cloud formations, and found that high concentrations of aerosols can increase thunderstorm activity by increasing the humidity in the air surrounding clouds. This relationship between aerosols and clouds has been termed as a “humidity-entrainment” mechanism.
The team of scientists ran simulations of clouds and showed the effects of high aerosol concentrations by increasing the amount of water droplets in clouds. After running multiple simulations, the study found that the “humidity-entrainment” mechanism, in which aerosol-laden clouds mix with and change the humidity of the surrounding air, is one explanation for how aerosols influence thunderstorm formation. This phenomenon especially occur in tropical regions where the air in general is relatively humid.
The method can prove beneficial in predicting thunderstorm activity in a region which might differ with changing aerosol levels and could be incorporated into weather and climate models. Speaking to MIT News, lead author of the study Cronin said that it is possible that by cleaning up pollution in the atmosphere, these places might experience fewer storms. He further said that as a whole, the study provides a way that humans may have a footprint on the climate that the scientists did not really appreciate much in the past.
When concentration of aerosol in an atmosphere rises, the tiny particles form equally tiny cloud droplets that don’t easily merge.