Thunderstorms Affect Air Quality Around Trees with Sharp Leaves, Here's How

According to a recent study, trees' electric discharges on their sharp, pointy leaves cause thunderstorms to have an impact on the quality of the air around them.

On tree leaves, weak electrical discharges known as corona can happen when thunderstorms rumble overhead.

A recent study led by a group of Penn State scientists found coronas produce significant quantities of atmospheric chemicals that may have an impact on the quality of the air near forests.

Jena Jenkins, a postdoctoral scholar from Penn State's Department of Meteorology and Atmospheric Science, said that while little is known about how widespread these discharges are, her group estimated that the coronas produced on trees during thunderstorms may have a significant effect on the surrounding atmosphere.

Coronas and Pointy Sharp Leaves

According to scientists, the same factors that cause lightning during thunderstorms also cause electric fields to form between the clouds and the ground.

Tall, angular objects, such as leaves high in a tree, strengthen the electric field further and can cause electrical failures, or coronas.

Jenkins said that according to calculations scientists have been able to make so far, they believe this can affect the air quality in and around trees and forests.

Accordign to 8 Billion Trees, there are approximately two trillion trees worldwide in regions where thunderstorms occur most often, and there are 1,800 thunderstorms active at any given moment.

The group discovered that coronas produce enormous quantities of hydroxyl (OH) and hydroperoxyl (HO2) radicals.

The scientists explained that the hydroxyl radical starts vital chemical processes in the atmosphere that produce ozone as well as aerosol particle pollution while purging the air of greenhouse gases (GHG) like methane.

OH Levels and Air Quality

In their research published in the Journal of Geophysical Research: Atmospheres, the scientists reported that around trees, corona-generated OH may ramp up during thunderstorms by about 100 up to 1,000 times the average levels.

The scientists pointed out that these increases in OH levels may affect air quality because OH reacts with hydrocarbons that are naturally released by leaves to generate particulate matter and ozone.

Willian Brune, a distinguished professor of meteorology from Penn State, explained that the hydroxyl radical helps to oxidize many pollutants in the atmosphere, including methane, a GHG, which enhances air quality and slows climate change.

However, such reactions can also produce ozone and tiny aerosol particles, which have a negative impact on the climate and air quality.

Therefore, it's crucial to comprehend all of the potential sources of OH in order to forecast future air quality and climate.

Read also: Strange, Upside-Down Lightning May Not be a Random Occurrence After All 

Eight Species, Wet Leaves, and UV Radiation

The research expands on a prior study led by Brune that discovered lightning as well as subvisible discharges in thunderstorm storm clouds are potentially important sources of global OH, contributing up to 2 to 16% of the OH chemistry of the planet's atmosphere.

Jenkins said that they observed huge quantities of this hydroxy radical being produced, despite the corona's charge being weaker compared to the lightning and sparks they had previously observed.

Eight different tree species' leaves were tested in the lab under a variety of conditions, including being wet to simulate rain, by the scientists.

The amount of OH and HO2 produced by corona discharges across all tree species and the amount of UV radiation generated by the discharges was found to be strongly correlated.

The scientists speculated that fieldwork-friendly UV radiation measurement equipment is more useful for conducting future field research.

More Studies

The number of coronas that form throughout thunderstorms, the length of time they last, and how variables like wind influence the process may all be better understood with more field research.

This research may contribute to a better understanding of how forests are impacted by air quality.

Jenkins said that This research may contribute to a better understanding of how forests are impacted by air quality. Moreover, the climatic changes may be causing a rise in the frequency of thunderstorms.

These are therefore valid reasons to continue learning about and comprehending these processes, Penn State reported.

David O. Miller, an assistant research professor at Penn State, graduate student Patrick McFarland, and undergraduate student Gabrielle Olson were the other researchers on this project, which is supported by the National Science Foundation.

Related article: How Lightning Helps Clean the Air by Breaking Down Greenhouse Gases