Electrical discharge from plants may be changing air quality in ways we didn’t expect : ScienceAlert

Electrical discharge from plants may be changing air quality in ways we didn't expect : ScienceAlert
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When flash of lightning flashes above, plants in the ground may respond in the same way.

Scientists have long known that plants and trees can emit tiny, visible electrical discharges from the tips of their leaves when the plants are trapped under electric fields generated by thunderstorms overhead. These discharges, known as corona, are sometimes visible as faint blue sparks that glow around charged objects.

Now, new research suggests those plant-based sparks may be messing with the environment. air quality in ways never before recognized. But it is not yet clear whether the impacts of these minishocks on the atmosphere are positive or negative.

In the study, published August 9 in the Journal of Geophysical Research: AtmospheresThe researchers recreated the electric fields of thunderstorms in a laboratory and analyzed the coronas emitted by eight plant species under a variety of conditions.

The results showed that all the coronas created a large number of radicals, chemicals containing unpaired electrons that are highly reactive with other compounds, which can significantly alter the quality of the surrounding air.

“Although little is known about the extent of these discharges, we estimate that crowns generated in trees under thunderstorms could have substantial impacts on the surrounding air,” said the study’s lead author. Jena Jenkinsan atmospheric scientist at Pennsylvania State University, said in a statement.

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The two radicals that give off the crowns of plants are hydroxyl (OH) and hydroperoxyl (HOtwo), which are negatively charged and are known to oxidize or steal electrons from several different chemical compounds, thus transforming them into other molecules.

The researchers were particularly interested in hydroxyl radical concentrations because they have a greater impact on air quality.

“The hydroxyl radical contributes to total atmospheric oxidation of many air pollutants,” study co-author William Brunemeteorologist at Penn State University, said in the statement.

For example, if a hydroxyl radical reacts with Greenhouse gasesLike methane, it can remove harmful molecules from the atmosphere and help fight climate changeBruno said.

But if the same radical reacts with oxygen, it can create ozone, which, despite playing an important role in the upper atmosphere, is toxic to humans. The radicals can also create aerosol particles that damage air quality, he added.

This is not the first time that researchers have shown the link between thunderstorms and hydroxyl radicals.

In 2021, a Brune-led research team discovered that lightning was a major progenitor of hydroxyl radicals in the atmosphere. In his article, published in the magazine Sciencesthe team theorized that thunderstorms could be directly responsible for up to a sixth of the hydroxyl radicals in the atmosphere.

In September, another team led by Brune published a follow-up study, published in the journal Earth, Atmospheric and Planetary Sciencesswhich showed that coronae produced by metallic objects such as telephone poles and transmission towers produce a slightly higher level of hydroxyl radicals than coronae from plants.

However, the levels of radicals produced by plant and artificial crowns are significantly lower than those produced directly by lightning.

“Although the charge generated by the [plant] corona was weaker than the sparks and lightning that we saw before, we still saw extreme amounts of this hydroxy radical being produced,” Jenkins said.

Considering the large number of trees that are present in lightning-prone areas, crowns produced by plants may represent a poorly studied source of radicals with a highly unpredictable effect on air quality, he added.

“There are about two trillion trees in areas where thunderstorms are most likely to occur around the world and there are 1,800 thunderstorms at any given time,” Jenkins said.

As a result, the researchers want to continue to study these coronas in greater detail to fully understand the effect they have on localized air quality and on a broader global scale.

“The hydroxyl radical is the most important scavenger in the atmosphere,” Jenkins said. “So having a better accounting of where these things are made can give us a more complete understanding of what’s going on in the atmosphere.”

Other studies suggest that thunderstorms may become more frequent and powerful due to the effects of human activity. climate changeso understanding the effects of thunderstorms on air quality is vital, he added.

During the experiments, the team made another discovery that could help speed up this field of research: leaf discharges emitted sharp spikes of ultraviolet radiation.

This could allow the team to indirectly study where coronas occur in the field and measure their effects on nearby air quality.

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This article was originally published by living science. Read the original article here.

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