Plants may react to lightning, according to researchers. It has long been known to scientists that when plants and trees are caught in the electrical fields generated by thunderstorms, tiny, visible electric discharges can be emitted from the tips of their leaves. The coronas that result from these discharges can occasionally be seen as faint blue sparks glowing around charged objects.
Recent studies have shown that these plant-based fires may be changing the local air quality in previously unnoticed ways. However, it is still unknown if these atmospheric microearthquakes have positive or detrimental effects. In the study, which was published on August 9 in the Journal of Geophysical Research: Atmospheres, researchers replicated electrical fields from thunderstorms in the lab and studied the coronas given off by eight plant species under different settings.
All of the coronas were shown to produce a large number of radicals, which are extremely reactive molecules with unpaired electrons that can dramatically affect the local air quality. The plant coronas release two types of radicals: hydroxyl (OH) and hydroperoxyl (HO2), both of which are negatively charged and are known to oxidize, or steal electrons from, a wide variety of chemical substances, therefore converting them into other molecules. Because of their increased impact on air quality, hydroxyl radical concentrations were of special interest to the researchers.
Removing harmful chemicals from the atmosphere by reacting with greenhouse gases like methane is one way to fight climate change. When the same radical combines with oxygen, however, it produces ozone, which is harmful to people despite being vital to the upper atmosphere’s function. He also noted that the radicals can contribute to poor air quality by producing particles called aerosols.
Researches have established a connection between thunderstorms and hydroxyl radicals before. Scientists discovered that lightning is a significant source of hydroxyl radicals in the atmosphere. The group proposed a theory in a study published in Science that thunderstorms may be directly responsible for up to 1/6th of the hydroxyl radicals in the atmosphere. Similarly, a follow-up study presented in September in the journal Earth, Atmospheric and Planetary Sciences found that metallic objects like power lines and transmission towers form coronas with a little greater quantity of hydroxyl than plant coronas. Plant coronas and manufactured coronas also produce radicals, albeit at far lower concentrations compared to those created by lightning.
