Beyond the familiar chaos of thunder and lightning lies a secret meteorological event.
It’s something that people have witnessed to speak of, but until now, has never been captured on film.
For over 40 years, atmospheric researchers have speculated about how trees interact with storms.
They believe trees may produce small electrical discharges when clouds pass overhead.
No researcher had ever documented this phenomenon in a natural environment. In the summer of 2024, a team from Penn State University set out to change that.
What it takes to track an atmospheric phantom
Penn State wanted to know if trees produce electrical sparks during real thunderstorms.
They used an unconventional method to find out.
They transformed a 2013 Toyota Sienna into a mobile laboratory equipped with cameras and other sensing devices.
The objective was twofold. Track severe storms and determine if trees could produce electrical discharges under real-world conditions.
Researchers spent all summer traveling up and down the eastern seaboard looking for a thunderstorm that would provide the right amount of data.
While they found many thunderstorms, the vast majority of those that occurred dissipated before they could get any usable information.
The researchers required both a powerful enough thunderstorm to generate high levels of electrical charges and favorable observation opportunities.
After several months of searching without success, the chase was becoming more promising.
Why a hidden electrical canopy matters
While this event seems like little more than a curiosity, it has more significance than initially meets the eye.
Scientists believe that trees produce these electrical discharges. Those discharges may contribute to breaking down pollutants in the atmosphere.
Therefore, forests may play a secret role in determining atmospheric composition during storms.
However, if trees discharge electricity during storms, millions of forested acres across the eastern U.S. could produce cumulative effects.
The potential interactions between the forest and the electrically charged atmosphere of storms could alter how we measure atmospheric chemistry.
How an invisible forest glow was finally captured
After several months of searching without success, they eventually experienced ideal conditions for witnessing this phenomenon.
The reason for this lies in the corona discharge process.
During a thunderstorm, clouds build up a large negative charge. The earth’s surface below responds with a large positive charge.
The positive charge accumulates at the highest points available — specifically, the leaves or branches of trees.
The charge reaches the very tip of each leaf.
There, the electric potential increases enough to energize the surrounding air. Upon returning to its normal state, it releases energy in the form of light.
Almost all of this light occurs in the ultraviolet range; therefore, most will remain invisible to human eyes.
Finally, after months of searching, researchers observed and recorded these glows.
The site was the University of North Carolina at Pembroke, where a prolonged storm lasted long enough to demonstrate the effect on many different trees.
The recorded sparks appeared as minute flashes jumping from one leaf to another in a display of light across the treetops, according to the Royal Meteorological Society.
What’s changed now that we’ve learned about electrical trees?
For years, scientists have wondered about trees in storms.
Were they simply passive objects affected by electrical energy? Or did they play an active role in generating that energy?
This study confirmed what scientists had hypothesized for years.
Trees participate actively in their local electrical environment.
The Penn State discovery changes what is known about the way the forest behaves during extreme weather conditions.
These crowns are full of electrical energy, which cannot be detected by any of man’s senses. This provides yet another level of unseen activity in nature.
These silent sparks may yet illuminate atmospheric chemistry and the hidden energies of our natural world.
Researchers continue to investigate how forests interact with the electrical dynamics of severe weather systems.
If a forest can make electrical exchanges with storm clouds, what other invisible conversations is nature having?