Trees Can Glow – and They’ve Been Captured Doing It on Camera for First Time

Key Takeaways

• First-ever field video of tree‑top corona discharges captured during storms
• Recorded 859 corona events on sweetgum and 93 on loblolly pine
• UV emissions from corona create hydroxyl radicals that cleanse atmospheric pollutants
• Leaf tips show damage where corona glows, raising ecological concerns
• New telescope‑UV camera system enables systematic study of forest electrical phenomena

Pulse Analysis

For decades scientists have suspected that the electric fields generated by thunderstorms could spark tiny corona discharges at the tips of leaves, but direct evidence in the wild remained elusive. The phenomenon, first observed in laboratory settings, involves a faint ultraviolet glow as a high‑voltage gradient ionizes the surrounding air. By adapting a 2013 Toyota Sienna with a telescopic weather rig, Penn State researchers finally captured the effect in situ, confirming that nature does indeed produce these micro‑sparks during intense convective storms.

The team’s Corona Observing Telescope System combines a Newtonian telescope, a UV‑sensitive camera, and atmospheric electricity sensors to isolate the faint glow from background lightning and solar radiation. Over a two‑hour storm in North Carolina, the system logged 859 corona events on a 100‑foot sweetgum and 93 on a neighboring loblolly pine, with each flash lasting from a split second to several seconds. The ultraviolet photons break apart water vapor, forming hydroxyl radicals—atmosphere’s primary oxidizer—that accelerate the breakdown of volatile organic compounds and methane. This natural cleansing mechanism suggests forests may contribute more actively to air quality than previously recognized.

Beyond chemistry, the observations raise ecological questions. Researchers noted microscopic leaf damage at discharge sites, hinting at a trade‑off between atmospheric benefits and tree health. Ongoing collaborations with ecologists aim to determine whether trees have evolved protective adaptations or if repeated corona exposure could impair growth. As climate models increasingly incorporate biogenic emissions, integrating corona‑driven hydroxyl production could refine predictions of pollutant dispersion and greenhouse‑gas lifetimes. The breakthrough underscores the value of field‑based discovery science in uncovering hidden processes that shape Earth’s climate system.