Scientists Capture Electric Glows on Treetops During Thunderstorms—A Phenomenon Theorized for 100 Years
For the first time, scientists observed corona discharges—faint electrical glows—shimmering on tree branches during thunderstorms, a phenomenon suspected for nearly a century. Using specialized UV cameras in a retrofitted minivan, researchers recorded hundreds of these weak electrical discharges on trees in North Carolina, revealing they create atmospheric chemicals that affect air quality.
Breakthrough Discovery
Scientists chasing thunderstorms in a retrofitted minivan finally captured something never seen before in nature: faint electrical glows shimmering from treetops during a storm. Corona discharges are weak electrical sparks that form on the tips of leaves when a thunderstorm's electric field builds up overhead.
The Research
To observe the phenomenon outdoors, the team created the Corona Observing Telescope System, a Newtonian telescope connected to a UV-sensitive camera that includes geolocation capabilities, sensors to measure atmospheric electricity, and calibration using a mercury lamp. Using this system in North Carolina, the team recorded 859 corona events on a sweetgum tree and 93 on a loblolly pine.
Scientific Significance
By counting the UV photons hitting their camera, the team could estimate how much electricity was actually flowing through the trees, with each corona pushing roughly one microamp of current. This discovery has major implications for understanding air quality and atmospheric chemistry during thunderstorms.