Storms reveal glowing treetops as corona discharges are captured on camera

Using a UV camera mounted on a research vehicle, scientists captured hundreds of tiny corona discharges glowing along treetops during thunderstorms, showing that nearly every leaf can glow under a storm’s electric field; each corona carries about a microamp of current and produces hydroxyl radicals that can scrub pollutants but may also damage leaves, with potential implications for forest chemistry and even storm dynamics, observed across multiple storms and tree species and reported in Geophysical Research Letters by Penn State researchers led by P. J. McFarland.