Lightning comes in more flavors than you can shake a metal rod at—positively or negatively charged, headed up or down, hitting the ground or another cloud. Atmospheric scientists know that ice particles in a thundercloud become slightly charged. Eventually, a negatively charged layer of the storm gets sandwiched between two positives. Electricity arcs among the layers, ionizing the air and making it glow. But experts have yet to understand the bolts’ behavior. Researchers are now tracking the radio waves and x-rays produced by lightning, and they’re even experimenting with synthetic strikes (made with rockets!). Here’s their current thinking.
Gigantic jet: About 80 percent of all storm discharges are intracloud. But if one heads up and hits a weak positive charge in the upper layer, it exits skyward.
Bolt from the blue: Gigantic jets can exit the cloud sideways and touch down miles away from the storm that spawned them under a clear blue sky.
Spider: These discharges travel up to 60 miles per second over huge distances, moving laterally through horizontal layers.
Beaded: Certain segments of the kinked ion channel seem to glow brighter when seen from a particular angle.
Forked: When too much negative charge builds up at the end of a bolt, its channel can split apart in midair to form two or more offshoots.
Ribbon: Multiple strikes sometimes share the same channel. If the wind blows the channel sideways, the eye perceives a band of light in the microseconds between strokes.
Zigzag: As a storm dissipates, air between the cloud and the ground holds pockets of charge. This produces bolts that hop groundward from one pocket to the next.
Ball: Grapefruit-sized, glowing spheres of electricity have been reported in the vicinity of thunderstorms. No one knows why.
Energetic narrow bipolar: These intracloud flashes are one of the strongest natural source of radio emissions. They last only 10 microseconds.
Red sprite: Positively charged cloud-to-ground lightning makes the cloud more negative. That negative field reaches upward above the cloud, where lower air densities mean less energy to produce a discharge—which then glows red.
Blue jet: According to one theory, negatively charged cloud-to-ground lightning makes the cloud more positive; the storm pumps the excess positivity skyward in a high-energy burst that makes the ionized air around it glow blue.
Photo illustration: John Blackford
Photograph by Olivier Vandeginste/atmospheres.be
dailybridgerton
jbbartram-illu
snowghoul
