Storms boil pots of gamma rays: The emissions may be key to atmospheric electricity

• Published in: Science news (Washington) Vol. 206; no. 7; p. 10
• Main Author: Conover, Emily
• Format: Magazine Article
• Language: English
• Published: Washington Society for Science & the Public 02-11-2024
• Subjects: Atmospheric electricity; Electric field strength; Electric fields; Emissions; Gamma rays; Outbursts; Reconnaissance aircraft; Retrofitting; Short pulses; Storms; Thunderstorms; Weather; γ Radiation
• EISSN: 1943-0930
• ISSN: 0036-8423

Above the cloud tops, thunderstorms emit high-energy radiation in the form of gamma rays. A retrofitted spy plane captured the gamma-ray outbursts, revealing that they are more complex and common than previously thought. The study identified a new type of gamma-ray blast called a flickering gamma-ray flash. The plane also detected longer, dimmer emissions known as gamma-ray glows, which were found to be persistent and prevalent. These glows were observed to brighten and dim repeatedly on timescales of seconds. The aircraft's sensors detected terrestrial gamma-ray flashes, including ones that were too dim to be seen by satellites. Thunderstorms produce gamma rays when electric fields inside storm clouds accelerate electrons, resulting in collisions with air molecules. The details behind the different types of gamma-ray outbursts and their relationship are not fully understood. The newfound flickering gamma-ray flashes could serve as a missing link between terrestrial flashes and glows. These flashes consist of short pulses of gamma rays that repeat over tens to hundreds of milliseconds. Many of the flickering gamma-ray flashes were followed by lightning, suggesting a possible role in initiating it. Gamma rays may also play a role in limiting the strength of electric fields in thunderclouds.