Gamma radiation from thunderstorms is the most energetic natural discharge on Earth
Not only electricity can illuminate a storm cloud.
Bright gamma-ray bursts, known as dark lightning or terrestrial gamma-ray bursts, also erupt during thunderstorms. And in rare cases, these powerful explosions—the most energetic radiation that occurs naturally on Earth—can even hit a passing plane , researchers reported Dec. 13 at a meeting of the American Geophysical Union. Zap can briefly expose passengers to dangerous levels of radiation.
For the first time registered in 1994 a year, according to estimates, dark lightning flashes around the world about a thousand times a day . But scientists have only a vague understanding of how it begins. They generally agree that dark lightning is caused by electric fields created by thunderstorms and lightning. These fields can propel electrons to speeds approaching the speed of light, building up devastating electron avalanches. When the stream particles hit atoms in the air, gamma radiation is released.
Dark lightning often occurs 10 to 15 kilometers in the sky, an altitude that airlines often fly to. The new analysis combines observations of dark lightning and airline routes to suggest that dark lightning could flash near an aircraft about once every 1 to 4 years, atmospheric scientist Melody Pallu said at the meeting. However, this is likely the “upper bound of the real probability” or even 10 times the actual speed, she said, mainly because the calculations did not take into account the pilots’ avoidance of thunderstorms.
Previous computer simulations showed that passengers flying within 200 meters of the point of initiation of a strong terrestrial gamma-ray burst could be exposed to radiation doses. exceeding 0.3 sieverts , said Pallu, who now works at the Astroparticle and Cosmology Laboratory in Paris. Such levels will exceed the level of occupational safety in 0.02 sievert per year, established by the International Commission on Radiological Protection.
Although the findings are somewhat murky, they do make one thing clear: further research is needed to find out how dark lightning affects passengers flying through the sky.
