⚡ Scientists discover how lightning is born: a chain reaction

Lightning has always fascinated humanity, but its precise origin in thunderclouds remained a mystery. A team of researchers believes they have solved this enigma thanks to a major discovery.

Scientists have identified how intense electric fields in clouds accelerate electrons, triggering chain reactions. These collisions generate X-rays and high-energy photons, ultimately sparking a lightning bolt.


The mathematical model developed by the team replicates conditions observed in thunderclouds. It explains how electrons, accelerated by electric fields, produce X-rays by colliding with air molecules. This phenomenon, known as electron avalanche, is key to understanding lightning initiation.

Simply put, electric fields in thunderclouds accelerate electrons to near-light speeds. These electrons collide with air molecules, releasing X-rays and high-energy photons.

This process creates an electron avalanche, where each collision generates new energetic particles. This chain reaction is at the origin of lightning initiation, a phenomenon occurring within milliseconds.

Specific conditions in clouds, such as the presence of ice crystals, can amplify these electric fields. This explains why some thunderstorms produce more lightning than others, depending on their internal structure.

Field observations, combined with simulations, helped validate this theory. Researchers used data from ground sensors, satellites, and high-altitude aircraft.

Terrestrial gamma-ray flashes (see next section), often without detectable optical or radio signals, also found an explanation. The model shows how these events can occur in very compact volumes. This explains why they may appear without lightning's usual signatures.

This research opens new perspectives for understanding extreme atmospheric phenomena. It could also have implications for aviation safety and thunderstorm forecasting. The model's equations are now available for other scientists.

What is a terrestrial gamma-ray flash?

Terrestrial gamma-ray flashes are bursts of high-energy radiation produced in thunderclouds. Unlike visible lightning, they don't always emit detectable light or radio waves.

These events result from relativistic electron avalanches, where particles reach extreme energies. They can occur in small cloud regions, making them difficult to observe without specialized instruments.

Terrestrial gamma-ray flashes are an example of energetic phenomena occurring in our atmosphere. Their study helps scientists better understand the physical processes at work during thunderstorms.