Is there evidence that cosmic rays trigger lightning – Wattwat?

Every second, through SpaceWeather.com, crossing the sky of the earth, nearly 50 lightning twists and turns. But despite the centuries of research, researchers are still uncertain about how bolts began. The electric field in ThunderCloud is usually too weak to ignite powerful emissions.

A new study just published Journal of Geophysical Research The observations titled 3D RF mapping and polarization show that lightning flashes are ignited by cosmic ray showers, which may have solved the mystery.

“We believe that most lightning flashes in thunderstorms are ignited by cosmic ray showers,” said Xuan-Min Shao, the lead author of the study.

To investigate the earliest moments of lightning composition, Xiao and his colleagues built a radio interferometer called “BIMAP-3D”. BIMAP-3D consists of 8 antennas from Los Alamos, which can create a three-dimensional image of lightning and finalize bolts inside ThunderClouds. Here is an example:

This is a massive thunderstorm bolt passed by Los Alamos on July 30, 2022. BIMAP-3D imaged more than 300 bolts during a 90-minute storm. This is a treasure trove of data.

The experimenters realized that some of the bolts they observed occurred in certain parts of the storm section, where the electric field was too weak to cause the “initial collapse event” (IBE) (ibe), which is the initial spark that makes the lightning move. Modern theories of relativistic electron avalanche cannot explain what they see. Their suspicion quickly focused on cosmic rays.

Cosmic rays are high-energy particles from distant supernova explosions and other violent events in the universe. They have been hitting Earth's atmosphere, forming a secondary spray of particles called “cosmic ray showers.” The average reader is familiar with these showers because we usually use the Earth's Sky Cosmic Ray balloons in California for monitoring.

One of the important things about cosmic ray showers is that they contain antimatter – positron and ordinary electrons. Los Alamos 3D Lightning Maps contains strong evidence. The magnetic fields of electrons and positrons bend in opposite directions, so they leave an opposite imprint on the polarization of lightning, which BIMAP-3D also measures.

“It took me a while to figure this out,” Xiao admitted. “I only started with electrons from the beginning, but couldn't explain the observations. It involves electrons and positrons, and all observations can be explained consistently.”

Pocitrons defend cosmic rays. “The cosmic ray shower provides an ionization path in the cloud, otherwise the lack of free electrons strongly favors the inference that most lightning flashes are ignited by cosmic rays,” the author wrote.

In fact, it is not clear how much lightning the Earth has sparked by cosmic rays. This method is needed to study more storms to improve statistics. “This will require a lot of long-term and high-quality lightning data,” said Shaw.

Functional photos: Lightning in Brazil. Image source: Sergio Mazzi

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