Scientists have unraveled the long-standing mystery of how lightning begins inside thunderclouds, offering the first quantitative, physics-based explanation for lightning initiation.
Why it matters: The findings provide a glimpse into the stormy heart of Earth’s atmosphere and connect the dots between X-rays, electric fields, and the physics of electron avalanches.
The details:
- Researchers used mathematical modeling to confirm and explain field observations of photoelectric phenomena in Earth’s atmosphere.
- Strong electric fields in thunderclouds accelerate electrons, which crash into molecules like nitrogen and oxygen, producing X-rays and initiating a deluge of additional electrons and high-energy photons.
- The model, known as the Photoelectric Feedback Discharge, simulates physical conditions in which a lightning bolt is likely to originate.
The equations used to create the model are available in the paper for other researchers to use in their own work.
What they’re saying:
- “Our findings provide the first precise, quantitative explanation for how lightning initiates in nature,” said Victor Pasko, professor of electrical engineering at Penn State.
- “We explained how photoelectric events occur, what conditions need to be in thunderclouds to initiate the cascade of electrons, and what is causing the wide variety of radio signals that we observe in clouds all prior to a lightning strike,” said Zaid Pervez, a doctoral student in electrical engineering.
The other side: The precise atmospheric events that trigger lightning within thunderclouds remained a perplexing mystery until now.
What’s next: The findings offer a glimpse into the stormy heart of Earth’s atmosphere and may lead to further advancements in understanding and predicting lightning.