Researchers Decode Lightning’s Radio Frequencies to Predict Weather

Researchers at Los Alamos National Laboratory (LANL) have made significant strides in understanding lightning by analyzing the radio frequencies it generates while still in the clouds. Their findings could enhance our ability to predict and prepare for severe weather events, which are becoming increasingly common.

Unveiling the Mysteries of In-Cloud Lightning

The LANL team, led by scientists Erin Lay and Amitabh Nag, has compiled the largest database of trans-ionospheric pulse pairs—very high-frequency radio signals produced by lightning in clouds. Over a two-month period, from January to June 2023, they gathered more than 76,000 signatures using a satellite-based radio frequency sensor orbiting approximately 22,000 miles above the Earth. This data was cross-referenced with ground lightning reports for accuracy.

The research primarily focuses on a powerful type of lightning known as compact intracloud discharges. These rapid bursts of in-cloud lightning generate electromagnetic pulses—one pulse travels upwards while the other moves downwards, reflecting off the Earth’s surface. The researchers noted that the strength of these pulses can vary significantly.

“It has long been a question why, in some cases, the second pulse that bounces back is stronger than the first,” Lay stated. By analyzing their amassed data based on altitude, the team discovered a correlation between the lightning’s location within the cloud and the relative strengths of the two pulses. “Whether the first or second pulse is stronger depends on where the lightning occurs in the cloud,” Lay explained.

The Structure of Thunderclouds and Its Implications

Thunderclouds typically have three layers: two positively charged layers sandwiching a negatively charged layer. Occasionally, a fourth negatively charged layer, known as the “screening charge” layer, forms at the cloud’s top. “This upper region is significant because we believe many of these events occur there,” Nag remarked.

Although compact intracloud discharges are relatively rare, they exhibit unique characteristics. Nag emphasized, “It’s a small fraction of lightning, but it is unique and very bright, illuminating both the Earth’s atmosphere and sending substantial energy into space.”

Looking ahead, Lay aims to gather more data and isolate additional variables. Increased statistics will allow the research team to explore further questions about the complex nature of lightning. “Understanding these phenomena helps us better comprehend how severe weather evolves and how it impacts our infrastructure, human safety, and wildlife,” Nag noted. “All of these factors are fundamentally interconnected, making it crucial to understand lightning and its behavior within clouds.”

As climate change intensifies weather events, insights gained from this research could play a vital role in developing strategies to mitigate risks associated with severe weather, ultimately protecting communities and ecosystems worldwide.