Collaborative research: lightning properties of downward terrestrial gamma-RAY flashes and superbolts

The National Science Foundation Office of Integrative Activities awarded the University of California Santa Cruz $646,707 on October 1, 2026, for collaborative research on lightning properties of downward terrestrial gamma-ray flashes and superbolts under the Geosciences program.

The research deploys new instrumentation and maintains an existing global network of sensors to investigate very strong lightning strikes known as superbolts and characterize how high-energy emission properties vary across different lightning phenomena. The project expands recent observations showing that terrestrial gamma-ray flashes, X-ray bursts from leader steps, and gamma-ray glows are not as distinct as historically recognized and exhibit several intermediate behaviors. The research team will continue and enhance worldwide observations of these phenomena and expand access to very low frequency and low frequency data to understand the lightning processes that produce high-energy emissions. The work has relevance to mitigating lightning impacts on infrastructure, assessing health hazards from lightning emissions, and includes significant student training for workforce development.

Performance runs from October 1, 2026, through September 30, 2029, at Santa Cruz, California. No subawards are planned for this award.

Abstract

Lightning is known to release high-energy radiation, such as X-rays and gamma-rays, that can provide insight into lightning processes and associated hazards. This project will deploy new instrumentation and maintain an existing global network of sensors to address questions about very strong lightning strikes known as superbolts, and determine how high energy emission characteristics change with different lightning properties. The project has relevance to mitigating lightning impacts on infrastructure and assessing health hazards of lightning emissions. There is also a significant student training aspect, which will enhance workforce development. This project expands upon recent observations that show that the three historically recognized forms of high-energy radiation from thunderstorms ? Terrestrial gamma RAY flashes (TGFS), X-RAY bursts from leader steps, and gamma-RAY glows ? Are not as distinct as previously recognized, and there are several kinds of intermediate behaviors. The research team plans to continue and enhance their worldwide set of observations of TGFS, glows, and leader X-rays, and expand access to very low frequency/low frequency (VLF/LF) data to understand the lightning processes that produce high-energy emissions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.