What makes “Flickering Gamma-ray Flashes” Flicker ?

In the project we want to uncover the hidden secrets of thunderstorms by studying mysterious, flickering bursts of high-energy radiation—what we call Flickering Gamma-ray Flashes. These flashes are brief, lasting only tens of milliseconds, yet they reveal surprising energetic processes occurring inside the storm clouds themselves. We believe that these gamma-ray flashes, together with related phenomena known as Glow Bursts and Gamma-ray Glows, are produced by an intriguing process called the "relativistic feedback discharge." In simple terms, as a storm builds up energy, it can trigger a self-sustained cascade of high-energy particles that spark these flashes and ultimately yield to the electric field to collapse, without requiring conventional lightning discharge. To unravel this mystery, we will combine observations from airplanes, satellites, and weather balloons with advanced computer simulations. This approach will allow us to explore how these energetic events develop and interact within thunderstorms. Additionally, our research might open innovative ways to remotely measure electrical activity in storms and provide new insights into processes that influence atmospheric chemistry—which could, in turn, affect climate models. Separately, because these powerful gamma-rays can trigger photonuclear reactions and generate isotopes like Carbon-14, our findings may also have important implications for radiocarbon dating in thunderstorm-active regions.

This research proposal, "What makes 'Flickering Gamma-ray Flashes' Flicker?", investigates a newly discovered high-energy phenomenon in thunderstorms. The project aims to understand the mechanisms behind Flickering Gamma-ray Flashes (FGFs) and their relationship to other thunderstorm phenomena like Gamma-Ray Glows and Glow Bursts. The research will develop advanced computer models and analyze data from multiple observation platforms to explore the role of relativistic feedback mechanisms and the importance of these processes in thunderstorm dynamics. Structured into five work packages over four years, the project involves international collaboration and aims to produce new insights, high-impact publications, and open-source models for the scientific community. Beyond advancing high-energy atmospheric physics, the project may have broader implications for understanding atmospheric electricity, climate science, and radiocarbon dating. This research builds on recent discoveries from the ALOFT Campaign in July 2023 and seeks to significantly contribute to our understanding of thunderstorms and their effects. This research proposal will also be complementary to two ongoing projects at the UiB HRT group, both recipients of a NFR grant: project number 325582 led by M. Marisaldi, and 335162 led by N. Lehtinen. See the full 11 pages project description.