Runaway processes in the upper and lower atmosphere: a change of paradigm

TL;DR

This paper unifies the understanding of high-energy atmospheric phenomena like TGFs, TGEs, and gamma-ray glows as different manifestations of the same runaway electron processes occurring at various atmospheric depths, challenging previous models.

Contribution

It introduces a unified framework that reinterprets these phenomena as related runaway processes, revises terminology, and challenges existing models attributing TGFs to lightning leaders.

Findings

Consistent spectral and temporal behavior across different observational scales.

Unified classification criteria based on physics rather than detection location.

Resolves contradictions and reshapes understanding of particle acceleration in thunderstorms.

Abstract

Relativistic Runaway Electron Avalanches (RREA) are central to understanding a spectrum of high-energy atmospheric phenomena, including Terrestrial Gamma-ray Flashes (TGFs), Thunderstorm Ground Enhancements (TGEs), and gamma-ray glows. Despite their common physical origin, these events are often treated separately due to differences in detection methods, duration, and altitude. In this work, we present a unified conceptual and observational framework that reinterprets these radiation bursts as manifestations of the same runaway processes occurring in distinct atmospheric depths. Integrating recent results from satellite (ASIM), aircraft (ALOFT), balloon (HELEN), and ground-based (SEVAN) experiments, we demonstrate consistent spectral and temporal behavior across scales. We propose a rational revision of current terminology and challenge longstanding models that attribute TGFs to lightning leader dynamics. This study resolves key contradictions in the field, establishes new classification criteria based on physics rather than detector location, and reshapes our understanding of particle acceleration in thunderstorms.