Researchers have made an astonishing discovery of complex gamma-ray emissions above thunderstorms, which has provided vital new data in the field for the first time in over a decade. Two main types of thunderstorm gamma-ray emissions previously known to scientists include terrestrial gamma-ray flashes and gamma-ray glows. Glows were found to be unexpectedly persistent and prevalent, covering large areas and observed in nine out of ten flights. The findings were reported in the journal Nature by physicist Nikolai Østgaard and colleagues, who were able to observe these phenomena on NASA’s ER-2 plane flying above storms in the Caribbean and Central America.
The gamma-ray glows observed on the flights were not static, as previously believed, but rather dynamic, constantly brightening and dimming on timescales of seconds. This discovery challenges current understanding and suggests that storms are constantly changing and active. The flights also detected terrestrial gamma-ray flashes, including dimmer ones that were previously missed by satellites, indicating that these phenomena are more common than previously thought. Thunderstorms produce gamma rays when electrons are accelerated in strong electric fields within the clouds, leading to more electrons and eventually the production of gamma rays.
The researchers also identified a new type of gamma-ray blast called a flickering gamma-ray flash, which appears to be a missing link between terrestrial gamma-ray flashes and gamma-ray glows. These flashes consist of short pulses of gamma rays that repeat over tens to hundreds of milliseconds. The flickering gamma-ray flashes were often followed by narrow bipolar events and lightning, suggesting a link between these phenomena that is not yet fully understood. The discovery of these flickering flashes adds another layer of complexity to the understanding of atmospheric electricity and the processes occurring within thunderclouds.
The researchers were able to capture the shimmering and flickering of gamma-ray outbursts over various timescales and intensities, expanding the current understanding of these phenomena. The discovery of the persistent and prevalent nature of gamma-ray glows challenges previous assumptions and highlights the dynamic nature of thunderstorms. The constant brightening and dimming of these glows suggest that storms behave like boiling pots, with activity occurring on rapid timescales. This groundbreaking research represents a significant advancement in the field of gamma-ray emissions and their association with thunderstorms.
Physicists and researchers not involved in the study have expressed amazement at the findings, emphasizing the importance and impact of the research. The discovery of the flickering gamma-ray flashes and their potential role in lightning initiation and the broader atmospheric electricity processes opens up new avenues for further research and investigation. Overall, this study provides a valuable contribution to the understanding of thunderstorm gamma-ray emissions and sheds light on the intricate processes occurring above the cloud tops during storms.
