A Significant Sudden Ionospheric Disturbance associated with Gamma-Ray Burst GRB 221009A

TL;DR

This paper reports the detection of a significant ionospheric disturbance caused by the gamma-ray burst GRB 221009A, demonstrating Earth's ionosphere can serve as a natural detector for such cosmic events.

Contribution

It presents the first observation of ionospheric effects from an extragalactic gamma-ray burst using VLF radio waves, highlighting a novel method for studying GRB impacts.

Findings

Detected ionospheric disturbance over northern Europe linked to GRB 221009A

Showed Earth's ionosphere can be used as a gamma-ray detector

Implications for studying planetary ionospheres' responses to cosmic events

Abstract

We report the detection of a significant ionospheric disturbance in the D-region of Earth's ionosphere which was associated with the massive gamma-ray burst GRB 221009A that occurred on October 9 2022. We identified the disturbance over northern Europe - a result of the increased ionisation by X- and gamma-ray emission from the GRB - using very low frequency (VLF) radio waves as a probe of the D-region. These observations demonstrate that an extra-galactic GRB can have a significant impact on the terrestrial ionosphere and illustrates that the Earth's ionosphere can be used as a giant X- and gamma-ray detector. Indeed, these observations may provide insights into the impacts of GRBs on the ionospheres of planets in our solar system and beyond.