Overview
- The paper in Earth, Planets and Space details continuous Arase observations of the May 10–11, 2024 Gannon superstorm and its impacts on near-Earth plasma.
- Within roughly nine hours, the plasmasphere’s outer boundary collapsed from about 44,000 km to near 9,600 km, shrinking to around one-fifth of its usual extent.
- Refilling took more than four days, marking the longest recovery recorded since Arase began monitoring in 2017.
- Researchers identify a 'negative storm' that altered ionospheric chemistry, reducing oxygen ions and starving the plasmasphere of particles needed to recover.
- The storm triggered satellite anomalies, disrupted GPS and radio communications, pushed auroras to mid-latitudes, and highlights the need for stronger space-weather forecasting.