Impacts of a solar superstorm on the global electric circuit
DOI: 10.1063/10.0039874
Impacts of a solar superstorm on the global electric circuit lead image
Space weather can perturb the Earth’s atmospheric electric field. In May 2024, a solar superstorm — the most intense in two decades — triggered a temporary, rapid decrease in galactic cosmic ray intensity and a simultaneous increase in solar energetic particle flux. These transient phenomena are called Forbush decrease (FD) and Ground Level Enhancement (GLE) events, respectively.
The extremity of the solar superstorm, and the unique combination of FD and GLE observed within it, presents a rare opportunity to link transient cosmic ray and solar energetic particle phenomena to variations in atmospheric electricity. This link reflects changes in the continuous flow of electricity in the atmosphere, known as the global electric circuit (GEC). Using data from the Gar station at the Qinghai–Tibet Plateau, Fu et al. report the GEC’s responses to the May 2024 geospace superstorm.
“Since the GEC is intimately related to thunderstorms and precipitation around the world, better models could help us understand how large solar events might influence global patterns of severe weather, improving the predictive capability of weather and space weather forecasting,” said author Gang Li.
The researchers characterized atmospheric electric field (AEF) signals observed in the event, linking them to geomagnetic conditions and magnetosphere compression. They then quantified AEF responses to GLE and FD.
The authors aim to eventually capture the GEC’s full spatial response from multiple worldwide stations.
“Modelers can now tune simulations based on how atmospheric conductivity and electric fields respond to FDs and GLEs, and simultaneous measurements of both the electric field and the air-Earth current density would provide the ‘smoking gun’ to confirm or debunk different mechanisms and scenarios,” said Li.
Source: “Global electric circuit response to the May 2024 geospace superstorm from China’s Gar station observation,” by Shuai Fu, Gang Li, J. Tacza, Tao Chen, and Jianan Peng, Physics of Fluids (2025). The article can be accessed at https://doi.org/10.1063/5.0292958 .
