Abstract China has established a ground‐based network system, that is the Chinese Meridian Project (CMP), to continuously monitor the geomagnetic field. The superstorm in May 2024 was analyzed using the CMP data. The negative peak of the horizontal geomagnetic field ( B h ) during the storm main phase at different CMP stations varied between −449 nT and −720 nT while the absolute peak value of the corresponding time derivative (d B h /d t ) varied from 32 nT/min to 60 nT/min. We adopted a geomagnetically induced current (GIC) model to investigate the impact of the storm on the Eastern Inner Mongolia Power Grid. The comparison between modeled and measured geomagnetically induced currents (GICs) at two substations showed a good agreement in timing and amplitude. The simulated GICs across the Eastern Inner Mongolia Power Grid service area identified the Tianjin South substation at 1,000 kV level as the most vulnerable part of the grid, with maximum GIC of 168.5 A. The GIC level, as an indicator, supports the conclusion that the effect of the May 2024 storm exceeds that of the November 2004 storm and is on a par with the March 1989 geomagnetic storm. Together with real‐time GIC monitoring, our approach has paved the way for future geomagnetic storm risk assessment and extreme space weather safeguard.
Wang et al. (Sun,) studied this question.