Statistical investigation of large geomagnetically induced current disturbance events: relationships with geomagnetic storms and interplanetary sources

IntroductionGeomagnetically induced currents (GICs) pose a critical space weather hazard to ground-based conductive infrastructure. Previous studies have commonly identified large GIC events using daily maximum amplitudes exceeding 10 A, a criterion that may obscure the detailed temporal structure of GIC disturbances.MethodsIn this study, we apply an improved identification criterion to systematically select 81 large GIC disturbance events from high-resolution (10 s) measurements at the Mäntsälä