Extreme value theory applied to the auroral electrojet indices

Abstract

By fitting the generalized Pareto distribution to the auroral electrojet (AE) index, negative shape parameters were obtained, suggesting the existence of an upper limit to the AE index.• Understanding the plateau of AE values is crucial for assessing the risks associated with extreme events.• Although values surpassing the upper limit are rare, their existence underscores the need for diligent precautions to mitigate the consequences of such extreme events and for careful consideration in planning and preparedness efforts.