Sign-Singularity Analysis of Field-Aligned Currents in the Ionosphere

Field-aligned currents (FACs) flowing in the auroral ionosphere are a complex system of upward and downward currents, which play fundamental role magnetosphere–ionosphere coupling ionospheric heating. Here, using data from ESA-Swarm multi-satellite mission, we studied structure FACs by investigating sign-singularity scaling features for two different conditions high-latitude substorm activity level as monitored AE index. The results clearly showed sign-singular character supporting filamentary nature these currents. Furthermore, found evidence occurrence topological change current systems, was accompanied at spatial scales larger than 30 km. This interpreted terms sort symmetry-breaking phenomenon due to dynamical transition FAC consequence wedge intensification during substorms.