Multifractal Analysis of Geomagnetically Induced Currents using Wavelet Leaders

The sun is constantly emitting electrons and ions as magnetized plasma, forming the solar wind and carrying with it the sun’s rotating magnetic field. The solar wind subsequently interacts with Earth’s magnetosphere and the magnetospheres of other planets. Occasionally large amounts of magnetized plasma are released at one time in a Corona mass ejection (CME). When the CME interacts with Earth’s magnetic field, it induces perturbations that may have a significant impact on critical infrastructure, for instance, by disturbing communication systems, and inducing currents on pipelines and electric power lines, which in turn may cause increased corrosion or blackouts, among other effects. In this dissertation, we analyze measured electrical signals provided to us by the Finnish Meteorological Institute, which were induced by geomagnetic storms on pipelines located in Finland and recorded in 2003. Specifically, we perform a wavelet leader multifractal analysis of these current signals to generate singularity spectra, and then using the bootstrapping technique, we apply statistical tests to show that these signals exhibit multifractal characteristics. We also performed surrogate testing to show that these characteristics were unique to the signal.