Multifractal structure of auroral electrojet index data

Using a multifractal approach, based on ''singularity analysis,'' we investigate the scaling properties of the auroral electrojet index (AE) time series. The existence of a multifractal structure in the AE time series is the signature of the occurrence of ''intermittence,'' which can be interpreted as an indication of turbulence in magnetospheric dynamics. Furthermore, a simple model, the P-model (a two-scale Cantor set), is shown in order to investigate the underlying multiplicative nature of the signal. This set displays many of the multifractal properties of the AE signal.