From normal state to magnetic storms in terms of fractal dynamics
  We show that distinctive alterations in scaling parameters of Dst index time series occur as a strong magnetic storm approaches. These alterations reveal a gradual reduction of complexity as the catastrophic event approaches. The increase of the susceptibility coupled with the transition from anti-persistent to persistent behavior may indicate that the onset of a severe magnetic storm is imminent. The preparation of a major magnetic storm could be studied in terms of "Intermittent Criticality". The analysis also suggests that the continuous scale invariance is partially broken into a discrete scale invariance symmetry. 
G. Balasis, P. Kapiris, K. Eftaxias