Berlin 2005 – wissenschaftliches Programm
EP 1.6: Vortrag
Freitag, 4. März 2005, 11:15–11:30, TU BH349
From normal state to magnetic storms in terms of fractal dynamics — •Georgios Balasis1, Panayiotis Kapiris2, and Konstantinos Eftaxias2 — 1GeoForschungsZentrum Potsdam, Telegrafenberg, D-14473, Potsdam, Germany — 2Faculty of Physics, University of Athens, Panepistimiopolis, Zografos, 15784 Athens, Greece
By monitoring the temporal evolution of fractal spectral characteristics in Dst time series we find distinctive symptoms indicating the approach to a major magnetic storm: (i) Emergence of long-range correlations. (ii) Gradual increase of the spatial correlation. (iii) Decrease of the fractal dimension with time, indicating strong anisotropy in substorm activity. (iv) Strong anti-persistent behavior in the first epoch of the precursory geomagnetic activity. (v) Decrease of the anti-persistent behavior with time. (vi) Emergence of persistency in the “tail” of the precursory epoch. (vii) Predominance of large geomagnetic events with time coupled with the appearance of higher frequencies in the spectrum. (viii) Significant acceleration of the energy release, i.e., increase of the susceptibility of the system with time. The question whether the evolution towards global instability is inevitable after the appearance of distinctive symptoms is discussed. The results could be studied in terms of “Intermittent Criticality”. The analysis suggests that the continuous scale invariance is partially broken into a discrete scale invariance symmetry.