TY  - JOUR
A1  - Zaourar, Naima
A1  - Hamoudi, Mohamed
A1  - Holschneider, Matthias
A1  - Mandea, Mioara
T1  - Fractal dynamics of geomagnetic storms
JF  - Arabian journal of geosciences
N2  - We explore fluctuations of the horizontal component of the Earth's magnetic field to identify scaling behaviour of the temporal variability in geomagnetic data recorded by the Intermagnet observatories during the solar cycle 23 (years 1996 to 2005). In this work, we use the remarkable ability of scaling wavelet exponents to highlight the singularities associated with discontinuities present in the magnetograms obtained at two magnetic observatories for six intense magnetic storms, including the sudden storm commencements of 14 July 2000, 29-31 October and 20-21 November 2003. In the active intervals that occurred during geomagnetic storms, we observe a rapid and unidirectional change in the spectral scaling exponent at the time of storm onset. The corresponding fractal features suggest that the dynamics of the whole time series is similar to that of a fractional Brownian motion. Our findings point to an evident relatively sudden change related to the emergence of persistency of the fractal power exponent fluctuations precedes an intense magnetic storm. These first results could be useful in the framework of extreme events prediction studies.
KW  - Geomagnetic field
KW  - Magnetosphere
KW  - Geomagnetic storm
KW  - Multiscale analysis
KW  - Spectral exponent
Y1  - 2013
U6  - https://doi.org/10.1007/s12517-011-0487-0
SN  - 1866-7511
VL  - 6
IS  - 6
SP  - 1693
EP  - 1702
PB  - Springer
CY  - Heidelberg
ER  -