![]() RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 5, NO. 5, PAGES 375–383, doi:10.2205/2003ES000138, 2003
Wavelet analysis of secular geomagnetic variationsN. M. Rotanova, T. N. Bondar, and E. V. Kovalevskaya Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, Troitsk, Moscow region, RussiaAbstract
[1] Temporal characteristics of secular variations ( SV ) over the last hundred of years are studied using
the wavelet transformation, providing estimates of dispersion and energy parameters of the process analyzed.
The presence of abrupt geomagnetic field variations of the intraterrestrial origin in periods of 1969-1970
and 1989-1990 is confirmed. The
SV process is, on the whole, nonfractal, and only two largest scales can be regarded
as monofractal. The
SV scale diagrams obtained from the wavelet analysis not only revealed singularities in the
SV field but also provided constraints on variations in its energy parameters throughout the time interval studied.
On the basis of the
SV phase portrayal constructed in our study, the limits of the
SV dynamic system are estimated
to be
2 Received 25 November 2003; published 2 December 2003. Keywords: geomagnetic field, secular variation, wavelet analysis, attractor. Powered by TeXWeb (Win32, v.2.0). |