Wavelet analysis of secular geomagnetic variations

Abstract

Abstract. 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 < d < 4. 1.