Irregularities in the Shift of Earth’s Geographical Pole and Jerks in the Geomagnetic Field

The results of an analysis of some irregularities in a series of coordinates of the shift in the geographic North Pole along Earth’s surface are presented in order to establish a temporal relationship between their appearance and some global jerks in the geomagnetic field. The calculations used average daily data from the IERS service on movement of the North Pole from 1962 to 2021, as well as information on global jerks in the geomagnetic field at all magnetic observatories on the globe. To identify and analyze irregularities in the movement of the pole along the Earth’s surface, the following methods were used: Fourier methods and wavelet analysis of time series, methods for determining the threshold of a fixed shape and minimax in the procedure for analyzing non-Gaussian noise, methods of phase and pseudophase space, as well as the stroboscopic method of constructing the Poincaré map. Analysis of local Fourier spectra and wavelet spectra reveal irregularities in the shift of the North Pole along the Earth’s surface in the following time intervals: 1967.04.09–1967.11.30, 1974.03.29–1974.09.12, 2005.11.03–2006.03.07, comparable to the appearance of global jerks in 1969, 1978 and local jerks in 2005. It is believed that the changes in energy that caused short-term deviations of the shift in the pole’s trajectory and return to the previous trajectory at cusp points are associated with singularities in the interaction of oscillations in Earth’s rotational and translational motion in the Solar System. The time of the appearance of irregularities on the graphs of the polar shift along the Earth’s surface in 1967 and 1974 is ahead of the time of the appearance of global jerks in the geomagnetic field.