Manifestation of solar and geodynamic activity in the dynamics of the Earth’s rotation

The relationships between different manifestations of solar and geomagnetic activity and the structural peculiarities of the dynamics of the pole wobble and irregularities in the Earth’s rotation are studied using singular spectrum analysis. There are two close major peaks and several lower ones in the same frequency range (1.1–1.3 years) in the Chandler wobble (CW) spectrum. Components in the geomagnetic activity were distinguished in the same frequency band (by the Dst and Ap indices). Six- to seven-year oscillations in the Earth’s rotation rate with a complex dynamics of amplitude variations are shown in variations in geomagnetic activity. It is revealed that secular (decade) variations in the Earth’s rotation rate on average repeat global variations in the secular trend of the Earth’s geomagnetic field with a delay of eight years during the whole observation period.