To understand core dynamics, insight from several possible observables is needed. By applying several separation methods, we show spatiotemporal variabilities in the magnetic and gravity fields related to the core dynamics. A 7-year oscillation is found in all conducted analyses. The results in the magnetic field reflect the core processes and the variabilities in the gravity field exhibit new findings that might be an interesting input to build an enhanced model of the Earth’s core.

While a 6-year oscillation has been reported for some time in the motions of the fluid outer core of the Earth, in the magnetic field and in the Earth rotation, novel results indicate that the climate system also oscillates at this 6-year frequency. This strongly suggests the existence of coupling mechanisms affecting the Earth system as a whole, from the deep Earth interior to the surface fluid envelopes.

Throughout the International Union of Geodesy and Geophysics' (IUGG's) centennial anniversary, the International Association of Geomagnetism and Aeronomy is holding a series of activities to underline the ground-breaking facts in the area of geomagnetism and aeronomy. Over 100 years, the history of this research is rich, and here we present a short tour through some of the IAGA's major achievements, starting with the scientific landscape before IAGA, through its foundation until the present day.

Decidated to the combined analysis of space weather data (geomagnetic activity, cosmic ray secondaries and ionospheric data) obtained during the September 2017 solar flares and geomagnetic storms, this study is an attempt to construct a technique for circumterrestrial physical data analysis in order to analyze various space weather effects and obtain new mutually supportive information during major space weather events on different phases of geomagnetic storm evolution.

By analyzing frequency constituents of declination secular variation at inter-decadal and sub-centennial timescales from geomagnetic observatories with data longer than 1 century and several historical data sets, we suggest that the geomagnetic jerk concept should be considered as a more general notion, namely the evolution of the secular variation as a result of the superposition of two (or more) constituents describing the effects of processes in the Earth’s core at two (or more) timescales.