Fig. 3

a SV of the Y-component from CHAOS-7.7 at different locations at the Earth’s surface from 2015 to 2021 (a vertical blue line for each year is also plotted). b Hovmöller diagrams showing the sign of the SA of the Y-component at three different latitude profiles (45º S, equator and 45º N). Red colour indicates positive values of SA (increasing trend in the SV), blue indicates negative values of SA (decreasing trend in the SV) and white corresponds to null SA (maximum or minimum in the SV). Yellow stars in a) show the location of the 10 selected observatories labelled by their IAGA code