Fig. 10

Left: annual average of the mean dipole component in magnetic coordinates associated with the remote magnetospheric field \(g_{rm}\) (line with circles), the sum of the remote \(g_{rm}\), close \(g_{m}\), and fluctuating \(g_{fm}\) magnetospheric fields (black line), and the COV-OBS.x2 model by Huder et al. (2020) (dashed line). The gray area represents the confidence interval predicted by \(E[g_{rm}+g_{m}+g_{fm}] \pm \sigma\) . Right: azimuthal component of the geomagnetic field taken during night-time and averaged over 10 days time periods at the level of four ground observatories, Niemegk (top left), Kakioka (top right), Hermanus (bottom left), and Canberra (bottom right). Red lines correspond to observatory data, black lines to the full Kalmag model predictions and blue lines to the Kalmag core field predictions