Fig. 3

Mean (\(\mu\), top) and root-mean-square (\(\sigma\), bottom) residuals (in nT) of the DIFI-2015b model for individual observatories and for the radial (r), polar (\(\theta\)) and azimuthal (\(\phi\)) components, as a function of quasi-dipole latitude. The mean and root-mean-square differences between DIFI-2015b predictions and independent observations at NCK and CBI during quiet times (as defined for this study) are also shown as filled squares with the same color code