Effect of l = 1, 2, 3 components (respectively top, middle, and bottom panels) of the SV on the shape and position of the auroral zones. For illustrative purposes, the actual SV has been magnified by a factor of 100. Left panels: the magnified SV components at the CMB. Middle and right panels: the northern and auroral zones, plotted with the centroid positions for the 2020 IGRF-13 model (red) and the same model, on top of which the SV shown in the left panels is added (blue).