Figure 1. Spatial power spectra of the geomagnetic field in 2016 according to the SIFmplus model (Olsen, Finlay, Kotsiaros, & Tøffner-Clausen, 2016) as a function of spherical harmonic degree n at Earth’s surface (diamonds) and at the core-mantle boundary (triangles; offset in amplitude). Units are µT2 for the surface field and mT2 for the core field.