Results for surface-based data available within a cap of semi-opening angle 30° and local spectra for a concentric cap of semi-opening angle 20°. Maps center and ranges are as in Fig. 4. Black dashed circle on maps indicates the region of data availability and black dotted circle indicates the region for local spectral calculation. Maps show the radial component B_r on the planet’s surface (r = 3393.5 km) of the (a) average local model and (b) difference between the model of Langlais et al. (2019) and the average local model from panel (a). (c) Local Mauersberger–Lowes power spectrum of each local model (grey lines) and localized spectrum (dotted line) from the model of Langlais et al. (2019). (d) Ratio between the local spectra of the local models and the localized spectrum of Langlais et al. (2019).