Fig. 13From: Evaluation of candidate models for the 13th generation International Geomagnetic Reference FieldSpatial map differences of \({\text{d}}B_z/{\text{d}}t\) (in nT/year) between IGRF-12 secular variation candidates and final IGRF-13 secular variation model over the 2015.0 to 2020.0 time period. We additionally include spatial map differences (against IGRF-13) of the mean and median of all IGRF-12 candidates, as well as the final IGRF-12 SV model in the bottom rowBack to article page