Fig. 3From: Regional geomagnetic core field and secular variation model over the Iberian Peninsula from 2014 to 2020 based on the R-SCHA techniqueBivariate histograms of the RMS of the residual of the range of parameters, limited to RMS<10. The purple stars indicate the value obtained as optimal in the Monte Carlo method. a Number of nodes (N) and b Lower limit of the cap (a)Back to article page