Fig. 8

Core surface radial field and its constituents. Upper plot: black—gufm1 unfiltered time series of the radial core field (location of NGK observatory); red—the inter-centennial constituent. Middle plot: inter-decadal constituent of the core surface field; Butterworth (color, cutoff—22 years) and running averages (black, 22-year window) filters. Lower plot: sub-centennial constituent of the gufm1 core surface field; Butterworth (color) and running averages (black) filters (numbers on curves—the cutoff/window length)