a) Time-latitude plot of the kinetic helicity variations . Zoomed-in plots of over t = 50−65 yrsb) and t = 225−240 yrsc). d) H_kin at ±10° (solid) and ± 25° (dashed) latitude for north (blue) and south (red) with the means over the whole time series indicated with an orange horizontal line. The data is averaged with a running mean over a 1-year window, to smooth out the dominant high-frequency component. The dotted lines show the radial magnetic field at ± 25° latitude, scaled to fit the plot. All quantities are plotted at R_s.