Power spectra of the absolute hemispheric asymmetry. The blue curve corresponds to the absolute asymmetry of the sunspot areas from the Greenwich/SOON data. The red curve gives the average power spectrum for the difference of the unsigned toroidal fluxes integrated between the equator and ±30/40° latitude). The latter is based on 1000 realizations of 500 year each from the Babcock–Leighton model with source fluctuations (Cameron & Schüssler 2017b). The pink shading indicates ±1 standard deviation from the mean.