Normalized hemispheric radio fluxes (in relative units). Top: normalized radio fluxes for the northern and southern hemisphere using high-latitude (blue for N, red for S), second high-latitude (light blue for N, orange for S), and all-hemispheric (cyan for N, magenta for S) time intervals (colors are the same as in the second panel of Fig. 1). Middle panel: yearly (thin blue) and 3 yr smoothed (thick blue) values of the normalized high-latitude radio flux for the northern hemisphere. A best-fit model consisting of two Fourier components is included as a black line. Bottom panel: same as in middle panel for the southern hemisphere, with blue color changed for red.