Isocontours of the ratio f/f_max, where f is the spot covering factor and f_max = 0.0059 its maximum value, versus time and longitude for the ME models with Q = 1.5. The two dashed black lines mark longitudes 0° and 360° beyond which the distributions are repeated to easily follow spot migration. The contour levels are separated by Δf = 0.1f_max with yellow indicating the maximum covering factor and dark blue the minimum. The dashed white lines trace the migration of the active regions associated with each active longitude (see the text).