Four EIT version (2) light curves, shown as small points, plotted against the cosine of SOHO's heliocentric inertial latitude. cos(lat) = 1, at the right-hand side of the plot, corresponds to a SOHO heliocentric latitude of 0°, or a viewing angle directly onto the equator. To prevent this plot from being dominated by the solar activity or rotation cycles, we divide each light curve into segments according to SOHO's heliocentric latitude and normalize the flux per segment (see text for details).