Variation in (panel a) autocorrelation at lag-1, (panel b) variance, and (panel c) spectral coefficient, α, calculated from detrended fluctuation analysis prior to the dimming event. The period from 1980–1990 is shown in gray, and the period from 1990 onward is shown in green. A visible rise can be seen leading towards the event. The calculated quantifier is plotted at the end time of the moving window.