Fig. 8

The intervals between successive arrivals at the monitor sites. On the left is a wavelet power spectrum with the inter-arrival interval plotted as a function of time of day for Golden Gate West (top) and Point Reyes bottom. The dashed line indicates a random distribution of intervals. On the left is the spectrum of intervals, determined using a Fourier transform. The solid line indicates the prevalent intervals while the dashed line indicates the random intervals. When the solid line crosses the dashed line, the intervals between arrivals are non-random