Quantifying Nonstationary Radioactivity Concentration Fluctuations Near Chernobyl: A Complete Statistical Description

We analyze nonstationary $^{137}$Cs atmospheric activity concentration fluctuations measured near Chernobyl after the 1986 disaster and find three new results: (i) the histogram of fluctuations is well described by a log-normal distribution, (ii) there is a pronounced spectral component with period T=1 y, and (iii) the fluctuations are long-range correlated. These findings allow us to quantify two fundamental statistical properties of the data - the probability distribution and the correlation properties of the time series. We interpret our findings as evidence that the atmospheric radionuclide resuspension processes are tightly coupled to the surrounding ecosystems and to large time scale weather patterns.