摘要：SummarySuperstatistics is a general method from nonequilibrium statistical physics which has been applied to a variety of complex systems, ranging from hydrodynamic turbulence to traffic delays and air pollution dynamics. Here, we investigate water quality time series (such as dissolved oxygen concentrations and electrical conductivity) as measured in rivers and provide evidence that they exhibit superstatistical behavior. Our main example is time series as recorded in the River Chess in South East England. Specifically, we use seasonal detrending and empirical mode decomposition to separate trends from fluctuations for the measured data. With either detrending method, we observe heavy-tailed fluctuation distributions, which are well described by log-normal superstatistics for dissolved oxygen. Contrarily, we find a double peaked non-standard superstatistics for the electrical conductivity data, which we model using two combinedχ2-distributions.Graphical abstractDisplay OmittedHighlights•Fluctuations of detrended water quality time series follow q-Gaussian distributions•Superstatistical long timescale is extracted from the detrended data•New type of superstatistics observed, which is well fitted by mixtureχ2-distributionsEnvironmental geochemistry; River geochemistry; Statistical physics
