Research On Complexity Of Atmospheric Acid Deposition

Considered as the result of the complex behavior of the open and dissipative atmosphere systems under pollution pressure, the complexity of atmospheric acid deposition was researched in the present dissertation, with combined methods of theoretic analysis, actual data analysis and computational simulation. The research content involved the complex behaviors and the relationship between their numerical complexity characteristics and air pollution, the evolution mechanism and the cellular automata model simulating the complexity. The main results are shown as follows:(1) The complexity degrees of H+, NO3- and SO42- deposition series are ranged between that of white noise and chaotic signal, and is more close to that of chaotic signal, indicating that there exist concurrently certainty and randomness in the acid deposition time series. H+series exhibits more deterministic than NO3- and SO42- series, with their complexity degrees increasing linearly as the logarithms of annual mean acid depositions increasing. The higher the acid deposition is, the higher the complexity degree of the series is, with its evolution behavior more similar to random process. And the lower the acid deposition is, the lower the complexity degree of the series is, with its evolution behavior more similar to chaotic process.(2) The probability density of concentration and deposition of H+,NO3- and SO42- exhibits double power-law with scale invariance property, which was ignored by the current method for pH calculation in environmental statistics by weighting the pH values with rainfall. It's thus believed more reasonable to take the crossover pH, which represents the mostly occurred pH in rain, as the representative pH value for a given district. It's also found that the probabilities of duration of acid/nonacid rain, the standard deviation and mean value of H+ deposition, the variation rate of successive acid deposition, and the influence of rainfall on rain acidity, obey power-law, and a mathematic model was built up to simulate these power-law properties.(3) H+ deposition series is similar to 1/fβnoise of self-affine fractal with self-similarity and long-range dependence, and the scaling behavior of long-range dependence stands in 1 month to 5 years. NO3- and SO42- deposition display similar behavior as that of H+ deposition, indicating that the relevant factors involving in acid deposition might obey the same evolution rules as that of H+ deposition. The long-range dependence of acid deposition might be related to the long-range climatic process and self-organized criticality of atmosphere.(4) Acid deposition time series behave to be multifractal, which is the result of combined effect of both long-range persistence and power-law involved in the series, and the width of singular spectrum f(α)-αincrease as mean pH value increasing. The higher the acid deposition, the wider the singular spectrum f(α)-αcurve, with its evolution behavior closer to random process.(5) Acid deposition system was proved to have the basic properties of chaotic system by employing multiple methods. The correlation dimension of acid deposition series increases linearly as mean pH value increasing, and the H+ deposition exhibits much more deterministic than NO3- and SO42- deposition.(6) Self-organized criticality was believed as one of the main mechanisms inducing acid deposition and its evolution, and the power-law, long-rang persistence and the fractal/multifractal properties are the extrinsic manifests of self-organized criticality of atmosphere system. The scaling exponentsα,β,γand critical scale Xc,nc depict the macro numerical properties of self-organized critical behavior of acid deposition, and reflect the impact of atmospheric environmental characteristics on the complex properties of acid deposition.(7) With the main physical and chemical processes taken as the local reciprocity rules, a cellular automata model (ACA) was built up to simulate the complex behaviors of acid deposition, and the main complex properties of acid deposition were recurred by the model. The basic method setting up the ACA model might be of general value to build up cellular automata model for complex system with multiple components and variables.