Ionic Composition Of Wet Deposition At The Mount Taishan And Study Of Air Transport

Study of precipitation chemistry is always one of the highlight and hotspot of atmospheric wet deposition in China. Evaluating the level of precipitation pollution, studying translation and transportation of pollutants and analyzing harm to environment are based on chemical composition of precipitation. The Mount Taishan is located in the eastern edge of Eurasia and the Midwest of East Asia with the altitude of 1545m. The Taishan mountain-top stands between the planetary boundary layer and the free troposphere where atmospheric turbulence is very notable. These conditions were of great benefit to dispersion and transmission of pollutants. So, the samples collected on the mountain-top were more representative of regional source of pollution. Considering its prominent character and location, analysis of wet deposition pollution at the Mount Taishan and transportation of pollutants are very important for the study on transportation of pollutants in East Asia.To understand the ionic composition characteristics of wet deposition and the source of pollutants at the Mount Taishan, the results of precipitation chemistry measurements at the Mount Taishan over 18 months from July 2004 to December are reported. The eleven indexes for 68 collected samples were measured including pH value, electrical conductivity, the major water-soluble anion (Mg²⁺, F", Cl^- NO₃^-, SO₄^2- and HCO₃^-) and cation (NH₄,⁺ K⁺, Na⁺ and Ca²⁺). The relationship between the indexes and their sources were analyzed. The air-masses of precipitation were simulated by Hybrid Single-Particle Lagrangian Integrated Trajectories model and classified. Finally, the analysis on the different air-masses of precipitation from different directions and routes impacted on the ionic composition of wet deposition was conducted.The results showed that the wet deposition at the Mount Taishan was acidic with the range and a volume-weighted average pH value of 3.57-7.57 and 4.63, respectively, and the frequency of acid wet deposition (pH<5.6) was 71 percent, strong acid precipitation (pH<4.5) account for 25 percent. The range of sum ion...