title: Wet precipitation chemistry at a high-altitude site (3,326 m a.s.l.) in the southeastern Tibetan Plateau.
abstract: This paper presents the results of wet precipitation chemistry from September 2009 to August 2010 at a high-altitude forest site in the southeastern Tibetan Plateau (TP). The alkaline wet precipitation, with pH ranging from 6.25 to 9.27, was attributed to the neutralization of dust in the atmosphere. Wet deposition levels of major ions and trace elements were generally comparable with other alpine and remote sites around the world. However, the apparently greater contents/fluxes of trace elements (V, Co, Ni, Cu, Zn, and Cd), compared to those in central and southern TP and pristine sites of the world, reflected potential anthropogenic disturbances. The almost equal mole concentrations and perfect linear relationships of Na(+) and Cl(-) suggested significant sea-salts sources, and was confirmed by calculating diverse sources. Crust mineral dust was responsible for a minor fraction of the chemical components (less than 15%) except Al and Fe, while most species (without Na(+), Cl(-), Mg(2+), Al, and Fe) arose mainly from anthropogenic activities. High values of as-K(+) (anthropogenic sources potassium), as-SO4(2-), and as-NO3(-) observed in winter and spring demonstrated the great effects of biomass burning and fossil fuel combustion in these seasons, which coincided with haze layer outburst in South Asia. Atmospheric circulation exerted significant influences on the chemical components in wet deposition. Marine air masses mainly originating from the Bay of Bengal provided a large number of sea salts to the chemical composition, while trace elements during summer monsoon seasons were greatly affected by industrial emissions from South Asia. The flux of wet deposition was 1.12 kg N ha(-1) year(-1) for NH4(+)-N and 0.29 kg N ha(-1) year(-1) for NO3(-)-N. The total atmospheric deposition of N was estimated to be 6.41 kg N ha(-1) year(-1), implying potential impacts on the alpine ecosystem in this region.
authors: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China.
authors: Bin
authors: B
authors: Liu
authors: Shichang
authors: S
authors: Kang
authors: Jimin
authors: J
authors: Sun
authors: Yulan
authors: Y
authors: Zhang
authors: Ri
authors: R
authors: Xu
authors: Yongjie
authors: Y
authors: Wang
authors: Yongwen
authors: Y
authors: Liu
authors: Zhiyuan
authors: Z
authors: Cong
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000531:Altitude; D011232:Chemical Precipitation; D002681:China; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005579:Fossil Fuels / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007221:Industry; D008903:Minerals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D012621:Seasons
chemical_list: D000393:Air Pollutants; D004391:Dust; D005579:Fossil Fuels; D008903:Minerals; D009584:Nitrogen