title: Seasonal variations and size distributions of water-soluble ions of atmospheric particulate matter at Shigatse, Tibetan Plateau.
abstract: Size-segregated atmospheric particulate matter (PM) samples were collected from July 2012 to September 2013 at Shigatse, high-altitude (3836 m above sea level) site on the south Tibetan Plateau (TP); objectives were to determine the characteristics and size distribution of water-soluble ions (WSIs). Eight major WSIs (Na(+), K(+), Mg(2+), Ca(2+), NH4(+), Cl(-), SO4(2-), and NO3(-)) were detected by ion chromatography. The total concentrations of WSIs were 6370 ± 1916 ng m(-3) in dry season (October - December, January - April), and 5261 ± 769 ng/m(3) during wet phase (May - September). The contribution of K(+) (130 ng m(-3)), Cl(-) (2035 ng m(-3)), SO4(2-) (1176 ng m(-3)), and NO3(-) (706 ng m(-3))(-)were significantly enhanced in dry season, and that of Na(+) (455 ng m(-3)), Mg(2+)(65.4 ng m(-3)), Ca(2+)(1034 ng m(-3)), and NH4(+) (1948 ng m(-3)) were significantly enhanced during wet phase. Mg(2+) and Ca(2+) were concentrated in the coarse mode, and the other ions concentrated in fine mode and coarse mode during two seasons. The correlation coefficients between K(+) and NH4(+), Cl(-), SO4(2-) and NO3(-) were 0.58 (P < 0.01), 0.40 (P < 0.05), 0.82 (P < 0.01) and 0.69 (P < 0.01), indicating their dominant contribution from biomass burning in dry season. The significant correlation between NH4(+) and HCO3(-) which were calculated by ion balance (r = 0.89, P < 0.01), suggesting the source from nitrogen fertilizers during wet phase.
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China. Electronic address: yyj800308@163.com.
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Yang
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Weather Modification Center of Tibet, Lhasa, 850000, China.
authors.forename: Junqing
authors.initials: J
authors.lastname: Liu
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China.
authors.forename: Yi'an
authors.initials: Y
authors.lastname: Di
authors.affiliation: National Research Center for Environmental Analysis and Measurement, Beijing 100029, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Du
authors.affiliation: School of Environmental Science and Engineering, Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing 210044, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000531:Altitude; D016000:Cluster Analysis; D004784:Environmental Monitoring / Q000379:methods*; D007477:Ions; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D012995:Solubility; D018609:Tibet; D014867:Water / Q000737:chemistry; D014887:Weather
chemical_list: D000393:Air Pollutants; D007477:Ions; D052638:Particulate Matter; D014867:Water
keywords: Seasonal variation; Size distribution; TP; WSIs