title: Chemical and optical properties of aerosols and their interrelationship in winter in the megacity Shanghai of China.
abstract: A field campaign on air quality was carried out in Shanghai in winter of 2012. The concentrations of NO, NO2, NOx, SO2, CO, and PM2.5 increased during haze formation. The average masses of SO4(2-), NO3(-) and NH4(+) were 10.3, 11.7 and 6.7 μg/m(3) during the haze episodes, which exceeded the average (9.2, 7.9, and 3.4 μg/m(3)) of these components in the non-haze days. The mean values for the aerosol scattering coefficient (bsp), aerosol absorption coefficient (bap) and single scattering albedo (SSA) were 288.7, 27.7 and 0.91 Mm(-1), respectively. A bi-peak distribution was observed for the mass concentrations of CO, NO, NO2, and NOx. More sulfate was produced during daytime than that in the evening due to photochemical reactions. The mass concentration of NH4(+) achieved a small peak at noontime. NO3(-) showed lower concentrations in the afternoon and higher concentrations in the early morning. There were obvious bi-peak diurnal patterns for bsp and bap as well as SSA. bsp and bap showed a positive correlation with PM2.5 mass concentration. (NH4)2SO4, NH4NO3, organic mass, elemental carbon and coarse mass accounted for 21.7%, 19.3%, 31.0%, 9.3% and 12.3% of the total extinction coefficient during non-haze days, and 25.6%, 24.3%, 30.1%, 8.1% and 8.2% during hazy days. Organic matter was the largest contributor to light extinction. The contribution proportions of ammonium sulfate and ammonium nitrate to light extinction were significantly higher during the hazy time than during the non-haze days.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Han
authors.affiliation: State Environmental Protection Key Laboratory of Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Qiao
authors.affiliation: State Environmental Protection Key Laboratory of Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Shanghai Meteorological Service, Shanghai 200000, China.
authors.forename: Jianfei
authors.initials: J
authors.lastname: Du
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. Electronic address: liuxingang@bnu.edu.cn.
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Environmental Protection Key Laboratory of Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
authors.forename: Shengrong
authors.initials: S
authors.lastname: Lou
authors.affiliation: State Environmental Protection Key Laboratory of Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China.
authors.forename: Changhong
authors.initials: C
authors.lastname: Chen
authors.affiliation: State Environmental Protection Key Laboratory of Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China. Electronic address: wanghl@saes.sh.cn.
authors.forename: Hongli
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
mesh_terms: D065638:Absorption, Radiation; D000336:Aerosols / Q000032:analysis* / Q000737:chemistry*; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry*; D002681:China; D002940:Circadian Rhythm; D002947:Cities; D004784:Environmental Monitoring; D007477:Ions / Q000032:analysis / Q000737:chemistry; D008027:Light; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D007477:Ions
keywords: Chemical apportionment; Diurnal variations; Optical properties; Shanghai