title: High Contributions of Secondary Inorganic Aerosols to PM2.5under Polluted Levels at a Regional Station in Northern China.
abstract: Daily PM2.5samples were collected at Shangdianzi (SDZ) regional site in Beijing-Tianjin-Hebei (BTH) region in 2015. Samples were subject to chemical analysis for organic carbon (OC), elemental carbon (EC), and major water-soluble inorganic ions. The annual average PM2.5mass concentration was 53 ± 36 μg·m-3with the highest seasonal average concentration in spring and the lowest in summer. Water-soluble inorganic ions and carbonaceous aerosols accounted for 34% ± 15% and 33% ± 9%, respectively, of PM2.5mass on annual average. The excellent, good, lightly polluted, moderately polluted, and heavily polluted days based on the Air Quality Index (AQI) of PM2.5accounted for 40%, 42%, 11%, 4%, and 3%, respectively, of the year. The sum of the average concentration of sulfate, nitrate, and ammonium (SNA) increased from 4.2 ± 2.9 μg·m-3during excellent days to 85.9 ± 22.4 μg·m-3during heavily polluted days, and their contributions to PM2.5increased from 15% ± 8% to 49% ± 10% accordingly. In contrast, the average concentration of carbonaceous aerosols increased from 9.2 ± 2.8 μg·m-3to 51.2 ± 14.1 μg·m-3, and their contributions to PM2.5decreased from 34% ± 6% to 29% ± 7%. Potential source contribution function (PSCF) analysis revealed that the major sources for high PM2.5and its dominant chemical components were within the area mainly covering Shandong, Henan, and Hebei provinces. Regional pollutant transport from Shanxi province and Inner Mongolia autonomous region located in the west direction of SDZ was also important during the heating season.
authors.affiliation: Meteorological Observation Center, China Meteorological Administration, Beijing 100081, China. liyang@cma.gov.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China. taojun@scies.org.
authors.forename: Jun
authors.initials: J
authors.lastname: Tao
authors.affiliation: Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada. leiming.zhang@canada.ca.
authors.forename: Leiming
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Meteorological Observation Center, China Meteorological Administration, Beijing 100081, China. jiaxiaofangstar@126.com.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Jia
authors.affiliation: Key Laboratory of Regional Climate-Environment for Temperate East Asia (RCE-TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. wuyf@mail.iap.ac.cn.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D000068476:Beijing; D002244:Carbon / Q000032:analysis; D002681:China; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000032:analysis; D009566:Nitrates / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D012621:Seasons; D013431:Sulfates / Q000032:analysis; D014867:Water / Q000032:analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D009566:Nitrates; D052638:Particulate Matter; D013431:Sulfates; D014867:Water; D002244:Carbon
keywords: backward trajectory analysis; chemical composition; potential source contribution function; regional transport