title: Online monitoring of water-soluble ionic composition of PM10 during early summer over Lanzhou City.
abstract: Lanzhou is one of the most aerosol-polluted cities in China. In this study, an online analyzer for Monitoring for AeRosols and GAses was deployed to measure major water-soluble inorganic ions in PM10 at 1-hour time resolution, and 923 samples were obtained from Apr 1 to May 24, 2011. During the field campaign, air pollution days were encountered with Air Quality Index more than 100 and daily average concentration of PM10 exceeding 150 microg/m3. Based on the variation of water-soluble ions and results of Positive Matrix Factorization 3.0 model execution, the air pollution days were classified as crustal species- or secondary aerosol-induced, and the different formation mechanisms of these two air pollution types were studied. During the crustal species pollution days, the content of Ca2+ increased and was about 2.3 times higher than the average on clear days, and the air parcel back trajectory was used to analyze the sources of crustal species. Data on sulfate, trace gases and meteorological factors were used to reveal the formation mechanism of secondary aerosol pollution. The sulfur oxidation ratio (SOR) was derived from the 923 samples, and the SOR had high positive correlation with relative humidity in early summer in Lanzhou.
authors: Jin
authors: J
authors: Fan
authors: Xiaoying
authors: X
authors: Yue
authors: Yi
authors: Y
authors: Jing
authors: Qiang
authors: Q
authors: Chen
authors: Shigong
authors: S
authors: Wang
mesh_terms: D000397:Air Pollution / Q000032:analysis*; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D007477:Ions / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry*
chemical_list: D007477:Ions; D052638:Particulate Matter