Chemical characterization of submicron particles during typical air pollution episodes in spring over Beijing

• Published in: Atmospheric and oceanic science letters = Daqi-he-haiyang-kexue-kuaibao 2016-07, Vol.9 (4), p.255-262
• Main Authors: YANG, Ting, SUN, Ye-Le, ZHANG, Wei, WANG, Zi-Fa, WANG, Xi-Quan
• Format: Article
• Language: English
• Subjects: Aerosols; Air pollution; Air quality; Ammonium; Ammonium compounds; Atmospheric particulates; Beijing; Dust; Dust storms; Haze; Mass; nitrate; Outdoor air quality; Particulate matter; pollution; secondary inorganic aerosols; 二次无机气溶胶; 北京; 可吸入颗粒物; 硝酸盐; 霾
• ISSN: 1674-2834; 2376-6123
• DOI: 10.1080/16742834.2016.1173509

Beijing experienced a long-lasting pollution episode in April 2012. Here, the authors characterize the sources and evolution processes of the pollution, with a focus on a haze and a dust episode that occurred during 15-30 April. All submicron aerosol species (PM 1 ) showed substantial increases during the haze episode (HE), with nitrate being the largest, contributing on average 32.2% of the non-refractory PM 1 (NR-PM 1 ) mass (maximum: ~42.0%), which was different from other seasons. Secondary inorganic aerosol (SIA) species (55.1 ± 23.8 μg m −3 ; SIA = nitrate, ammonium, sulfate) played enhanced roles in the haze formation, accounting for 66.5% of the total NR-PM 1 mass. In contrast to the HE, organics exhibited their highest levels (8.9 ± 5.4 μg m −3 ) among the NR-PM 1 aerosol species during the dust episode, accounting for 64.0% on average. SIAs exhibited low concentration levels (4.6 ± 4.2 μg m −3 ) during the dust episode, contributing only 34.0% to the total NR-PM 1 mass. This study suggests that air quality improvement strategies should be designed according to aerosol particle characteristics and formation mechanisms.