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 1...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 （PM1） showed substantial increases during the haze episode （HE）, with nitrate being the largest, contributing on average 32.2% of the non-refractory PM;（NR-PM1） mass （maximum： -42.0%）, which was different from other seasons. Secondary inorganic aerosol （SIA） species （55.1 ± 23.8 lag m-3; SIA = nitrate, ammonium, sulfate） played enhanced roles in the haze formation, accounting for 66.5% of the total NR-PM1 mass. In contrast to the HE, organics exhibited their highest levels （8.9 ± 5.4 lag m-3） among the NR-PM 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-PM1 mass. This study suggests that air quality improvement strategies should be designed according to aerosol particle characteristics and formation mechanisms.展开更多
基金supported by the National Key Basic Research Program of China[grant number 2014CB447900]the National Natural Science Foundation of China[grant number 41305115]+2 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences[grant number XDB05020501]the Project of High-resolution Earth Observation System[grant number 05-Y30B02-9001-13/15-7-WX02]Commonwealth Project in Ministry of Environmental Protection[grant number 201309011]
文摘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 （PM1） showed substantial increases during the haze episode （HE）, with nitrate being the largest, contributing on average 32.2% of the non-refractory PM;（NR-PM1） mass （maximum： -42.0%）, which was different from other seasons. Secondary inorganic aerosol （SIA） species （55.1 ± 23.8 lag m-3; SIA = nitrate, ammonium, sulfate） played enhanced roles in the haze formation, accounting for 66.5% of the total NR-PM1 mass. In contrast to the HE, organics exhibited their highest levels （8.9 ± 5.4 lag m-3） among the NR-PM 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-PM1 mass. This study suggests that air quality improvement strategies should be designed according to aerosol particle characteristics and formation mechanisms.
