Urban Aerosol Characteristics during the World Expo 2010 in Shanghai

• DOI: 10.4209/aaqr.2012.02.0024
• Publication Date: 2013-01-22T06:23:11Z
• Authors: Min Zhang; Jianmin Chen; Xianyao Chen; Tiantao Cheng; Yuanling Zhang; Hefeng Zhang; Aijun Ding; Meng Wang; Abdelwahid Mellouki
• Keywords: Particle (ecology); Ultrafine particle

During the World Exposition 2010, which ran from May to October, emission control measures were implemented in Shanghai and surrounding areas improve air quality. This study evaluated effects of regional transport on aerosol characteristics under these controlled local conditions using a month’s worth observations number size distributions (10 nm–10 μm) chemical compositions aerosols. Back-trajectories Lagrangian dispersion model combined analyze pollution related mechanisms. Two classes aerosols identified compared. Class I was clear condition with ocean-oriented masses. Particle counts this class dominated by particles range 20–40 nm, NH4+ mainly present form (NH4)2SO4. A strong peak at noontime indicated that particle formation or growth process promoted photochemical process. II characterized as masses originating areas. The analysis showed increases concentrations total water soluble ions about 17% 350%, respectively, compared episodes. fraction 50–200 nm increased sharply almost 50% counts. An examination diurnal pattern major suggested increase mode (50–200 nm) due presence enough precursor gases. (NH4)2SO4 NH4NO3. Although during Expo significantly limited emissions, our results indicate cities responsible for higher trace gases volume concentrations, along large Aitken particles.