鹤山大气超级站旱季单颗粒气溶胶化学特征研究

Single-particle chemical characterization of aerosols at the Heshan atmospheric supersite during the dry season

利用单颗粒气溶胶飞行时间质谱等仪器在鹤山大气超级站开展综合观测,结合ART-2a自适应共振神经网络聚类算法,将2013年11月4日~2013年12月30日期间监测到的1637330个细颗粒分成9类：EC-Fresh颗粒、EC-Nitrate/Sulfate颗粒、K-EC颗粒、Ca-EC颗粒、ECOC颗粒、OC-Levoglucosan颗粒、OC-Nitrate/Sulfate颗粒、K-Nitrate/Sulfate颗粒和Metal-rich颗粒.结果表明：该大气超级站所在地区旱季霾日有利于与水溶性二次无机组分混合的EC-Nitrate/Sulfate颗粒、K-Nitrate/Sulfate颗粒的累积;晴朗天更有利于二次有机组分在气溶胶颗粒中生成,雨天受当地排放源的影响显著,含有较高EC-Fresh和K-EC颗粒.相关性的研究发现,EC-Nitrate/Sulfate颗粒与能见度有良好的相关性,它们对霾的形成有至关重要的作用.

Single-particle chemical characteristics of atmospheric aerosols were studied by a single-particle aerosol mass spectrometry（SPAMS） at the Heshan atmospheric supersite of Guangdong in the dry season（November 4 to December 30） in 2013. Over 1.6 × 10~6 fine particles were characterized by the SPAMS with the ART-2a neural network algorithms. All the particles were classified into 9 main categories： elemental carbon（EC）-Fresh, EC-Nitrate/Sulfate, K-EC, Ca-EC, internally mixed elemental-organic carbon（ECOC）, organic carbon（OC）-Levoglucosan, OC-Nitrate/Sulfate, K-Nitrate/Sulfate and Metal-rich particles. Results showed that those particles rich in secondary water soluble ions, like EC-Nitrate/Sulfate, K-Nitrate/Sulfate particles, were enhanced in hazy days at Heshan supersite during the measurement campaign. Furthermore, secondary organic components more favored partitioning to particle phase in sunny days. In rainy days, however, there were more EC-fresh particles and K-EC particles which likely were influenced by local emissions. Finally, EC-Nitrate/Sulfate particles may have a vital role on the formation of haze as they had a good correlation with visibility.