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Distinct Ultrafine‐ and Accumulation‐Mode Particle Properties in Clean and Polluted Urban Environments
Author(s) -
Wang Yuying,
Li Zhanqing,
Zhang Renyi,
Jin Xiaoai,
Xu Weiqi,
Fan Xinxin,
Wu Hao,
Zhang Fang,
Sun Yele,
Wang Qiuyan,
Cribb Maureen,
Hu Dawei
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl084047
Subject(s) - ultrafine particle , nucleation , aerosol , particle (ecology) , differential mobility analyzer , environmental science , environmental chemistry , materials science , mode (computer interface) , tandem , chemical physics , atmospheric sciences , chemistry , meteorology , nanotechnology , physics , geology , composite material , oceanography , organic chemistry , computer science , operating system
Abstract In this study, we report the phenomenon of fast changes in aerosol hygroscopicity between clean and polluted periods observed frequently in urban Beijing during winter using a hygroscopicity tandem mobility analyzer. The cause of this phenomenon and the formation process of particles in different modes are discussed. During clean periods, ultrafine‐mode particles (i.e., nucleation and Aitken modes) stem mainly from nucleation events with subsequent growth. During heavily polluted periods, ultrafine‐mode particles originate chiefly from primary emissions. Larger‐mode particles like accumulation‐mode particles are mainly from primary emissions during clean periods and aqueous reactions during polluted periods. This finding based on hygroscopicity tandem mobility analyzer measurements can make up the deficiency of mass‐dependent instruments in analyzing sources and chemical processes of ultrafine‐mode particles.