Academic Journal
Mixing state and particle hygroscopicity of organic-dominated aerosols over the Pearl River Delta region in China
| العنوان: | Mixing state and particle hygroscopicity of organic-dominated aerosols over the Pearl River Delta region in China |
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| المؤلفون: | Hong, Juan, Xu, Hanbing, Tan, Haobo, Yin, Changqing, Hao, Liqing, Li, Fei, Cai, Mingfu, Deng, Xuejiao, Wang, Nan, Su, Hang, Cheng, Yafang, Wang, Lin, Petäjä, Tuukka, Kerminen, Veli-Matti |
| المصدر: | eISSN: 1680-7324 |
| سنة النشر: | 2019 |
| المجموعة: | Copernicus Publications: E-Journals |
| الوصف: | Simultaneous measurements of aerosol hygroscopicity and particle-phase chemical composition were performed at a suburban site over the Pearl River Delta region in the late summer of 2016 using a self-assembled hygroscopic tandem differential mobility analyzer (HTDMA) and an Aerodyne quadruple aerosol chemical speciation monitor (ACSM), respectively. The hygroscopic growth factor (HGF) of the Aitken mode (30 nm, 60 nm) and accumulation mode (100 nm, 145 nm) particles were obtained under 90 % relative humidity (RH). An external mixture was observed for particles of every size during this study, with a dominant mode of more-hygroscopic (MH) particles, as aged aerosols dominated due to the anthropogenic influence. The HGF of less-hygroscopic (LH) mode particles increased, while their number fractions decreased during the daytime due to a reduced degree of external mixing that probably resulted from the condensation of gaseous species. These LH mode particles in the early morning or late afternoon could be possibly dominated by carbonaceous material emitted from local automobile exhaust during rush hours. During polluted days with air masses flowing mainly from the coastal areas, the chemical composition of aerosols had a clear diurnal variation and a strong correlation with the mean HGF. Closure analysis was carried out between the HTDMA-measured HGF and the ACSM-derived hygroscopicity using various approximations for the hygroscopic growth factor of organic compounds (HGF org ). Considering the assumptions regarding the differences in the mass fraction of each component between PM 1 and 145 nm particles, the hygroscopicity-composition closure was achieved using an HGF org of 1.26 for the organic material in the 145 nm particles and a simple linear relationship between the HGF org and the oxidation level inferred from the O:C ratio of the organic material was suggested. Compared with the results from other environments, HGF org obtained ... |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | https://acp.copernicus.org/articles/18/14079/2018/ |
| DOI: | 10.5194/acp-18-14079-2018 |
| الاتاحة: | https://doi.org/10.5194/acp-18-14079-2018 https://acp.copernicus.org/articles/18/14079/2018/ |
| رقم الانضمام: | edsbas.CB5A461E |
| قاعدة البيانات: | BASE |
| DOI: | 10.5194/acp-18-14079-2018 |
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