Secondary organic aerosols (SOA) in the atmosphere have received widespread attention in the global academic community. In order to understand SOA in the North China atmosphere, Wang Yu, a master student of our institute from Prof. Chandra Mouli Pavuluri group, studied Tianjin aerosols for SOA tracers and published an article entitled "Characterization of Secondary Organic Aerosol Tracers over Tianjin, North China during Summer to Autumn" in the journal ACS Earth and Space Chemistry with Tianjin University as the first unit and as the first author. This paper studied characteristics and molecular distributions of SOA tracers derived from isoprene, α/β-pinene, β-caryophyllene, and aromatic hydrocarbons in PM2.5 collected at an urban and a background sites in Tianjin, North China during summer and autumn 2018.
The results showed that concentrations of total isoprene SOA tracers were twice those of α/β-pinene in summer, while they were the opposite in autumn, followed by β-caryophyllinic acid and 2,3-dihydroxy-4-oxopentanoic acid (2,3-DHOPA), the only tracers derived from β-caryophyllene and toluene, respectively. The isoprene and α/β-pinene SOA tracers were abundant in summer, whereas β-caryophylinic acid and 2,3-DHOPA dominated in autumn. Temporal variations and linear relations of SOA tracers with ambient temperature and molecular markers (levoglucosan and hopanes) together with the air mass trajectories implied that the SOA derived from terrestrial vegetation and marine biota and biomass burning was high in summer and autumn, respectively, while that derived from fossil fuel combustion and its processing during long-range atmospheric transport were significant in both seasons. The estimated SOA derived from aromatics was found to be most abundant, followed by that from sesquiterpenes, monoterpenes, and isoprene, respectively. The contribution of total SOC to OC and WSOC varied between 4.16% and 23.7% and 6.28-30.7%, respectively, in which biogenic SOC accounted for about 50% in summer and 40% in autumn, indicating significant loading of SOA over Tianjin, North China.
Y. Wang, C. M. Pavuluri*, P. Q. Fu, P. Li, Z. Dong, Z. Xu, H. Ren, Y. Fan, L. Li, Y.-L. Zhang, and C.-Q. Liu. Characterization of Secondary Organic Aerosol Tracers over Tianjin, North China during Summer to Autumn. ACS Earth & Space Chemistry.
https://pubs.acs.org/doi/10.1021/acsearthspacechem.9b00170.
