Atmos. Chem. Phys., 21, 10589–10608, 2021 https://doi.org/10.5194/acp-21-10589-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Tracer-based source apportioning of atmospheric organic carbon and the influence of anthropogenic emissions on secondary organic aerosol formation in Hong Kong Yubo Cheng1, Yiqiu Ma1,2, and Di Hu1,2 1State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, China 2Hong Kong Baptist University Institute of Research and Continuing Education, Shenzhen Virtual University Park, Shenzhen, 518057, China Correspondence: Di Hu (
[email protected]) Received: 14 January 2021 – Discussion started: 20 January 2021 Revised: 29 April 2021 – Accepted: 19 May 2021 – Published: 14 July 2021 Abstract. Here we conducted comprehensive chemical char- ate linear regression analysis showed that NOx processing acterization and source apportionment of 49 PM2:5 samples played a key role in both daytime and nighttime SOA produc- collected in Hong Kong. Besides the major aerosol con- tion in the region. Moreover, sulfate had a significant positive stituents, 39 polar organic species, including 14 secondary linear relationship with SOCPMF and SS-related SOC, and organic aerosol (SOA) tracers of isoprene, monoterpenes, particle acidity was significantly correlated with SOC from β-caryophyllene, and naphthalene, were quantified using the aging of BB. gas chromatography–mass spectrometry (GC–MS). Six fac- tors, i.e., SOA, secondary sulfate (SS), biomass burning (BB)/SOA, sea salt, marine vessels, and vehicle emissions, were apportioned by positive matrix factorization (PMF) 1 Introduction as the major sources of ambient organic carbon (OC) in Hong Kong.