Articles | Volume 16, issue 3
Atmos. Chem. Phys., 16, 1713–1728, 2016
Atmos. Chem. Phys., 16, 1713–1728, 2016

Research article 15 Feb 2016

Research article | 15 Feb 2016

Continuous measurements at the urban roadside in an Asian megacity by Aerosol Chemical Speciation Monitor (ACSM): particulate matter characteristics during fall and winter seasons in Hong Kong

C. Sun1, B. P. Lee1, D. Huang2, Y. Jie Li3, M. I. Schurman1, P. K. K. Louie4, C. Luk4, and C. K. Chan1,2,5 C. Sun et al.
  • 1Division of Environment, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
  • 2Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
  • 3Faculty of Science and Technology, University of Macau, Taipa, Macau, China
  • 4Hong Kong Environmental Protection Department, Wan Chai, Hong Kong, China
  • 5School of Energy and Environment, City University of Hong Kong, Hong Kong, China

Abstract. Non-refractory submicron aerosol is characterized using an Aerosol Chemical Speciation Monitor (ACSM) in the fall and winter seasons of 2013 on the roadside in an Asian megacity environment in Hong Kong. Organic aerosol (OA), characterized by application of Positive Matrix Factorization (PMF), and sulfate are found to be dominant. Traffic-related organic aerosol shows good correlation with other vehicle-related species, and cooking aerosol displays clear mealtime concentration maxima and association with surface winds from restaurant areas. Contributions of individual species and OA factors to high NR-PM1 are analyzed for hourly data and daily data; while cooking emissions in OA contribute to high hourly concentrations, particularly during mealtimes, secondary organic aerosol components are responsible for episodic events and high day-to-day PM concentrations. Clean periods are either associated with precipitation, which reduces secondary OA with a lesser impact on primary organics, or clean oceanic air masses with reduced long-range transport and better dilution of local pollution. Haze events are connected with increases in contribution of secondary organic aerosol, from 30 to 50 % among total non-refractory organics, and the influence of continental air masses.

Short summary
This study presents results of long-term submicron aerosol measurements in Hong Kong. The presented work covers fall and winter 2013. It serves to characterize aerosol in a densely built-up urban area of a typical Asian megacity with strong primary emission sources from vehicles and cooking and presents an in-depth analysis of distinct clean and heavily polluted time periods tied with meteorological data and other gas-phase species observed in the study period.
Final-revised paper