Case Study
Hong Kong Air Quality
impact of air mass origins on the hygroscopic growth of aerosol

The Brechtel Humidified Tandem Differential Mobility Analyzer (HTDMA, see Lopez-Yglesias et al. (2014) Aer. Sci. & Tech.) and a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) were used to study the impact of air mass origins on the hygroscopic growth of aerosol at the Hong Kong University of Science and Technology Supersite, located at a coastal suburban site in Hong Kong. Particle water uptake at 90% relative humidity showed a clear decrease when the air mass changed from maritime or coastal to continental with corresponding increases observed in the aerosol organic loading. The HTDMA allowed rapid and continuous water uptake measurements to be made in the field so that correlations with changes in chemical composition could be explored with fine detail (see M. C. Yeung et al (2014) JGR) for more detail.

Chak K. Chan, Ph.D.
Professor, Dept. of Chemical and Biomolecular Engineering
Hong Kong University of Science and Technology