Doctor of Philosophy
School of Chemistry
Atmospheric particle properties were measured in the South Eastern coastal city of Wollongong, Australia, during an intensive field campaign known as Measurement of Urban, Marine and Biogenic Air (MUMBA), between 15th January and 16th February 2013. A scanning mobility particle sizer (SMPS) was operated to measure particle number size distributions ranging from 14 nm to 660 nm in diameter. Principal component analysis was applied to the entire data measured by SMPS and, based on strong component loadings (value > 0.75), three size fractions (i) Small (NS) :15 nm < Dp < 50 nm, (ii) Medium (NM) :60 nm < Dp < 150 nm and (iii) Large (NL) :210 nm < Dp < 450 nm were revealed. The three size fractions described 89% of the dataset cumulative variance. The daily pattern of particle number size distribution revealed morning, afternoon and night peaks. Traffic emissions and marine aerosols were the major contributors of particles observed in the morning, when the NS fraction dominated. A mixture of marine aerosols and secondary aerosols from photochemical oxidation was the main contributor during the afternoon. The Port Kembla Steel Works and the urban areas were the major contributors of particles at night. Secondary organic aerosols were identfied by a mass ratio of organic carbon to elemental carbon (OC/EC) of greater than 1, and this was commonly observed. A weak correlation (R2 = 0.3) between OC and EC indicated that there were multiple sources of both OC and EC.
Dominick, Doreena, Characteristics of Aerosol Particles: Concentration, Particle Size and Formation Mechanisms in Urban-Marine Environments, Doctor of Philosophy thesis, School of Chemistry, University of Wollongong, 2018. https://ro.uow.edu.au/theses1/527