The ambient aerosol characterization during the prescribed bushfire season in Brisbane 2013.
Prescribed burnings are conducted in Queensland each year from August until November aiming to decrease the impact of bushfire hazards and maintain the health of vegetation. This study reports chemical characteristics of the ambient aerosol, with a focus on source apportionment of the organic aerosol (OA) fraction, during the prescribed biomass burning (BB) season in Brisbane 2013. All measurements were conducted within the International Laboratory for Air Quality and Health (ILAQH) located in Brisbane's Central Business District. Chemical composition, degree of ageing and the influence of BB emission on the air quality of central Brisbane were characterized using a compact Time of Flight Aerosol Mass Spectrometer (cToF-AMS). AMS loadings were dominated by OA (64%), followed by, sulfate (17%), ammonium (14%) and nitrates (5%). Source apportionment was applied on the AMS OA mass spectra via the multilinear engine solver (ME-2) implementation within the recently developed Source Finder (SoFi) interface. Six factors were extracted including hydrocarbon-like OA (HOA), cooking-related OA (COA), biomass burning OA (BBOA), low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), and nitrogen-enriched OA (NOA). The aerosol fraction that was attributed to BB factor was 9%, on average over the sampling period. The high proportion of oxygenated OA (72%), typically representing aged emissions, could possess a fraction of oxygenated species transfored from BB components on their way to the sampling site.
International Laboratory for Air Quality and Health, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4001, Australia.
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Milic
International Laboratory for Air Quality and Health, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4001, Australia. Electronic address: b.miljevic@qut.edu.au.
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Miljevic
International Laboratory for Air Quality and Health, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4001, Australia.
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Alroe
International Laboratory for Air Quality and Health, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4001, Australia.
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Mallet
Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, 5232 Villigen PSI, Switzerland.
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Canonaco
Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, 5232 Villigen PSI, Switzerland.
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Prevot
International Laboratory for Air Quality and Health, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4001, Australia.
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Ristovski
D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D005390:Fires; D011793:Queensland
D000336:Aerosols; D000393:Air Pollutants
Aerosol mass spectrometry; Air quality; Biomass burning; Organic aerosol; Source apportionment