Characterization of urban aerosol in Cork city (Ireland) using aerosol mass spectrometry
- ISSN: 1680-7324
- DOI: 10.5194/acp-13-4997-2013
Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles charac- terized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich par- ticle types, internally mixed to different proportions with elemental carbon (EC), sulphate and nitrate, while the re- maining 7% was predominantly inorganic in nature. Non- refractory PM1 aerosol was characterized using a High Res- olution Time-of-Flight Aerosol Mass Spectrometer (Aero- dyne HR-ToF-AMS) and was also found to comprise organic aerosol as the most abundant species (62 %), followed by ni- trate (15 %), sulphate (9%) and ammonium (9%), and chlo- ride (5 %). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, “hydrocarbon-like” organic aerosol (HOA) comprised 20% of the mass, “low-volatility” oxygenated organic aerosol (LV-OOA) comprised 18 %, “biomass burning” organic aerosol (BBOA) comprised 23 %, non-wood solid-fuel com- bustion “peat and coal” organic aerosol (PCOA) comprised 21 %, and finally a species type characterized by primary m/z peaks at 41 and 55, similar to previously reported “cook- ing” organic aerosol (COA), but possessing different diurnal variations to what would be expected for cooking activities, contributed 18 %. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Geoscientific Despite wood, coal and peat being minor fuel types used for Instrumentation domestic space heating in urban areas, their relatively low Methods and combustion efficiencies result in a significant contribution to Data Systems Open Access PM1 aerosol mass (44%and 28%of the total organic aerosol mass and non-refractory total PM1, respectively).