Restriction lift date: 2023-05-05
Nature and origin of black carbon in Ireland
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University College Cork
Black carbon (BC) particles are important atmospheric radiative forcing agents and also have a negative effect on human health. In this study, a seven wavelength, dual spot aethalometer, was used to determine the equivalent BC (eBC) concentrations at four locations in Ireland; Killarney, Enniscorthy, Birr and Dublin. The aethalometer data were combined with other measurements and meteorological parameters to determine the sources of the particles observed at the monitoring sites. The mean eBC concentrations measured in Killarney and Enniscorthy were higher than those in Dublin during the winter months, while the concentrations in Birr were only marginally lower. The aethalometer source apportionment model was used to show that domestic solid fuel burning accounted for 61%, 81% and 63% of eBC mass in Killarney, Enniscorthy and Birr respectively. The average diurnal profiles for eBC at these three locations showed a minor peak during morning hours attributed to traffic and a very large peak during the evening due to solid fuel burning. Results from two years of continuous measurements at an urban background location in Dublin, showed a strong seasonal variation in eBC. Higher concentrations were measured during winter due to solid fuel burning, which accounted for 57% of eBC during the winter of 2016/2017, and 50% during the winter of 2017/2018. The diurnal profile for Dublin during winter was similar to that observed at the other three sites. During summer, eBC levels were much lower and dominated by traffic emissions. The parameters used in the source apportionment model were explored and site-specific absorption Ångström exponents (α) and Mass Absorption Cross-section (MAC) values were also derived to provide an indication of the different aerosol properties at each location. The results of the source apportionment at all four sites correlate strongly with those from other instruments deployed during the campaigns. The BC levels recorded in Dublin were compared to historical measurements of black smoke in Dublin, Belfast, London and Paris, from 1963 to 2003. Large decreases in BS concentrations (over 90%) have been observed in each city and are related to legislative changes introduced in each jurisdiction over the decades. Overall, this work has highlighted the ability of the aethalometer to measure eBC concentrations in real-time and derive contributions from both solid fuel burning and traffic emissions.
Black carbon , Air Pollution , Atmospheric aerosol
Buckley, P. C. 2019. Nature and origin of black carbon in Ireland. PhD Thesis, University College Cork.