| 1. |
- Boman, Johan, 1955, et al.
(författare)
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Elemental content of PM2.5 aerosol particles collected in Göteborg during the Göte-2005 campaign in February 2005
- 2009
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 9, s. 2597-2606
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Tidskriftsartikel (refereegranskat)abstract
- The Göte-2005 measurement campaign aimed at studying the influence of the winter thermal inversions on urban air pollution. Elemental speciation of PM2.5 aerosol particles, collected on Teflon filters at three urban sites and one rural site in the Göteborg region, was a major part of the study. Trace element analysis was done by Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry and the concentrations of S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Br and Pb were determined. The elemental content of the particles, local wind speed and direction, and backward trajectories were used to investigate possible sources for the pollutants. We concluded that S, V, Ni, Br, and Pb had their main sources outside the central Göteborg area, since elevated concentrations of these elements were not observed during an inversion episode. Sea traffic and harbour activities were identified, primarily by the S and V content of the particles. This study showed that the elemental analysis by EDXRF presents valuable information for tracing the origin of air masses arriving at a measurement site.
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| 2. |
- Hallquist, Mattias, 1969, et al.
(författare)
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The formation, properties and impact of secondary organic aerosol: Current and emerging issues
- 2009
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 9:14, s. 5155-5236
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Tidskriftsartikel (refereegranskat)abstract
- Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.
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| 3. |
- Szidat, S., et al.
(författare)
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Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in Göteborg, Sweden
- 2009
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 9:5, s. 1521-1535
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Tidskriftsartikel (refereegranskat)abstract
- Particulate matter was collected at an urban site in Göteborg (Sweden) in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC) concentrations were 2.1–3.6μgm−3, 1.8–1.9μgm−3, and 2.2– 3.0μgm−3 for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC), organic carbon (OC), water-insoluble OC (WINSOC), and watersoluble OC (WSOC) were analyzed for 14C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and 14C analysis and combined using Latin-hypercube sampling (LHS). For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol(SOA) formation. During both seasons, a more pronounced fossil signal was observed for G¨oteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas longrange transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of G¨oteborg during winter.
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