Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in G\uf6teborg, Sweden

Particulate matter was collected at an urbansite in G\uf6teborg (Sweden) in February/March 2005 and inJune/July 2006. Additional samples were collected at arural 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/summerconditions, respectively. Elemental carbon (EC), organiccarbon (OC), water-insoluble OC (WINSOC), and watersolubleOC (WSOC) were analyzed for 14C in order to distinguishfossil from non-fossil emissions. As wood burning isthe single major source of non-fossil EC, its contribution canbe quantified directly. For non-fossil OC, the wood-burningfraction was determined independently by levoglucosan and14C 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 atthe 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\ua8oteborg 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 longrangetransport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations oflevoglucosan and other monosaccharide anhydrides were lowfor the urban and the rural site in the area of G\ua8oteborg during winter