Abstract
Abstract. In the present study, source apportionment of the ambient summer and winter time particulate carbonaceous matter (PCM) in aerosol particles (PM1 and PM10) has been conducted for the Norwegian urban and rural background environment. Statistical treatment of data from thermal-optical, 14C and organic tracer analysis using Latin Hypercube Sampling has allowed for quantitative estimates of seven different sources contributing to the ambient carbonaceous aerosol. These are: elemental carbon from combustion of biomass (ECbb) and fossil fuel (ECff), primary and secondary organic carbon arising from combustion of biomass (OCbb) and fossil fuel (OCff), primary biological aerosol particles (OCPBAP, which includes plant debris, OCpbc, and fungal spores, OCpbs), and secondary organic aerosol from biogenic precursors (OCBSOA). Our results show that emissions from natural sources were particularly abundant in summer, and with a more pronounced influence at the rural compared to the urban background site. 80% of total carbon (TCp, corrected for the positive artefact) in PM10 and ca. 70% of TCpin PM1 could be attributed to natural sources at the rural background site in summer. Natural sources account for about 50% of TCp in PM10 at the urban background site as well. The natural source contribution was always dominated by OCBSOA, regardless of season, site and size fraction. During winter anthropogenic sources totally dominated the carbonaceous aerosol (80–90%). Combustion of biomass contributed slightly more than fossil-fuel sources in winter, whereas emissions from fossil-fuel sources were more abundant in summer. Mass closure calculations show that PCM made significant contributions to the mass concentration of the ambient PM regardless of size fraction, season, and site. A larger fraction of PM1 (ca. 40–60%) was accounted for by carbonaceous matter compared to PM10 (ca. 40–50%), but only by a small margin. In general, there were no pronounced differences in the relative contribution of carbonaceous matter to PM with respect to season or between the two sites.
Highlights
Particulate carbonaceous matter (PCM) is found to constitute 10–40 % of PM10 levels at rural and natural background sites in Europe (Yttri et al, 2007a; Putaud et al, 2004)
The carbonaceous aerosol concentrations observed at the urban background site is in the lower range of that previously reported for Norwegian urban areas (Yttri et al, 2005, 2009), whereas it is in the upper range of what has been observed for the rural environment (Yttri et al, 2007a)
The levels of OCp and TCp should be considered as conservative estimates, as the quartz-behind-quartz fiber filter setup (QBQ) sampling approach account for the positive but not the negative sampling artefact of OC.The mean positive artifact of OC ranged from 18 ± 8.6 % for the urban background site in winter to 50 ± 14 % at the rural background site in winter
Summary
Particulate carbonaceous matter (PCM) is found to constitute 10–40 % (mean 30 %) of PM10 levels at rural and natural background sites in Europe (Yttri et al, 2007a; Putaud et al, 2004). PCM consists largely of organic matter (OM), and usually smaller quantities of so-called elemental or black carbon (EC or BC). OM is dominated by its carbon content (OC), but with associated oxygen, hydrogen, nitrogen, and sulphur. The sum of EC and OC is referred to as total carbon (TC). (Table 1 summarizes the notation used in the present study.) Recent reviews have highlighted the complexity of the carbonaceous aerosol both in terms of composition and Published by Copernicus Publications on behalf of the European Geosciences Union. Yttri et al.: Source apportionment of carbonaceous aerosol
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
