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| Titel |
Receptor modelling of fine particles in southern England using CMB including comparison with AMS-PMF factors |
| VerfasserIn |
J. Yin, S. A. Cumberland, R. M. Harrison, J. Allan, D. E. Young, P. I. Williams, H. Coe |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 4 ; Nr. 15, no. 4 (2015-02-26), S.2139-2158 |
| Datensatznummer |
250119464
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| Publikation (Nr.) |
 copernicus.org/acp-15-2139-2015.pdf |
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| Zusammenfassung |
| PM2.5 was collected during a winter campaign at two southern England
sites, urban background North Kensington (NK) and rural Harwell (HAR), in
January–February 2012. Multiple organic and inorganic source tracers were
analysed and used in a Chemical Mass Balance (CMB) model, which apportioned
seven separate primary sources, that explained on average 53% (NK) and
56% (HAR) of the organic carbon (OC), including traffic, woodsmoke, food
cooking, coal combustion, vegetative detritus, natural gas and dust/soil.
With the addition of source tracers for secondary biogenic aerosol at the NK
site, 79% of organic carbon was accounted for. Secondary biogenic sources
were represented by oxidation products of α-pinene and isoprene, but
only the former made a substantial contribution to OC. Particle source
contribution estimates for PM2.5 mass were obtained by the conversion
of the OC estimates and combining with inorganic components ammonium
nitrate, ammonium sulfate and sea salt. Good mass closure was achieved with
81% (92% with the addition of the secondary biogenic source) and
83% of the PM2.5 mass explained at NK and HAR respectively, with the
remainder being secondary organic matter. While the most important sources
of OC are vehicle exhaust (21 and 16%) and woodsmoke (15 and
28%) at NK and HAR respectively, food cooking emissions are also
significant, particularly at the urban NK site (11% of OC), in addition
to the secondary biogenic source, only measured at NK, which represented
about 26%. In comparison, the major source components for PM2.5 at
NK and HAR are inorganic ammonium salts (51 and 56%), vehicle exhaust
emissions (8 and 6%), secondary biogenic (10% measured at NK
only), woodsmoke (4 and 7%) and sea salt (7 and 8%), whereas
food cooking (4 and 1%) showed relatively smaller contributions to
PM2.5. Results from the CMB model were compared with source
contribution estimates derived from the AMS-PMF method. The overall mass of
organic matter accounted for is rather similar for the two methods. However,
appreciably different concentrations were calculated for the individual
primary organic matter contributions, although for most source categories
the CMB and AMS-PMF results were highly correlated (r2 = 0.69–0.91).
In comparison with the CMB model, the AMS appears to overestimate the
biomass burning/coal and food cooking sources by a factor of around 1.5 to 2
while estimates of the traffic source are rather similar for each model. The
largest divergence is in the primary/secondary organic matter split, with
the AMS estimating an appreciably smaller secondary component. Possible
reasons for these discrepancies are discussed, but despite these substantial
divergences, the strong correlation of the two methods gives some confidence
in their application. |
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