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| Titel |
Sources of organic carbon in fine particulate matter in northern European urban air |
| VerfasserIn |
S. Saarikoski, H. Timonen, K. Saarnio, M. Aurela, L. Järvi, P. Keronen, V.-M. Kerminen, R. Hillamo |
| 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 ; 8, no. 20 ; Nr. 8, no. 20 (2008-10-29), S.6281-6295 |
| Datensatznummer |
250006428
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| Publikation (Nr.) |
 copernicus.org/acp-8-6281-2008.pdf |
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| Zusammenfassung |
| A major fraction of fine particle matter consists of organic carbon (OC) but
its origin is still inadequately known. In this study the sources of OC were
investigated in the northern European urban environment in Helsinki,
Finland. Measurements were carried out over one year and they included both
filter (PM1) and online methods. From the filter samples OC, elemental
carbon (EC), water-soluble OC (WSOC), levoglucosan and major ions were
analyzed. Filter data together with the concentrations of inorganic gases
were analyzed by Positive matrix factorization (PMF) in order to find the
sources of OC (and WSOC) on an annual as well as on a seasonal basis. In
order to study the diurnal variation of sources, OC and EC were measured by
a semicontinuous OC/EC analyzer and major ions were determined by a
Particle-into-Liquid Sampler coupled to ion chromatographs. According to
PMF, OC concentrations were impacted by four sources: biomass combustion,
traffic, long-range transport and secondary production. On an annual basis
the OC concentration was dominated by secondary organic aerosol (SOA). Its
contribution to OC was as high as 64% in summer, which besides
anthropogenic sources may also result from the large biogenic volatile
organic carbon (VOC) emissions in the boreal region. In winter biomass
combustion constituted the largest fraction in OC due to domestic wood
combustion for heating purposes. Traffic contributed to OC from 15 to
27%. Regarding the diurnal variation, the contribution from traffic was
higher from 08:00 to 18:00 on weekdays than on weekends. The contribution
from long-range transport to OC was 24% on average. All four sources also
influenced the WSOC concentrations, however, the contribution of SOA was
significantly larger for WSOC than OC. |
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