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Titel |
Seasonal variations of stable carbon isotopic composition and biogenic tracer compounds of water-soluble organic aerosols in a deciduous forest |
VerfasserIn |
Y. Miyazaki, P. Q. Fu, K. Kawamura, Y. Mizoguchi, K. Yamanoi |
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 ; 12, no. 3 ; Nr. 12, no. 3 (2012-02-03), S.1367-1376 |
Datensatznummer |
250010635
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Publikation (Nr.) |
copernicus.org/acp-12-1367-2012.pdf |
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Zusammenfassung |
To investigate the seasonal changes in biogenic water-soluble organic carbon
(WSOC) aerosols in a boreal forest, aerosol samples were collected
continuously in the canopy of a deciduous forest in northern Japan during
2009–2010. Stable carbon isotopic composition of WSOC
(δ13CWSOC) in total suspended particulate matter (TSP) exhibited a
distinct seasonal cycle, with lower values from June through September
(−25.5±0.5 ‰). This cycle follows the net CO2 exchange between
the forest ecosystem and the atmosphere, indicating that
δ13CWSOC likely reflects the biological activity at the forest
site. WSOC concentrations showed the highest values in early summer and
autumn. Positive matrix factorization (PMF) analysis indicated that the
factor in which biogenic secondary organic aerosols (BSOAs) dominated
accounted for ~40 % of the highest concentrations of WSOC, where
BSOAs mostly consisted of α-/β-pinene SOA. In addition,
primary biological aerosol particles (PBAPs) made similar contributions
(~57 %) to the WSOC near the forest floor in early summer. This
finding indicates that the production of both primary and secondary WSOC
aerosols is important during the growing season in a deciduous forest. The
methanesulfonic acid (MSA) maximum was also found in early summer and had a
distinct vertical gradient with larger concentrations near the forest floor.
Together with the similar vertical gradients found for WSOC and
δ13CWSOC as well as the α-/β-pinene SOA tracers,
our results indicate that the forest floor, including ground vegetation and
soil, acts as a significant source of WSOC in TSP within a forest canopy at
the study site. |
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