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Titel |
Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning |
VerfasserIn |
P. Q. Fu, K. Kawamura, J. Chen, J. Li, Y. L. Sun, Y. Liu, E. Tachibana, S. G. Aggarwal, K. Okuzawa, H. Tanimoto, Y. Kanaya, Z. F. Wang |
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. 18 ; Nr. 12, no. 18 (2012-09-18), S.8359-8375 |
Datensatznummer |
250011451
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Publikation (Nr.) |
copernicus.org/acp-12-8359-2012.pdf |
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Zusammenfassung |
Organic tracer compounds, as well as organic carbon (OC), elemental carbon
(EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios
(δ13C) of total carbon (TC) have been investigated in aerosol samples
collected during early and late periods of the Mount Tai eXperiment 2006
(MTX2006) field campaign in the North China Plain. Total solvent-extractable
fractions were investigated by gas chromatography/mass spectrometry. More
than 130 organic compounds were detected in the aerosol samples. They were
grouped into twelve organic compound classes, including biomass burning
tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA)
tracers, and anthropogenic tracers such as phthalates, hopanes and
polycyclic aromatic hydrocarbons (PAHs). In early June when the field
burning activities of wheat straws in the North China Plain were very
active, the total identified organics (2090 ± 1170 ng m−3) were
double those in late June (926 ± 574 ng m−3). All the compound
classes were more abundant in early June than in late June, except phthalate
esters, which were higher in late June. Levoglucosan (88–1210 ng m−3,
mean 403 ng m−3) was found as the most abundant single compound in early
June, while diisobutyl phthalate was the predominant species in late June.
During the biomass-burning period in early June, the diurnal trends of most
of the primary and secondary organic aerosol tracers were characterized by
the concentration peaks observed at mid-night or in early morning, while in
late June most of the organic species peaked in late afternoon. This
suggests that smoke plumes from biomass burning can uplift the aerosol
particulate matter to a certain altitude, which could be further transported to and
encountered the summit of Mt. Tai during nighttime. On the basis of the
tracer-based method for the estimation of biomass-burning OC, fungal-spore
OC and biogenic secondary organic carbon (SOC), we estimate that an average
of 24% (up to 64%) of the OC in the Mt. Tai aerosols was due to
biomass burning in early June, followed by the contribution of isoprene SOC
(mean 4.3%). In contrast, isoprene SOC was the main contributor (6.6%)
to OC, and only 3.0% of the OC was due to biomass burning in late June.
In early June, δ13C of TC (−26.6 to −23.2‰, mean −25.0‰) were
lower than those (−23.9 to −21.9‰, mean −22.9‰) in late June. In
addition, a strong anti-correlation was found between levoglucosan and
δ13C values. This study demonstrates that crop-residue burning
activities can significantly enhance the organic aerosol loading and alter the organic
composition and stable carbon isotopic composition of aerosol particles in the
troposphere over the North China Plain. |
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