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Titel |
Ionic and carbonaceous compositions of PM10, PM2.5 and PM1.0 at Gosan ABC Superstation and their ratios as source signature |
VerfasserIn |
S. Lim, M. Lee, G. Lee, S. Kim, S. Yoon, K. Kang |
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. 4 ; Nr. 12, no. 4 (2012-02-21), S.2007-2024 |
Datensatznummer |
250010737
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Publikation (Nr.) |
copernicus.org/acp-12-2007-2012.pdf |
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Zusammenfassung |
PM1.0, PM2.5, and PM10 were sampled at Gosan ABC Superstation
on Jeju Island from August 2007 to September 2008. The carbonaceous aerosols
were quantified with the thermal/optical reflectance (TOR) method, which
produced five organic carbon (OC) fractions, OC1, OC2, OC3, OC4, and
pyrolyzed organic carbon (OP), and three elemental carbon (EC) fractions,
EC1, EC2, and EC3. The mean mass concentrations of PM1.0, PM2.5,
and PM10 were 13.7 μg m−3, 17.2 μg m−3, and 28.4 μg m−3,
respectively. The averaged mass fractions of OC and EC were 23.0% and
10.4% for PM1.0, 22.9% and 9.8% for PM2.5, and 16.4% and 6.0% for PM10. Among the OC and EC sub-components, OC2 and
EC2+3 were enriched in the fine mode, but OC3 and OC4 in the coarse mode.
The filter-based PM1.0 EC agreed well with black carbon (BC) measured
by an Aethalometer, and PM10 EC was higher than BC, implying less light
absorption by larger particles. EC was well correlated with sulfate,
resulting in good relationships of sulfate with both aerosol scattering
coefficient measured by Nephelometer and BC concentration. Our measurements
of EC confirmed the definition of EC1 as char-EC emitted from smoldering
combustion and EC2+3 as soot-EC generated from higher-temperature combustion
such as motor vehicle exhaust and coal combustion (Han et al., 2010). In
particular, EC1 was strongly correlated with potassium, a traditional
biomass burning indicator, except during the summer, when the ratio of EC1
to EC2+3 was the lowest. We also found the ratios of major chemical species
to be a useful tool to constrain the main sources of aerosols, by which the
five air masses were well distinguished: Siberia, Beijing, Shanghai, Yellow
Sea, and East Sea types. Except Siberian air, the continental background of
the study region, Beijing plumes showed the highest EC1 (and OP) to sulfate
ratio, which implies that this air mass had the highest net warming by
aerosols of the four air masses. Shanghai-type air, which was heavily
influenced by southern China, showed the highest sulfate enhancement. The
highest EC2+3/EC1 ratio was found in aged East Sea air, demonstrating a
significant influence of motor vehicle emissions from South Korea and Japan
and less influence from industrial regions of China. The high ratio results
from the longer residence time and less sensitivity to wet scavenging of
EC2+3 compared to EC1, indicating that soot-EC could have greater
consequence in regional-scale warming. |
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