 |
| Titel |
Application of positive matrix factorization in estimating aerosol secondary organic carbon in Hong Kong and its relationship with secondary sulfate |
| VerfasserIn |
Z. B. Yuan, J. Z. Yu, A. K. H. Lau, P. K. K. Louie, J. C. H. Fung |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 1 ; Nr. 6, no. 1 (2006-01-02), S.25-34 |
| Datensatznummer |
250003292
|
| Publikation (Nr.) |
 copernicus.org/acp-6-25-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| Secondary organic carbon (SOC) is often a significant portion of organic
carbon (OC) in ambient particulate matter (PM). The levels and seasonal
patterns of SOC in Hong Kong were examined using more than 2000 PM10
measurements made over a 4.5-year period (1998–2002) in a network of ten air
quality monitoring stations. The positive matrix factorization (PMF) model
was used to analyze this large data set for source identification and
apportioning. SOC was subsequently estimated to be the sum of OC present in
the secondary sources, i.e., secondary sulfate, secondary nitrate, and
secondary organic aerosol. The annual average SOC as estimated by the PMF
method was 4.25 μg C/m3 while the summer average was
1.66 μg C/m3 and the winter average was 7.05 μg C/m3. In
comparison, the method that uses EC as a tracer for primary carbonaceous
aerosol sources to derive SOC overestimated SOC by 70–212% for the summer
samples and by 4–43% for the winter samples. The overestimation by the EC
tracer method resulted from the inability of obtaining a single OC/EC ratio
that represented a mixture of primary sources varying in time and space.
We found that SOC and secondary sulfate had synchronous seasonal variation
and were correlated in individual seasons, suggesting common factors that
control their formation. Additionally, the presence of SOC was found to be
enhanced more than that of secondary sulfate in the winter. We postulate this
to be a combined result of favorable partitioning of semivolatile SOC species
in the particle phase and more abundant SOC precursors in the winter. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|