 |
| Titel |
Modeling of HCHO and CHOCHO at a semi-rural site in southern China during the PRIDE-PRD2006 campaign |
| VerfasserIn |
X. Li, F. Rohrer, T. Brauers, A. Hofzumahaus, K. Lu, M. Shao, Y. H. Zhang, A. Wahner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 22 ; Nr. 14, no. 22 (2014-11-21), S.12291-12305 |
| Datensatznummer |
250119180
|
| Publikation (Nr.) |
 copernicus.org/acp-14-12291-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| HCHO and CHOCHO are important trace gases in the atmosphere,
serving as tracers of VOC oxidations. In the past decade, high
concentrations of HCHO and CHOCHO have been observed for the
Pearl River Delta (PRD) region in southern China. In this study, we performed
box model simulations of HCHO and CHOCHO at a semi-rural site
in the PRD, focusing on understanding their sources and sinks and factors
influencing the CHOCHO to HCHO ratio
(RGF). The model was constrained by the
simultaneous measurements of trace gases and radicals. Isoprene oxidation by
OH radicals is the major pathway forming HCHO, followed by
degradations of alkenes, aromatics, and alkanes. The production of
CHOCHO is dominated by isoprene and aromatic degradation;
contributions from other NMHCs are of minor importance. Compared to the
measurement results, the model predicts significant higher HCHO and
CHOCHO concentrations. Sensitivity studies suggest that fresh
emissions of precursor VOCs, uptake of HCHO and CHOCHO by
aerosols, fast vertical transport, and uncertainties in the treatment of dry
deposition all have the potential to contribute significantly to this
discrepancy. Our study indicates that, in addition to chemical considerations
(i.e., VOC composition, OH and NOx levels), atmospheric
physical processes (e.g., transport, dilution, deposition) make it difficult
to use the CHOCHO to HCHO ratio as an indicator for the origin
of air mass composition. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|