Atmos. Chem. Phys. Discuss., 13, 17643-17674, 2013
www.atmos-chem-phys-discuss.net/13/17643/2013/
doi:10.5194/acpd-13-17643-2013
© Author(s) 2013. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Observation of biogenic secondary organic aerosols in the atmosphere of a mountain site in central China: temperature and relative humidity effects
J. J. Li1, G. H. Wang1, J. J. Cao1, X. M. Wang2, and R. J. Zhang3
1State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China
2State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
3Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

Abstract. Secondary organic aerosols (SOA) derived from isoprene, pinene and caryophyllene were determined for PM10 and size-segregated (9-stage) aerosols collected at the summit (2060 m, a.s.l.) of Mt. Hua, central China during the summer of 2009. Concentrations of estimated isoprene, α-/β-pinene and β-caryophyllene derived SOC are 81± 53, 29 ± 14 and 98 ± 53 ng m−3, accounting for 2.7± 1.0%, 0.8 ± 0.2% and 2.1 ± 1.0% of OC, respectively. Concentrations of biogenic (BSOA, the isoprene/pinene/caryophyllene oxidation products) and anthropogenic (ASOA, mainly aromatic acids) SOA positively correlated with temperature (R=0.57–0.90). However, a decreasing trend of BSOA concentration with an increase in relative humidity (RH) was observed during the sampling period, although a clear trend between ASOA and RH was not found. Based on the AIM Model calculation, we found that during the sampling period an increase in RH resulted in a decrease in the aerosol acidity and thus reduced the effect of acid-catalysis on BSOA formation. Size distribution measurement showed that most of the determined isoprene derived SOA may form in aerosol phase and enriched in the fine mode (<2.1μm). 3-Hydroxyglutaric acid, 3-methyl-1,2,3-butanetricarboxylic acid and β-caryophyllinic acid are only presented in fine particles. However, cis-pinonic acid presents a large peak in the coarse mode (>2.1 μm) due to its highly volatile nature.

Citation: Li, J. J., Wang, G. H., Cao, J. J., Wang, X. M., and Zhang, R. J.: Observation of biogenic secondary organic aerosols in the atmosphere of a mountain site in central China: temperature and relative humidity effects, Atmos. Chem. Phys. Discuss., 13, 17643-17674, doi:10.5194/acpd-13-17643-2013, 2013.
 
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