Atmospheric OH reactivities in the Pearl River Delta – China in summer 2006: measurement and model results
-
Published:2010-11-30
Issue:22
Volume:10
Page:11243-11260
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
Lou S.,Holland F.,Rohrer F.,Lu K.,Bohn B.,Brauers T.,Chang C.C.,Fuchs H.,Häseler R.,Kita K.,Kondo Y.,Li X.,Shao M.,Zeng L.,Wahner A.,Zhang Y.,Wang W.,Hofzumahaus A.
Abstract
Abstract. Total atmospheric OH reactivities (kOH) have been measured as reciprocal OH lifetimes by a newly developed instrument at a rural site in the densely populated Pearl River Delta (PRD) in Southern China in summer 2006. The deployed technique, LP-LIF, uses laser flash photolysis (LP) for artificial OH generation and laser-induced fluorescence (LIF) to measure the time-dependent OH decay in samples of ambient air. The reactivities observed at PRD covered a range from 10 s−1 to 120 s−1, indicating a large load of chemical reactants. On average, kOH exhibited a pronounced diurnal profile with a mean maximum value of 50 s−1 at daybreak and a mean minimum value of 20 s−1 at noon. The comparison of reactivities calculated from measured trace gases with measured kOH reveals a missing reactivity of about a factor of 2 at day and night. The reactivity explained by measured trace gases was dominated by anthropogenic pollutants (e.g., CO, NOx, light alkenes and aromatic hydrocarbons) at night, while it was strongly influenced by local, biogenic emissions of isoprene during the day. Box model calculations initialized by measured parameters reproduce the observed OH reactivity well and suggest that the missing reactivity is contributed by unmeasured, secondary chemistry products (mainly aldehydes and ketones) that were photochemically formed by hydrocarbon oxidation. Overall, kOH was dominated by organic compounds, which had a maximum contribution of 85% in the afternoon. The paper demonstrates the usefulness of direct reactivity measurements, emphasizes the need for direct measurements of oxygenated organic compounds in atmospheric chemistry studies, and discusses uncertainties of the modelling of OVOC reactivities.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference73 articles.
1. Andreae, M. O. and Merlet, P.: Emission of trace gases and aerosols from biomass burning, Global Biogeochem. Cy., 15, 955–966, 2001. 2. Apel, E. C., Brauers, T., Koppmann, R., Bandowe, B., Bo{ß meyer}, J., Holzke, C., Tillmann, R., Wahner, A., Wegener, R., Brunner, A., Jocher, M., Ruuskanen, T., Spirig, C., Steigner, D., Steinbrecher, R., Alvarez, E. G., Müller, K., Burrows, J. P., Schade, G., Solomon, S. J., Ladstätter-Weiß enmayer, A., Simmonds, P., Young, D., Hopkins, J. R., Lewis, A. C., Legreid, G., Reimann, S., Hansel, A., Wisthaler, A., Blake, R. S., Ellis, A. M., Monks, P. S., and Wyche, K. P.: Intercomparison of oxygenated volatile organic compound measurements at the SAPHIR atmosphere simulation chamber, J. Geophys. Res., 113, D20307, https://doi.org/10.1029/2008JD009865, 2008. 3. Bohn, B., Corlett, G K., Gillmann, M., Sanghavi, S., Stange, G., Tensing, E., Vrekoussis, M., Bloss, W J., Clapp, L J., Kortner, M., Dorn, H.-P., Monks, P S., Platt, U., Plass-Dülmer, C., Mihalopoulos, N., Heard, D E., Clemitshaw, K C., Meixner, F X., Prevot, A. S H., and Schmitt, R.: Photolysis frequency measurement techniques: results of a comparison within the ACCENT project, Atmos. Chem. Phys., 8, 5373–5391, https://doi.org/10.5194/acp-8-5373-2008, 2008. 4. Bradsher, K.: Trucks Power China's Econonomy, at a Suffocating Cost, The New York Times – Online Edition, NY, USA, 8 December, 2007. 5. Brasseur, G. P., Prinn, R. G., and Pszenny, A. P. (eds.): Atmospheric Chemistry in a Changing World, The IGBP Series, Springer, Berlin, Germany, 2003.
Cited by
211 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|