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| Titel |
Biogenic Volatile Organic Compounds (BVOCs) and their oxidation products at two Mediterranean background sites |
| VerfasserIn |
Cécile Debevec, Stéphane Sauvage, Valérie Gros, Jean Sciare, Michael Pikridas, Sébastien Dusanter, Thierry Leonardis, Vincent Gaudion, Laurence Depelchin, Isabelle Fronval, Roland Sarda-Estève, Dominique Baisnee, Emily Vasiliadou, Chrysanthos Savvides, Cerise kalogridis, Vincent Michoud, Nadine Locoge |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250151105
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| Publikation (Nr.) |
 EGU/EGU2017-15652.pdf |
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| Zusammenfassung |
| In the framework of the ChArMEx (Chemistry Aerosol Mediterranean Experiments)
program, this work aims at providing a better characterization of the sources and fate of
VOCs impacting the Mediterranean region as well as conducting a parallel between organic
aerosol and gas phase composition. To reach these objectives, on-line measurements of a
large number of VOCs were conducted by flame ionization detection/gas chromatography
and proton transfer reaction mass spectrometry at two Mediterranean receptor sites,
Cape Corsica in summer 2013 and the Cyprus Atmospheric Observatory (CAO) in
March 2015. Additionally, off-line air samples were collected on cartridges. On-line
submicron aerosol chemical composition was performed in parallel with an aerosol mass
spectrometer. VOCs Sources were identified using positive matrix factorization
(PMF) tool and discussed in previous studies (Michoud et al., submitted, Debevec et
al., submitted). This work focuses on BVOCs measured at these sampling sites
(especially on their levels, speciation, variability and processes). Different speciation of
monoterpenes was noticed at these sites. Even if monoterpenes were mainly composed of
β-pinene at both sites (34 % - 38 % of the total monoterpenes mass concentration),
α-terpinene was observed in higher proportion at Cape Corsica (21 %) than CAO (2 %)
while lower proportion of α-pinene was measured (Cape Corsica: 24 %, CAO:
35 %). Biogenic sources were found to be significant contributors to the VOCs
concentrations observed at these sampling sites (Cape Corsica: 20%, CAO: 36 %) but
have shown different variabilities. At Cape Corsica, a primary and a secondary
biogenic factor were identified, both correlating with air temperature and exhibiting a
clear diurnal profile. At CAO, two different biogenic factors were identified with
distinct diurnal profiles, the first one driven by isoprene was correlated with air
temperature and the second one, driven by monoterpenes, showed maxima during
nighttime. This nocturnal variability could be driven by nighttime emissions, chemical
decay or dynamical processes; all these assumptions will be discussed here. From
PMF factors identified, measured oxygenated VOCs were apportioned among their
potential different origins (either biogenic or anthropogenic and either primary or
secondary). Finally, a parallel between organic aerosol and gas phase composition
was conducted to better highlight the relationship between the two phases. The
diurnal variability of secondary organic aerosol appeared to be influenced by biogenic
contributions.
References.
Debevec, C., Sauvage, S., Gros, V., Sciare, J., Pikridas, M., Stavroulas, I., Salameh, T.,
Leonardis, T., Gaudion, V., Depelchin, L., Fronval, I., Sarda-Esteve, R., Baisnee, D.,
Bonsang, B., Savvides, C., Vrejoussis, M. and Locoge, N.: Origin and variability of volatile
organic compounds observed at an Eastern Mediterranean background site (Cyprus),
submitted to ACPD.
Michoud, V., Sciare, J., Sauvage, S., Dusanter, S., Leonardis, T., Gros, V., Kalogridis,
A.-C., Zannoni, N., Féron, A., Petit, J.-E., Creen, V., Baisnée, D., Sarda-Estève, R.,
Bonnaire, N., Marchand, N., DeWitt, H. L., Pey, J., Colomb, A., Gheussi, F., Szidat, S.,
Stavroulas, I., Borbon, A. and Locoge, N.: Organic carbon at a remote site of the western
Mediterranean Basin: composition, sources and chemistry during the ChArMEx SOP2 field
experiment, submitted to ACPD. |
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