Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 17, 12509-12531, 2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
23 Oct 2017
Modelling organic aerosol concentrations and properties during ChArMEx summer campaigns of 2012 and 2013 in the western Mediterranean region
Mounir Chrit1, Karine Sartelet1, Jean Sciare2,7, Jorge Pey3,a, Nicolas Marchand3, Florian Couvidat4, Karine Sellegri5, and Matthias Beekmann6 1CEREA, Joint Laboratory École des Ponts ParisTech – EDF R&D, Université Paris-Est, 77455 Champs-sur-Marne, France
2LSCE, CNRS-CEA-UVSQ, IPSL, Université Paris-Saclay, Gif-sur-Yvette, France
3Aix-Marseille University, CNRS, LCE UMR 7376, Marseille, France
4INERIS, Verneuil-en-Halatte, France
5Laboratoire de Météorologie Physique (LaMP), UMR 6016 CNRS/UBP, of the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Aubière, France
6LISA, UMR CNRS 7583, IPSL, Université Paris-Est Créteil and Université Paris Diderot, France
7EEWRC, The Cyprus Institute, Nicosia, Cyprus
anow at: The Geological Survey of Spain, IGME, 50006 Zaragoza, Spain
Abstract. In the framework of the Chemistry-Aerosol Mediterranean Experiment, a measurement site was set up at a remote site (Ersa) on Corsica Island in the northwestern Mediterranean Sea. Measurement campaigns performed during the summers of 2012 and 2013 showed high organic aerosol concentrations, mostly from biogenic origin. This work aims to represent the organic aerosol concentrations and properties (oxidation state and hydrophilicity) using the air-quality model Polyphemus with a surrogate approach for secondary organic aerosol (SOA) formation. Biogenic precursors are isoprene, monoterpenes and sesquiterpenes. In this work, the following model oxidation products of monoterpenes are added: (i) a carboxylic acid (MBTCA) to represent multi-generation oxidation products in the low-NOx regime, (ii) organic nitrate chemistry and (iii) extremely low-volatility organic compounds (ELVOCs) formed by ozonolysis. The model shows good agreement of measurements of organic concentrations for both 2012 and 2013 summer campaigns. The modelled oxidation property and hydrophilic organic carbon properties of the organic aerosols also agree reasonably well with the measurements. The influence of the different chemical processes added to the model on the oxidation level of organics is studied. Measured and simulated water-soluble organic carbon (WSOC) concentrations show that even at a remote site next to the sea, about 64 % of the organic carbon is soluble. The concentrations of WSOC vary with the origins of the air masses and the composition of organic aerosols. The marine organic emissions only contribute to a few percent of the organic mass in PM1, with maxima above the sea.

Citation: Chrit, M., Sartelet, K., Sciare, J., Pey, J., Marchand, N., Couvidat, F., Sellegri, K., and Beekmann, M.: Modelling organic aerosol concentrations and properties during ChArMEx summer campaigns of 2012 and 2013 in the western Mediterranean region, Atmos. Chem. Phys., 17, 12509-12531,, 2017.
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