Atmospheric Oxidation processes and Aging of SOA in the Western Mediterranean Sea
Abstract
ERSA (Cape Corsica, France) is a remote site influenced by biogenic emissions and aged anthropic airmasses from the nearby continent. In summer, organic aerosols are, for a largepart, of biogenic origins. However, the origins of organic aerosols varyduring the year as shown by variations of their observed concentrations andproperties (O:C and oxidation state). Modelling of aging of organics iscrucial to represent the variations of organic concentrations and propertiesin the model. The formation of secondary organic aerosols in the air-qualityplateform Polyphemus was recently modified to represent more accuratelyorganic aerosols during summer time at ERSA. Organic compounds were found to not be enough oxidized. In this respect, twoformation processes were included into the model and evaluated in order to improve the model performance. The first one is the autoxidation process which is based on the ozonolysis of biogenic volatile organic compounds especially monoterpenes and leads to the formation of extremely low volatile organic compounds (ELVOC). The second one is organic nitrate formation mechanism in which OH, NO, HO2 and NO3 radicals play an important role. Organic aerosols are found to be much less oxidized in winter compared tosummer. A sensitivity study of emissions and aging of anthropic intermediate and semivolatile organic compounds is performed in order to as their impact onorganic aerosol concentrations and properties at ERSA.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A33A0195C
- Keywords:
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- 0317 Chemical kinetic and photochemical properties;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES