engleski

Seasonality and possible sources of marine secondary organic aerosols: Insight in organosulfur contribution

One of the largest uncertainties in climate change predictions is due to poor understanding of the formation of secondary organic aerosol (SOA). Recently, organosulfur compounds (OSs) have been indicated as an important class of organic compounds in fine aerosols and serve as markers for multiphase chemical processes leading to SOA formation, especially in marine regions1. Despite the fact that large portion of marine atmosphere is influenced by continental inputs, marine aerosol constitutes one of the most important natural aerosol systems at the global level and triggers substantial research on its origin and chemical composition2. A sea surface microlayer (SML) as the very uppermost layer of the ocean at the air-sea interface has a unique role in linking the ocean and the atmosphere by hindering a range of global dynamic exchange processes and it also serves as a medium for transportation of marine organic matter up into the atmosphere3. However, despite the recent efforts to investigate the nature of atmospheric OSs, their abundance and sources in the aerosols, especially of the marine atmosphere, are largely unknown, mainly because of the lack of accurate methodological approach capable for their quantification. A unique work on a detail chemical analysis of PM2.5 organic matter obtained during one year study at Middle Adriatic Sea coastal area will be presented. A novel methodological approach including IC and ICP-OES enabled quantification of the total OSs in seasonal samples With regard to the secondary origin of marine organic aerosols, seasonal variability of water soluble organic carbon, dicarboxylic acids, methanesulfonic acid, non-sea-salt sulfates, and total surfactants will be presented as well. In addition, the results will be combined with hydrological as well as chemical and biological parameters obtained for the marine SML samples to elucidate the seasonal characteristics of marine SOA, including OSs, and to reveal their possible sources.

marine aerosols ; sea surface microlayer ; organic matter ; organosulfur ; SOA

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