| Περίληψη: | Atmospheric particulate mattercan cause serious health problems in human health. Also they can reduce the visibility and they act as cloud condensation nuclei. Through the absorption and the scattering they can have a big influence on the energy balance of the planet.
The organic components of particulate matter contribute more than 50% to their total mass. Organic aerosols (OA) are emitted into the atmosphere directly as primary organic aerosols or they can be formed through the condensation of low volatility products, which are formed through the oxidation of volatile organic compounds, on existing particles.
The contribution of secondary organic aerosol in the atmosphere is most of the times more significant than this of primary organic aerosol. Our limited knowledge about the chemical identity of thousands of organic compounds limits significantly our ability to determine their sources and their properties.
In this study we developed an algorithm which has the ability to determine the sources of the emissions of the OA as well as how many generations of oxidation reactions OA has undergone. This algorithm was used in parallel with a chemical transport model for the first time in Europe. The results showed that the sources of OA can vary significantly with the season and the region that we study. The source of residential wood burning was the most significant source during winter for all regions of Europe (20-60% of OA depending on the region). During autumn the wildfires was the most significant source especially in Russia (38%) and Balkans (36%), while during summer the biogenic emissions were the most significant source producing secondary organic aerosol. The emissions from road transport contribute less than 20% for the most of the regions, something that is in agreement with the measurements.
Also a significant percentage of the OA had undergone 2 or more than 2 generations of oxidations for all periods in Europe. This percentage of “aged” OA increases from 50% during winter to 70% during summer and autumn. For remote sites such as Finokalia the contribution of multiply oxidized OA is about 90% for all periods.
Also in this study we developed a method for the estimation of the local and long range transport for a specified urban site from continuous measurements. In addition we performed sensitivity analysis of a chemical transport model for the simulation of the biomass burning source, simulated separately from all the other sources of OA.
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