CAEmissionMonitor – Determination of primary carbonaceous aerosol emission rates and formation rate of secondary organic aerosol

Monitoring of particulate matter (PM) in the atmosphere is essential for the successful implementation of preventive measures aiming to reduce the harmful impact of air pollution on human health, cultural heritage, ecosystem, and its impact on the Earth’s climate. Both, air pollution and climate change, have synergistic effects: climate change can impact air quality and, conversely, air quality can impact climate change. Different components of particulate matter have either warming or cooling effects on the climate, which makes aerosols one of the most uncertain parameter in climate models. The carbonaceous aerosol fraction is an important component of atmospheric particulate matter, generally representing 20% and 50% of the total aerosol mass. Black carbon is emitted by incomplete combustion from primary, mainly anthropogenic sources, including industrial emissions, road transport, and domestic heating. As such, it can be used as a good indicator of emissions. On the other hand, organic aerosols can be either emitted from primary sources or formed in the atmosphere by secondary formation. To evaluate the trends of emissions of atmospheric pollutants, emission inventories have to be recorded on the national level and reported to the European Union (EMEP/EEA Air Pollutant emission inventory). However, these inventories are prone to significant uncertainties and are not useful on the local level to evaluate air pollution abatement measures or short-term air quality prediction. To assess the efficiency of abatement measures, the meteorologically driven variation of air pollutants must be decoupled from the dynamics of the sources. Besides, the photochemical processes, which drive the formation of secondary organic aerosol, are not fully understood but represent important information for climate models. The proposed project aims to develop a simplified and reliable method for the determination of carbonaceous aerosol primary emission fluxes and secondary formation rate with high time resolution, where the dynamics of the atmosphere and dispersion characteristics within the planetary boundary layer will be assessed by using natural radioactive noble gas radon (Rn-222) as a tracer. The main project goal can be separated into two specific objectives: the first one will be focused to the development and validation of the mixing layer height model, which describes the influence of meteorology on the dispersion of air pollutants; whereas the second one will focus on the characterization of primary emission fluxes and calculation of secondary organic aerosol formation. The reliable results of mixing layer height will be used for top-down modeling of emission rates of carbonaceous aerosol from primary sources and the formation rate of secondary organic aerosols. The tool can provide valuable information to authorities for the implementation and evaluation of air quality action plans by indicating the strength of different emissions sources, especially from road traffic and biomass burning. On the other hand, improved knowledge about the secondary organic aerosol formation will significantly increase the performance of the chemical transport model and thus reduce the uncertainty of climate models. The project will introduce novel research ideas and new findings in understanding the main anthropogenic and natural sources of carbonaceous aerosols and their transformations in the atmosphere, which will enhance Slovenian and European competitiveness in atmospheric sciences. In addition, the new method will positively impact the competitiveness of Aerosol company in the global market, as the method represents a new opportunity for the use of instruments developed by Aerosol.