The main scope of the SAPIENTIAM (Secondary organic Aerosols Production in pre-and post-Industrial-like ENvironments: The Impact of biogenic and Anthropogenic emissions on climate) project is the identification of innovative mechanisms to describe and investigate the atmospheric composition in pristine environment that are affected by the anthropogenic emissions. The latter, such as nitrogen oxides (NOx, e.g NO and NO2), are related to human activities in post-industrial scenarios. In detail, the project studies the effect of NOx emissions on Secondary Organic Aerosol (SOA) formation and its chemical compositions. Moreover, we investigate the production and the gas to particle partitioning of organonitrates (ONs, e.g. ΣRO2NO2, and ΣRONO2). Despite the SOA yield as a function of different NOx regimes have been investigated in previous studies, further laboratory experiments are necessary, as the dependency is not univocally determined, to explore the chemistry in chamber conditions that represent more realistically atmospheric concentrations. Particulate matters, which can be emitted both by anthropogenic and biogenic activities, play a significant role in the radiative forcing, i.e. on climate change, via direct and indirect effects; they affect also the atmospheric visibility, and their adverse impact on human health has been demonstrated. At the same time, the ONs represent reservoir species for NO2, and the reaction cycle for their reaction strongly affects the tropospheric ozone (O3) production, which is a greenhouse gas with important oxidative capacity. As a consequence, the study of SOA and ONs production in different NOx regimes has important, different effects in terms of both climate change and air quality, with interdisciplinary impact on society in terms of policy and economy.
The SAPIENTIAM project allowed to produce more and innovative knowledge about the role played by the ONs in SOA formation, chemical composition and yield. The gas-to-particle partition of ONs it seems to be really important in new particle formation events and the chamber experiments results have positive feedback in field campaigns data analysis and help to their interpretation.
