Factor separation in air quality simulations

The aim of this modelling study is to quantify the effects of transboundary processes, anthropogenic and biogenic emissions on tropospheric ozone production and accumulation. The proposed methodology, based on the use of the factor separation technique, allows to evaluate the maximum feasible efficiency of anthropogenic emission control strategies over a domain, a useful information when implementing ozone control policies. The proposed case study focuses on the effectiveness of emission control policies over the Po Valley region (northern Italy), a very polluted area in Europe characterized by critical ozone levels during summer periods, due to high anthropogenic emissions and stagnating meteorological conditions. The study allows to identify two regions in the study domain, that require the implementation of different pollution abatement policies: (1) the central urbanized area, that is sensitive to the local anthropogenic emission reduction measures, and (2) the northern mountain region, where the implementation of international policies is required because of the limited effectiveness of local reduction strategies.