A modelling study of air pollution in urban areas

[摘要] Anthropogenic NOx emissions from traffic have the potential to change atmospheric chemical composition, and lead to the production of pollutants that can have an adverse impact on human health and the environment. In this study, the formation and loss of nitryl chloride, nitrogen dioxide and secondary inorganic (nitrate) aerosol are explored using a zero dimensional (0-D) box model based on the near-explicit Master Chemical Mechanism (MCM). ClNO2 production, photolysis, chlorine atom sources, and chlorine chemical reactions are incorporated into a box model. The performance of the model was evaluated against measurements. The model was able to reproduce the ClNO2 diurnal profile close to the observations. The evaluated model was then used to explore the effect of the projected increase in mean summer temperature of the UK by 2050 on the formation and impacts of ClNO2 chemistry. The box model was used to explore six NOx emissions scenarios to investigate the effect of temporal NOx emission distribution (changing emissions with time) from vehicles on a number of tropospheric chemical species. The change in NO2 mixing ratios from different emission scenarios were used to estimate the number of deaths, due to exposure to NO2. The scenarios in which NO2 concentrations were very different to the base case were used in a case study to examine the best way of reducing NO2 concentrations. Finally, the box model was used to predict the formation of nitrate aerosol from N2O5 heterogeneous reactions. The effects of temporal NOx emissions and ClNO2 chemistry on the concentration of nitrate aerosol were also investigated. The results obtained from this study showed the capability of the 0-D box model in predicting gas phase chemical compounds and aspects of particulate matter from heterogeneous reactions, and in simulating NOx emission scenarios and their impacts on air quality.

[发布机构] University:University of Birmingham;Department:School of Geography, Earth and Environmental Sciences

[关键词] Q Science;QD Chemistry