High-resolution air quality modeling in a medium-sized city in the tropical Andes: Assessment of local and global emissions in understanding ozone and PM10 dynamics

Application of high-resolution air quality models in the Andes Region is scarce, especially in medium-sized cities of South America, which are undergoing a fast urban growth, increasing the risk associated with air pollution episodes. In this study, the WRF-Chem model was applied for analyzing the influence of local and global emission inventories (EI) in the representation of O-3 and PM10 concentrations in the medium-sized Andean city of Manizales, Colombia. Furthermore, the relative impact of anthropogenic emissions on O-3 and PM10 dynamics was evaluated. The use of local emission fluxes allowed significant improvements in O-3 representation, characterized by better performance metrics (MGE, RMSE and r coefficient of 7.6 ppb, 8.8 ppb, and 0.81 respectively) than that obtained from the use of the EDGAR-HTAP global database (MGE = 11.6 ppb, RMSE = 13.9 ppb and r = 0.64). In terms of PM10 concentrations, better metrics were obtained using the local EI (MGE = 10 mu g/m(3) and RMSE = 11.5 mu g/m(3)), compared with those from the global EI (MGE = 28 mu g/m(3) and RMSE = 28.8 mu g/m(3)). Analysis of the relative impact of anthropogenic emissions suggests that PM10 levels and ozone chemistry in the urban area of Manizales were controlled by emissions of its precursors from on-road vehicular sources and possible transport of O-3 at a regional scale from near rural zones. Results obtained highlight the importance of estimating and improving local EIs in medium-sized cities, for a more realistic analysis of emission impacts.