Development and evaluation of a comprehensive atmospheric emission inventory for air quality modeling in the megacity of Bogotá

We built an emission inventory (EI) for the megacity of Bogotá, Colombia for 2012, which for the first time augments traditional industrial and mobile sources by including commercial sources, biogenic sources, and resuspended dust. We characterized the methodologies for estimating each source annually, and allocated the sources to hourly and 1 km spatial resolution for use as inputs for air quality modeling purposes. A resuspended particulate matter (RPM) emission estimate was developed using the first measurements of road dust loadings and silt content for the city. Results show that mobile sources dominate emissions of CO (80%), CO (99%), VOC (68%), NO (95%), and SO (85%). However, the newly estimated RPM comprises 90% of total PM emissions, which are at least onefold larger than the PM emissions from combustion processes. The 2012 EI was implemented in a chemical transport model (CTM) in order to understand the pollutants\u27 fate and transport. Model evaluation was conducted against observations from the city\u27s air quality monitoring network in two different periods. Modeling results for O3 concentrations showed a good agreement, with mean fractional bias (MFB) of +11%, and a mean fractional error (MFE) of +35% with observations, but simulated PM concentrations were strongly biased high (MFB +57%, MFE +68%), which was likely due to RPM emissions being overestimated. NO , CO, and SO were also biased high by the model, which was probably due to emissions not reflecting current fleet conditions. Future work aims to revise emission factors for mobile sources, which are the main sources of pollutants to the atmosphere. 2 2 x 2 10 10 10 x