Development and Evaluation of a Comprehensive Atmospheric Emission Inventory for Air Quality Modeling in the Megacity of Bogotá

Abstract

Abstract: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 2 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 2 (80%), CO (99%), VOC (68%), NO x (95%), and SO 2 (85%). However, the newly estimated RPM comprises 90% of total PM 10 emissions, which are at least onefold larger than the PM 10 emissions from combustion processes. The 2012 EI was implemented in a chemical transport model (CTM) in order to understand the pollutants' fate and transport. Model evaluation was conducted against observations from the city's air quality monitoring network in two different periods. Modeling results for O 3 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 10 concentrations were strongly biased high (MFB +57%, MFE +68%), which was likely due to RPM emissions being overestimated. NO x , CO, and SO 2 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.

Long-term brown carbon and smoke tracer observations in Bogotá, Colombia: association with medium-range transport of biomass burning plumes

“…According to the air quality monitoring stations in the city, the annual average PM 2.5 concentration was 19 µg m −3 during 2019, with a strong seasonal cycle during which monthly mean PM 2.5 between February and March can reach 35 µg m −3 and decrease to 11 µg m −3 in July. Primary aerosol emissions are estimated to be 2600 t yr −1 , with a large contribution from diesel-powered public transport buses and cargo trucks (Pachón et al, 2018). Road dust resuspension emissions are highly uncertain but are thought to significantly contribute to primary emissions (Pachón et al, 2018).…”

“…Elemental carbon is known to have a visible light absorption coefficient larger than that of any other aerosol component and to substantially impact Earth's radiation budget and climate. Due to its optical properties, EC is sometimes measured through light absorption techniques and when measured this way is referred to as equivalent black carbon (eBC) (Petzold et al, 2013). BC is the secondlargest contributor to anthropogenic radiative forcing, with open burning of forests and savannas being the largest source (Stohl et al, 2015;Bond et al, 2013).…”

Long-term Brown Carbon and Smoke Tracer Observations in Bogotá, Colombia: Association to Medium-Range Transport of Biomass Burning Plumes

“…was 19 µg m −3 during 2018, with a strong seasonal cycle in which monthly-mean PM 2.5 between February and March can reach 35 µg m −3 and decrease to 11 µg m −3 in July. Primary aerosol emissions are estimated to be 2600 tons/year, with a substantial contribution from diesel powered public transport buses and cargo trucks (Pachón et al, 2018). Road dust resuspension emissions are highly uncertain, but are thought to contribute significantly to primary emissions (Pachón et al, 2018).…”

“…Primary aerosol emissions are estimated to be 2600 tons/year, with a substantial contribution from diesel powered public transport buses and cargo trucks (Pachón et al, 2018). Road dust resuspension emissions are highly uncertain, but are thought to contribute significantly to primary emissions (Pachón et al, 2018). There are no significant emission sources or urbanized areas West of the city (Figure 1b).…”

Spatial Disaggregation of Particulate Matter Emission Inventory in the Metropolitan Area of Aburr\'a Valley for Air Quality Modelling

“…Data assimilation was used to adjust the emissions, and due to the persistent low bias the best performance was obtained by strongly increasing the emissions over the entire domain. Despite repeated studies showing that the EDGAR inventory has its limitations for application over Colombian (Gonzalez et al, 2017;Pachón, Galvis, Lombana, Carmona, Fajardo, Rincón, Meneses, Chaparro, Nedbor-Gross and Henderson, 2018;Nedbor-Gross, Henderson, Pérez-Peña and Pachón, 2018), this database is still the only one available that includes all species necessary for air quality simulations over a large region of the northeast Andes domain.…”