Portal de Eventos, Congreso Colombiano y Conferencia Internacional de Calidad del Aire y Salud Pública

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Multi-year Observations of Black Carbon and Brown Carbon in Bogota, Colombia: Identification of potential biomass burning emission areas through the relation of Tracers and Number of Fires.
Juan Manuel Rincon Riveros, Ricardo Morales Betancourt, Luis Carlos Belalcazar

Última modificación: 17/06/2019

Resumen


Biomass burning pollution sources can produce regional and global impacts on air quality. South America is one of largest contributors to biomass burning emissions (BB) globally. After Amazonia, BB emissions from the grassland plains of Northern South America (NSA), where both wildfires and agricultural burns occur regularly, are the most significant. The BB season in NSA is characterized by a different seasonality compared to that of Amazonia, with numerous fires occurring between January and March. In this work, we report 3 years of continuous equivalent Black Carbon (eBC) and Brown Carbon (BrC) measurements from an Aethalometer AE33-7. This data is used to identify and quantify the contribution of biomass burning from NSA to Bogota, Colombia's. The measurement site is located upwind of Bogota, at a hill-top 500 meters above the plateau where the city is located. Additionally, PM2.5 off-line data using a low-vol sampler and 37 mm quartz filters, has been collected during two three-month long field campaigns. The first campaign was carried out from January to March 2018 (high BB emissions in NSA) and the second one between July and August 2018 (low BB emissions in NSA). The filter samples were analyzed in Colorado State University quantifying biomass burning tracers such as Levoglucosan and potassium ion. OC/EC data was also retrieved from the filter samples. MODIS Active Fire Data and HYSPLIT back‐trajectories were used to support the identification of potential biomass burning plumes transported to the city during the fires season. We analyzed the relationship between BrC, OC, Potassium ion, and levoglucosan to identify signals of regional transport of BB aerosols. We found a maximum BB contribution of 10% to light-absorbing aerosols during the high number of fires season and a 1% BB contribution during the low number of fires season. Our results indicate potential biomass burning transport events from wildfires were observed during the months of January and April. Besides, we found a higher correlation between BB tracers and fires located in 400 km buffer. In addition, we identified potential source regions that could impact Bogotas air quality.