AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
First Year of Black Carbon and Brown Carbon Measurements in a Mountain Top Station in Bogotá, Colombia
RICARDO MORALES BETANCOURT, Luis Carlos Belalcazar, Diego Miguel Quirama, Juan Manuel Rincón, Juan Felipe Mendez, Universidad de los Andes
Abstract Number: 631 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Biomass burning aerosol emissions represent an important contribution to global atmospheric aerosol loadings. Emissions associated to wildfires and biomass burning can significantly degrade regional air quality. Furthermore, the light-absorbing nature of particles emitted during biomass burning have a substantial impact on the global and local radiation budget through direct and indirect effects. The seasonality of biomass burning emissions in Amazonia during the dry season have been extensively studied given its large contribution to the global inventory of carbonaceous aerosols. However, the seasonal cycle and regional impacts of biomass burning emissions in northern South America have received considerably less attention. In this study, we report the first year of continuous measurements of equivalent Black Carbon (eBC) in a mountain top site in the North Central Andes mountain range. Previous studies have shown a close relationship between the number of hot spots detected through remote sensing in the eastern plains of Colombia, and fine particulate matter concentration in several cities in the Andean region. In our study, eBC concentrations were monitored from April 2016 to present, with a 7-wavelength Aethalometer. The contribution of biomass burning to the light-absorbing aerosol particle concentration was performed through spectral analysis of the absorption coefficient. Two alternative for the spectral analysis were explored in this study: a two-wave-length model (Sandradewi et al 2004), and a multi-wavelength optical method (Massabo et al. 2015). A systematic back-trajectory analysis was performed for the full year of measurements, suggesting that several events occurred were long-range transport of biomass burning aerosol reached our station. A careful screening of the measurements is performed to minimize interference of emissions from the city of Bogota. A clear seasonal cycle is observed in the data, with episodes of several days in which the contribution of biomass burning can be up to 30% of the total light-absorbing aerosol concentration.