Modelling the Contribution of the Cerrado Fires to the Brazilian Emissions of Fine Particulate Matter (PM2.5 µm) Associated with Biomass Burning

Abstract

Biomass burning is one the main sources of emission of trace gases and aerosols into the atmosphere, impacting over the Earth’s climate, air quality and human health. Moreover, it is fundamental to estimate the burned biomass and its respective emission during the combustion process. Among the aerosols emitted, we can highlight the fine particulate matter with diameter of less than 2.5 micrometers (PM_{2.5 µm}), which is a risk factor for respiratory diseases and impacts on the global radiative budget. In Brazil, studies show that fires associated to land-use and land-cover change (LULCC) is one of the main sources of emissions to the atmosphere. Moreover, the Cerrado is highlighted, which is suffering an intense LULCC process since the 1970s. We aimed to estimate the mass of PM_{2.5 µm} emitted from biomass burning in Brazil and the respective contribution of the Cerrado, as well as the spatial and temporal variability of PM_{2.5 µm} in the Cerrado during the 2009-2015 period. To estimate the emissions, we used orbital data from MODIS and SEVIRI sensors as inputs in the 3BEM_FRP approach implemented in the PREP-CHEM-SRC tool. Results showed that, on average, 1.63 million tons of PM_{2.5 µm} are annually emitted in Brazil, however, approximately 37 % of this amount is originated in the Cerrado. We have that emissions are concentrated in the North, the current agricultural expansion frontier in the biome, while temporally emissions are concentrated in September. Our results qualify future studies to analyze the impact of these emissions on climate and human health.