Characterization and Trends of Fine Particulate Matter (PM2.5) Fire Emissions in the Brazilian Cerrado during 2002–2017

Guilherme Augusto Verola Mataveli,Maria Elisa Siqueira Silva,Daniela De Azeredo França,Gabriel Bertani,Francielle Da Silva Cardozo,Gabriel De Oliveira,Gabriel Pereira,Nathaniel Alan Brunsell

doi:10.3390/rs11192254

Abstract

Fire occurrence is a major disturbance in the Brazilian Cerrado, which is driven by both natural and anthropogenic activities. Despite increasing efforts for monitoring the Cerrado, a biome-scale study for quantifying and understanding the variability of fire emissions is still needed. We aimed at characterizing and finding trends in Particulate Matter with diameter less than 2.5 µm (PM2.5) fire emissions in the Brazilian Cerrado using the PREP-CHEM-SRC emissions preprocessing tool and Moderate Resolution Imaging Spectroradiometer (MODIS) active fires datasets for the 2002–2017 period. Our results showed that, on average, the Cerrado emitted 1.08 Tg year−1 of PM2.5 associated with fires, accounting for 25% and 15% of the PM2.5 fire emissions in Brazil and South America, respectively. Most of the PM2.5 fire emissions were concentrated in the end of the dry season (August, 0.224 Tg month−1 and September, 0.386 Tg month−1) and in the transitional month (October, 0.210 Tg month−1). Annually, 66% of the total emissions occurred over the savanna land cover; however, active fires that were detected in the evergreen broadleaf land cover tended to emit more than active fires occurring in the savanna land cover. Spatially, each 0.1° grid cell emitted, on average, 0.5 Mg km−2 year−1 of PM2.5 associated with fires, but the values can reach to 16.6 Mg km−2 year−1 in a single cell. Higher estimates of PM2.5 emissions associated with fires were mostly concentrated in the northern region, which is the current agricultural expansion frontier in this biome. When considering the entire Cerrado, we found an annual decreasing trend representing -1.78% of the annual average PM2.5 emitted from fires during the period analyzed, however, the grid cell analysis found annual trends representing ± 35% of the annual average PM2.5 fire emissions.

Highlights

Biomass burning is known as one of the most important sources of emission of gases and aerosols into the atmosphere [1,2]
The Cerrado emitted 1.08 Tg year−1 of PM2.5 associated with fires, accounting for 25% and 15% of the PM2.5 fire emissions that were estimated in Brazil and in South America, respectively
Brazilian emissions corresponded to 59% of the South American emissions during the 2002–2017 period, similar to the result of [40], who found that, during the 2003–2015 period, 60% of the PM2.5 fire emissions occurring in South America were originated in the Brazilian territory

Summary

Introduction

Biomass burning is known as one of the most important sources of emission of gases and aerosols into the atmosphere [1,2]. Global carbon fire emissions are estimated to be 2.2 Pg C year−1 [3] and, impact the composition of the atmosphere [4,5]. PM2.5 that are emitted from fires are important, which, despite only composing approximately 0.5% of the total fire emission components, are associated with deoxyribonucleic acid (DNA) damage and cell death in human lung cells [9] and estimated to be responsible for 339,000 deaths annually when considering global wild and prescribed forest fires, tropical deforestation fires, peat fires, agricultural burning, and grass fires [8]. Climate variability is an important fire-driver in tropics [16], where the risk of fire occurrence is expected to increase due to climate warming [18]

Results

Discussion

Conclusion