Characterization and Trends of Fine Particulate Matter (PM2.5) Fire Emissions in the Brazilian Cerrado during 2002–2017
Department of Geography, University of São Paulo (USP), São Paulo 05508-000, Brazil
Remote Sensing Division, National Institute for Space Research (INPE), São José dos Campos 12227-010, Brazil
Department of Geography and Atmospheric Science, University of Kansas (KU), Lawrence, KS 64045, USA
Department of Geosciences, Federal University of São João del-Rei (UFSJ), São João del-Rei 36307-352, Brazil
Author to whom correspondence should be addressed.
now at: National Center for Early Warning and Monitoring of Natural Disasters (CEMADEN), São José dos Campos 12247-016, Brazil.
Remote Sens. 2019, 11(19), 2254; https://doi.org/10.3390/rs11192254
Received: 13 June 2019 / Revised: 15 August 2019 / Accepted: 20 August 2019 / Published: 27 September 2019
(This article belongs to the Special Issue Remote Sensing of Biomass Burning)
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.