Global estimation of burned area using MODIS active fire observations

Abstract

Abstract. We present a method for estimating monthly burned area globally at 1° spatial resolution using Terra MODIS data and ancillary vegetation cover information. Using regression trees constructed for 14 different global regions, MODIS active fire observations were calibrated to ''true'' burned area estimates derived from 500-m MODIS imagery based on the conventional assumption that burned area is proportional to counts of fire pixels. Unlike earlier methods, we allow the constant of proportionality to vary as a function of tree and herbaceous vegetation cover, and the mean size of monthly cumulative fire-pixel clusters. In areas undergoing active deforestation, we implemented a subsequent correction based on tree cover information and a simple measure of fire persistence. Regions showing good agreement between predicted and observed burned area included Boreal Asia, Central Asia, Europe, and Temperate North America, where the estimates produced by the regression trees were relatively accurate and precise. Poorest agreement was found for southern-hemisphere South America, where predicted values of burned area are both inaccurate and imprecise; this is most likely a consequence of multiple factors that include extremely persistent cloud cover, and degradation of the quality of the 500-m burned area maps used for calibration. Application of our approach to the nine remaining regions yielded comparatively accurate, but less precise, estimates of monthly burned area. We applied the regional regression trees to the entire archive of Terra MODIS fire data to produce a monthly global burned area data set spanning late 2000 through mid-2005. Annual totals derived from this approach showed good agreement with independent annual estimates available for nine Canadian provinces, the United States, and Russia. With our data set we estimate the global annual burned area for the years 2001–2004 to vary between 2.97 million and 3.74 million km2, with the maximum occurring in 2001. These coarse-resolution burned area estimates may serve as a useful interim product until long-term burned area data sets become available.

Atmospheric deposition—Another source of nutrients enhancing primary productivity in the eastern tropical Indian Ocean during positive Indian Ocean Dipole phases

“…Worldwide, there are areas of upwelling near main wildfire areas, such as the Mauritanian upwelling, Namibian upwelling, and Benguela upwelling, off the west coast of Africa [Giglio et al, 2006;Patti et al, 2008]. In these upwelling areas, atmospheric deposition from the world's largest BAs (northern and southern hemispheres of Africa) [Giglio et al, 2006] should be considered as another source of nutrients modulating new productivity.…”

Multi-year MODIS active fire type classification over the Brazilian Tropical Moist Forest Biome

“…The Brazilian Tropical Moist Forest Biome (BTMFB) supports the world's largest contiguous area of tropical forest and has experienced high rates of deforestation over the last few decades (Fearnside 2007;Numata et al 2011) and extensive annual burning (Setzer and Pereira 1991;Giglio et al 2006;Chen et al 2011;Morton et al 2013). Fire is used as the primary tool for forest and agricultural land clearing and the majority of fires are thought to be anthropogenic.…”

A new, global, multi‐annual (2000–2007) burnt area product at 1 km resolution

“…Schultz [2002] used ATSR fire count data; Sukhinin et al [2004] used AVHRR data; Giglio et al [2006] and Smith et al [2007] used MODIS active fire data. These authors highlight the lack of accurate, consistent long-term information on global burnt area as the reason for their decision to use active fire data.…”