Analysis of daily, monthly, and annual burned area using the fourth-generation global fire emissions database (GFED4)

We describe the fourth generation of the Global Fire Emissions Database (GFED4) burned area data set, which provides global monthly burned area at 0.25° spatial resolution from mid-1995 through the present and daily burned area for the time series extending back to August 2000. We produced the full data set by combining 500 m MODIS burned area maps with active fire data from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) family of sensors. We found that the global annual area burned for the years 1997 through 2011 varied from 301 to 377 Mha, with an average of 348 Mha. We assessed the interannual variability and trends in burned area on the basis of a region-specific definition of fire years. With respect to trends, we found a gradual decrease of 1.7 Mha yr–1 (–1.4% yr–1) in Northern Hemisphere Africa since 2000, a gradual increase of 2.3 Mha yr–1 (+1.8% yr–1) in Southern Hemisphere Africa also since 2000, a slight increase of 0.2 Mha yr–1 (+2.5% yr–1) in Southeast Asia since 1997, and a rapid decrease of approximately 5.5 Mha yr–1 (–10.7% yr–1) from 2001 through 2011 in Australia, followed by a major upsurge in 2011 that exceeded the annual area burned in at least the previous 14 years. The net trend in global burned area from 2000 to 2012 was a modest decrease of 4.3 Mha yr–1 (–1.2% yr–1). We also performed a spectral analysis of the daily burned area time series and found no vestiges of the 16 day MODIS repeat cycle.