Assessing variability and long-term trends in burned area by merging multiple satellite fire products

L Giglio,R S Defries,J T Randerson,D C Morton,G R Van Der Werf,G J Collatz,P S Kasibhatla

doi:10.5194/bg-7-1171-2010

L Giglio, R S Defries + Show 5 more

Open Access

https://doi.org/10.5194/bg-7-1171-2010

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Abstract

Abstract. Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and the Along-Track Scanning Radiometer (ATSR) allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3) estimates of trace gas and aerosol emissions.

Highlights

As Earth-system modeling efforts increasingly recognize and include fire as an important process in the terrestrial carbon cycle, there remains a strong need for long term, spatiallyand temporally-explicit global burned area data sets
These include: 1) the 1-km L3JRC product (Tansey et al, 2008), currently spanning April 2000– March 2007, and produced from SPOT VEGETATION imagery with a modified version of the Tansey et al (2004) Global Burnt Area (GBA) 2000 algorithm; 2) the 1-km GLOBCARBON burned area product, currently spanning April 1998–December 2007, derived from SPOT VEGETATION, Along-Track Scanning Radiometer (ATSR-2), and Advanced ATSR (AATSR) imagery using a combination of mapping algorithms (Plummer et al, 2006); and 3) the Roy et al (2008) 500-m Moderate Resolution Imaging Spectroradiometer (MODIS) burned area product (MCD45A1), generated from Terra and Aqua MODIS imagery and available
We used a combination of active fire observations from multiple satellites, 500-m MODIS burned area maps, local regression, and regional regression trees to produce a hybrid, global, monthly burned area data set from July 1996 through mid-2009

Summary

Introduction

As Earth-system modeling efforts increasingly recognize and include fire as an important process in the terrestrial carbon cycle, there remains a strong need for long term, spatiallyand temporally-explicit global burned area data sets Among other purposes, such data are essential for quantifying pyrogenic trace gas and aerosol emissions, discriminating natural versus anthropogenic contributions to global change, and identifying feedbacks between fire and climate change (Langmann et al, 2009). In response to this need, a growing number of multi-year, satellite-based global burned area products have been made publicly available over the past several years. In GFED2, burned area was estimated indirectly using monthly active fire observations from the MODIS, ATSR, and Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) sensors, drawing upon a relatively small set of MODIS 500-m burned area observations (Giglio et al, 2006b; van der Werf et al, 2006)

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