Abstract
Abstract. Africa is the single largest continental source of biomass burning emissions. Here we conduct the first analysis of one full year of geostationary active fire detections and fire radiative power data recorded over Africa at 15-min temporal interval and a 3 km sub-satellite spatial resolution by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) imaging radiometer onboard the Meteosat-8 satellite. We use these data to provide new insights into the rates and totals of open biomass burning over Africa, particularly into the extremely strong seasonal and diurnal cycles that exist across the continent. We estimate peak daily biomass combustion totals to be 9 and 6 million tonnes of fuel per day in the northern and southern hemispheres respectively, and total fuel consumption between February 2004 and January 2005 is estimated to be at least 855 million tonnes. Analysis is carried out with regard to fire pixel temporal persistence, and we note that the majority of African fires are detected only once in consecutive 15 min imaging slots. An investigation of the variability of the diurnal fire cycle is carried out with respect to 20 different land cover types, and whilst differences are noted between land covers, the fire diurnal cycle characteristics for most land cover type are very similar in both African hemispheres. We compare the Fire Radiative Power (FRP) derived biomass combustion estimates to burned-areas, both at the scale of individual fires and over the entire continent at a 1-degree scale. Fuel consumption estimates are found to be less than 2 kg/m2 for all land cover types noted to be subject to significant fire activity, and for savanna grasslands where literature values are commonly reported the FRP-derived median fuel consumption estimate of 300 g/m2 is well within commonly quoted values. Meteosat-derived FRP data of the type presented here is now available freely to interested users continuously and in near real-time for Africa, Europe and parts of South America via the EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites) Land Surface Analysis Satellite Applications Facility (http://landsaf.meteo.pt/). Continuous generation of these products will allow the types of analysis presented in this paper to be improved and extended, and such multi-year records should allow relationships between climate, fire and fuel to be further examined.
Highlights
Biomass burning is a key Earth system process, a major element of the terrestrial carbon cycle and a globally significant source of atmospheric trace gases and aerosols (Hao et al, 1996; Andreae and Merlet, 2001)
Burning of biomass is accompanied by a wide variety of characteristic spectral signatures that can be detected by remote sensing, including those related to thermal emissions from actively burning fires, to the albedo and spectral reflectance changes induced by newly burned surfaces, and to the presence of smoke plumes containing trace gas and aerosols in highly elevated concentrations (Trentmann et al, 2002; Jost et al, 2003)
In order to examine fuel consumption densities calculated for much larger areas than are covered by the eighteen fires examined in the previous Section, the 1◦ gridded Fire Radiative Energy (FRE)-derived total fuel consumption measures were combined with burned area estimates made for the same grid cell and taken from the widely used GFEDv2 database
Summary
Biomass burning is a key Earth system process, a major element of the terrestrial carbon cycle and a globally significant source of atmospheric trace gases and aerosols (Hao et al, 1996; Andreae and Merlet, 2001). Roberts et al.: Annual african biomass burning temporal dynamics the study of biomass burning (Dozier, 1981) Most such studies have relied on data from polar-orbiting satellites, but their restricted overpass frequency, coupled with the diurnal fire cycle, means that the information provided typically represents a limited temporal sample that may not be fully consistent with the need to link emissions estimates to models of atmospheric transport and chemistry (Moula et al, 1996; Wittenberg et al, 1998; Hyer et al, 2007). Improved quantification of other carbon sources (and sinks), and how these might be made to vary with altered land use practices for example, may offer the potential to enable African nations to derive improved benefits in future
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
