Screening the ESA ATSR-2 World Fire Atlas (1997–2002)

Abstract

Abstract. The European Space Agency (ESA) World Fire Atlas (WFA), for the period 1997–2002, is built using night time data from the Along Track Scanning Radiometer (ATSR) onboard the Second European Remote-Sensing Satellite (ERS-2). The spatial resolution of the data is 1 km and the satellite revisiting period is 3 days at the equator. The WFA is the first and longest archive of global fire observations and has been used in numerous biomass burning studies. Known limitations of the WFA are the inclusion of warm surfaces, gas flares, and city lights, and an underestimation of actual global fire activity, due to the time of satellite overpass. Nevertheless, it has been considered that the WFA contains a relatively small proportion of observations that do not correspond to vegetation fires. We used ancillary land cover, night-lights and volcanic activity datasets, combined with statistical techniques to detect the occurrence of space-time clusters, to screen the algorithm 2 (308°K threshold) WFA data for the period 1997–2002. During the study period, the annual percentage of false alarms and non-vegetation fires varied from a minimum value of 20.6% in 1997 to a maximum of 27.9% in 1998. Gas flares and hot bare soils are the major sources of false alarms and non-vegetation fires.

Net ecosystem fluxes of isoprene over tropical South America inferred from Global Ozone Monitoring Experiment (GOME) observations of HCHO columns

“…Enhanced HCHO production from elevated isoprene emissions during August -October (when temperatures and light levels are highest) and release of HCHO from smouldering fires will contribute to this slight phase lag [Yokelson et al, 1997]. Sampling and instrumental issues associated with the firecount data, such as nighttime measurements and inclusion of nonvegetation fires [Mota et al, 2006], will also likely contribute to this phase difference.…”

“…First, the ATSR firecount data are mapped on to the GEOS-Chem grid (2°Â 2.5°), and HCHO data falling in grid points where there is active fire are excluded from subsequent analysis. We recognize the shortcomings of the firecount data [Mota et al, 2006] but they nevertheless provide valuable information on the location and frequency of active fires. Second, we use elevated NO 2 columns as a marker of biomass burning to discard corresponding HCHO columns.…”

Development of a virtual active fire product for Africa through a synthesis of geostationary and polar orbiting satellite data

“…To this end, thermal remote sensing data from a variety of polar orbiting and geostationary platforms have been distilled into multi-annual and global compilations of active fire products (Arino and Rosaz, 1999;Stroppiana et al, 2000;Giglio et al, 2003;Justice et al, 2002;Mota et al, 2006). Such datasets have principally been used to investigate the spatial and temporal distributions of vegetation fires (Cooke et al, 1996;Dwyer et al, 1999Dwyer et al, , 2000Csiszar et al, 2005;Giglio et al, 2006a;Pu et al, 2007), but active fire pixel counts have also been related to burned area (Scholes et al, 1996a;Giglio et al, 2006b) in order to estimate trace gas and aerosol emissions (Scholes et al, 1996b;van der Werf et al, 2003van der Werf et al, , 2006 via heritage calculation methods (Seiler and Crutzen, 1980).…”

Tracking Fires in India Using Advanced Along Track Scanning Radiometer (A)ATSR Data

“…Also, as this instrument is having radiometric sensitivity, it allows detection of little or not much extended fires. The detection capability of the 3.7 μm channel ranges from a burning area of 0.1 ha at 600 to 0.01 ha at 800 K. In this study we used only the dataset created with the 308 K threshold, designated algorithm 2 [45][46][47][48][49]. Nine year fire locations were obtained in ASCII format from WFA and exported to ESRI shape file and were extracted for the study region.…”