Biomass burning is one of the major pollution sources of the Earth's atmosphere, releasing large amounts of gaseous (CO, NOX , hydrocarbons, etc.) and particulate (aerosol) emissions [Crutzen and Andreae, 1990; Andreae, 1991; Leuine, 1991]. Furthermore, fires in forests and savannas have an important ecological influence, especially in the tropics [Goldammer, 1990; Kozlowski and Ahlgren, 1974]. Yet, no global survey of fire incidence as a function of time and geographic region is available at this time. The recent release of the NASA/Space Shuttle Earth Observations Project (SSEOP) data base provides an opportunity to investigate the global distribution of large fires.