Remote sensing of biomass burning associated with deforestation

A new method has been developed for the global assessment of trace gases and particulates emission from tropical biomass burning. The method is based on remote sensing of one emitted product - particulates. It uses daily meteorological satellite data with resolution of one km2. The visible (0.63 rim) and near Infrared (0.84 rim) bands are used to determine the mass of particulates in the emitted smoke and to estimate the relative contribution of flaming and smoldering fires to the resulting smoke. The mid-IR (3.5-3.9 rim) and the thermal infrared (1 0.5-1 1 .4 ji.m) bands are used to detect and count fires in order to integrate the smoke result with the whole season and for the whole area of interest. The thermal channels are sensitive enough to detect flaming fires as small as lOm*lOm and smoldering fires as small as 30m*30m. The detected mass of emitted particulates is converted into a mass of emitted trace gases using published relations between the emitted particulates and trace gases for the flaming and smoldering phases. The.technique can be applied to regions where intensive biomass burning takes place. It is capable of monitoring the extent of current biomass burning, to discover new deforestation frontiers (unknown otherwise), and to estimate quantitative contribution of biomass burning to changes in atmospheric composition. The method has been applied to a limited area where substantial deforestation has taken place. Analysis of the 1987 burning season shows that in Brazil (in a limited area between 6.5-15.5 south and 55-67 west) during the three months of the dry season (July 1 till Sept. 30) there are up to 8000 fires a day (observed from space) each contributing 4,500 tons of C02, 750 tons of CO and 26 tons of CH4 to the atmosphere. During the dry season of 1 987, it is estimated that 240,000 fires were burning in this area resulting in the emission of 1.1013 of particulates, 71 012 g of CH4, 21 014 g of CO and 1 •1 015 g of CO2. A comparison to estimates of global emissions is also given.