Monitoring Global Fires from EOS - MODIS The MODIS Fire Science Team : Yoram

NASA plans to launch the Moderate Resolution Imaging Spectroradiometer (MODIS) on the polar orbiting Earth Observation System (EOS) for morning and evening global observations in 1998 and afternoon and night observations in 2000. These 4 MODIS daily fire observations will advance global fire monitoring with special 1 km resolution fire channels at 4 μm and 11 μm, with high saturation at 500K and 400K respectively. MODIS data will also be used to monitor burn scars, vegetation type and condition, smoke aerosols, water vapor and clouds for overall monitoring of the fire process and its effects on ecosystems, the atmosphere and climate. The MODIS fire science team is preparing a series of algorithms for routine monitoring of fires and their properties. These algorithms are being designed to allow fire identification and characterization as well as mapping of burn scars. Using the elevation above background of the thermal signature, fires are separated from the background signal and evaluated. A data base of the daily fire occurrence and location, the apparent thermal energy emitted from the fire and a rough estimate of the smoldering/flaming ratio is generated from the thermal signature and archived. This information is expected to be used in monitoring the spatial and temporal distribution of fires in different ecosystems, in detecting changes in the fire distribution, new fire frontiers, wild fires, and changes in the density of the fires or their relative strength. This information will be used for the subsequent estimation of the emissions of trace gases and particulates from the fires. The MODIS active fire product will be generated at a lkm resolution and summarized on a grid of 10 km and 0.5° resolution. Fire information will be presented as a daily product and summarized as eight day and monthly products. Amongst other product enhancement activities in the post-launch period, we plan to combine the MODIS 2 or 4 daily fire products with a detailed diurnal cycle of the fires from geostationary satellites. Global lkm AVHRR data are currently being used to prototype aspects of the MODIS global fire products. Sensitivity studies, and analyses of aircraft and satellite data from the Yellowstone wild fire of 1988 and prescribed fires in the Smoke Cloud and Radiation (SCAR) field experiments are being used to evaluate and validate the fire algorithms and to establish the relationship between the fire apparent properties and the emission of aerosol and trace gases from the fire.