image: Widespread agricultural burning continues throughout Sierra Leone. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies aboard NASA's Aqua satellite captured an image of smoke and fires burning on March 29, 2015. The location, widespread nature, and number of fires suggest that these fires were deliberately set to manage land. Farmers often use fire to return nutrients to the soil and to clear the ground of unwanted plants. While fire helps enhance crops and grasses for pasture, the fires also produce smoke that degrades air quality. Each hot spot, which appears as a red mark, is an area where the thermal detectors on the MODIS instrument recognized temperatures higher than background. When accompanied by plumes of smoke, as in this image, such hot spots are diagnostic for fire. view more
Credit: Image: NASA Jeff Schmaltz, MODIS Rapid Response Team. Text: NASA Goddard Space Flight Center, Lynn Jenner