File:Fires and Poor Air Quality in West Africa (MODIS 2020-01-23).jpg

English: On January 21, 2020, NASA’s Terra satellite passed over West Africa, allowing the Moderate Resolution Imaging Spectroradiometer (MODIS) on board to acquire a true-color image of hundreds of fires burning underneath an expansive shroud of smoke.

Fire activity in this region cycles with the season. In the Sahel and savannas just south of the Sahara Desert, the agricultural burning season begins in Northern Hemisphere fall and progresses toward a peak of activity in mid-winter.

Each red “hot spot” marks where the thermal bands on the instrument detected increased temperature. When combined with typical smoke, as in this image, such hot spots mark actively burning fire. Fires are burning across the entire region, except for where little vegetation exists. Clusters are especially heavy in Ghana (west), with Nigeria (east), also filled with high numbers of fire. The widespread nature, location, and time of year strongly suggest that these fires have been set to clear or manage land for agricultural purposes. A heavy covering of gray smoke stretches over the entire region, even reaching north to the Sahara. The smoke is so thick over some areas that it obscures the feature of the land beneath.