Fires were burning across central Africa in late December 2004. The widespread nature of the fires and the time of year indicates that these fires are being set intentionally for agricultural purposes. Though not necessarily immediately hazardous, such large-scale burningand the resulting smokecan have a strong impact on weather, climate, human health, and natural resources. The following images were captured by the Moderate Resolution Imaging Spectroradiometer (MODIS).
29 December 2004 Fires in Western Africa On December 29, 2004, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASAs Aqua satellite captured this image of West Africa, showing the annual agricultural burning season fully underway. MODIS detected hundreds, possibly thousands, of fires, and their locations are marked with red dots. The image is centered on Côte D’Ivoire (Ivory Coast). Within the country, some regions were dotted with numerous scattered fires, while in other regions, for example the central and northeastern areas, fires are concentrated. December is one of the months in which farmers and herders engage in agricultural burning, and most of these fires are probably agricultural fires. People set fires to clear farmland of the previous season’s crop stubble, to stimulate the growth of new, more nourishing grasses, and in some cases, to clear woodlands and rainforests to create more room for agricultural activities. Although agricultural fires are not necessarily immediately hazardous, the in-correct use of fire and the high frequency of burning has devastating long term effects on soil productivity.
The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions.
Image courtesy Jacques Descloitres, MODIS Rapid Response Team, NASA-Goddard Space Flight Center
Carbon Monoxide over Africa
November marks the beginning of the fire season in the Sahel, where fire is used to clear land and prepare fields for planting. Such fires are not harmful of themselves, but they do release particles and gases into the atmosphere that impact climate and human health. One of the gases released in combustion is carbon monoxide, so it is not surprising that the Measurements of Pollution in the Troposphere (MOPITT) instrument aboard the NASAs Terra satellite detected enhanced levels of carbon monoxide (CO) over Central and West Africa in November 2004.
The false-color image above shows carbon monoxide concentrations at 700 hPa in the atmosphere (about 3 km altitude) during the week of November 21-28, 2004. Missing data due to persistent cloud coverage are color-coded in gray. Red and yellow colors show the CO produced by the vegetation fires and being transported by the South-East Trade winds out onto the Atlantic Ocean. Somewhat enhanced CO concentrations are also evident in parts of Southern Africa. As the fire season starts in West-Central Africa, the vegetation fires in the Southern part of the continent are dying down with the onset of the wet season. The fire season in West-Central Africa typically runs from November to April.
NASA image created by Jesse Allen, EarthObservatory, using data provided courtesy of the NCAR and University of Toronto MOPITTteams.
For background information on theFire Situation in Africa see: