NOAA SATELLITES MONITOR STIFLING DROUGHT IN HORN OF AFRICA
April 20, 2005 — NOAA satellites have detected areas of stifling drought conditions in parts of Kenya, Ethiopia and Somalia for the sixth year in a row. These conditions leave the region with threats of starvation, water shortages, widespread crop losses and disease outbreaks, according to researchers at the NOAA Satellite and Information Service. (Click NOAA satellite image for larger view of vegetation health in Africa from 2004-2005. Click here for high resolution version, which is a large file. Please credit “NOAA.”)
The 2005 drought gripped the region, known as the Horn of Africa, in January and continues to impact areas of eastern Kenya, southeastern Ethiopia and northern and central Somalia. At stake now is the minor agricultural season, which runs from March through May, and normally provides enough food to sustain the population through the fall when the next harvest becomes available.
"If the drought continues, any hope of success for a decent early-stage agricultural season in the Horn would be seriously at risk," said Felix Kogan of the NOAA Office of Research and Applications, a part of the Satellite and Information Service. "We are issuing a drought alert to notify humanitarian and relief agencies of these potentially deadly conditions so that hopefully lives can be saved."
NOAA's administrator said the agency's satellites are key in the developing Global Earth Observation System of Systems, or GEOSS, which seeks to link the world's existing environmental-monitoring technologies into a coordinated system of systems. GEOSS would better predict weather and climate changes and prepare against natural hazards, such as drought.
"Detecting this drought in the Horn of Africa, and alerting the proper officials early enough to lessen the damages, is a clear example of what GEOSS really means," said retired Navy Vice Admiral Conrad C. Lautenbacher, Jr., Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. "NOAA satellites, which are already instrumental in weather and climate forecasting at home, are bringing value to people throughout the world." (Click NOAA satellite image for larger view of drought across the Horn of Africa from 2000 to 2005. Please credit “NOAA.”)
NOAA's Polar-orbiting Operational Environmental Satellites helped researchers track the ongoing drought conditions. POES constantly circle the Earth in orbits that provide two views each day of the entire planet, while supporting NOAA's long-range weather and climate forecasts and search and rescue operations.
One of the satellites' instruments, Advanced Very High Resolution Radiometer sensor, or AVHRR, measures the amount of solar reflection from green vegetation based on chlorophyll content. (Chlorophyll, the green pigment in plants, transforms energy from sunlight into chemical energy.)
The more solar energy plants absorb means less energy reflected back into space. The AVHRR sensor measures the reflected energy, or radiance. NOAA researchers combine the POES visible, near infrared and infrared measurements to develop several indices to calculate moisture, thermal conditions and the overall health of the vegetation.
"Since 2000, drought conditions have affected nearly 20 percent of the world's land mass," Kogan added. "This method has proven successful over the years, and we'll continue using it as a way to warn the global community about the dangers of long-term drought."
NOAA, an agency of the U.S. Department of Commerce, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation's coastal and marine resources.
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