Floods and droughts in East Africa are often unleashed by far-away events in the tropical Pacific—the warm (El Niño) or cool (La Niña) phases of the El Niño-Southern Oscillation (ENSO). A catastrophic drought is currently wreaking havoc in wide regions of Kenya, Ethiopia, Djibouti and Somalia, affecting food security and putting millions of people in urgent need of assistance. Scientists have attributed the severe drying to La Niña conditions that prevailed from June 2010 to May 2011 in the Pacific.
The waxing and waning of rainfall in eastern tropical Africa in unison with ENSO is nothing unusual and existed already 20,000 years ago, according to a study published in the August 5 issue of Science by a group of scientists from Germany, Switzerland, the US, the Netherlands, and Belgium. (EurekAlert)