El Niño is a local warming of surface waters which takes place in the entire equatorial zone of the central and eastern Pacific Ocean off the Peruvian coast and which affects the atmospheric circulation world-wide. It usually peaks around Christmas, hence the name of the phenomenon: El Niño (Spanish for Christ Child). La Niña refers to the “cold” equivalent of El Niño.
Like most atmospheric phenomena, it occurs at more or less regular intervals (pseudo-cycles) and, as such, there is nothing “abnormal” in the occurrence of El Niño. The last phenomenon was in 1997-98, when it had strong adverse effects on agricultural production in South America and South East Asia. Uncertainty continues to prevail about a fully-fledged El Niño developing this year. While satellites observed a moderate increase of Sea Surface Temperatures (SST) from September 2001, the typical changes in the global atmospheric circulation have not taken place. Furthermore, the end of April witnessed a relative cooling of the Pacific SSTs off the South American coast. Nevertheless, analysts indicate that a well developed warm El Niño-Southern Oscillation (ENSO) could yet be triggered this year by relatively minor factors, such as strong easterly winds over the Pacific. Thus, the situation continues to be closely monitored.
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