UNDERSTANDING AND PREDICTING ENSO

Throughout the 1960's and 1970's, oceanographers referred to the large‐scale warming of the equatorial eastern and central Pacific as El Niño. This anomalous warming was later shown to be associated with anomalies in the upper ocean thermal structure throughout the equatorial Pacific Ocean. At about the same time, scientists realized that the Southern Oscillation was intimately related to the large‐scale changes in the tropical Pacific Ocean. In brief, the Southern Oscillation represents the variability in the Indo‐Pacific Walker circulation in the tropics, and is manifest as a displacement of the convection over the maritime continent, and is associated with large‐scale anomalies in the surface wind and sea level pressure throughout the tropical Pacific (and into the Indian Ocean) basin. Copyright 1995 by the American Geophysical Union.