Understanding and Predicting El Niño and Southern Oscillation

This chapter reviews basic concepts about the El Niño/Southern Oscillation (ENSO) cycle and its global climatic impacts. It also highlights progress in understanding, observing, and predicting ENSO timescale variations, focusing on the 2015–16 El Niño as a case study. This El Niño was one of the strongest on record; its evolution and many of its far-field impacts were remarkably well predicted at lead times of 6–9 months. Despite progress to date, however, there are many outstanding issues that need to be addressed to improve our understanding and ability to predict ENSO.