El Nino and the Southern Oscillation is by far the most striking phenomenon caused by the interplay of ocean and atmosphere. It can be explained neither in strictly oceanographic nor strictly meteorological terms. This volume provides a brief history of the subject, summarizes the oceanographic and meteorological observations and theories, and discusses the recent advances in computer modeling studies of the phenomenon. It includes a comprehensive and up-to-date research survey and discusses in detail sophisticated computer models. It provides a clear exposition of the major problems which prevent more accurate predictions of El Nino.