This second edition retains the general structure of the first edition, but has been updated in the light of recent oceanographic research, and improved as a teaching text on the basis of feedback from past students and other readers. Notable additions include new sections addressing the topic of numerical modelling, and more discussion of natural oscillations in the ocean-atmosphere system (previously confined to the El Niño phenomenon). In particular, the Chapter on the North Atlantic now includes a discussion of the North Atlantic Oscillation, as well as of the Great Salinity Anomaly. In the final Chapter, treatment of water mass formation has been updated to reflect recent ideas about the processes involved and how they relate to climatic change over different time-scales, from decades to millennia. High quality full colour diagrams Substantial chapter summaries ideal for revision Answers, hints and notes for questions at back of the book