With great progress being made in science and technology, we are becoming more interested in finding out how the climate system, including the oceanic general circulation, works on our planet. This book is written for the general reader who is searching for knowledge about oceanic circulation and its relevance to climate and the global environment on Earth.

During the process of collecting the materials for this book, I have tried to achieve a sensible balance between the physical concepts fundamental to the oceanic circulation, well-established theories, and recent developments associated with the frontiers in our field. As its title suggests, the book is about the wind-driven and thermohaline processes in the oceans. Although many theories about the oceanic general circulation have developed over recent decades, it is clear that our understanding of the circulation remains rudimentary at best. Since this book is intended as a textbook for graduate students, I have made a major effort to describe and explain the physical aspects of the circulation without relying on the sometimes complicated mathematics. To aid the reader, I have included many diagrams illustrating the physics.

In terms of the theoretical part of the book, I have made every effort to present new theories and thoughts about the energetic theory of the oceanic general circulation. Although energetics is one of the fundamental aspects of any dynamical system, the importance of examining the energetics of the oceanic general circulation has so far not been widely appreciated.