This monograph is the outcome of an attempt by the authors to present a synthesis of the studies on physical processes in the Tropical Indian Ocean (TIO) in relation to air-sea interaction, monsoon/climate variability and biological productivity through a review of the published work so far and analysis of the latest available data sets. Various oceanic features and processes in the upper 1000 m of the TIO are described and discussed. An Oceanographic Atlas prepared for this purpose is appended to the monograph. The monograph consists of six chapters. Chapter 1 entitled ‘Introduction’, gives the significant/special features of TIO, the names of various expeditions/experiments carried out in this region and the scope of the different aspects covered in the monograph. Chapter 2 deals with the features of surface parameters/fields. Chapter 3 describes the hydrographic features in the upper 1000 m. Chapter 4 gives a comprehensive account of upwelling processes in the TIO. Chapter 5 deals with internal waves. Summary of the results and a few suggestions for improving our understanding of the physical processes are included in Chapter 6 entitled ‘Concluding Remarks’.