TABLE OF CONTENTS 



Page 



FOREWORD '•' 



PREFACE V 



LIST OF FIGURES AND TABLES vlii 



INTRODUCTION 



1 



SOURCES AND TREATMENT OF DATA 1 



GENERAL OCEANOGRAPHY AS RELATED TO SOUND VELOCITY 

 STRUCTURES '^ 



Surface Water Masses 

 Subsurface Water Masses 

 Intermediate Water Masses 

 Deep Water Masses 



SOUND VELOCITY PERTURBATIONS 7 



DEEP SOUND CHANNEL ^^ 



DEEP SOUND VELOCITY PROFILES ^^ 



SEASONAL CRITICAL DEPTHS 21 



SUMMARY 2^ 



CONCLUSIONS 2^ 



APPENDICES 



A. SELECTED SOUND VELOCITY CROSS-SECTIONS 31 



B. SELECTED SOUND VELOCITY AND T-S PROFILES ^9 



T-S Relations in the North Indian Ocean 

 General Comments 

 Treatment of Data 



C. GENERAL FLOW AT THE SURFACE AND AT SUBSURFACE AND 

 INTERMEDIATE DEPTHS ^^ 



REFERENCES ^^ 



V 



