The ocean evokes the most romantic images of nature. It is the eternally hostile element that has taken a heavy toll for every act of discovery, sometimes in human lives. No wonder there has always been a romantic aura about those who take to the sea, be they pirates, fishermen, sailors, the ocean itself, have or even oceanographers. Their exploits, and provided ample food for thought and poetic inspiration. Clearly, man kind owes much to the ocean for the progress of civilization. There is more to wresting the ocean's secrets from its depths than simply the excitement of struggling with the elements. It is the thrill of ideas, of discoveries made by scientific analysis of oceanic phenomena. There have been quite a few renowned oceanographers who have never set foot aboard ship. All they did was to use the general laws of fluid behavior and mathematical formulas as tools to study the ocean and to predict events. Amazing 'armchair' discoveries of currents and deep sea flows, subsequently confirmed by observations at sea, are fascinat ing. What a scientist feels when uncovering the true behavior of oceanic phenomena in abstract columns of numbers, in long and cumbersome, or sometimes intriguingly simple, mathematical relations, is exhilara tion. My objective has been to bring this delightful esthetic pleasure within everyone's reach - the outcome is this book. It was about twelve years ago when I first recognized the inherent harmony of the theory of currents. I was probably prompted by H.
Table of Contents1 Sea-air interaction.- 1.1 Interdependence of natural phenomena.- 1.2 Cycles in the ocean-atmosphere system.- 1.3 Heat engines in the atmosphere.- 1.4 Sources of instability in the ocean.- 2 How ocean currents are studied.- 2.1 Unity of ocean waters.- 2.2 The major ocean currents.- 2.3 General ocean circulation.- 2.4 Exploration of ocean currents and their use in practice.- 2.5 Current measurements.- 2.6 Mapping of ocean currents.- 2.7 Modeling oceanic phenomena.- 3 Causes of ocean currents.- 3.1 Evolution of the theories of currents.- 3.2 Horizontal pressure gradient.- 3.3 Coriolis force.- 3.4 Geostrophic balance.- 3.5 Climatic factors and currents.- 3.6 Turbulence, viscosity and mixing.- 3.7 Wind-driven currents.- 3.8 Baroclinic model.- 3.9 Depth of no-motion.- 4 Turbulence and rotation of waters in oceans and seas.- 4.1 Turbulence: methods and concepts.- 4.2 Turbulence and stratification.- 4.3 Locally isotropic turbulence.- 4.4 Sources of energy supplied to oceanic motions of different scales.- 4.5 Vorticity or curl page.- 4.6 Integral circulation and stream function.- 4.7 Sea gyres in the Northern Hemisphere.- 4.8 Topographic effects in integral circulation.- 5 Westward intensification of surface currents.- 5.1 Mysteries of the Gulf Stream.- 5.2 Why is the Gulf Stream in the west?.- 5.3 Vorticity theory of the Gulf Stream on the ?-plane.- 5.4 ‘Viscous’ Gulf Stream.- 5.5 Gulf Stream as an inertial flow.- 5.6 Why does the Gulf Stream leave the coast?.- 5.7 The nature of the Gulf Stream meanders and rings.- 5.8 Why are ‘gulf streams’ weak in the south? Ill.- 6 Countercurrents and eddies.- 6.1 Instabilities of ocean flows.- 6.2 Features of the equatorial zone of the oceans.- 6.3 The nature of equatorial countercurrents.- 6.4 Equatorial undercurrents.- 6.5 Another unknown countercurrent.- 6.6 Eddies in the subtropical Atlantic.- 7 Deep-ocean circulation.- 7.1 Effects of wind-driven circulation on ocean structure.- 7.2 Some approaches to studying deep-ocean circulation.- 7.3 Classic scheme of deep-ocean circulation.- 7.4 T-S relationships and water masses of the World Ocean.- 7.5 Dynamic theory of abyssal circulation.- 7.6 Sources of deep and bottom water in the World Ocean.- 7.7 Deep western boundary currents.- 7.8 Water exchange in the World Ocean.- 8 Currents and climate.- 8.1 Short-term cycles in the ocean-atmosphere system.- 8.2 The World Ocean and ice ages.- 8.3 The ocean and the problem of global power production.- 8.4 Currents and transformation of the Earth’s climate.- 8.5 Regional climate modifications.- References and bibliography.