Deep Convection And Deep Water Formation In The Oceans

This book contains articles presenting current knowledge about the formation and renewal of deep waters in the ocean. These articles were presented at an international workshop at the Naval Postgraduate School in Monterey in March 1990. It is the first book entirely devoted to the topic of deep water formation in which articles have been both selected and reviewed, and it is also the first time authors have addressed both surface and deep mixed layers. Highlighted are: past and recent observations (description and analysis), concepts and models, and modern techniques for future research. Thanks to spectacular advances realised in computing sciences over the last twenty years this volume includes a number of sophisticated numerical models. Observational as well as theoretical studies are presented and a clear distinction is established between open-ocean deep convection and shelf processes, both leading to deep- and bottom-water formation. The main subject addressed is the physical mechanism by which the deep water in the ocean can be renewed. Ventilation occurs at the surface in areas called the gills, where water is mixed and oxygenated before sinking and spreading in the abyss of the deep ocean. This phenomenon is a very active area for both experimentalists and theoreticians because of its strong implications for the understanding of the world ocean circulation and Earth climate. This major theme sheds light on specific and complex processes happening in very restricted areas still controlling three quarters of the total volume of the ocean. All articles include illustrations and a bibliography. This book will be of particular interest to physical oceanographers, earth scientists, environmentalists and climatologists.

This book contains articles presenting current knowledge about the formation and renewal of deep waters in the ocean. These articles were presented at an international workshop at the Naval Postgraduate School in Monterey in March 1990. It is the first book entirely devoted to the topic of deep water formation in which articles have been both selected and reviewed, and it is also the first time authors have addressed both surface and deep mixed layers. Highlighted are: past and recent observations (description and analysis), concepts and models, and modern techniques for future research. Thanks to spectacular advances realised in computing sciences over the last twenty years this volume includes a number of sophisticated numerical models. Observational as well as theoretical studies are presented and a clear distinction is established between open-ocean deep convection and shelf processes, both leading to deep- and bottom-water formation. The main subject addressed is the physical mechanism by which the deep water in the ocean can be renewed. Ventilation occurs at the surface in areas called the gills , where water is mixed and oxygenated before sinking and spreading in the abyss of the deep ocean. This phenomenon is a very active area for both experimentalists and theoreticians because of its strong implications for the understanding of the world ocean circulation and Earth climate. This major theme sheds light on specific and complex processes happening in very restricted areas still controlling three quarters of the total volume of the ocean. All articles include illustrations and a bibliography. This book will be of particular interest to physical oceanographers, earth scientists, environmentalists and climatologists.

Formation of the deepest waters of the World Ocean occurs in limited regions of the global ocean, primarily in the northern North Atlantic where North Atlantic Deep Water (NADW) is formed, and at a number of sites around the continental margins of Antarctica where Antarctic Bottom Waters (AABW) are formed. The deepwater formation processes play a significant role in determining the large-scale physical and biogeochemical properties of the deep ocean. These limited regions provide a conduit from the surface into the vast volumes of water in the deep ocean. We report in this chapter on observed physical and biochemical changes in the deep ocean and discuss these in the context of deepwater formation. Intensive observation programs in the North Atlantic during the past decades have demonstrated that there have been significant changes in the volumes and properties of Upper and Lower NADW as well as AABW. Studies have found systematic warming of AABW during the past two decades along a number of its major flow pathways, as well as evidence for a reduction in overall volume of AABW in the global deep ocean. Lower NADW, on the other hand, has been undergoing systematic cooling for the past four decades, whereas Upper NADW (primarily Labrador Sea Water) has been exposed to large decadal variability, both in properties and formation rates. In total, the deepwaters of the World Ocean (beneath ca. 2000–3000m) have warmed during the past two decades. Changes in the deep ocean can have enormous influence on Earth’s climate. Warming of the deep ocean makes a significant contribution to global sea level rise. The capacity of the deep ocean to take up and store anthropogenic CO2 has and will have a major impact on the CO2 content of the atmosphere now and far into the future. Paleooceanographic studies have provided evidence that despite the century-long timescales associated with renewal of deepwater, rapid, major changes in deepwater formation and deep ocean circulation have occurred in the past, resulting in rapid changes in Earth’s climate. Continued monitoring and analysis are necessary to follow and understand the changes in the deep ocean—this is a very important component of Earth’s climate.

The NATO ASI held in the Geophysical Institute, University of Alaska Fairbanks, June 17-28, 1991 was, we believe, the first attempt to bring together geoscientists from all the disciplines related to the solar system where fluid flow is a fundamental phenomenon. The various aspects of flow discussed at the meeting ranged from the flow of ice in glaciers, through motion of the solar wind, to the effects of flow in the Earth's mantle as seen in surface phenomena. A major connecting theme is the role played by convection. For a previous attempt to review the various ways in which convection plays an important role in natural phenomena one must go back to an early comprehensive study by 1. Wasiutynski in "Astro physica Norvegica" vo1. 4, 1946. This work, little known now perhaps, was a pioneering study. In understanding the evolution of bodies of the solar system, from accretion to present-day processes, ranging from interplanetary plasma to fluid cores, the understanding of flow hydrodynamics is essentia1. From the large scale in planetary atmospheres to geological processes, such as those seen in magma chambers on the Earth, one is dealing with thermal or chemical convection. Count Rumford, the founder of the Royal Institution, studied thermal convection experimentally and realized its practical importance in domestic contexts.

" ... as soon as one has traversed the greater part of the wild sea, one comes upon such a huge quantity of ice that nowhere in the whole world has the like been known." "This ice is of a wonderful nature. It lies at times quite still, as one would expect, with openings or large fjords in it; but sometimes its movement is so strong and rapid as to equal that of a ship running before the wind, and it drifts against the wind as often as with it." Kongespeilet - 1250 A.D. ("The Mirror of Kings") Modern societies require increasing amounts influence on the water mass and on the resulting of scientific information about the environment total environment of the region; therefore, cer tain of its characteristics will necessarily be in whieh they live and work. For the seas this information must describe the air above the sea, included.

This book explores recent developments in theoretical research and data analysis of real-world complex systems, organized in three parts, namely Entropy, information, and complexity functions Multistability, oscillations, and rhythmic synchronization Diffusions, rotation, and convection in fluids The collection of works devoted to the memory of Professor Valentin Afraimovich provides a deep insight into the recent developments in complexity science by introducing new concepts, methods, and applications in nonlinear dynamical systems covering physical problems and mathematical modelling relevant to economics, genetics, engineering vibrations, as well as classic problems in physics, fluid and climate dynamics, and urban dynamics. The book facilitates a better understanding of the mechanisms and phenomena in nonlinear dynamics and develops the corresponding mathematical theory to apply nonlinear design to practical engineering. It can be read by mathematicians, physicists, complex systems scientists, IT specialists, civil engineers, data scientists, and urban planners.

One of the most crucial but still very poorly understood topics of oceanographic science is the role of ocean processes in contributing to the dynamics of climate and global change. This book presents a series of high level lectures on the major categories of ocean/atmosphere processes. Three of these major issues are the focus of the lectures: (1) air--sea interaction processes; (2) water mass formation, dispersion and mixing; (3) general circulation, with specific emphasis on the thermohaline component. Global examples in the world ocean are provided and discussed in the lectures. In parallel, the Mediterranean Sea is a laboratory basin in providing analogues of the above global processes relevant to climate dynamics. They include the Mediterranean thermohaline circulation with its own `conveyor belt'; intermediate and deep water mass formation and transformations, dispersion and mixing. No other book in the field provides a review of fundamental lectures on these processes, coupled with global examples and their Mediterranean analogues.