Residual Overturning Circulation and Its Connection to Southern Ocean Dynamics

Residual Overturning Circulation and Its Connection to Southern Ocean Dynamics PDF Author: Madeleine Kendall Youngs
Publisher:
ISBN:
Category :
Languages : en
Pages : 145

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Book Description
Over the last 20 years, our understanding of the meridional overturning circulation has improved, but primarily in a two-dimensional, zonally-averaged framework. In this thesis, I have pushed beyond this simplification and shown that the additional complexity of meanders, storm tracks, and other zonal asymmetries is necessary to reproduce the lowest-order behavior of the overturning circulation. First I examined the role of basin width for determining whether the Atlantic or Pacific oceans experience deep convection. I used a two layered model and a rectangular single-basin model to show that the basin width, in combination with scalings for the overturning circulation make the overturning relatively weaker in the wider basin, priming it for a convection shut down. In addition to this large-scale work, I have examined Southern Ocean-like meanders using a hierarchy of idealized models to understand the role of bottom topography in determining how the large-scale circulation responds to climate change scenarios. These are useful because they preserve the lowest-order behavior, while remaining simple enough to understand. I tested the response of the stratification and transport in the Southern Ocean to changes in wind using a highly-idealized two-layer quasi-geostrophic model. In addition to showing that meanders are necessary to reproduce the behavior of the Southern Ocean, I found that strong winds concentrate the baroclinic and barotropic instabilities downstream of the bottom topography and weaken the instabilities elsewhere due to a form-drag process. With weak winds, however, the system is essentially symmetric in longitude, like a flat-bottomed ocean. This result is consistent with observations of elevated turbulence down-stream of major topography in the Southern Ocean. My next study investigated a more realistic Southern Ocean-like channel, with and without bottom topography, and examined the three-dimensional circulation in order to understand where vertical transport occurs and develop a picture of the pathways taken by each individual water parcel. I found that the vertical transport happens in very isolated locations, just downstream of topography. Finally, I added a biogeochemical model to my simulations and found that carbon fluxes are enhanced near topography, again highlighting the role of zonal asymmetries.

Residual Overturning Circulation and Its Connection to Southern Ocean Dynamics

Residual Overturning Circulation and Its Connection to Southern Ocean Dynamics PDF Author: Madeleine Kendall Youngs
Publisher:
ISBN:
Category :
Languages : en
Pages : 145

Get Book Here

Book Description
Over the last 20 years, our understanding of the meridional overturning circulation has improved, but primarily in a two-dimensional, zonally-averaged framework. In this thesis, I have pushed beyond this simplification and shown that the additional complexity of meanders, storm tracks, and other zonal asymmetries is necessary to reproduce the lowest-order behavior of the overturning circulation. First I examined the role of basin width for determining whether the Atlantic or Pacific oceans experience deep convection. I used a two layered model and a rectangular single-basin model to show that the basin width, in combination with scalings for the overturning circulation make the overturning relatively weaker in the wider basin, priming it for a convection shut down. In addition to this large-scale work, I have examined Southern Ocean-like meanders using a hierarchy of idealized models to understand the role of bottom topography in determining how the large-scale circulation responds to climate change scenarios. These are useful because they preserve the lowest-order behavior, while remaining simple enough to understand. I tested the response of the stratification and transport in the Southern Ocean to changes in wind using a highly-idealized two-layer quasi-geostrophic model. In addition to showing that meanders are necessary to reproduce the behavior of the Southern Ocean, I found that strong winds concentrate the baroclinic and barotropic instabilities downstream of the bottom topography and weaken the instabilities elsewhere due to a form-drag process. With weak winds, however, the system is essentially symmetric in longitude, like a flat-bottomed ocean. This result is consistent with observations of elevated turbulence down-stream of major topography in the Southern Ocean. My next study investigated a more realistic Southern Ocean-like channel, with and without bottom topography, and examined the three-dimensional circulation in order to understand where vertical transport occurs and develop a picture of the pathways taken by each individual water parcel. I found that the vertical transport happens in very isolated locations, just downstream of topography. Finally, I added a biogeochemical model to my simulations and found that carbon fluxes are enhanced near topography, again highlighting the role of zonal asymmetries.

Ocean Dynamics

Ocean Dynamics PDF Author: Dirk Olbers
Publisher: Springer Science & Business Media
ISBN: 364223450X
Category : Science
Languages : en
Pages : 717

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Book Description
Ocean Dynamics’ is a concise introduction to the fundamentals of fluid mechanics, non-equilibrium thermodynamics and the common approximations for geophysical fluid dynamics, presenting a comprehensive approach to large-scale ocean circulation theory. The book is written on the physical and mathematical level of graduate students in theoretical courses of physical oceanography, meteorology and environmental physics. An extensive bibliography and index, extensive side notes and recommendations for further reading, and a comparison with the specific atmospheric physics where applicable, makes this volume also a useful reading for researchers. Each of the four parts of the book – fundamental laws, common approximations, ocean waves, oceanic turbulence and eddies, and selected aspects of ocean dynamics – starts with elementary considerations, blending then classical topics with more advanced developments of fluid mechanics and theoretical oceanography. The last part covers the theory of the global wind-driven circulation in homogeneous and stratified regimes, the circulation and overturning in the Southern Ocean, and the global meridional overturning and thermohaline-driven circulation. Emphasis is placed on simple physical models rather than access to extensive numerical results, enabling students to understand and reproduce the complex theory mostly by analytical means. All equations and models are derived in detail and illustrated by numerous figures. The appendix provides short excursions into the mathematical background, such as vector analysis, statistics, and differential equations

Ocean Circulation Theory

Ocean Circulation Theory PDF Author: Joseph Pedlosky
Publisher: Springer Science & Business Media
ISBN: 366203204X
Category : Science
Languages : en
Pages : 463

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Book Description
An overview of the advances made in the last decade and a half in this field. Based on an advanced graduate level course, the book represents fundamental insights into the structure of the physical theory of the large-scale dynamics of the oceans. The author has maintained throughout a blend of analytical and numerical results so as to achieve as deep a physical understanding of the dynamics of the large-scale circulations as possible. The results of the theories are compared with observations and the success or inadequacies of the theories are highlighted. Topics of particular interest are: theory of the wind-driven circulation, the thermocline, the equatorial circulation and the abyssal circulation. Much of the material - previously scattered throughout the literature - has been collated here for the first time.

Fundamentals of Ocean Climate Models

Fundamentals of Ocean Climate Models PDF Author: Stephen Griffies
Publisher: Princeton University Press
ISBN: 0691187126
Category : Science
Languages : en
Pages : 553

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Book Description
This book sets forth the physical, mathematical, and numerical foundations of computer models used to understand and predict the global ocean climate system. Aimed at students and researchers of ocean and climate science who seek to understand the physical content of ocean model equations and numerical methods for their solution, it is largely general in formulation and employs modern mathematical techniques. It also highlights certain areas of cutting-edge research. Stephen Griffies presents material that spans a broad spectrum of issues critical for modern ocean climate models. Topics are organized into parts consisting of related chapters, with each part largely self-contained. Early chapters focus on the basic equations arising from classical mechanics and thermodynamics used to rationalize ocean fluid dynamics. These equations are then cast into a form appropriate for numerical models of finite grid resolution. Basic discretization methods are described for commonly used classes of ocean climate models. The book proceeds to focus on the parameterization of phenomena occurring at scales unresolved by the ocean model, which represents a large part of modern oceanographic research. The final part provides a tutorial on the tensor methods that are used throughout the book, in a general and elegant fashion, to formulate the equations.

Atmospheric and Oceanic Fluid Dynamics

Atmospheric and Oceanic Fluid Dynamics PDF Author: Geoffrey K. Vallis
Publisher: Cambridge University Press
ISBN: 1139459961
Category : Science
Languages : en
Pages : 772

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Book Description
Fluid dynamics is fundamental to our understanding of the atmosphere and oceans. Although many of the same principles of fluid dynamics apply to both the atmosphere and oceans, textbooks tend to concentrate on the atmosphere, the ocean, or the theory of geophysical fluid dynamics (GFD). This textbook provides a comprehensive unified treatment of atmospheric and oceanic fluid dynamics. The book introduces the fundamentals of geophysical fluid dynamics, including rotation and stratification, vorticity and potential vorticity, and scaling and approximations. It discusses baroclinic and barotropic instabilities, wave-mean flow interactions and turbulence, and the general circulation of the atmosphere and ocean. Student problems and exercises are included at the end of each chapter. Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-Scale Circulation will be an invaluable graduate textbook on advanced courses in GFD, meteorology, atmospheric science and oceanography, and an excellent review volume for researchers. Additional resources are available at www.cambridge.org/9780521849692.

Bottom Gravity Currents and Overflows in Deep Channels of the Atlantic Ocean

Bottom Gravity Currents and Overflows in Deep Channels of the Atlantic Ocean PDF Author: Eugene G. Morozov
Publisher:
ISBN: 9783030830755
Category :
Languages : en
Pages : 0

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Book Description
This book is dedicated to the analysis of bottom waters flows through underwater channels of the Atlantic Ocean. The study is based on recent observations of the authors, analysis of historical data, numerical modeling, and literature review. For example, studying both the measurements from the World Ocean Circulation experiment in the 1990s and recent measurements reveals the decadal variations of water properties in the ocean. Seawater is cooled at high latitudes, descends to the ocean bottom, and slowly flows to the tropical latitudes and further. This current is slow in the deep basins, but intensifies in the abyssal channels connecting the basins. The current overflows submarine topographic structures and sometimes forms deep cataracts when water descends over slopes by several hundred meters. The flow of Antarctic Bottom Water (AABW) is studied on the basis of CTD sections combined with Lowered Acoustic Doppler Profiling (LADCP) carried out annually, and long-term moored measurements of currents. This book is a collection of oceanographic data, interpretation, and analysis, which can be used by field oceanographers, specialists in numerical modeling, and students who specialize in oceanography. .

Ocean Mixing

Ocean Mixing PDF Author: Michael Meredith
Publisher: Elsevier
ISBN: 0128215135
Category : Science
Languages : en
Pages : 386

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Book Description
Ocean Mixing: Drivers, Mechanisms and Impacts presents a broad panorama of one of the most rapidly-developing areas of marine science. It highlights the state-of-the-art concerning knowledge of the causes of ocean mixing, and a perspective on the implications for ocean circulation, climate, biogeochemistry and the marine ecosystem. This edited volume places a particular emphasis on elucidating the key future questions relating to ocean mixing, and emerging ideas and activities to address them, including innovative technology developments and advances in methodology. Ocean Mixing is a key reference for those entering the field, and for those seeking a comprehensive overview of how the key current issues are being addressed and what the priorities for future research are. Each chapter is written by established leaders in ocean mixing research; the volume is thus suitable for those seeking specific detailed information on sub-topics, as well as those seeking a broad synopsis of current understanding. It provides useful ammunition for those pursuing funding for specific future research campaigns, by being an authoritative source concerning key scientific goals in the short, medium and long term. Additionally, the chapters contain bespoke and informative graphics that can be used in teaching and science communication to convey the complex concepts and phenomena in easily accessible ways. - Presents a coherent overview of the state-of-the-art research concerning ocean mixing - Provides an in-depth discussion of how ocean mixing impacts all scales of the planetary system - Includes elucidation of the grand challenges in ocean mixing, and how they might be addressed

Essentials of Atmospheric and Oceanic Dynamics

Essentials of Atmospheric and Oceanic Dynamics PDF Author: Geoffrey K. Vallis
Publisher: Cambridge University Press
ISBN: 1108586856
Category : Science
Languages : en
Pages : 368

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Book Description
This is a modern, introductory textbook on the dynamics of the atmosphere and ocean, with a healthy dose of geophysical fluid dynamics. It will be invaluable for intermediate to advanced undergraduate and graduate students in meteorology, oceanography, mathematics, and physics. It is unique in taking the reader from very basic concepts to the forefront of research. It also forms an excellent refresher for researchers in atmospheric science and oceanography. It differs from other books at this level in both style and content: as well as very basic material it includes some elementary introductions to more advanced topics. The advanced sections can easily be omitted for a more introductory course, as they are clearly marked in the text. Readers who wish to explore these topics in more detail can refer to this book's parent, Atmospheric and Oceanic Fluid Dynamics: Fundamentals and Large-Scale Circulation, now in its second edition.

Ocean Dynamics and the Carbon Cycle

Ocean Dynamics and the Carbon Cycle PDF Author: Richard G. Williams
Publisher: Cambridge University Press
ISBN: 1139496778
Category : Science
Languages : en
Pages : 433

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Book Description
This textbook for advanced undergraduate and graduate students presents a multidisciplinary approach to understanding ocean circulation and how it drives and controls marine biogeochemistry and biological productivity at a global scale. Background chapters on ocean physics, chemistry and biology provide students with the tools to examine the range of large-scale physical and dynamic phenomena that control the ocean carbon cycle and its interaction with the atmosphere. Throughout the text observational data is integrated with basic physical theory to address cutting-edge research questions in ocean biogeochemistry. Simple theoretical models, data plots and schematic illustrations summarise key results and connect the physical theory to real observations. Advanced mathematics is provided in boxes and appendices where it can be drawn on to assist with the worked examples and homework exercises available online. Further reading lists for each chapter and a comprehensive glossary provide students and instructors with a complete learning package.

Deep Convection and Deep Water Formation in the Oceans

Deep Convection and Deep Water Formation in the Oceans PDF Author: Simon Chu
Publisher: Elsevier
ISBN: 0080870953
Category : Science
Languages : en
Pages : 395

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Book Description
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.