Download or read book Measurements of Ocean Surface Turbulence and Wave Turbulence Interactions PREPRINT written by and published by . This book was released on 2008 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The uppermost layers of the ocean, along with the lower atmospheric boundary layer, play a crucial role in the air-sea fluxes of momentum, heat, and mass, thereby providing important boundary conditions for both the atmosphere and the oceans that control the evolution of weather and climate. In particular, the fluxes of heat and gas rely on exchange processes through the molecular layers, which are usually located within the viscous layer, which is in turn modulated by the waves and the turbulence at the free surface. The understanding of the multiple interactions between molecular layers, viscous layers, waves, and turbulence is therefore paramount to an adequate parameterization of these fluxes. In this paper, the authors present evidence of a clear coupling between the surface waves and the surface turbulence. When averaged over time scales longer than the wave period, this coupling yields a spatial relationship between surface temperature, divergence, and vorticity fields that is consistent with spatial patterns of Langmuir turbulence. The resulting surface velocity field is hyperbolic, suggesting that significant stretching takes place in the surface layers. On time scales for which the surface wave field is resolved, they show that the surface turbulence is modulated by the waves in a manner qualitatively consistent with rapid distortion theory.
Download or read book Advances in Coastal and Ocean Engineering written by M. Brocchini and published by World Scientific. This book was released on 2002 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a useful source of ideas and information for scientists whose work involves understanding and modelling turbulent flows with free surfaces. It has the following merits: (1) It provides a framework for developing the analysis of this field, which, although important, has received only limited study; (2) It recognizes the importance of the two-phase nature of strongly disturbed free surface flows, with both natural and technological applications; (3) It suggests possible lines of future research (especially experimental) to quantify the characteristics of flow regimes which are mainly known qualitatively at present.
Download or read book Turbulence in the Ocean written by Monin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four years have elapsed since the preparation of the original Russian version of this book. This is a long time when dealing with such actively expanding fields of oceanography as research into small-scale structures and the investigation of hydro physical processes. Over this period new quick-response devices have been developed and successfully used for measurements taken in various ocean areas. Improvements in high-frequency meters used to measure hydrophysical parameters has enabled workers to obtain more accurate absolute values of the fluctuations measured by such devices. In view of this scientific progress, some of the ideas presented in this book now require additional explanation. Great care should be used in dealing with the absolute fluctuation values of hydro physical fields, since the methods used for the determination of the accuracy of the high-frequency measuring devices have been imperfect in the past. Never theless, it would appear that the results of the investigations summarized in this book have not lost their importance, and that the established laws governing small-scale pro cesses in the ocean are of a sufficiently universal nature and, as such, have not been shattered with the qualitative and quantitative advances in devices used for measurements taken in oceans. The authors feel that their work is of interest to English-speaking readers. The appearance of the English translation of the book is, to a very large extent, due to the tremendous amount of editing work brilliantly done by Prof. H. Tennekes.
Download or read book Measurement of Near Sea Surface Turbulence and Possible Wave Influence written by and published by . This book was released on 1977 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements were made at three levels above the sea surface to observe possible wave influence on turbulence parameters. Two levels, at one and three meters above the sea surface were mounted on a small floating platform tethered to the bow of the R/V Acania. The third level, at 6.6 meters above the sea surface, was mounted on a boom on the bow of the ship. Measurements were made of mean wind, mean temperature, mean humidity, and of the fluctuating temperatures and velocities at all three levels. These data were interpreted on the basis of empirically derived expressions describing the temperature structure function parameter, (C sub T) squared, and the rate of dissipation of turbulent kinetic energy. For optical relevance, (C sub T) squared was related to the refractive index structure function parameter. Results show qualitatively that there is a substantial wave influence near the sea surface, and that the system and procedures used to obtain the data produce valid measurements for deriving the wave influence on turbulence and on optical transmission in the near sea surface layer adjacent to the waves.
Download or read book Turbulent Fluxes Through the Sea Surface Wave Dynamics and Prediction written by A. Favre and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: A primary aim of the NATO Science Committee since its estab lishment in 1958 has been to· further international scientific co operation among scientists from the member countries of the Alliance. Almost all fields of basic science have received sub stantial support for the purposes of enhancing exchange of inform ation, providing opportunities for advanced instruction and collaborative research. Up to 1977, more than 10,000 fellowships have been awarded to allow scientists to complete their scientific education in another country and more than 1,500 joint research projects involving scientists in at least two different countries per project have been financed by the Committee. In addition, more than 800 advanced study institutes have been held under NATO auspices which have allowed more than sixty thousand scientists to get together to hear leading scientists lecture on advanced research topics on the frontier of research of many disciplines and to discuss the most recent results of their research activi ties. The Science Committee also identifies specific areas as deserving special encouragement or preferential support for limited periods. A variety of mechanisms - research grants, study visits, conferences, etc. - is utilized to stimulate greater international activity. This effort is embodied in several individual programmes, each guided by a special programme panel of internationally eminent experts. Air-sea interaction is one of these programmes.
Download or read book Interaction of Strong Turbulence with Free Surfaces written by M. Brocchini and published by World Scientific Publishing Company Incorporated. This book was released on 2002-01-01 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: ...useful source of ideas and information for scientists whose work involves understanding and modelling turbulent flows with free surfaces
Download or read book Turbulence Fluxes written by and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under the sponsorship of this grant a pitot tube for turbulence and eddy-correlation flux measurements from vertical profilers in the ocean was developed. The development of the pitot tube led to the first critical assessment of mixing efficiencies in the ocean. These show a variability that may be due to the form of the initial instability, once again emphasizing the need to examine the physics of the instability process leading to the turbulence. The development also led to the introduction of new scalings for turbulent dissipation rate and eddy diffusivity based on the energy-containing scales of the turbulence -- this is significant in that it does not require resolution of dissipation scales and eases the measurement requirements. Measurements in mixed layers led to the discovery of the superadiabatic surface layer during convection. The analogy between the temperature structure of the convective boundary layers of ocean and atmosphere have been elucidated. Turbulence measurements near the surface led to the community's acknowledgement that turbulence beneath a free surface cannot be predicted by standard wall boundary layer scaling. A theory of wave-turbulence interactions was developed as an attempt to explain the physics of the conversion of wave energy to turbulence which leads to the observed enhanced turbulence in the wave zone. Measurements off northern California following local storms led to detailed observations of the decay of a near-inertial wave, from which we were able to quantify the energy loss to turbulence for the first time. Small scale conductivity measurements using a new sensor led to the first estimates of salinity variance dissipation rate. This required quantifying the role of the temperature salinity cross-spectrum to the conductivity spectrum, a factor not widely appreciated in our field.
Download or read book Small Scale Turbulence and Mixing in the Ocean written by J.C.J. Nihoul and published by Elsevier. This book was released on 1988-05-01 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the 19th International Liège Colloquium on Ocean Hydrodynamics, the programme of which focused on the relationships between small-scale mixing and large-scale features, transports and processes. The presentation of papers on various methods of parameterization of small-scale turbulent mixing for numerical ocean models was particularly encouraged and this resulted in more than a third of the papers presented at the Colloquium dealing in one way or another with the parameterization problems; many of these papers demonstrate the direct results of modelling. These proportions are well reflected in this volume of proceedings and thus emphasize once more the importance of small-scale turbulence research for such vital practical applications as ocean modelling and forecasting.
Download or read book Marine Turbulence written by J.C.J. Nihoul and published by Elsevier. This book was released on 1980-01-01 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine Turbulence
Download or read book Measurement of Near Sea Surface Turbulence and Possible Wave Influence written by James H. Corbin and published by . This book was released on 1977 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements were made at three levels above the sea surface to observe possible wave influence on turbulence parameters. Two levels, at one and three meters above the sea surface were mounted on a small floating platform tethered to the bow of the R/V Acania. The third level, at 6.6 meters above the sea surface, was mounted on a boom on the bow of the ship. Measurements were made of mean wind, mean temperature, mean humidity, and of the fluctuating temperatures and velocities at all three levels. These data were interpreted on the basis of empirically derived expressions describing the temperature structure function parameter, (C sub T) squared, and the rate of dissipation of turbulent kinetic energy. For optical relevance, (C sub T) squared was related to the refractive index structure function parameter. Results show qualitatively that there is a substantial wave influence near the sea surface, and that the system and procedures used to obtain the data produce valid measurements for deriving the wave influence on turbulence and on optical transmission in the near sea surface layer adjacent to the waves.
Download or read book Marine Turbulence written by Helmut Z. Baumert and published by Cambridge University Press. This book was released on 2005-04-04 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive overview of marine turbulence and mixing for students, scientists, engineers.
Download or read book Advances In Wave Turbulence written by Victor Shrira and published by World Scientific. This book was released on 2013-05-10 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave or weak turbulence is a branch of science concerned with the evolution of random wave fields of all kinds and on all scales, from waves in galaxies to capillary waves on water surface, from waves in nonlinear optics to quantum fluids. In spite of the enormous diversity of wave fields in nature, there is a common conceptual and mathematical core which allows to describe the processes of random wave interactions within the same conceptual paradigm, and in the same language. The development of this core and its links with the applications is the essence of wave turbulence science (WT) which is an established integral part of nonlinear science.The book comprising seven reviews aims at discussing new challenges in WT and perspectives of its development. A special emphasis is made upon the links between the theory and experiment. Each of the reviews is devoted to a particular field of application (there is no overlap), or a novel approach or idea. The reviews cover a variety of applications of WT, including water waves, optical fibers, WT experiments on a metal plate and observations of astrophysical WT.
Download or read book A Study of Turbulence and Fine Scale Temperature Variability of the Ocean Thermal Boundary Layer Under Breaking Surface Waves written by Johannes Richard Gemmrich and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Although turbulence near the ocean surface is of great significance to the air-sea exchange of heat, gas and momentum it is a poorly understood phenomenon especially at high wind speeds when vertical transfer processes tend to be greatest. This work evaluates ocean surface turbulence at high sea states by exploiting heat as a naturally occurring passive tracer. To this end, a freely drifting instrument with a mechanically driven temperature profiler, fixed depth thermistors and conductivity cells was used to monitor the fine scale temperature structure and breaking wave activity. These open ocean measurements form the basis for a comprehensive account of the near surface turbulence field. Temperature profiles reveal a rich fine structure which, when combined with independent air-sea heat flux measurements reveal the presence of a surface layer of wave enhanced turbulence, modulated by subsurface advection associated with Langmuir circulation. The concept of wave enhanced turbulence, previously based on observations in fetch limited environments, is here extended to open ocean storm conditions. Generation of turbulence depends on the scale and frequency of breaking events. Our observations, which span a wide range of conditions from a coastal strait to the open ocean, show that wind speed or wave age are inadequate predictors of the occurrence frequency of wave breaking, motivating a scaling based on energy input. The decay of turbulence following wave breaking proceeds more rapidly than for isotropic turbulence, permitting generation of a thermal boundary layer a few centimetres thick, which accounts for brief temperature fluctuations observed beneath breaking waves. Advection due to Langmuir circulation also leaves its signature on the near surface temperature field. Both advection and enhanced diffusion are reconciled in a two-dimensional model of the upper ocean boundary layer, providing a framework for studying Langmuir circulation and upper ocean turbulence in terms of the measured temperature structure. The depth integrated dissipation derived from a model analysis of the data closely matches the energy input into the wave field, identifying breaking waves as the major source of turbulent kinetic energy.
Download or read book The Interaction of Ocean Waves and Wind written by Peter Janssen and published by Cambridge University Press. This book was released on 2004-10-28 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was published in 2004. The Interaction of Ocean Waves and Wind describes in detail the two-way interaction between wind and ocean waves and shows how ocean waves affect weather forecasting on timescales of 5 to 90 days. Winds generate ocean waves, but at the same time airflow is modified due to the loss of energy and momentum to the waves; thus, momentum loss from the atmosphere to the ocean depends on the state of the waves. This volume discusses ocean wave evolution according to the energy balance equation. An extensive overview of nonlinear transfer is given, and as a by-product the role of four-wave interactions in the generation of extreme events, such as freak waves, is discussed. Effects on ocean circulation are described. Coupled ocean-wave, atmosphere modelling gives improved weather and wave forecasts. This volume will interest ocean wave modellers, physicists and applied mathematicians, and engineers interested in shipping and coastal protection.
Download or read book Surface Waves and Fluxes written by G.L. Geernaert and published by Springer. This book was released on 1990-07-31 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the Conference on Air-Sea Interaction in January 1986, it was suggested to me by David Larner of Reidel Press that it may be timely for an updated compendium of air-sea interaction theory to be organized, developed, and published. Many new results were emerging at the time, i.e., results from the MARSEN, MASEX, MILDEX, and TOWARD field projects (among others) were in the process of being reported and/or published. Further, a series of new experiments such as FASINEX and HEXOS were soon to be conducted in which new strides in our knowledge of air-sea fluxes would be made. During the year following the discussions with David Larner, it became apparent that many of the advances in air-sea interaction theory during the 1970s and 1980s were associated with sponsor investments in satellite oceanography and, in particular, remote sensing research. Since ocean surface remote sensing, e.g., scatterometry and SAR, requires intimate knowledge of ocean surface dynamics, advances in remote sensing capabilities required coordinated research in air-sea fluxes, wave state, scattering theory, sensor design, and data exploitation using environmental models. Based on this interplay of disciplines, it was decided that this book be devoted to air sea interaction and remote sensing as multi-disciplinary activities.
Download or read book Physics of Wave Turbulence written by Sébastien Galtier and published by Cambridge University Press. This book was released on 2022-12-22 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: A century ago, Lewis Fry Richardson introduced the concept of energy cascades in turbulence. Since this conceptual breakthrough, turbulence has been studied in diverse systems and our knowledge has increased considerably through theoretical, numerical, experimental and observational advances. Eddy turbulence and wave turbulence are the two regimes we can find in nature. So far, most attention has been devoted to the former regime, eddy turbulence, which is often observed in water. However, physicists are often interested in systems for which wave turbulence is relevant. This textbook deals with wave turbulence and systems composed of a sea of weak waves interacting non-linearly. After a general introduction which includes a brief history of the field, the theory of wave turbulence is introduced rigorously for surface waves. The theory is then applied to examples in hydrodynamics, plasma physics, astrophysics and cosmology, giving the reader a modern and interdisciplinary view of the subject.
Download or read book Wave Turbulence written by Sergey Nazarenko and published by Springer. This book was released on 2011-08-17 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave Turbulence refers to the statistical theory of weakly nonlinear dispersive waves. There is a wide and growing spectrum of physical applications, ranging from sea waves, to plasma waves, to superfluid turbulence, to nonlinear optics and Bose-Einstein condensates. Beyond the fundamentals the book thus also covers new developments such as the interaction of random waves with coherent structures (vortices, solitons, wave breaks), inverse cascades leading to condensation and the transitions between weak and strong turbulence, turbulence intermittency as well as finite system size effects, such as “frozen” turbulence, discrete wave resonances and avalanche-type energy cascades. This book is an outgrow of several lectures courses held by the author and, as a result, written and structured rather as a graduate text than a monograph, with many exercises and solutions offered along the way. The present compact description primarily addresses students and non-specialist researchers wishing to enter and work in this field.
