Download or read book Importance of Topography in Generation and Preparation of Internal Waves written by Helmuth Sandstrom and published by . This book was released on 1966 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Importance of Topography in Generation and Propogation of Internal Waves written by Helmuth Sandstrom and published by . This book was released on 1966 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Importance of Topography in Generation and Propagation of Internal Waves written by and published by . This book was released on 1966 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Asymmetrical Topography on the Generation of Internal Waves written by Michael Peter Angus and published by . This book was released on 2012 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Generation of Internal Waves Over Idealized 3 D Topography by Tidal Forcing written by James R. Munroe and published by . This book was released on 2003 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observation of High Frequency Internal Waves in the Pacific Ocean written by Robert Libman Zalkan and published by . This book was released on 1968 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of high frequency internal waves were made from 1 to 14 December 1966, in the deep sea off Baja, California. The fluctuations of the depth of an isotherm were measured with a three-element horizontal array attached to a stable platform. The waves are characterized as a broad band phenomenon with a continuous distribution in frequency. For short intervals of time, a narrow frequency band within the continuum is adequately described as a horizontally plane wave of a single vertical mode. Furthermore, this simplified structure is stationary over time spans of several days. High modes are present in the low frequency waves. Above 4 cycles per hour, however, the first mode predominates. The spectral shape is consistent with the shear limited equilibrium spectrum proposed by Phillips (1966). In addition, the predominance of the first mode at high frequencies further emphasizes the importance of shear instability in internal wave propagation. The horizontal properties of the wave field indicate well-defined directions of narrow-band propagation. These directions and the dispersive properties of the propagation have led to the identification of local topographic features in generating areas of internal waves. (Author).

Download or read book Internal Waves and Mean Flow in the Presence of Topography written by Keshav Jayakrishnan Raja and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal waves play an important role in many processes in oceans. The interaction be-tween internal waves and ocean topography has been an active field of research for long. Yetthere are many questions remaining on the topic. In this thesis, two main processes are ex-amined namely, the reflection of internal wave beams on a slope, and generation of lee wavesover a three-dimensional obstacle, using laboratory experiments and numerical simulations.The nonlinear reflection of an internal wave beam on a uniform slope is studied using two-dimensional inviscid theory and numerical simulations. The resonant triadic interactionsamong the incident, reflected and second harmonic wave beams are investigated developingon existing theory and verifying them with results for numerical simulations.In the case of reflection of three-dimensional internal wave beams, a strong mean horizon-tal flow is found to be induced by the wave beam, which perturbs the wave field and weakensthe second harmonics. The generation of this wave-induced mean flow is examined usingresults from experiments and three-dimensional numerical simulations. Furthermore, theeffects of background rotation on the wave induced mean flow are also studied using numer-ical simulations.The Antarctic Circumpolar Current is considered as one of the main sources of mixing inoceans. Laboratory modelling of the Antarctic Circumpolar Current was done in the Coriolisplatform at LEGI to study the topography induced drag on the current. The experiment andits results are also presented.

Download or read book Laboratory and Numerical Studies of Internal Wave Generation and Propagation in the Ocean written by Benjamin Thomas King and published by . This book was released on 2010 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal waves are generated in the ocean by oscillating tidal flow over bottom topography such as ridges, seamounts, and continental slopes. They are similar to the more familiar surface waves, but not being constrained to move on the surface, propagate throughout the bulk of the world oceans. Internal waves transmit energy over thousands of kilometers, ultimately breaking and releasing their energy into turbulence and mixing. Where these internal waves are generated, as well as where and how they break and cause mixing, has important effects on the general circulation of the ocean, which is in turn a major component in earth's climate. As a first step in a more thorough understanding of the evolution of internal waves in the ocean, it is important to characterize their generation. The two-dimensional generation problem has been studied for four decades, with ample experimental, numerical, and theoretical results. Most of this past work has also been done using linear, inviscid approximations. However, wave generation in the ocean is three-dimensional (3D), and in many locations, nonlinear and viscous effects can be significant. Recent advances in experimental and numerical techniques are only now making the fully nonlinear, 3D generation process accessible. We utilize these new techniques to perform both laboratory experiments and numerical simulations on internal wave generation in 3D. We find that a significant component of the internal wave field generated by tidal flow over 3D topography is radiated in the direction perpendicular to the tidal forcing direction. This could lead to substantial improvements of global internal wave generation models. In addition, we have developed a new method for statistical analysis of ocean data sets, and have found large regions in the deep ocean where internal waves may not propagate. This will also have important effects on the way researchers study the propagation of internal waves, which, when propagating downward, were previously thought to always reflect from the sea floor.

Download or read book Internal Wave Generation Over Rough Sloped Topography written by Lauren E. Eberly and published by . This book was released on 2012 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internal waves exist everywhere in stratified fluids - fluids whose density changes with depth. The two largest bodies of stratified fluid are the atmosphere and ocean. Internal waves are generated from a variety of mechanisms. One common mechanism is wind forcing over re- peated sinusoidal topography, like a series of hills. When modeling these waves, linear theory has been employed due to its ease and low computational cost. However, recent research has shown that non-linear effects, such as boundary layer separation, may have a dramatic impact on wave generation. This research has consisted of experimentation on sloped, sinusoidal hills. As of yet, no experimental research has been done to characterize internal wave generation when repeated sinusoidal hills lie on a sloped surface such as a continental slope or a foothill. In order to perform this experiment, a laboratory was built which employed the synthetic schlieren method of wave visualization. Measurements were taken to find wind speed, boundary layer thickness, and density perturbation. From these data, an analysis was performed on wave propagation angle, wave am- plitude, and pressure drag. The result of the analysis shows that when wind blows across a series of sloped sinusoidal hills, fluid becomes trapped in the troughs of the hills resulting in a lower apparent forcing amplitude. The generated waves contain less energy than linear predictions. Ad- ditionally, the sloped hills produce waves which propagate at an angle away from the viewer. A necessary correction, which shifts from the reference frame of the observer to the reference plane of the waves is described. When this correction is applied, it is shown that linear theory may only be applied for low Froude numbers. At high Froude numbers, the effect of the boundary layer is great enough that the wave characteristics deviate significantly from linear theory predictions. The analyzed data agrees well with previous studies which show a similar deviation from linear theory.

Download or read book Ocean Mixing written by Michael Meredith and published by Elsevier. This book was released on 2021-09-16 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Topographic and Rotation Effects on Gravity Wave Dynamics in the Atmosphere written by Triantaphyilos R. Akylas and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical models for the generation of gravity internal waves by flow over topography have been developed, in an effort to understand the role of orographically induced gravity waves in atmospheric turbulence production. For given background wind speed and distribution of buoyancy frequency, the location of the tropopause (the borderline between the troposphere and the stratosphere) is found to have a significant effect, consistent with observations of increased gravity-wave activity over New Mexico when the tropopause is 10-11 km above ground. Based on a finite-amplitude hydrostatic model that accounts for three dimensional effects, a theoretical explanation has been proposed for certain intense oblique gravity wave trains observed downstream of islands. Finally, the effects of periodic variations in the background buoyancy frequency have been studied, Under certain conditions, such fluctuations are found to cause trapping of mountain waves well below the tropopause while, in other instances, they result in unusually strong gravity-wave activity owing to a resonance phenomenon.

Download or read book Scattering of Internal Waves at Finite Topography written by Xianbing Liu and published by . This book was released on 1998 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Topographic and Rotation Effects on Gravity Wave Dynamics in the Atmosphere written by Triantaphyilos R. Akylas and published by . This book was released on 2001 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Internal Wave Generation in the Presence of Turning Depths written by Matthew C. Drake and published by . This book was released on 2012 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the ocean, internal gravity waves are generated by tidal flow over sea floor topography. An internal gravity wave is only able to freely propagate if the buoyancy frequency is greater than the driving frequency, where the buoyancy frequency is proportional to the square root of the density gradient. A turning depth is defined as a height below which the buoyancy frequency is less than the driving frequency. King et al. showed that turning depths for internal waves generated by lunar tidal flow exist in the ocean, at varying heights from the sea floor [11]. The present study is the first to examine the generation and propagation of internal waves by tidal flow over topography that lies below a turning depth. I use laboratory experiments and numerical simulations to examine the effect of these turning depths on energy flux of the internal waves generated by tidal flow over topography. I find excellent agreement between numerical and laboratory work, and I show that the internal wave energy is strongly damped by the presence of a turning depth above the topography. Further, this has strong implications for ocean energy budget calculations.

Download or read book Radiation and Dissipation of Internal Waves Generated by Geostrophic Motions Impinging on Small scale Topography written by Maxim Anatolevich Nikurashin and published by . This book was released on 2009 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations and inverse models suggest that small-scale turbulent mixing is enhanced in the Southern Ocean in regions above rough topography. The enhancement extends 1 km above the topography suggesting that mixing is supported by breaking of gravity waves radiated from the ocean bottom. In other regions, gravity wave radiation by bottom topography has been primarily associated with the barotropic tide. In this study, we explore the alternative hypothesis that the enhanced mixing in the Southern Ocean is sustained by internal waves generated by geostrophic motions flowing over bottom topography. Weakly-nonlinear theory is used to describe the internal wave generation and the feedback of the waves on the zonally averaged flow. A major finding is that the waves generated at the ocean bottom at finite inverse Froude numbers drive vigorous inertial oscillations. The wave radiation and dissipation at equilibrium is therefore the result of both geostrophic flow and inertial oscillations and differs substantially from the classical lee wave problem. The theoretical predictions are tested versus two-dimensional and three-dimensional high resolution numerical simulations with parameters representative of the Drake Passage region. Theory and fully nonlinear numerical simulations are used to estimate internal wave radiation from LADCP, CTD and topography data from two regions in the Southern Ocean: Drake Passage and the Southeast Pacific. The results show that radiation and dissipation of internal waves generated by geostrophic motions reproduce the magnitude and distribution of dissipation measured in the region.

Download or read book Internal Gravity Waves in the Shallow Seas written by Stanisław R. Massel and published by Springer. This book was released on 2015-07-07 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a comprehensive study of the internal ocean waves, which play a very important role in ocean physics providing mechanisms for ocean water mixing and circulation, as well as the transportation of gases, nutrients, and a very large number of marine organisms in the ocean body. In contrast to surface waves, the literature on internal waves is not so numerous, mainly due to the difficulties in experimental data collection and in the mathematical description of internal wave propagation. In this book, the basic mathematical principles, a physical description of the observed phenomena, and practical theoretical methods of determination of wave parameters as well as the original method of observation using moving sensors are presented. Special attention is paid to internal wave propagation over changing bottom topographies in shallow seas such as the Baltic Sea. The book is supplemented with an extended list of relevant and extended bibliographies, a subject index, and an author index.