Author: Andrew P. MackPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 198
Book Description
High-frequency Internal Waves in the Upper Eastern Equatorial Pacific
Author: Andrew P. MackPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 198
Book Description
Observation of High Frequency Internal Waves in the Pacific Ocean
Author: Robert Libman ZalkanPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 158
Book Description
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).
Upper Ocean Internal Waves in the Central Equatorial Pacific
Author: Timothy John BoydPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 478
Book Description
Observation of High Frequency Internal Waves in the Pacific Ocean
Author: Robert Libman ZALKANPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 128
Book Description
Dynamics of Internal Gravity Waves in the Ocean
Author: Yu.Z. Miropol'skyPublisher: Springer Science & Business Media
ISBN: 9401713251
Category : Science
Languages : en
Pages : 413
Book Description
This monograph creates a systematic interpretation of the theoretical and the most actual experimental aspects of the internal wave dynamics in the ocean. Firstly, it draws attention to the important physical effects from an oceanographical point of view which are presented in mathematical descriptions. Secondly, the book serves as an introduction to the range of modern ideas and the methods in the study of wave processes in dispersive media. The book is meant for specialists in physics of the ocean, oceanography, geophysics, hydroacoustics.
Interpretation of Equatorial Current Meter Data as Internal Waves
Author: Martin Benno BlumenthalPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 860
Book Description
Garrett and Munk use linear dynamics to synthesize frequency-wavenumber energy spectra for internal waves (GM72, GM75, GM79). The GM internal wave models are horizontally isotropic, vertically symmetric, purely propagating, and universal in both time and space. This set of properties effectively eliminates all the interesting physics, since such models do not allow localized sources and sinks of energy. Thus an important step in understanding internal wave dynamics is to make measurements of deviations from the simple GM models. This thesis continues the search for deviations from the GM models. It has three advantages over earlier work: extensive data from an equatorial region, long time series (2 years), and relatively sophisticated linear internal wave models. Since the GM models are based on mid-latitude data, having data from an equatorial region which has a strong mean current system offers an opportunity to examine a region with a distinctly different basic state. The longer time series mean there is a larger statistical ensemble of realizations, making it possible to detect smaller internal wave signals. The internal wave models include several important extensions to the GM models: horizontal anisotropy and vertical asymmetry, resolution between standing modes and propagating waves, general vertical structure, and kinematic effects of mean shear flow. Also investigated are the effects of scattering on internal waves, effects that are especially strong on the equator because the buoyancy frequency variability is a factor of ten higher than at mid-latitudes. In the high frequency internal wave field considered (frequencies between .125 cph and .458 cph), several features are found that are not included in the GM models. Both the kinematic effects of a mean shear flow and the phase-locking that distinguishes standing modes from propagating waves are observed. There is a seasonal dependence in energy level of roughly 10% of the mean level. At times the wave field is zonally and vertically asymmetric, with resulting energy fluxes that are a small (4% to 10%) fraction of the maximum energy flux the internal wave field could support. The fluxes are, however, as big as many of the postulated sources of energy for the internal wave field.
A Satellite Study of Ocean Internal Waves
Author: Constance SawyerPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 84
Book Description
Observations of Internal Waves in the Upper Ocean
Author: Robert PinkelPublisher:
ISBN:
Category : Internal waves
Languages : en
Pages : 346
Book Description
Profiles of temperature versus depth in the top 440 m of the sea were taken repeatedly at three horizontal locations surrounding the Research Platform FLIP. The time fluctuation of the temperature profiles was used to determine isotherm displacement and slope variation in the region 60-400 m. Measurements were taken during three FLIP operations. Two were off the California coast, in November 1972 and June 1973. Horizontal and vertical coherence measurements indicate that the internal wavefield can be divided into two frequency regions. Above 2 cph the bandwidth of energetic horizontal and vertical wavenumbers is comparatively narrow. The isotherm displacement spectrum and slope spectrum have irregular slopes. A comparison of the two spectra indicate that first mode is strongly dominant. Below 2 cph, the bandwidth of energetic wavenumbers is broader, corresponding to many energetic modes.
Internal Gravity Waves in the Equatorial Pacific
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Mixing in the ocean surface layer is an important process in the transport of heat, momentum, and CO[sub 2] into the deep ocean, For example, the flux of heat into the cold, upwelling water in equatorial regions provides one of the major heat sources driving the ocean circulation. Direct measurements of the ocean mixed layer have provided good estimates of the bulk layer properties. However, estimates of the small-scale effects of intenial waves and related turbulence have remained ambiguous because of the difficulty in observing these processes. Until more detailed measurements become available, numerical models can provide a convenient and cost-effective way to analyze the details of the surface mixed layer. Modeling the surface layer of the equatorial Pacific Ocean is challenging because of the strong vertical current shear and density stratification common to the region. The primary zonal current is the eastward flowing Equatorial Undercurrent (EUC) centered at roughly 120 m depth, with a speed of about 1.5 ms[sup [minus]1] as shown in Figure 1. The EUC is forced by a zonal pressure gradient resulting from the westward directed surface wind stress. Above the EUC, the wind stress directly forces thee South Equatorial Current (SEC), which flows westward with a speed of about 0.5 ms[sup [minus]1]. The shear zone generated by these currents is marginally stable and exhibits a diurnal cycle of turbulence dependent on convection forced by surface cooling. In addition, surface convection forces internal gravity waves, which can transport momentum away from the surface current to deeper waters. In this report, we discuss recent modeling results for the equatorial Pacific showing the generation of convection, turbulence, and internal waves.
The Near-Surface Layer of the Ocean
Author: Alexander SolovievPublisher: Springer Science & Business Media
ISBN: 1402040539
Category : Science
Languages : en
Pages : 586
Book Description
Until the 1980s, a tacit agreement among many physical oceanographers was that nothing deserving attention could be found in the upper few meters of the ocean. The lack of adequete knowledge about the near-surface layer of the ocean was mainly due to the fact that the widely used oceanographic instruments (such as bathythermographs, CTDs, current meters, etc.) were practically useless in the upper few meters of the ocean. Interest in the ne- surface layer of the ocean rapidly increased along with the development of remote sensing techniques. The interpretation of ocean surface signals sensed from satellites demanded thorough knowledge of upper ocean processes and their connection to the ocean interior. Despite its accessibility to the investigator, the near-surface layer of the ocean is not a simple subject of experimental study. Random, sometimes huge, vertical motions of the ocean surface due to surface waves are a serious complication for collecting quality data close to the ocean surface. The supposedly minor problem of avoiding disturbances from ships’ wakes has frustrated several generations of oceanographers attempting to take reliable data from the upper few meters of the ocean. Important practical applications nevertheless demanded action, and as a result several pioneering works in the 1970s and 1980s laid the foundation for the new subject of oceanography – the near-surface layer of the ocean.