Internal wave

About: Internal wave is a research topic. Over the lifetime, 8311 publications have been published within this topic receiving 221331 citations. The topic is also known as: Internal_wave.

Ocean waves and oscillating systems : linear interactions including wave-energy extraction

Abstract: 1. Introduction 2. Mathematical description of oscillations 3. Interaction between oscillations and waves 4. Gravity waves on water 5. Wave-body interactions 6. Wave-energy absorption by oscillating bodies 7. Wave interactions with oscillating water columns Bibliography Index.

Gravitational radiation from first-order phase transitions.

Abstract: We consider the stochastic background of gravity waves produced by first-order cosmological phase transitions from two types of sources: colliding bubbles and hydrodynamic turbulence. First we discuss the fluid mechanics of relativistic spherical combustion. We then numerically collide many bubbles expanding at a velocity v and calculate the resulting spectrum of gravitational radiation in the linearized gravity approximation. Our results are expressed as simple functions of the mean bubble separation, the bubble expansion velocity, the latent heat, and the efficiency of converting latent heat to kinetic energy of the bubble walls. A first-order phase transition is also likely to excite a Kolmogoroff spectrum of turbulence. We estimate the gravity waves produced by such a spectrum of turbulence and find that the characteristic amplitude of the gravity waves produced is comparable to that from bubble collisions. Finally, we apply these results to the electroweak transition. Using the one-loop effective potential for the minimal electroweak model, the characteristic amplitude of the gravity waves produced is h≃1.5×10^-27 at a characteristic frequency of 4.1 × 10^-3 Hz corresponding to Ω∼10^-22 in gravity waves, far too small for detection. Gravity waves from more strongly first-order phase transitions, including the electroweak transition in nonminimal models, have better prospects for detection, though probably not by LIGO.

Scaling turbulent dissipation in the thermocline

Abstract: By comparing observations from six diverse sites in the mid-latitude thermocline, we find that, to within a factor of 2, 〈eIW〉=7×10‐10〈N2/N02〉〈S104/SGM4〉 W kg‐1, where 〈eIW〉 is the average dissipation rate attributable to internal waves; N0 = 0.0052 s−1 is a reference buoyancy frequency; S10 is the observed shear having vertical wavelengths greater than 10 m; and SGM is the corresponding shear in the Garrett and Munk spectrum of internal waves. The functional form agrees with estimates by McComas and Muller and by Henyey, Wright, and Flatte of the rate of energy transfer within the internal wave spectrum, provided the energy density of the internal waves is treated as a variable instead of one of the constant parameters. Following Garrett and Munk, we assume that 〈S104/SGM4〉=〈EIW2/EGM2〉, where EIW is the observed energy density and EGM is the energy density used by Garrett and Munk. The magnitude of eIW is twice that of Henyey et al. and one third that of McComas and Muller. Thus the observations agree with predictions sufficiently well to suggest that (1) a first-order understanding of the link between internal waves and turbulence has been achieved, although Henyey et al. made some ad hoc assumptions and Garrett and Munk's model does not match important features in the internal wave spectrum reported by Pinkel, and (2) the simplest way to obtain average dissipation rates over large space and time scales is to measure 〈N2/N02〉〈S104/SGM4〉. Even though the observations were taken at latitudes of 42°−11.5°, the variability in the Coriolis parameter ƒ was too limited for a conclusive test of the ƒ dependence also predicted for 〈eIW〉 by the wave-wave interaction models. An exception to the scaling occurs east of Barbados in the thermohaline staircase that is apparently formed and maintained by salt fingers. Although e in the staircase is very low compared with rates at mid-latitude sites, it is 8 times larger than predicted for e due only to internal waves.

Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data

Abstract: How and where the ocean tides dissipate their energy are long-standing questions that have consequences ranging from the history of the Moon to the mixing of the oceans. Historically, the principal sink of tidal energy has been thought to be bottom friction in shallow seas. There has long been suggestive evidence, however, that tidal dissipation also occurs in the open ocean through the scattering by ocean-bottom topography of surface tides into internal waves, but estimates of the magnitude of this possible sink have varied widely. Here we use satellite altimeter data from Topex/Poseidon to map empirically the tidal energy dissipation. We show that approximately 10(12) watts--that is, 1 TW, representing 25-30% of the total dissipation--occurs in the deep ocean, generally near areas of rough topography. Of the estimated 2 TW of mixing energy required to maintain the large-scale thermohaline circulation of the ocean, one-half could therefore be provided by the tides, with the other half coming from action on the surface of the ocean.

Internal solitons in the andaman sea.

Abstract: The solitary wave is a localized hydrodynamic phenomenon that can occur because of a balance between nonlinear cohesive and linear dispersive forces in a fluid. It has been shown theoretically, and observed experimentally, that some solitary waves have properties analogous to those of elementary particles, and the waves have therefore been named solitons. During a measurement program in the Andaman Sea near northern Sumatra, large-amplitude, long internal waves were observed with associated surface waves called tide rips. Using theoretical results from the physics of nonlinear waves, it is shown that the internal waves are solitons and their interactions with surface waves are described.