Fully nonlinear numerical simulations are performed to examine the behavior of large-amplitude internal gravity waves incident upon a level where the Doppler-shifted frequency of the waves is comparable to the background buoyancy frequency. Although linear theory predicts that the waves should reflect if the Doppler-shifted frequency is greater than the buoyancy frequency, it is found that nonl...

We study properties of solitary wave solutions of three evolution equations arising in the modeling of internal waves Our experiments indicate that broad classes of initial data resolve into solitary waves but also suggest that solitary waves do not interact exactly thus suggesting two of these equa tions are not integrable In the course of our numerical simulations interesting meta stable quas...

The generation of internal gravity waves by tidal flow over topography is an important oceanic process that redistributes tidal energy in the ocean. Internal waves reflect from boundaries, creating harmonics and mixing. We use laboratory experiments and two-dimensional numerical simulations of the Navier–Stokes equations to determine the value of the topographic slope that gives the most intens...

Stratified hydrostatic fluids have linear internal gravity waves with different phase speeds and vertical profiles. Here a simplified set of partial differential equations (PDE) is derived to represent the nonlinear dynamics of waves with different vertical profiles. The equations are derived by projecting the full nonlinear equations onto the vertical modes of two gravity waves, and the result...

My long-term goal is improving our understanding of interactions between sub-grid scale models and numerical errors, which affect simulation skill for physical and biological processes in estuaries and coastal ocean environments. For prognostic simulations, slow accumulation of truncation-level errors will progressively distort model results. Present sub-grid scale models selectively address ce...

This paper studies the internal wave band of temperature fluctuation spectra in the coastal zone of Pacific ocean. It is observed that on the central Mexican Pacific Shelf in the high-frequency band of temperature spectra the spectral exponent tends to ∼ω−1 at the time of spring tide and ω−2 at the time of neap tide. On the western shelf of the Japan/East Sea, in the ≪ω≪N∗ range, where N∗ is t...

The formation of internal waves from evanescent regions is studied experimentally with a Gaussian topography and varying natural frequency (N) profiles. When a topography is encompassed by an evanescent region, where N is less than the imposed excitation frequency, only evanescent waves are generated. The amplitude of these evanescent waves decay at an exponential rate while traveling verticall...

Oceanic internal waves are general known ubiquitous physical process in South China Sea (SCS). Many publications have investigated this process Based on in-situ measurements and/or remote sensing observations. However, seldom in-situ measurements lasted more than a month, even a week. Therefore, the consequent study can only demonstrate short-term case studies. There was no way to study the tem...

We study the diffusion-limited reaction A+A<-->A in various spatial dimensions to observe the effect of internal fluctuations on the interface between stable and unstable phases. We find that, similar to what has been observed in d = 1 dimensions, internal fluctuations modify the mean-field predictions for this process, which is given by Fisher's reaction-diffusion equation. In d>1 the front di...