|
|
|
|
|
| Kudryavtsev, V; Hauser, D; Caudal, G; Chapron, Bertrand. |
| normalized radar cross section (NRCS) over the sea surface. However, these models are not able to correctly reproduce the NRCS in all configurations. In particular, even if they may provide consistent results for vertical transmit and receive (VV) polarization, they fail in horizontal transmit and receive (HH) polarization. In addition, there are still important discrepancies between model and observations of the radar modulation transfer function (MTF), which relates the modulations of the NRCS to the long waves. In this context, we have developed a physical model that takes into account not only the Bragg mechanism but also the non-Bragg scattering associated with radio wave scattering from breaking waves. The same model was built to explain both the... |
| Tipo: Text |
Palavras-chave: Radar cross section; Ocean surface; Surface gravity waves; Wave breaking; Modulation transfer function; Non Bragg scattering. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10183/9581.pdf |
| |
|
|
| Rascle, N; Ardhuin, Fabrice; Queffeulou, Pierre; Croize-fillon, Denis. |
| Ocean surface mixing and drift are influenced by the mixed layer depth, buoyancy fluxes and currents below the mixed layer. Drift and mixing are also functions of the surface Stokes drift U, volume Stokes transport T-s, a wave breaking height scale H-swg, and the flux of energy from waves to ocean turbulence Phi(oc). Here we describe a global database of these parameters, estimated from a well-validated numerical wave model, that uses traditional forms of the wave generation and dissipation parameterizations, and covers the years 2003-2007. Compared to previous studies, the present work has the advantage of being consistent with the known physical processes that regulate the wave field and the air-sea fluxes, and also consistent with a very large number of... |
| Tipo: Text |
Palavras-chave: Ocean mixing; Surface drift; Air sea fluxes; Surface gravity waves. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5903.pdf |
| |
|
|
| Suzuki, Nobuhiro. |
| The governing equations of a surface wave field and a coexisting roll–streak circulation typical of Langmuir circulations or submesoscale frontal circulations are derived to better describe their two-way interactions. The gradients and vertical velocities of the roll–streak circulation induce wave refraction, amplitude modulation and higher-order waves. These changes then produce wave–wave nonlinear forces and divergence of the wave-induced mass transport, both of which in turn affect the circulation. To accurately represent these processes, both a wave theory and a wave-averaged theory are developed without relying on any extrapolation, any spatiotemporal mapping or an approximation that treats the wave-induced mass divergence as being concentrated at the... |
| Tipo: Text |
Palavras-chave: General fluid mechanics; Wave-turbulence interactions; Surface gravity waves. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00589/70080/68060.pdf |
| |
|
|
| Nouguier, Frederic; Chapron, Bertrand; Guerin, Charles-antoine. |
| We revisit and supplement the description of gravity waves based on perturbation expansions in Lagrangian coordinates. A general analytical framework is developed to derive a second-order Lagrangian solution to the motion of arbitrary surface gravity wave fields in a compact and vectorial form. The result is shown to be consistent with the classical second-order Eulerian expansion by Longuet-Higgins (J. Fluid Mech., vol. 17, 1963, pp. 459-480) and is used to improve the original derivation by Pierson (1961 Models of random seas based on the Lagrangian equations of motion. Tech. Rep. New York University) for long-crested waves. As demonstrated, the Lagrangian perturbation expansion captures nonlinearities to a higher degree than does the corresponding... |
| Tipo: Text |
Palavras-chave: Surface gravity waves; Waves/free-surface flows. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00274/38476/37042.pdf |
| |
|
|
| Ardhuin, Fabrice; Herbers, T. H. C.. |
| Oceanic pressure measurements, even in very deep water, and atmospheric pressure or seismic records, from anywhere on Earth, contain noise with dominant periods between 3 and 10 s, which is believed to be excited by ocean surface gravity waves. Most of this noise is explained by a nonlinear wave-wave interaction mechanism, and takes the form of surface gravity waves, acoustic or seismic waves. Previous theoretical work on seismic noise focused on surface (Rayleigh) waves, and did not consider finite-depth effects on the generating wave kinematics. These finite-depth effects are introduced here, which requires the consideration of the direct wave-induced pressure at the ocean bottom, a contribution previously overlooked in the context of seismic noise. That... |
| Tipo: Text |
Palavras-chave: Acoustics; Geophysical and geological flows; Surface gravity waves. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00125/23580/21479.pdf |
| |
|
|
| Lindgren, Georg; Prevosto, Marc. |
| Water particle orbits are key elements in the Lagrange wave formulation. The stochastic Miche implementation of the Lagrange model is a linear Gaussian two-dimensional or three-dimensional space-time model which exhibits typical nonlinear wave characteristics when transformed to Eulerian coordinates. This paper investigates the statistical relation between the degree of front-back asymmetry of individual waves and the orbit orientation for the particle located at the wave maximum at the point of observation. It is shown that, in the Lagrangian model with statistical front-back symmetry, for individual waves there is a clear connexion between the degree of individual wave asymmetry and the orientation of the randomly deformed elliptic orbit: a steep front... |
| Tipo: Text |
Palavras-chave: Computational methods; Surface gravity waves; Ocean processes. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/76986/78255.pdf |
| |
|
|
|
