Oceanic isopycnal slope spectra. Part I: Internal waves
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2007 |
| Auteurs (2) | : | KLYMAK Jody,m MOUM James |
| Revue scientifique | : | Journal of Physical Oceanography |
| Volume | : | 37 |
| Fascicule | : | 5 |
| Pages | : | 1215-1231 |
| DOI | : | 10.1175/JPO3073.1 |
| URL | : | - |
| Abstract | : | Horizontal tow measurements of internal waves are rare and have been largely supplanted in recent decades by vertical profile measurements. Here, estimates of isotherm displacements and turbulence dissipation rate from a towed vehicle deployed near Hawaii are presented. The displacement data are interpreted in terms of horizontal wavenumber spectra of isopycnal slope. The spectra span scales from 5 km to 0.1 m, encompassing both internal waves and turbulence. The turbulence subrange is identified using a standard turbulence fit, and the rest of the motions are deemed to be internal waves. The remaining subrange has a slightly red slope (phi similar to k (-1/2)(x)) and vertical coherences compatible with internal waves, in agreement with previous towed measurements. However, spectral amplitudes in the internal wave subrange exhibit surprisingly little variation despite a four-order-of-magnitude change in turbulence dissipation rate observed at the site. The shape and amplitude of the horizontal spectra are shown to be consistent with observations and models of vertical internal wave spectra that consist of two subranges: a "linear" subrange (phi similar to k(z)(0)) and a red "saturated" subrange (phi similar to k(z)(-1)). These two subranges are blurred in the transformation to horizontal spectra, yielding slopes close to those observed. The saturated subrange does not admit amplitude variations in the spectra yet is an important component of the measured horizontal spectra, explaining the poor correspondence with the dissipation rate. |
| Mots-clés | : | DISSIPATION; ENERGY; GRAVITY-WAVES; MICROSTRUCTURE; MIDDLE ATMOSPHERE; SATURATION; STRAIN; TIDES; TURBULENCE; VERTICAL SHEAR |
| Commentaire | : | Times Cited in Web of Science Core Collection: 27 |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Klymak JM, Moum J (2007) Oceanic isopycnal slope spectra. Part I: Internal waves. J Phys Oceanogr 37: 1215-1231 | doi: 10.1175/JPO3073.1
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