Internal waves across the Pacific
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Non |
| Statut de publication | : | Publié |
| Année de publication | : | 2007 |
| Auteurs (6) | : | ALFORD Matthew,h MACKINNON J,a ZHAO Z,x PINKEL R KLYMAK Jody,m PEACOCK T |
| Revue scientifique | : | Geophysical Research Letters |
| Volume | : | 34 |
| Fascicule | : | 24 |
| Pages | : | |
| DOI | : | 10.1029/2007GL031566 |
| URL | : | - |
| Abstract | : | The long-range propagation of the semidiurnal internal tide northward from the Hawaiian ridge and its susceptibility to parametric subharmonic instability (PSI) at the "critical latitude,'' lambda(c) = 28.8 degrees N, were examined in spring 2006 with intensive shipboard and moored observations spanning 25-37 degrees N along a tidal beam. Velocity and shear at lambda(c) were dominated by intense vertically-standing, inertially-rotating bands of several hundred meters vertical wavelength. These occurred in bursts following spring tide, contrasting sharply with the downward-propagating, wind-generated features seen at other latitudes. These marginally-stable layers (which have inverse 16-meter Richardson number Ri(16)(-1) = 0.7) are interpreted as the inertial waves resulting from PSI of the internal tide. Elevated near-inertial energy and parameterized diapycnal diffusivity, and reduced asymmetry in upgoing/downgoing energy, were also observed at and equatorward of lambda(c). Yet, simultaneous moored measurements of semidiurnal energy flux and 1-km-deep velocity sections measured from the ship indicate that the internal tide propagates at least to 37 degrees N, with no detectable energy loss or phase discontinuity at lambda(c). Our observations indicate that PSI occurs in the ocean with sufficient intensity to substantially alter the inertial shear field at and equatorward of lambda(c), but that it does not appreciably disrupt the propagation of the tide at our location. |
| Mots-clés | : | ENERGY FLUXES; NORTH PACIFIC; OCEAN; PROPAGATION; TIDE; WATERS |
| Commentaire | : | Times Cited in Web of Science Core Collection: 101 |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Alford MH, MacKinnon JA, Zhao ZX, Pinkel R, Klymak JM, Peacock T (2007) Internal waves across the Pacific. Geophys Res Lett 34 | doi: 10.1029/2007GL031566
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