A Large-scale Observational View of Internal Tide Intermittency on Continental Margins
Abstract
While barotropic tides are essentially deterministic, baroclinic tides are often intermittent, owing to the fact that their propagation speeds and efficiency of generation are sensitive to background currents and stratification. As a result, amplitudes and phases of the internal tide are modulated in time, which can lead to non-stationary patterns of constructive and destructive interference. Here we decompose moored current records from continental margins around the world into phase-coherent and phase-incoherent motions, the latter of which describes the intermittent nature of the tides. These analyses are used to illustrate how internal tides in different regions have apparently differing timescales of predictability. There are numerous implications, since cross-margin exchanges and vertical mixing may be strongly influenced by the strength and timing of the internal wave field.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMOS44C..05N
- Keywords:
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- 4500 OCEANOGRAPHY: PHYSICAL;
- 4524 OCEANOGRAPHY: PHYSICAL / Fine structure and microstructure;
- 4544 OCEANOGRAPHY: PHYSICAL / Internal and inertial waves;
- 4568 OCEANOGRAPHY: PHYSICAL / Turbulence;
- diffusion;
- and mixing processes