Internal Tides signature in frequency-wavenumber SSH spectra

Marion Orsztynowicz (LEGOS, France)


Claire Dufau (CLS, France); Loren Carrere (CLS, France); Rosemary Morrow (LEGOS, France); Gérald Dibarboure (CLS, France); Pierre-Yves Le traon (Mercatror Océan, France)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: Tides, internal tides and high-frequency processes

Presentation type: Type Poster

Altimeter 1D (wavenumber) spectra computed from along-track Sea Level Anomalies (SLA) exhibit linear slope between large and small scales linked to the geostrophic turbulence and its energy cascades in the mesoscale band ( Le Traon et al. 2008 ). In some areas of the ocean, peaks of energy also appear at mesoscale (~120km) on these spectra, affecting sensitively the slope estimation.
In this paper, a 2D frequency-wavenumber spectral analysis permits to link this energy peak to the aliased time period of the M2 tidal wave. This energy-peak can be then reduced in the 1D wavenumber spectra deduced from 2D spectra. Maximum of peak reduction is obtained where internal tides are known to affect the Ocean (Shriver et al. 2014, Richman, 2012). Reduction of internal tides signal directly in along-track SLA is tested in this paper.
Marion Orsztynowicz