Mesoscale/sub-mesoscale dynamics and SWOT

P.Y. Le Traon, P. Klein, B. Chapron, J. Isern (Ifremer), G. Dibarboure (CLS)

Altimeter wavenumber spectral slopes in the mesoscale band very closely follow a k-11/3 slope as predicted by surface quasi-geostrophic theory (SQG) (Le Traon et al;, 2008; Lapeyre and Klein, 2006; Klein et al., 2007)

SQG could thus be a much better dynamical framework than the QG turbulence theory to describe the ocean surface dynamics.

These results point out the important dynamical role of small scale structures. They also offer new perspectives for the analysis and interpretation of satellite data.

In particular, the joint use of SST, OC and altimetry should allow a much better description of the 3D ocean state (including vertical velocity) (Isern et al. , 2006)

Le Traon et al., JPO, 2008

Proposed investigations

Analysis of sampling capabilities of SWOT using very high resolution basin scale models (1 -2 km) (SSH, velocity and vorticity). Analysis of SWOT measurement errors (white/correlated noise, roll errors) and their impact on mission objectives. Use tools developed and tested for conventional multiple altimeter and WSOA studies (Le Traon et al. 2001, Le Traon and Dibarboure, 2002).

Science investigations on mesoscale/submesoscale dynamics. Use very high resolution model to characterize mesoscale/submesoscale signals and the potential contribution of SWOT.

Analyze the synergy of high resolution altimetry with SST, OC and SAR data in the framework of SQG dynamics. Use of SSH, SST and OC to reconstruct 3 D ocean circulation (incl. Vorticity and vertical velocity) (Isern et al., 2006, 2008). Impact for ocean forecasting.

These activities should be carried out in the framework of our Alti-Ka and Jason-2 (PI: B. Chapron) proposals