Variability of sub-mesoscale dynamics in the North Atlantic ocean from a 1/60° ocean model simulation.

Julien Le Sommer (CNRS, LGGE, France)


Jean-Marc Molines (CNRS, LGGE, France); Alexandre Jaymond (Univ. Grenoble Alpes, LGGE, France); Bernard Barnier (CNRS, LGGE, France); Thierry Penduff (CNRS, LGGE, France); Emmanuel Cosme (Univ. Grenoble Alpes, LGGE, France)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Science II: Mesoscale and sub-mesoscale ocean processes: current understanding and preparation for SWOT

Presentation type: Type Poster

Several physical processes contribute to energize oceanic flows at scales smaller than the first baroclinic Rossby radius (frontogenesis, mixed-layer instabilities, current-topography interactions...). But the relative strength of these processes and their impact on energy cascades at basin scale is still poorly unknown. Recent studies also suggest that sub-mesoscale dynamics may exhibit a distinctive seasonal cycle at mid-latitudes.
In this poster, we use several years of a sub-mesoscale-permitting, North Atlantic ocean/sea-ice model simulation performed at an unprecedented 1/60° resolution with 300 vertical levels. We describe the spatio-temporal variability of dynamical regimes at scales <100km at mid and high latitudes within the basin in terms of velocity wavenumber spectra and in terms of small scale variance of relative vorticity. Our results show in particular how the seasonal cycle of surface stratification in the subpolar gyre leads to a strong seasonal modulation of submesoscale activity at high latitudes. We will finally discuss how future wide-swath altimetric missions (SWOT) will sample these dynamical regimes.

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Julien Le Sommer