Combining altimetry, numerical modeling and in-situ observations for the observation and the understanding of fine scale coastal processes in the Bay of Biscay

Florence Toublanc (LEGOS/CNRS, France)


Nadia Ayoub (LEGOS/CNRS, France); Florence Birol (CTOH/LEGOS, France); Patrick Marsaleix (LA/CNRS, France); Nicolas Fuller (CTOH/LEGOS, 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

The aim of this work is to study mesoscale processes occurring in the Bay of Biscay, using coastal altimetry products (X-TRACK, CTOH) from the Jason missions, 3D numerical modeling (SYMPHONIE code) and a wide range of in-situ datasets (tide gauges, buoys, salinity and temperature databases, …).

The SYMPHONIE configuration is characterized by a variable horizontal resolution, from 3 km in the open sea to less than 800 m on the shelf, and less than 300 m in the Gironde estuary and the Pertuis Charentais. This approach allows the representation of different scales, without using nested grids.

The sea surface elevation signature and the geostrophic currents derived from along-track altimetry are compared and analyzed in complement to other data (SST satellite products, surface buoys, moorings) and numerical simulations. Preliminary model results show a good agreement between estimated and observed SST and SSS. Surface geostrophic currents associated with the slope currents and mesoscale eddies are also obtained numerically in the southern Bay of Biscay.

First, we analyze the SLA data close to the coast and the main corrections (tides, wet tropo, SSB). The seasonal and interannual variability of the slope currents and the shelf circulation is then more particularly investigated. Both modeling results and altimetric data are processed to produce monthly means of along-track geostrophic currents (by year and also for the longest period available). Ultimately, these products could be used by the community as diagnostic tools for their models. We investigate as well the impact of the MDT on the sea surface elevation and on the geostrophic currents.

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Florence Toublanc