Observing the short scale ocean variability in the Western Mediterranean Sea by using a coastal multi-satellite altimetry product and models
Jérôme Bouffard(1) , Laurent Roblou(1) , Yves Ménard(2) , Patrick Marsaleix(3) , and Pierre De Mey(1)
14 avenue Edouard Belin,
(2) CNES, 18 avenue Edouard Belin, 31400 Toulouse, France
(3) L.A., 14 avenue Edouard Belin, 31400 Toulouse, France
Thanks to the space and temporal resolution of satellite altimetry, the sea surface topography is commonly accessible for the deep ocean. However, the coastal oceanic dynamic is much more complex and is characterized by a wide range of spatial and temporal scales rending its observation difficult in the classical altimetric product.
A coastal, multi-satellite (Topex/Poseidon, Jason1, Envisat, GFO) altimetric dataset at a 10-20 htz sample rate is processed in the Western Mediterranean Sea. In addition to coastal-dedicated instrumental and environmental corrections, orbit errors have been minimized with a linear regression method. The high frequency reponse of the ocean to the tidal and atmospheric forcings has been corrected using a high resolution barotropic hydrodynamic simulation (Mog2D model).
In order to validate this multi-satellite altimetric data set, sea level anomalies time series are compared with tide gauges records and with a 3D circulation simulation (Symphonie model). The comparisons exhibit coherent patterns and differences in both temporal and spatial scales. In addition, the combined use of the improved altimetric data set and hydrodynamic modelling permits to produce noise level charts for the different altimetric missions.
This preparatory work emphasizes the potential of multi-satellite altimetry to observe meso-scale dynamics and contributes to the configuration toward assimilation of multi-satellite altimetric data in coastal hydrodynamical models.