On the assimilation of high frequency altimeters wave data in coastal wave model

Lotfi Aouf (Division Marine et Océanographie Météo-France, France)


Alice Dalphinet (Meteo-France, France); Sergei Badulin (Shirshov Institute of Oceanography, Russia)

Event: 2018 Ocean Surface Topography Science Team Meeting

Session: Application development for Operations

Presentation type: Type Poster

Waves in coastal zone are strongly affected by uncertainties related to bathymetry, surface currents and wind variability such as in the Mediterranean sea. It is then an important challenge to constrain coastal wave models with high frequency altimeters wave data. Improving the sampling of altimeters data from 7 to 1 km will increase the impact on wave forecasting near the coast.
Until now only 1-Hz wave data are already used in operational regional wave model of Meteo-France. This work aims to evaluate the impact of the assimilation of high frequency 40-Hz wave data provided by Saral/Altika in regional and coastal wave models. The operational wave model MFWAM for the french coasts with a grid size of 2.5 km is used in this study. The model is forced by high resolution winds provided by the AROME atmospheric model. Also boundary conditions are provided by the global wave model. An interpolation gridding technique is implemented in order to average 40 Hz SWH on regular grid of 1 km. Several assimilation tests have been performed with scaled data and adjustments on the correlation model for the assimilation have been optimized. The validation of the results is developed by using coastal wave buoys. A comparison with the assimilation of 1-Hz wave data is also examined.
The results shows that the impact of the assimilation is significant. We also discussed the persistency of the assimilation of high frequency data during the forecast period. Storm cases in the Mediterranean sea and in the channel have been investigated to evaluate the impact of the assimilation on the coastal waves submersion warning.
Further conclusions and comments will be added in the final paper.

Poster show times:

Room Start Date End Date
Foyer, Salao Nobre & tent Thu, Sep 27 2018,18:00 Thu, Sep 27 2018,20:00
Foyer, Salao Nobre & tent Fri, Sep 28 2018,14:00 Fri, Sep 28 2018,15:00
Lotfi Aouf
Division Marine et Océanographie Météo-France