The impact of using the upgraded processing of ASAR-Level2 wave products in the assimilation system

International audience; The ASAR data provided by the upgraded level 2 wave mode have been used in the assimilation system developed at Meteo France. Two periods of last week of May and the month of July 2004 are considered for this study. The validation of upgraded level-2 wave mode with the WAM model showed the improvement of the wave parameters and their consistency. The assimilation runs have been performed with ASAR wave spectra from the new and old level-2 wave mode. Two cases of wavelength cutoff have been investigated in order to evaluate their impact on the results. Statistical analysis in comparison with altimeter Jason-1 and buoys data exhibits a positive impact for the upgraded level-2 wave mode in terms of root mean square error of significant wave height. Furthermore, the accepted ASAR wave spectra in the analysis process are well increased.