CoAuthors

Alice Dalphinet (Meteo France, France); Daniele Hauser (CNRS/LATMOS, France)

Directional wave observations from satellite play a key role to better forecasting sea state and correcting swell properties from open ocean to coastal areas. Recent improvements in SWIM wave data processing (IPF-6) have led to ensure a better wave spectra, particularly in ocean regions dominated by crossing seas. An upgraded reprocessing of level 2 SWIM wave data of CFOSAT has been performed since the beginning of the mission. This work aims to evaluate the assimilation of the new reprocessed SWIM spectral data into the MFWAM wave model. Several model simulations are implemented with the assimilation of directional spectra and wave heights provided by SWIM in a global configuration. The wave model is forced by IFS-ECMWF atmospheric forcing. Validation has been performed with independent wave data for 2021.
The results show that the impact of assimilating reprocessed directional spectra positively affects wave heights in ocean regions dominated by long swells and in the marginal ice zone. We also see an impact on the peak period in mid-latitudes and tropical ocean regions. We investigated the impact of reprocessed data on the dominant wave direction, particularly during cyclonic season. Validation with independent data shows a slight improvement in SWH estimation compared with the previous processing IPF-5. In this work, we used the assimilation of reprocessed SWIM directional spectra to calibrate the wave/ice interactions source term in the MFWAM model. Results on wave attenuation in a marginal ice zone such as the Weddell Sea show an improvement in the estimation of integrated sea-state parameters. Analysis is conducted to investigate the impact of the assimilation of reprocessed wave spectra on ocean circulation by using 1D ocean mixed layer model.
Further results will be discussed in the final presentation.