Abstract's details
On the assimilation of upgraded L2 SWOT-swath SWH in the wave model MFWAM
Event: 2025 SWOT Science Team Meeting
Session: Oceanography: Wind and Waves
Presentation type: Poster
The wave data from SWOT-swath have demonstrated significant benefit for sea state forecasting during extreme storm events. Recently, improvements concerning Level 2 (L2) processing of Significant Wave Heights (SWH) from SWOT-swath have been developed in the latest version called “PIC2”. The objective of this work is to assess the impact of the assimilation of SWH retrieved from SWOT Level 2 processing (PIC2) on the forecasting of wave parameters both globally and in regional coastal area such as IBI (Iberian-Biscay-Ireland).
Wave model runs using the MFWAM model in a global configuration have been conducted with and without the assimilation of SWOT wave data over the recent period from December 2024 to March 2025. The validation of these results was performed using independent altimeter SWH data, as well as drifting buoys of the MELODI type from EODYN deployed in the Indian Ocean.
Results indicate a substantial impact of SWOT-swath assimilation, with a significant reduction in bias and scatter index of SWH compared to altimeter data. Notably, the bias reduction is consistent across all ranges of SWH values.
This work also presents a combined data assimilation approach, integrating SWOT SWH with recent wave spectra derived from L3 wave data with wavelengths exceeding 500 meters, developed within the SWOT mission framework. Additional simulations incorporating combined assimilation of CFOSAT wave spectra has been also investigated, and the impact on integrated wave parameters forecasts will be analyzed.
Finally, we will evaluate the validation of these recent assimilation experiment using MELODI and OMB buoys wave data collected during the “One Ocean Expedition” summer school organized by ESA.
Wave model runs using the MFWAM model in a global configuration have been conducted with and without the assimilation of SWOT wave data over the recent period from December 2024 to March 2025. The validation of these results was performed using independent altimeter SWH data, as well as drifting buoys of the MELODI type from EODYN deployed in the Indian Ocean.
Results indicate a substantial impact of SWOT-swath assimilation, with a significant reduction in bias and scatter index of SWH compared to altimeter data. Notably, the bias reduction is consistent across all ranges of SWH values.
This work also presents a combined data assimilation approach, integrating SWOT SWH with recent wave spectra derived from L3 wave data with wavelengths exceeding 500 meters, developed within the SWOT mission framework. Additional simulations incorporating combined assimilation of CFOSAT wave spectra has been also investigated, and the impact on integrated wave parameters forecasts will be analyzed.
Finally, we will evaluate the validation of these recent assimilation experiment using MELODI and OMB buoys wave data collected during the “One Ocean Expedition” summer school organized by ESA.
Contribution: ST2025OS4-On_the_assimilation_of_upgraded_L2_SWOT-swath_SWH_in_the_wave_model_MFWAM.pdf (pdf, 3664 ko)
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