New directional wave satellite observations : Towards improved wave forecasts and climate description in Southern Ocean

• Published in: Geophysical Research Letters
• Main Authors: Aouf, Lotfi, Hauser, Danièle, Bertrand, Chapron, Toffoli, A., Tourrain, C., Peureux, C.
• Other Authors: Centre national de recherches météorologiques (CNRM), Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), University of Melbourne, Centre National d'Études Spatiales Toulouse (CNES), Collecte Localisation Satellites (CLS), Centre National d'Études Spatiales Toulouse (CNES)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Pacific; Southern Ocean
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03008401; https://hal-insu.archives-ouvertes.fr/insu-03008401v3/document; https://hal-insu.archives-ouvertes.fr/insu-03008401v3/file/2020GL091187.pdf; https://doi.org/10.1029/2020GL091187

International audience In spite of continous improvements of ocean wave models in the last decades, results still show large in certain condition, in particular in strongly forced conditions, as encountered in the Southern Ocean, where strong westerly winds generate some of the fiercest waves on Earth in almost unlimited fetch conditions. The newly launched Chinese-French Oceanography Satellite (CFOSAT) provides directional spectra of ocean waves for both wind seas and swells. Compared to Synthetic Aperture Radar (SAR), it resolves shorter wavelengths, which dominates in non-fully developed wind waves. Here we demonstrate that the assimilation of the wave number components from CFOSAT spectra produce more accurate predictions of wave growth than assimilation of significant wave height alone and results in a notable reduction of model bias in the Southern Ocean, especially in the Pacific Ocean sector. In addition results also indicate a downward shift of the wave age consistent with theoretical wave growth curves.