Type of dataset: Level-2P Derived products from SWIM instrument of CFOSAT

Digital Object Identifiers (DOIs): 

•  Level-2P Derived products from SWIM instrument of CFOSAT : 10.24400/527896/a01-2024.005 - more metadata

Condition of access: Level-2P Derived products from SWIM instrument of CFOSAT is distributed by AVISO under standard AVISO+ license agreement.

Use: Ocean circulation, current component, wave current

Description: Products containing Stokes drift contributions and spectral shape parameters estimated from SWIM spectra and numerical modeling. 
The Stokes drift represents the Lagrangian mean current induced solely by surface waves. While its effect is strongest at the ocean surface, it can remain significant down to several tens of meters below the surface. 
The main novelty of v2.0 is the availability of a comprehensive set of wave spectral shape parameters designed to characterize both omnidirectional and directional (2D) wave spectra. These parameters are widely adopted by the wave modeling community to describe key aspects of sea-state dynamics and wave spectrum properties. In particular, they provide valuable indicators for assessing the likelihood of extreme wave events, including rogue waves through metrics such as the Benjamin–Feir Index, as well as the probability of hazardous conditions associated with crossing seas using parameters such as the Cross-Sea Index and Cross-Trough Correlation. 
Together, these new parameters offer enhanced capabilities for the analysis of sea-state variability, wave interactions, and extreme ocean conditions.

Geographic coverage: Global

Citation: Any use of this dataset must cite its DOI 10.24400/527896/a01-2024.005 as well as the following sentence: "This SWIM Level-2P Derived product was produced by CLS in the frame of the FRench Oceanographic Ground Segment (FROGS) of the CFOSAT Mission and distributed by AVISO+ with the support of CNES."

Resources: 

• User manual
• Averseng et al., 2025, Wave spectral shape parameters in L2PDER products
• Hauser et al., "New Observations From the SWIM Radar On-Board CFOSAT: Instrument Validation and Ocean Wave Measurement Assessment," in IEEE Transactions on Geoscience and Remote Sensing, vol. 59, no. 1, pp. 5-26, Jan. 2021, https://doi.org/10.1109/TGRS.2020.2994372.
• Breivik, Ø., P. A. E. M. Janssen, and J. Bidlot, 2014: Approximate Stokes Drift Profiles in Deep Water. J. Phys. Oceanogr., 44, 2433–2445, https://doi.org/10.1175/JPO-D-14-0020.1.
• Peureux, C., Benetazzo, A., and Ardhuin, F.: Note on the directional properties of meter-scale gravity waves, Ocean Sci., 14, 41–52, https://doi.org/10.5194/os-14-41-2018, 2018.
• Elfouhaily, T., B. Chapron, K. Katsaros, and D. Vandemark (1997), A unified directional spectrum for long and short wind-driven waves, J. Geophys. Res., 102(C7), 15781–15796, https://doi.org/10.1029/97JC00467.
• Pierson Jr., W. J., and L. Moskowitz (1964), A proposed spectral form for fully developed wind seas based on the similarity theory of S. A. Kitaigorodskii, J. Geophys. Res., 69(24), 5181–5190, https://doi.org/10.1029/JZ069i024p05181.
• Kenyon, K. E. (1969), Stokes drift for random gravity waves, J. Geophys. Res., 74(28), 6991–6994, https://doi.org/10.1029/JC074i028p06991.