EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Wave-current Interactions in the Aghulas current: Impact on ship behavior

Clément Le Goff1, Alexey Mironov1, and Bertrand Chapron2
Clément Le Goff et al.
  • 1eOdyn, Plouzane, France (
  • 2LOPS, IFREMER, Plouzane, France (

Ocean waves Interacting with large scale ocean currents is a frequent cause of sea-state variability [Ardhuin et al 2017, Quilfen et al 2018, Quilfen and Chapron 2019]. Such situations can lead to sea-state hazards, crucial for shipping security. The Great Agulhas current system is an area of very intensive maritime traffic, where dangerous localized sea-state amplification by the current has quite regularly been reported. 

In absence of wind and wave-induced motions, the heading and drift of every ship along its trajectory can be estimated from the near-surface oceanic current map. This first guess can then be compared with real ship parameters obtained from satellite-collected ship Automatic Identification System (AIS) messages. During Southwestern storm-swell wave conditions, with wind and waves aligned against the current, some ships experience pronounced navigation difficulties, slowing down up to 2 m/s,  and frequently maneuvering to keep their heading perpendicular to dominant waves. Superposed multiple individual ship trajectories can then help map anomalous areas, and to relate them to localized strong wave-current effects such as large refraction of waves by the oceanic current.

[Ardhuin et al 2017] : Ardhuin, F., S. T. Gille, D. Menemenlis,C. B. Rocha, N. Rascle, B. Chapron, J. Gula, and J. Molemaker (2017), Small-scale open ocean
currents have large effects on wind wave heights, J. Geophys. Res. Oceans, 122, 4500–4517, doi:10.1002/2016JC012413.

[Quilfen et al 2018] :Quilfen Yves, Yurovskaya M., Chapron Bertrand, Ardhuin Fabrice (2018). Storm waves focusing and steepening in the Agulhas current: Satellite observations and modeling. Remote Sensing Of Environment, 216, 561-571. Publisher's official version :

[Quilfen and Chapron, 2019] : Quilfen, Y., & Chapron, B. (2019). Ocean surface wave-current signatures from satellite altimeter measurements.
Geophysical Research Letters, 46.


How to cite: Le Goff, C., Mironov, A., and Chapron, B.: Wave-current Interactions in the Aghulas current: Impact on ship behavior, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20307,, 2020