Ocean wave science

When looking at the ocean we see waves that have been generated by the wind. The random combination of waves in a particular location and time is called the sea state. This sea state plays many roles in the Earth System and in our measurement systems. These different roles reveal particular aspects and help quantify different properties of ocean waves. Because of this complementarity it is interesting to combine different points of view when studying wind-generated waves. Our wave research group builds on pre-existing expertise at Ifremer, and was started thanks to the support of a European Research Council (ERC) "Young Investigator Award". We combine 

- ocean remote sensing

- physical oceanography

- marine meteorology

-seismology

-coastal dynamics

Our team is particularly working on the use and interpretation of novel data sources (from satellites, stereo-video cameras, seismometers) and the improvement on numerical wave models. These same models are used for marine weather forecasting in most meteorological agencies (NOAA/NCEP, Meteo France, Environnement Canada, UK MetOffice, ECMWF ...). 

Seismology

Remote sensing

Measurements of ocean properties from space that use radar or other techniques are generally influenced by ocean waves. Remote sensing is also a way to measure wave properties. IOWAGA uses satellite data to provide a validation for the numerical model results, but also provides parameters, derived from these models, that can be used to correct for wave effects in measurements of sea surface salinity, winds, sea level ...

Wave observation and forecasting

Wave-current interactions

Wind-generated waves are sensitive to ocean currents that lead to refraction, changes in wave celerity, and possibly local amplification up to breaking. In turn waves can accelerate currents due to breaking and waves contribute to the drift of near-surface water and floating objets. These interactions have been used to measure currents. Ongoing work at LOPS goes along these ideas, helping to improve methods for measuring currents, and getting a better representation of current effects on waves and all their consequences. 

Coastal dynamics

Air sea fluxes

Infragravity waves

Infragravity waves are generated at the shoreline and radiate across ocean basins, and are characterized by periods typically in the range 30-300 s. The height of infragravity waves often dominates the wave height right at the shoreline, and they are very important for coastal inundation and sediment transport. Amplitudes in the open ocean are much weaker, from a few millimeters to a few centimeters, and a typical wavelength around 10 km. That can still be an issue for precise sea level measurements from satellite, for example with the SWOT mission.  These oscillations are also a source of seismic waves that are recorded everywhere on Earth, including some of the Earth "normal modes".  Our team at LOPS has been working on all these aspects, from the shore to the deep ocean and solid Earth to remote sensing.