Experimental setup and first measurements of wind-wave interaction from the LéXPLORE platform on Lake Geneva

The interaction between wind and water waves is a complex process at the interface of two turbulent fluids. In this context, lakes provide conditions of intermediate complexity between the open ocean and wave tank experiments, allowing the investigation of fetch-limited wave responses under both directional and turbulent wind regimes, and in the absence of swells.

We developed an experimental setup installed on the LéXPLORE research platform on Lake Geneva (Switzerland) [1] to record the spatial and temporal variations of the water surface elevation using a pair of stereo cameras, as well as in situ wind profiles obtained with ultrasonic anemometers. To reconstruct the surface elevation and generate local directional spectra, we employ the optimised WASS algorithm [2], which has already proven effective during oceanic expeditions. The motion of the platform is tracked using an inertial measurement unit, which also helps refine wind-speed estimates. Moreover, the wave data are compared with in situ measurements acquired by buoys.

The LéXPLORE platform is ideally located for our study, as it simplifies the physical analysis and interpretation of the measurements. It lies far enough from the coast to ignore boundary effects, in deep water where bathymetry influences on wave propagation can be neglected, and at long fetch (for south-westerly winds) where wind forcing is maximised.

We will present the experimental setup and preliminary results on the reconstruction of directional spectra under different wind regimes during an experimental campaign in Spring 2026. 

[1] Wüest et al., WIREs Water 8, e1544 (2021)

[2] Bergamasco et al., Computers and Geosciences 107, 28 (2017)