A New Platform for the Determination of Air Sea Fluxes (OCARINA) Overview and First Results
The present paper describes a new type of floating platform that was specifically designed for estimating air sea fluxes, investigating turbulence characteristics in the atmospheric surface boundary layer, and studying wind wave interactions. With its design, it can be deployed in the open ocean or in shallow water areas. The system is designed to be used from a research vessel. It can operate for ~10 hours as a drifting wave rider and three hours under power. Turbulence and meteorological instrument packages are placed at a low altitude (1 1.5 m) It was deployed for validation purposes during the FROMVAR 2011 experiment off the west coast of Brittany (France) Wind friction velocity and surface turbulent buoyancy flux were estimated using eddy covariance, spectral, bulk and profile methods. The comparisons of the four methods show a reasonable agreement except for the spectral buoyancy flux. This suggests that the platform design is correct. Also the wind measured at a fixed height above the sea shows spectral coherence with wave heights, such that wind and swell are in phase, with largest wind values on top of swell crests. This result in qualitative agreement with current model predictions supports the capability of OCARINA to investigate wind swell interactions.