Speaker: Yuliya Troitskaya, Institute of Applied Physics RAS, Nizhny Novgorod, Russia, and Nizhny Novgorod State University, Nizhny Novgorod, Russia
Date: Tuesday, February 18, 2014
Place: FL 2 - 1022
This talk presents our recent results of comprehensive study of air-sea interaction under severe wind conditions. An experimental campaign aimed at investigation of the mechanism of anomalously low aerodynamic roughness of sea surface under hurricanes recently observed in field and laboratory experiments was carried out in the high-speed wind wave flume of the Institute of Applied Physics RAS. The experiments included simultaneous measurements of air flow velocity by contact and remote methods and 3D wind wave spectra. The tendency to saturation of the surface drag was observed for wind speeds exceeding 25 m/s, accompanied by the saturation of wind-wave slopes. For interpretation of the experiment, a quasi-linear theory of wind-wave coupling was developed. Verification of the model by numerical (DNS) and physical laboratory experiments is described. In the last part of the talk application of the model in field conditions is described. Parameterization of the surface drag coefficient based on calculations within the quasi-linear model for the model wind-wave spectra is suggested.