Collaborative Research: A Laboratory Experiment to Quantify the Impact of Whitecap Foam on Air-Sea Momentum Transfer

This project is motivated by the need to improve parameterization of air-to-sea momentum fluxes. This research is expected to result in an in-depth understanding of the impact whitecap foam has on momentum transfer at the air-sea interface. The impact of whitecap foam on air-sea momentum flux will be studied in the laboratory environment using the Air-Sea Interaction Saltwater Tank (ASIST) at the University of Miami.

The results will lead to improved parameterization of the momentum transfer at the air-sea interface which is important for ocean and climate modeling, hurricane forecasting, and modeling waves which effect coastal erosion and offshore energy.

This project will quantify the impact of whitecap foam on air-sea momentum transfer using the Air-Sea Interaction Saltwater Tank (ASIST) at the University of Miami. Foam will be generated by purging air through gas permeable tubing to imitate residual foam which lingers on the surface after a wave has broken. Wind will then be blown over the foam patch and turbulent momentum flux measured at two locations downwind for comparison to clean, foam-free water.

The experiment will be conducted using a range of wind speeds and foam areas. Both fresh water and natural sea water will be used and bubble size and stability will be adjusted by altering surfactant concentrations. The outcome of this research will be a quantification of the impact whitecap foam has on air-sea momentum transfer by altering the surface roughness over a variety of conditions.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.