1. Air-sea momentum transfer in high wind conditions: laboratory experiments. Ivan Savelyev Sponsored by: Advisors: Brian Haus and Mark Donelan

2. Background Early theoretical works: Jeffreys, H., 1924 Miles, J. W., 1957 Airflow separation, sheltering hypothesis. Analytical solution for wind-wave generation. Experimental efforts: Snyder et al. 1981, Hsiao et al. 1983, Donelan 1999, Donelan et al. 2006, Laboratory and field observations of wave induced static pressure fluctuations.

3. Experiment Setup Air-Sea Interactions Salt-Water Tank at RSMAS, University of Miami. Dimensions: 15x1x1 meters, Maximum wind speed U=30 m/s, Fully programmable wave-maker with wave height up to H = 10 cm.

4. Wave-follower experimental setup.

5. Wave-follower in motion

6. Digital Laser Elevation Gauge (DLEG)

7. DLEG image of the air-sea interface at

10. Figure 2 from “On the limiting aerodynamic roughness of the ocean in very strong winds”, Donelan et al., 2004.

11. Summary and future work 1) The new high precision wave-follower system was developed and proofed to be successful. 2) First wave-follower based static pressure measurements show that wave growth function keeps growing quadratically as wind forcing enters hurricane-like conditions. 3) Both dimensional and non-dimensional approaches are necessary to resolve form drag contribution to a total drag in high-wind conditions. 4) In the future experiments will be studied as a function of wind speed, wind forcing and wave steepness.