Laboratory observations of spray generation over fresh and salt water in very high winds (Invited Presentation)

To determine the effect that sea spray has on the bulk momentum transfer coefficient between the air and water in very high winds a series of comprehensive laboratory experiments were conducted in the Air-Sea Interaction Saltwater Facility (ASIST) at the University of Miami. The spray concentrations due to wind-wave interactions were measured in both fresh and saltwater in very high winds for sizes ranging from 5x10-3 µm to ~600 µm. The results show different size distributions in salt and fresh –water as expected. There was a distinct shift to larger spray droplets in salt water, this is in contrast to the much smaller bubble size distributions and larger overall concentrations of bubbles. Imaging of the air-sea interface during spray generation has revealed the intermittent presences of Kelvin-Helmholtz like instabilities, which may provide a mechanism for the enhanced spume generation.