The coupled air-sea boundary layers play an important role in the fluxes of momentum, mass, heat, and moisture between the ocean and the atmosphere and sea-spray is involved all these air-sea transfers. Indeed, while suspended in the air, even for a short time, water droplets have time to exchange significant amounts of heat, moisture, and momentum with the atmosphere. In fact, evidence suggests that a significant amount of the air-sea heat flux is carried by the sea-spray. However, there is still no consensus as to the range of wind speeds over which sea-spray effects cannot be neglected. Furthermore, because of their mass and surface area, the larger so-called spume droplets have the largest potential for exchanging momentum and heat with the air. Yet, these large droplets generally fall back shortly after being generated and remain within a wave height of the surface thereby evading traditional "fixed" measurement techniques. In addition, the detailed physics of their generation mechanism is not yet know, thereby preventing adequate modeling. The project is concerned with the source function and generation mechanism for these large droplets.
Better knowledge about the generation of large water droplets at the surface of the ocean, which may have the potential impact on the overall balance of the multiple transfers between the atmosphere and the ocean is needed. This might be especially significant in high wind speed regimes such as hurricanes. While this work deals with specific aspects of small-scale air-sea interaction, it has much broader impacts and societal benefit beyond the scientific community. The broader impact of this research will include an improved understanding of the coupling of the oceans and the atmosphere, which will lead to better coupled models of weather and climate. Our ability to predict seasonal fluctuations and secular climate change has an important impact multiple industries and markets, as well as national disaster and threat preparedness. Ultimately, good national and international environmental policy relies on a solid scientific basis for decision making, and the work will contribute to that effort. Results from this research will be disseminated in professional journal publications and conferences, and, where appropriate, more popular avenues of publication. For example, the PI participates in multiple outreach programs involving visits of the unique Air-Sea Interaction facility at the University of Delaware, Lab demonstrations, and teaching during a residential summer camp designed to provide a college-like experience to high school juniors and seniors.
