CAREER: Airflow Separation Above Wind-Waves

University Of Delaware, Newark DE

Investigators

Abstract

This CAREER project is an integrated program of research and education that will improve our understanding of the effects airflow separation above the ocean surface waves on the air-sea flux of momentum, and expose minority high school students to geosciences fields. Intellectual Merit: The coupled air-sea boundary layers play an important role in the multiple fluxes between the ocean and the atmosphere. In particular the stress (drag) on the ocean?s surface is a crucial parameter for both short term forecasting and the modeling of long-term global climate trends. However, the effects of airflow separation are not well understood. For example, while hurricane track forecasts have significantly improved in the past few years, hurricane intensity forecasts are essentially unchanged since 1970. This is in part due to a lack of understanding of the complex physics involved in the air-sea fluxes of momentum when airflow separation is present. The proposed research program is concerned with the role of airflow separation in influencing the air-sea momentum flux. Specifically, the investigator will perform laboratory and possibly field experiments to examine the detailed structure of the separated airflow above the waves in order to determine what processes and factors (wavelength, slope, phase, asymmetry...) lead to airflow separation, and assess the impact of airflow separation on the air-sea momentum balance. After gaining critical physical insight in the controlled laboratory environment, the feasibility of making field measurements of the separated airflow structure by taking PIV velocity data above the waves along with thermographic measurements of surface velocity and breaking waves. A supporting eddy covariance flux package and altimetry systems will also be deployed. Broader Impact: 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 on fisheries, agriculture, the energy industry and commodity markets, the construction and insurance industries, and disaster/threat preparedness. Results from this research will be disseminated in professional journal publications and conferences, and, where appropriate, more popular avenues of publication. The educational component of this project has obvious broader impacts with direct exposure to Physical Sciences fields for promising minority high school students through the development of a curriculum to be taught by the PI in an established outreach program at the University of Delaware. The material will be further developed into high school teaching modules in Oceanography which will be distributed to local science teachers via a web based interface and the annual workshop currently held by the College of Marine and Earth Studies. Where appropriate, this will be integrated with ongoing research in the PI?s laboratory. . These activities will provide students with a better sense of science as a potential career choice as well as improve their general knowledge of the scientific fields. The project will also form the basis for the doctoral research of a graduate student and will provide material and provide facilities for undergraduate projects and undergraduate summer fellows in the laboratory. The investigator will continue his efforts to promote science and research to a broader audience (K-12 and public) through laboratory visits and informational scientific talks to the public, web broadcasting of public lectures, and special events.