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.
This project is a combined research program on the interaction between the wind and the surface of the ocean, and an educational/outreach program focused on marine science. The research part of this project was focused on the study of the airflow above small wind waves at the surface of the ocean. It is now well known that small scale surface waves at the surface of the ocean (from small ripples to waves that are a few feet in lengths), provide the roughness through which energy is transferred between the air and the water. Understanding the detail physics of these transfers allows us to make predictions on how winds and the ocean interact. This is important for example in storm predictions. A good example of this is the recent hurricane Sandy during which the waves that were generated caused significant damage to the shoreline and the coastal infrastructure. Not only were these waves generated by the winds inside the hurricane, but the waves also provide the roughness that slows down and weaken the winds inside a storm. Understanding how the transfers of energy between the wind and the waves happen is crucial to our ability to predict waves and wave damage. With enhance prediction ability, we can also improve our preparedness both with better infrastructure and with adequate public warming and evacuation procedures. The work performed in that project participated in that effort on a fundamental level. We performed laboratory experiments aimed at looking at the details of the turbulence in the air above the waves. How project specifically looked at how that turbulence interacts with the waves to transfer more or less energy from the wind to the waves, and vice versa. We discovered that airflow separation (a phenomena not well understood up to now) has significant effect on the overall air-sea energy balance. Our measurements provide a deeper understanding of the energy transfers between the wind and the waves. In addition, we found that the airflow separation may have important implications in the generation of sea spray which also is important in the formation of tropical storms. The educational component of this project involved the development of a residential summer camp aimed at providing an educational and research experience in oceanography for rising junior and senior high school students. The Summer TIDE Program is a 13-day instructional camp for high school students. This summer program focuses on the atmospheric, oceanic, and biogeochemical processes at work in the Delaware Bay. Camp academic activities include classroom instruction, discussions, lectures and visits to modern oceanographic/atmospheric laboratories, as well as field excursions to the Delaware Bay for sampling and exploration. The students gain an understanding of various subjects such as sea breeze, tides, waves, air-sea interactions and storms, habitat loss, species adaptation, salt-water marsh filtration, sediment transport, regional/local climate change, mitigation/adaptation opportunities, local impacts and strategies, and alternative energy. Curriculum and lectures developed for this camp were made available to high school students for use in the classroom.
