Collaborative Research: Internal Waves and Mixing on the Near-Critical Oregon Continental Slope

Oregon State University, Corvallis OR

Investigators

Abstract

ABSTRACT OCE-0350543 Breaking of shoaling internal waves is a likely cause for the enhanced mixing observed above continental slopes. The PI's will deploy moored profilers and use ship-based instruments to examine the internal wave climate and energy budget on the Oregon continental slope. Particular attention will be paid to the low-mode internal wave energy-flux impinging onto the slope from the deep ocean, its interaction with cross-isobath topography, and the relationship between cross-isobath energy-flux convergence and turbulent energy dissipation/mixing. This approach allows quantification of an energy budget between incoming and outgoing internal waves, and the turbulent sink. Based on the physical characteristics of the area and on earlier work on the Virginia continental slope, it is expected that the energetics will be dominated by incident low-mode internal tides being critically reflected to high wavenumbers, with consequent elevated losses to turbulence. Sampling will capture the impinging low-mode energy flux and the reflected/scattered low and high wavenumbers. The Turbulent dissipation and mixing will be measured from overturning scales and inferred from finescale parameterizations which showed skill on the Virginia continental slope and on the flanks of the Hawaiian Ridge. The results of this research will contribute to better understanding of the sinks for internal waves generated in the deep ocean and the role of elevated turbulence on the continental slope in abyssal mixing. Broader Impacts: Where and how mixing and turbulent dissipation takes place are long-standing and fundamental questions with far-reaching implications for large scale ocean circulation. The results of this research will contribute to better understanding of these areas. In addition this project will also integrate ocean waves into pre-college classrooms through existing programs at K-6 and high-school levels. At least one female graduate student will participate in the research cruise.