Measuring the turbulent kinetic energy (TKE) budget and momentum flux beneath breaking waves using an autonomous underwater vehicle

GSTDTAP

项目编号	1829952
	Measuring the turbulent kinetic energy (TKE) budget and momentum flux beneath breaking waves using an autonomous underwater vehicle
	Nicholas Nidzieko
主持机构	University of California-Santa Barbara
项目开始年	2018
	2018-10-01
项目结束日期	2021-09-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	674144(USD)
国家	美国
语种	英语
英文摘要	Surface gravity waves are fundamental to the exchange of momentum, energy, heat, and gases between the atmosphere and the ocean. This project will make detailed, comprehensive measurements of the turbulent stress beneath surface waves using an autonomous underwater vehicle. The data will be analyzed to quantify momentum and energy transfer, and are expected to inform how turbulence is parameterized and accounted for in numerical models. Advancing our understanding of the nature of turbulent exchange driven by surface gravity waves has important and immediate implications for coastal wind-driven circulation and heat exchange within the world's oceans. In coastal margins, where natural and built environments often interact, in situ-measurements of wind- and wave- driven mixing can inform research and management efforts in predicting the fate of pollutants, larvae, sediments, and nutrients. Additionally, this investigation enhances the measurement capabilities of a highly-capable autonomous underwater vehicle. Such enhancements to research infrastructure will enable lines of inquiry into other areas of interest, including internal wave breaking over continental shelves and enhanced mixing due to biophysical interactions of coral and submerged vegetation. Few studies have measured the turbulent kinetic energy and dissipation beneath breaking waves, because direct measurements of turbulent Reynolds stress and the full TKE budget in the oceanic surface boundary layer are hampered by constraints associated with typical observational platforms. While significant advances have been made using observations from stationary or floating platforms in combination with numerical simulations, we still lack the necessary data to understand the structure and transiency of wave-driven turbulence in the coastal ocean, where swell and a dynamic wind environment contribute to an ever-evolving sea state. Consequently, the inclusion of surface wave effects in turbulence closure schemes relies heavily on numerical modeling results rather than direct observations. This project will measure the turbulent Reynolds stress and terms in the turbulent kinetic energy budget of a wave-affected surface layer using an autonomous underwater vehicle equipped with microstructure probes and fast velocimeters. This will provide an unprecedented picture of how surface gravity waves structure turbulent mixing and hence momentum transfer beneath the water surface and how that turbulent structure changes in the presence of swell, variable wind forcing, and with the evolution of a wind sea. The novel AUV-based measurements conducted for this project will be transformative because these high-resolution observations are necessary to advance understanding of how to simultaneously parameterize both vortex straining and turbulent injections as mechanisms of momentum exchange across the air-sea interface, particularly in transient conditions. The results will inform future modeling efforts through analysis of momentum and energy transfer within the framework of second moment closure schemes and ultimately improve our ability to predict the fate and transport of nutrients, sediments, plankton, larvae, and pollutants in the coastal ocean. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/73557
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Nicholas Nidzieko.Measuring the turbulent kinetic energy (TKE) budget and momentum flux beneath breaking waves using an autonomous underwater vehicle.2018.