Collaborative Research: Hydraulic Control and Mixing of the Deep Ocean Flow through the Samoan Passage

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项目编号	1658027
	Collaborative Research: Hydraulic Control and Mixing of the Deep Ocean Flow through the Samoan Passage
	Glenn Carter
主持机构	University of Hawaii
项目开始年	2017
	2017-03-15
项目结束日期	2020-02-29
资助机构	US-NSF
项目类别	Standard Grant
项目经费	194671(USD)
国家	美国
语种	英语
英文摘要	The large-scale circulation of the ocean also known as the Meridional Overturning Circulation (MOC) comprises a series of shallow and deep water currents that transport mass, heat, carbon, and nutrients around the globe. The Samoan Passage, which carries the majority of the transport in its deep northward branch, is an important element of the Pacific Ocean circulation system. Recent observations supported by a previously funded NSF project have identified a previously unknown split of the flow between a deeper eastern channel and multiple shallower, western pathways within the Samoan Passage complex. Additional changes such as a warming and weakening of the flow through the passage have also been observed over the past twenty years, which supports the need for long-term observations. This project will examine the dynamics of the flow through the Samoan Passage in detail using a combination of observations, theory and numerical models. Currently, there are no deep ocean monitoring system deployed in the Pacific MOC and this project has the potential to aid in the development of an observing system that can complement the one currently deployed in the Atlantic. Climate models predict a weakening of the global overturning circulation, which could be confirmed or refuted with these observing systems. The knowledge gained from the proposed work can likely be applied to similar deep passages and fracture zones around the world. Two early career scientists, summer undergraduates, a graduate student and a post-doctoral researcher will gain valuable training in modern methods used in oceanography through this project. Diverse outreach activities are planned to engage the public with the results and knowledge gained from this project through collaborations with a modern dance company, and the Birch Aquarium and a high school in San Diego. Extensive measurements collected under previous NSF funding, including a combination of moored time series and deep towed measurements will be used to study hydraulic effects on the flow in the Samoan Passage. Strong turbulent mixing was observed as the flow passes through and over various constrictions and sills, thereby substantially altering its water mass characteristics. The recent measurements indicate hydraulic criticality of the flow through the Samoan Passage, at least at one major sill. The three specific objectives of this project include: investigating the influence of hydraulic processes on mixing and friction at various sills, studying hydraulic criticality and implications for transport and partition of the flow through and around the Samoan Passage, and informing an efficient monitoring strategy for the flow through the Samoan Passage. As a result of this project, hydraulic theory will be improved and observationally validated, making it applicable to dense overflows in other passages and to the flow in the multitude of fracture zones that are believed to be important drivers for abyssal upwelling.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/70877
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Glenn Carter.Collaborative Research: Hydraulic Control and Mixing of the Deep Ocean Flow through the Samoan Passage.2017.