气候变化领域集成服务门户(CCPortal): Rates and Mechanisms of Turbulent Mixing in a Coastal Embayment of the West Antarctic Peninsula

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DOI	10.1029/2020JC016861
	Rates and Mechanisms of Turbulent Mixing in a Coastal Embayment of the West Antarctic Peninsula
	Scott R.M.; Brearley J.A.; Naveira Garabato A.C.; Venables H.J.; Meredith M.P.
发表日期	2021
ISSN	21699275
卷号	126 期号:5
英文摘要	Quantifying and understanding the processes driving turbulent mixing around Antarctica are key to closing the Southern Ocean's heat budget, an essential component of the global climate system. In 2016, a glider deployed in Ryder Bay, West Antarctic Peninsula, collected hydrographic and microstructure data, obtaining some of the first direct measurements of turbulent kinetic energy dissipation off West Antarctica. Elevated dissipation O(10−8) W kg−1 is found above a topographic ridge separating the 520-m-deep bay, where values are O(10−10) W kg−1, from a deep fjord of the continental shelf, suggesting the ridge is important in driving upward mixing of warm Circumpolar Deep Water. The 12 glider transects reveal significant temporal variability in hydrographic and dissipation conditions. Mooring-based current and nearby meteorological data are used to attribute thermocline shoaling (deepening) to Ekman upwelling (downwelling) at Ryder Bay's southern boundary, driven by ∼3-day-long south-westward (north-westward) wind events. Anticyclonic winds generated near-inertial shear in the bay's upper layers, causing elevated bay-wide shear and dissipation ∼1.7 days later. High dissipation over the ridge appears to be controlled hydraulically, being co-located (and moving) with steeply sloping isopycnals. These are observed in ∼60% of the transects, with a corresponding mean upward heat flux of ∼2.4 W m−2. The ridge, therefore, provides sustained heat to the base of the thermocline, which can be released into overlying waters during the bay-wide, thermocline-focused dissipation events (mean heat flux of ∼1.3 W m−2). This highlights the role of ridges, which are widespread across the West Antarctic Peninsula, in the regional heat budget. © 2021. The Authors.
英文关键词	autonomous glider; heat fluxes; hydraulic control; near-inertial shear; topographic ridge; turbulent mixing
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186344
作者单位	British Antarctic Survey, Cambridge, United Kingdom; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton, United Kingdom
推荐引用方式 GB/T 7714	Scott R.M.,Brearley J.A.,Naveira Garabato A.C.,et al. Rates and Mechanisms of Turbulent Mixing in a Coastal Embayment of the West Antarctic Peninsula[J],2021,126(5).
APA	Scott R.M.,Brearley J.A.,Naveira Garabato A.C.,Venables H.J.,&Meredith M.P..(2021).Rates and Mechanisms of Turbulent Mixing in a Coastal Embayment of the West Antarctic Peninsula.Journal of Geophysical Research: Oceans,126(5).
MLA	Scott R.M.,et al."Rates and Mechanisms of Turbulent Mixing in a Coastal Embayment of the West Antarctic Peninsula".Journal of Geophysical Research: Oceans 126.5(2021).