气候变化领域集成服务门户(CCPortal): Asymmetric Internal Tide Generation in the Presence of a Steady Flow

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DOI	10.1029/2020JC016503
	Asymmetric Internal Tide Generation in the Presence of a Steady Flow
	Dossmann Y.; Shakespeare C.; Stewart K.; Hogg A.M.
发表日期	2020
ISSN	21699275
卷号	125 期号:10
英文摘要	The generation of topographic internal waves (IWs) by the sum of an oscillatory and a steady flow is investigated experimentally and with a linear model. The two forcing flows represent the combination of a tidal constituent and a weaker quasi-steady flow interacting with an abyssal hill. The combined forcings cause a coupling between internal tides and lee waves that impacts their dynamics of IWs as well as the energy carried away. An asymmetry is observed in the structure of upstream and downstream IW beams due to a quasi-Doppler shift effect. This asymmetry is enhanced for the narrowest ridge on which a superbuoyancy (ω > N) downstream beam and an evanescent upstream beam are measured. Energy fluxes are measured and compared with the linear model, that has been extended to account for the coupling mechanism. The structure and amplitude of energy fluxes match well in most regimes, showing the relevance of the linear prediction for IW wave energy budgets, while the energy flux toward IW beams is limited by the generation of periodic vortices in a particular experiment. The upstream-bias energy flux—and consequently net horizontal momentum—described in Shakespeare (2020, https://doi.org/10.1175/JPO-D-19-0179.1) is measured in the experiments. The coupling mechanism plays an important role in the pathway to IW-induced mixing, that has previously been quantified independently for lee waves and internal tides. Hence, future parameterizations of IW processes ought to include the coupling mechanism to quantify its impact on the global distribution of mixing. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	energy fluxes; internal waves; light attenuation technique; linear model
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/186633
作者单位	LEMTA, UMR 7563, Université de Lorraine, CNRS, F-54500, Vandoeuvre-les-Nancy, France; Research School of Earth Sciences, The Australian National University, Canberra, ACT, Australia; ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
推荐引用方式 GB/T 7714	Dossmann Y.,Shakespeare C.,Stewart K.,et al. Asymmetric Internal Tide Generation in the Presence of a Steady Flow[J],2020,125(10).
APA	Dossmann Y.,Shakespeare C.,Stewart K.,&Hogg A.M..(2020).Asymmetric Internal Tide Generation in the Presence of a Steady Flow.Journal of Geophysical Research: Oceans,125(10).
MLA	Dossmann Y.,et al."Asymmetric Internal Tide Generation in the Presence of a Steady Flow".Journal of Geophysical Research: Oceans 125.10(2020).