气候变化领域集成服务门户(CCPortal): Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal-Inertial Resonance: Numerical Experiments

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DOI	10.1029/2020JC016208
	Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal-Inertial Resonance: Numerical Experiments
	Fearon G.; Herbette S.; Veitch J.; Cambon G.; Lucas A.J.; Lemarié F.; Vichi M.
发表日期	2020
ISSN	21699275
卷号	125 期号:9
英文摘要	The land-sea breeze is resonant with the inertial response of the ocean at the critical latitude of 30°N/S. 1-D vertical numerical experiments were undertaken to study the key drivers of enhanced diapycnal mixing in coastal upwelling systems driven by diurnal-inertial resonance near the critical latitude. The effect of the land boundary was implicitly included in the model through the “Craig approximation” for first-order cross-shore surface elevation gradient response. The model indicates that for shallow water depths (<∼100 m), bottom shear stresses must be accounted for in the formulation of the “Craig approximation,” as they serve to enhance the cross-shore surface elevation gradient response, while reducing shear and mixing at the thermocline. The model was able to predict the observed temperature and current features during an upwelling/mixing event in 60 m water depth in St Helena Bay (∼32.5°S, southern Benguela), indicating that the locally forced response to the land-sea breeze is a key driver of diapycnal mixing over the event. Alignment of the subinertial Ekman transport with the surface inertial oscillation produces shear spikes at the diurnal-inertial frequency; however their impact on mixing is secondary when compared with the diurnal-inertial resonance phenomenon. The amplitude of the diurnal anticyclonic rotary component of the wind stress represents a good diagnostic for the prediction of diapycnal mixing due to diurnal-inertial resonance. The local enhancement of this quantity over St Helena Bay provides strong evidence for the importance of the land-sea breeze in contributing to primary production in this region through nutrient enrichment of the surface layer. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	coastal upwelling; diapycnal mixing; diurnal-inertial resonance; inertial oscillations; land-sea breeze; phytoplankton blooms
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/186679
作者单位	Department of Oceanography, University of Cape Town, Rondebosch, South Africa; Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM, Univ. Brest - CNRS - IRD - Ifremer, Brest, France; South African Environmental Observation Network, Egagasini Node, Cape Town, South Africa; Nansen-Tutu Centre, Marine Research Institute, Department of Oceanography, University of Cape Town, Rondebosch, South Africa; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Univ Grenoble Alpes, Inria, CNRS, Grenoble INP, LJK, Grenoble, France; Marine and Antarctic Research Centre for Innovation and Sustainability (MARIS), University of Cape Town, Rondebosch, South Africa
推荐引用方式 GB/T 7714	Fearon G.,Herbette S.,Veitch J.,et al. Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal-Inertial Resonance: Numerical Experiments[J],2020,125(9).
APA	Fearon G..,Herbette S..,Veitch J..,Cambon G..,Lucas A.J..,...&Vichi M..(2020).Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal-Inertial Resonance: Numerical Experiments.Journal of Geophysical Research: Oceans,125(9).
MLA	Fearon G.,et al."Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal-Inertial Resonance: Numerical Experiments".Journal of Geophysical Research: Oceans 125.9(2020).