The Vertical Structure of Internal Lee-Wave-Driven Benthic Mixing Hotspots

doi:10.1175/JPO-D-22-0268.1

IOCAS-IR > 海洋环流与波动重点实验室

	The Vertical Structure of Internal Lee-Wave-Driven Benthic Mixing Hotspots
	He, Ying1,2,4 ; Hibiya, Toshiyuki 2,3,5
	2024
发表期刊	JOURNAL OF PHYSICAL OCEANOGRAPHY
ISSN	0022-3670
卷号	54 期号:1 页码:253-263
通讯作者	He, Ying(heying@cma.gov.cn) ; Hibiya, Toshiyuki(thib001@kaiyodai.ac.jp)
摘要	In global ocean circulation and climate models, bottom-enhanced turbulent mixing is often parameterized such that the vertical decay scale of the energy dissipation rate C is universally constant at 500 m. In this study, using a nonhydrostatic two-dimensional numerical model in the horizontal-vertical plane that incorporates a monochromatic sinu-soidal seafloor topography and the Garrett-Munk (GM) background internal wave field, we find that C of the internal lee-wave-driven bottom-enhanced mixing is actually variable depending on the magnitude of the steady flow U0, the hori-zontal wavenumber kH, and the height hT of the seafloor topography. When the steepness parameter (Sp = NhT/U0 where N is the buoyancy frequency near the seafloor) is less than 0.3, internal lee waves propagate upward from the seafloor while interacting with the GM internal wave field to create a turbulent mixing region with C that extends farther upward from the seafloor as U0 increases, but is nearly independent of kH. In contrast, when Sp exceeds 0.3, inertial oscillations (IOs) not far above the seafloor are enhanced by the intermittent supply of internal lee-wave energy Doppler-shifted to the near -inertial frequency, which occurs depending on the sign and magnitude of the background IO shear. The composite flow, consisting of the superposition of U0 and the IOs, interacts with the seafloor topography to efficiently generate internal lee waves during the period centered on the time of the composite flow maximum, but their upward propagation is inhibited by the increased IO shear, creating a turbulent mixing region of small C.
关键词	Diapycnal mixing Internal waves Numerical analysis/modeling Parameterization
DOI	10.1175/JPO-D-22-0268.1
收录类别	SCI
语种	英语
资助项目	Japanese Ministry of Education, Culture, Sports, Science and Technology[JP15H05824] ; University of Tokyo ; Fan Wang and Jianing Wang of the Institute of Oceanology at CAS ; China Scholarship Council
WOS研究方向	Oceanography
WOS类目	Oceanography
WOS记录号	WOS:001143925900004
出版者	AMER METEOROLOGICAL SOC
WOS关键词	ROUGH TOPOGRAPHY ; STRATIFIED FLOW ; TIME SCALES ; OCEAN ; TURBULENCE ; DISSIPATION ; AMPLITUDE
引用统计
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/184339
专题	海洋环流与波动重点实验室
通讯作者	He, Ying; Hibiya, Toshiyuki
作者单位	1.Chinese Acad Sci, Inst Oceanol, Ctr Ocean Mega Sci, Key Lab Ocean Circulat & Waves, Qingdao, Peoples R China 2.Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo, Japan 3.Univ Chinese Acad Sci, Beijing, Peoples R China 4.Prediction China Meteorol Adm, Ctr Earth Syst Modeling, Beijing, Peoples R China 5.Tokyo Univ Marine Sci & Technol, Tokyo, Japan
第一作者单位	中国科学院海洋研究所
通讯作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	He, Ying,Hibiya, Toshiyuki. The Vertical Structure of Internal Lee-Wave-Driven Benthic Mixing Hotspots[J]. JOURNAL OF PHYSICAL OCEANOGRAPHY,2024,54(1):253-263.
APA	He, Ying,&Hibiya, Toshiyuki.(2024).The Vertical Structure of Internal Lee-Wave-Driven Benthic Mixing Hotspots.JOURNAL OF PHYSICAL OCEANOGRAPHY,54(1),253-263.
MLA	He, Ying,et al."The Vertical Structure of Internal Lee-Wave-Driven Benthic Mixing Hotspots".JOURNAL OF PHYSICAL OCEANOGRAPHY 54.1(2024):253-263.