Article
Environmental Sciences
Bing Yang, Po Hu, Yijun Hou
Summary: Based on analysis of in situ observations, remote sensing, and data, the characteristics of near-inertial waves induced by tropical storm Noul in the South China Sea were studied. It was found that the near-inertial waves were influenced by a southwestward moving anticyclonic eddy and had comparable spectral density with internal tides. The downward propagation of near-inertial energy was concentrated in smaller wavenumber bands and influenced by mesoscale eddies.
Article
Oceanography
Feilong Lin, Lijuan Zhu, Beifeng Zhou, Tao Ding, Weifang Jin, Chujin Liang
Summary: This study, based on observations, examines the characteristics of near-inertial waves (NIWs) near the seabed during the passage of tropical cyclones (TCs). The research reveals that TCs can significantly enhance the near-inertial kinetic energy (NIKE) near the seabed and result in the formation of elongated near-inertial current (NIC) ellipses. These features are attributed to the reflection of NIWs near the seabed and may lead to shear instability.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2022)
Article
Environmental Sciences
Ruhui Huang, Xiaohui Xie, Jianyu Hu, Zhenyu Sun
Summary: The study investigates the spatial-temporal variations of near-inertial waves (NIWs) in the northern South China Sea after Typhoon Haima using mooring observations. Different locations responded differently to the typhoon, with varying characteristics and frequencies of NIWs. The study suggests that the mean background flow plays an important role in redistributing the energy of the upper ocean imported from typhoons.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Engineering, Marine
Bing Yang, Po Hu, Yijun Hou
Summary: This study identified six episodes of near-inertial internal waves (NIWs) on the East China Sea (ECS) continental slope, showing characteristics such as subsurface amplification and varying frequencies. The NIWs exhibited both red-shifted and blue-shifted frequencies vertically, with e-folding times ranging from 4 to 11 days.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Marine
Anzhou Cao, Zheng Guo, Yunhe Pan, Jinbao Song, Hailun He, Peiliang Li
Summary: The study validated that the hybrid coordinate ocean model could reproduce typhoon-induced NIWs, and further investigated the NIWs induced by typhoon Megi in 2010 in the South China Sea. It was found that near-inertial kinetic energy induced by Megi was concentrated in the SCS Basin, with NIWs propagating vertically to 1000 m depth. The damping and modal content of Megi-induced NIWs varied depending on location, with longer e-folding times and enhanced higher modes observed in certain regions after the passage of the typhoon.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Oceanography
Tomoharu Senjyu, Hong-Ryeol Shin
Summary: Near-inertial internal waves were intermittently observed in the abyssal Yamato and Tsushima Basins of the Japan Sea, showing vertically coherent phase and intensification with depth. The observed flow characteristics suggest a superposition of downward-propagating NIWs excited by strong wind events and upward-propagating NIWs bouncing off the seabed, potentially promoting vertical mixing in the deep sea during significant NIW events.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Review
Oceanography
Xiaodong Huang, Siwei Huang, Wei Zhao, Zhiwei Zhang, Chun Zhou, Jiwei Tian
Summary: This study examines the temporal variability of internal solitary waves (ISWs) in the northern South China Sea (SCS) on hourly, intraseasonal, seasonal, and interannual timescales. The results show significant variations of ISWs over multiple timescales, influenced by tides and mesoscale processes.
PROGRESS IN OCEANOGRAPHY
(2022)
Article
Engineering, Marine
Huaqian Hou, Tengfei Xu, Bin Li, Bing Yang, Zexun Wei, Fei Yu
Summary: We report the direct and quantitative measurement of five significant near-inertial waves (NIWs) events observed in the northern South China Sea. The results show that these events lead to strong shearing and play an important role in deep water mixing. NIWs generated by typhoons are the most regular, while those formed spontaneously lack this feature. The strongest NIWs events were caused by a combination of shelf wave attenuation and monsoon. Additionally, a horizontally propagated NIWs event with relatively weak dispersion was also discovered.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Elizaveta Khimchenko, Alexander Ostrovskii, Alexey Klyuvitkin, Leonid Piterbarg
Summary: This observational study examines the seasonal variability of near-inertial internal waves (NIWs) in the central part of the Black Sea. The analysis reveals that the motions near the local inertial frequency f are predominantly anticyclonic and show a blue-shift of the peaks of NIWs to higher frequencies. The blue-shift is stronger in the summer, reaching up to 1.038f. It is found that the intensification of NIWs is minimal in the summer and reaches its maximum in the autumn-winter period.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Oceanography
Yonggui Ma, Dongxiao Wang, Yeqiang Shu, Ju Chen, Yunkai He, Qiang Xie
Summary: Moored current observations in the northwestern South China Sea captured two events of near-inertial waves induced by tropical cyclones, which propagated to the seafloor from the mixed layer base at different speeds related to the background vorticity. Bottom NIWs showed different frequency shifts when the observation site was located outside/inside an anticyclonic eddy, and had high vertical shear, potentially playing an important role in deep mixing in the abyssal ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Yunchao Yang, Xiaodong Huang, Wei Zhao, Chun Zhou, Zhiwei Zhang, Shoude Guan, Jiwei Tian
Summary: In the equatorial Indian Ocean, the influence of equatorial Kelvin waves on nonlinear internal waves (NLIWs) in the Andaman Sea has been found. Downwelling Kelvin waves can reduce the amplitude of NLIWs, while upwelling Kelvin waves can enhance the amplitude. These findings provide credible evidence that basin-scale waves can remotely modulate small-scale internal waves in marginal seas.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Oceanography
Xiaojiang Zhang, Xiaodong Huang, Yunchao Yang, Wei Zhao, Huizan Wang, Chunxin Yuan, Jiwei Tian
Summary: High-resolution mooring observations have revealed a cascade process from internal solitary waves (ISWs) to turbulent mixing through high-frequency internal waves near the maximum local buoyancy frequency (near -N waves) in the deep water of the northern South China Sea (SCS). Near -N waves, with a peak frequency of 20 cph, were observed riding on the parent ISW and extending to its rear face. These near -N waves occurred primarily around the thermocline and induced large isothermal displacements with an amplitude of 12 m. The energy of near -N waves accounted for 5% of the parent ISW energy, and their instability suggested rapid dissipation.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Engineering, Marine
Suyun Noh, SungHyun Nam
Summary: This study presents statistical analysis of the nonseasonal variability of near-inertial internal wave (NIW) kinetic energy 400 m below the surface mixed layer in the southwestern East Sea. The results show that negative relative vorticity and strong total strain significantly enhance NIW kinetic energy at 400 m. Additionally, certain years and decades exhibit significantly higher NIW kinetic energy compared to others. The nonseasonal variations in NIW kinetic energy below the surface mixed layer are influenced by NIW trapping and wave capture process.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Zhiling Ouyang, Ze Liu, Yunfei Sun, Bing Yang, Yijun Hou
Summary: Based on data collected in the East China Sea, this study investigated the characteristics of near-inertial waves induced by Typhoon Mitag in October 2019, finding that the near-inertial kinetic energy was concentrated above 290 m and subsurface-intensified. The analysis showed that the near-inertial waves played an important role in upper ocean mixing, despite the spectral density of semidiurnal internal tide peak overwhelming that of the NIWs.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Environmental Sciences
Zhipeng Zhang, Hongzhou Xu, Philip A. Vetter, Qiang Xie, Xiaohui Xie, Wei Song, Chuan Tian
Summary: This study investigated the vertical distribution and temporal variation of internal tides (ITs) and near-inertial waves (NIWs) near the Nansha area in the southeastern South China Sea using a mooring current dataset. Results showed that ITs were mainly dominated by O1, K1, and M2, with diurnal ITs being the most energetic components. Near-inertial waves were observed propagating upward in phase and downward in energy. During the northeast monsoon period, near-inertial energy had a large magnitude due to strong wind forcing.
FRONTIERS IN MARINE SCIENCE
(2021)