Generation and evolution on symmetric ocean inner waves in unstable background flow

Zhao Yanling; Lu Xu; Huang Hong; Liu Saisai; Zhang Ming

doi:10.3969/j.issn.0253-4193.2020.11.002

Volume 42 Issue 11

Dec. 2020

Turn off MathJax

Article Contents

Article Navigation > Haiyang Xuebao > 2020 > 42(11): 12-22

Zhao Yanling，Lu Xu，Huang Hong, et al. Generation and evolution on symmetric ocean inner waves in unstable background flow[J]. Haiyang Xuebao，2020, 42(11)：12–22 doi: 10.3969/j.issn.0253-4193.2020.11.002

Citation:

PDF( 2618 KB)

Generation and evolution on symmetric ocean inner waves in unstable background flow

doi: 10.3969/j.issn.0253-4193.2020.11.002

1.
The PLA 31010 Units, Beijing 100081, China
2.
The PLA 32021 Units, Beijing 100094, China
3.
Laboratory of Atmospheric Circulation and Short-range Climate Forecast, Meteorological and Oceanographic College, National University of Defense Technology, Nanjing 211101, China

Received Date: 2019-12-23
Rev Recd Date: 2020-02-16

Available Online: 2020-11-30

Publish Date: 2020-11-25

Abstract

Abstract

Using the two-dimensional non-static numerical model, which neglect the submarine topography but consider the pycnocline and background shear flow, the numerical experiment was made on the generation and evolution of linear and nonlinear symmetric ocean internal waves in the unstable downward shear background flow. After analyzing and comparing the results, the main conclusions are as follows: the linear internal wave strength is exponentially growing with integral time, and there’s symmetric instability of the wave, while nonlinear internal wave strength is growing quasi-linearly in the development stage, and finally enters the stabilization stage. The linear growing is much faster than the nonlinear growing and the latter has a stabilizing effect. For linear and nonlinear symmetric internal waves, there are maximum value of potential density perturbation, which is captured by the pycnocline. This is consistent with actual observations. The stream function and potential density perturbation are well coordinated, which is reflected in the positive and negative centers of the potential density perturbation corresponding to the rising and sinking movements of the stream function, respectively. This shows that there is a slantwise convection occurred from the bottom of the sea and the pycnocline is the top cover. For linear internal waves, with the increase of integral time, its waveform is basically the same and the positive and negative amplitude is also about the same. There are two slantwise circulations that grow in opposite signs and between them is a strong slantwise upwelling. The waveform of nonlinear internal wave changes with the integration time and the number of slantwise circulations is also increasing, resulting in the stronger negative circulations and a sharp increase in the horizontal gradient of stream function and potential density perturbation. The sharp increase can be regarded as an interruption.
- numerical experiment,
- ocean internal wave,
- unstable shear background flow,
- symmetric instability

FullText(HTML)

References(25)

References

[1]	方欣华, 杜涛. 海洋内波基础和中国海内波[M]. 青岛: 中国海洋大学出版社, 2005. Fang Xinhua, Du Tao. Fundamentals of Oceanic Internal Waves and Internal Waves in the China Seas[M]. Qingdao: China Ocean University Press, 2005.
[2]	Guo Daquan, Zhan Peng, Kartadikaria A R, et al. On the generation and evolution of internal solitary waves in the southern Red Sea[C]//EGU General Assembly 2015. Vienna, Austria: EGU, 2015.
[3]	Bulatov V V, Vladimirov Y V. Internal gravity waves in horizontally inhomogeneous ocean[M]//Velarde M, Tarakanov R, Marchenko A. The Ocean in Motion. Cham: Springer, 2018: 109−126.
[4]	Mathur M. Simultaneous generation and scattering of internal tides by ocean floor topography[C]//68th Annual Meeting of the APS Division of Fluid Dynamics. Boston, Massachusetts: APS, 2015.
[5]	王金虎, 陈旭, 徐洋. 粗糙地形对内波生成影响的实验研究[J]. 海洋与湖沼, 2016, 47(4): 706−713. doi: 10.11693/hyhz20160100006 Wang Jinhu, Chen Xun, Xu Yang. Laboratory study on internal wave generation in rough topography[J]. Oceanologia et Limnologia Sinica, 2016, 47(4): 706−713. doi: 10.11693/hyhz20160100006
[6]	Moum J N, Farmer D M, Smyth W D, et al. Structure and generation of turbulence at interfaces strained by internal solitary waves propagating shoreward over the continental shelf[J]. Journal of Physical Oceanography, 2003, 33(10): 2093−2112. doi: 10.1175/1520-0485(2003)033<2093:SAGOTA>2.0.CO;2
[7]	Kalashnik M V. Generation of internal gravity waves by vortex disturbances in a shear flow[J]. Izvestiya, Atmospheric and Oceanic Physics, 2014, 50(6): 638−647. doi: 10.1134/S0001433814060115
[8]	Mack A P, Hebert D. Mixing structure of high-frequency internal waves in the upper eastern equatorial Pacific[J]. Journal of Physical Oceanography, 1999, 29(12): 3090−3100. doi: 10.1175/1520-0485(1999)029<3090:MSOHFI>2.0.CO;2
[9]	Lozovatsky I. Internal waves and shear instability in the southern bay of Bengal[R]. American Geophysical Union, Ocean Sciences Meeting 2016. 2016.
[10]	Zhang Shuang, Alford M H. Instabilities in nonlinear internal waves on the Washington continental shelf[J]. Journal of Geophysical Research: Oceans, 2015, 120(7): 5272−5283.
[11]	Yuan Yeli, Wan Zhenwen, Zhang Qinghua. A motion instability formation mechanism of the multi-core structure of the East China Sea Kuroshio[J]. Science in China Series D: Earth Sciences, 2003, 46(2): 182−192. doi: 10.1360/03yd9017
[12]	Yuan Yeli, Zheng Quanan, Dai Dejun, et al. The mechanism of internal waves in the Luzon Strait[J]. Journal of Geophysical Research: Oceans, 2006, 111(C11): C11S17.
[13]	张铭, 张立凤, 安洁. 大气波谱分析及其不稳定性[M]. 北京: 气象出版社, 2008. Zhang Ming, Zhang Lifeng, An Jie. The Spectrum Analysis and Instability of Atmospheric Wave[M]. Beijing: Meteorological Press, 2008.
[14]	穆穆. 大气运动的非线性稳定与不稳定问题研究[J]. 中国科学院院刊, 2001, 16(6): 432−435. doi: 10.3969/j.issn.1000-3045.2001.06.008 Mu Mu. Nonlinear stability and instability of atmospheric motions[J]. Bulletin of the Chinese Academy of Sciences, 2001, 16(6): 432−435. doi: 10.3969/j.issn.1000-3045.2001.06.008
[15]	Ai Congfang, Ding Weiye. A 3D unstructured non-hydrostatic ocean model for internal waves[J]. Ocean Dynamics, 2016, 66(10): 1253−1270. doi: 10.1007/s10236-016-0980-9
[16]	张翔, 邓冰, 张铭, 等. 背景流与地形对海洋内波影响初探[J]. 海洋预报, 2012, 29(3): 26−35. doi: 10.3969/j.issn.1003-0239.2012.03.005 Zhang Xiang, Deng Bing, Zhang Ming, et al. Preliminary study of background current and topography offects on ocean internal wave[J]. Marine Forecasts, 2012, 29(3): 26−35. doi: 10.3969/j.issn.1003-0239.2012.03.005
[17]	邓冰, 张宇飞, 张铭. 海洋内波发展演变数值试验[J]. 海洋科学进展, 2017, 35(1): 62−72. doi: 10.3969/j.issn.1671-6647.2017.01.007 Deng Bing, Zhang Yufei, Zhang Ming. Numerical experiments of oceanic internal wave evolution[J]. Advances in Marine Science, 2017, 35(1): 62−72. doi: 10.3969/j.issn.1671-6647.2017.01.007
[18]	邓冰, 张铭. 海洋内部波动的波谱和谱函数I·数学模型和计算方法[J]. 水动力学研究与进展A辑, 2006, 21(2): 259−266. doi: 10.3969/j.issn.1000-4874.2006.02.016 Deng Bing, Zhang Ming. Spectrum and spectral function analysis of wave in ocean Part I·mathematic model and numerical method[J]. Journal of Hydrodynamics, 2006, 21(2): 259−266. doi: 10.3969/j.issn.1000-4874.2006.02.016
[19]	Alford M H, Peacock T, MacKinnon J A, et al. The formation and fate of internal waves in the South China Sea[J]. Nature, 2015, 521(7550): 65−69. doi: 10.1038/nature14399
[20]	Kurkina O E, Kurkin A A, Pelinovsky E N, et al. Structure of currents in the soliton of an internal wave[J]. Oceanology, 2016, 56(6): 767−773. doi: 10.1134/S0001437016060072
[21]	邓冰, 张宇飞, 朱娟, 等. 海洋剪切流下失稳内波流场及传播的理论分析[J]. 海洋预报, 2016, 33(3): 1−8. doi: 10.11737/j.issn.1003-0239.2016.03.001 Deng Bing, Zhang Yufei, Zhu Juan, et al. Theoretical analysis on the stream structure and propagation of unstable ocean internal wave at background shear flow[J]. Marine Forecasts, 2016, 33(3): 1−8. doi: 10.11737/j.issn.1003-0239.2016.03.001
[22]	邓冰, 张翔, 张铭. 背景流中海洋内波垂向结构的计算和分析[J]. 海洋科学进展, 2014, 32(2): 121−129. doi: 10.3969/j.issn.1671-6647.2014.02.001 Deng Bing, Zhang Xiang, Zhang Ming. Calculation and analysis of vertical structure of internal wave in background current[J]. Advances in Marine Science, 2014, 32(2): 121−129. doi: 10.3969/j.issn.1671-6647.2014.02.001
[23]	Zhang Yufei, Deng Bing, Zhang Ming. Analysis of the relation between ocean internal wave parameters and ocean surface fluctuation[J]. Frontiers of Earth Science, 2019, 13(2): 336−350. doi: 10.1007/s11707-018-0735-7
[24]	张立凤, 张铭. 非均匀层结下的对称不稳定[J]. 大气科学, 1997, 21(5): 627−632. doi: 10.3878/j.issn.1006-9895.1997.05.14 Zhang Lifeng, Zhang Ming. Symmetric instability in nonhomogeneous stratification[J]. Chinese Journal of Atmospheric Sciences, 1997, 21(5): 627−632. doi: 10.3878/j.issn.1006-9895.1997.05.14
[25]	Huang Sixun, Zhang Ming. Study on atmospheric travelling wave solutions and review of its present developments[J]. Advances in Atmospheric Science, 1993, 10(4): 435−446. doi: 10.1007/BF02656968