Coherent and incoherent internal tides in the southern South China Sea -- Journal of Oceanology and Limnology,2016,34(6):1374-1382

	Cite this paper:
	LIU Qian, XIE Xiaohui, SHANG Xiaodong, CHEN Guiying. Coherent and incoherent internal tides in the southern South China Sea[J]. Journal of Oceanology and Limnology, 2016, 34(6): 1374-1382

Coherent and incoherent internal tides in the southern South China Sea

LIU Qian^1,2, XIE Xiaohui¹, SHANG Xiaodong¹, CHEN Guiying¹

1 State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;
2 University of Chinese Academy of Sciences, Beijing 100049, China

Abstract:

Coherent and incoherent internal tides (CITs and ICITs) in the southern South China Sea were investigated from two sets of 18-month mooring current records. The CITs were mainly composed of diurnal Q₁, O₁, P₁ and K₁ and semidiurnal M₂. The observed diurnal internal tides (ITs) were more coherent than the semidiurnal constituents. Coherent diurnal variance accounted for approximately 58% of the diurnal motion, whereas semidiurnal tides contained a much smaller fraction (35%) of coherent motion. The ICITs mainly consisted of motion at non-tidal harmonic frequencies around the tidal frequency, and showed clear intermittency. The modal decomposition of CITs and ICITs showed that CITs were dominated by mode-1, whereas mode-1 and higher modes in ICITs signals showed comparable amplitudes. CITs and ICITs accounted for approximately 64% and 36% of the total kinetic energy of internal tides, respectively.

Key words: internal tides|coherent|incoherent|kinetic energy|South China Sea

Received: 2015-06-04 Revised: 2015-08-29

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Articles by XIE Xiaohui

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