Characteristics of turbulence in the Changjiang River Estuary and its adjacent waters in summer

Wang Kou; Li Bo; Li Aiguo; Wang Penghao; Pei Shengxin

doi:10.12284/hyxb2021172

Volume 43 Issue 11

Dec. 2021

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Wang Kou，Li Bo，Li Aiguo, et al. Characteristics of turbulence in the Changjiang River Estuary and its adjacent waters in summer[J]. Haiyang Xuebao，2021, 43(11)：22–31 doi: 10.12284/hyxb2021172

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Characteristics of turbulence in the Changjiang River Estuary and its adjacent waters in summer

doi: 10.12284/hyxb2021172

Wang Kou^1
,,
Li Bo^{1
,
,},
Li Aiguo²,
Wang Penghao³,
Pei Shengxin¹

1.
Marine Science and Technology College, Zhejiang Ocean University, Zhoushan 316022, China
2.
Zhoushan Natural Resources Surveying and Mapping Design Center, Zhoushan 316021, China
3.
College of Meteorology and Oceanography, National University of Defense Technology, Nanjing 211100, China

Received Date: 2021-01-17
Rev Recd Date: 2021-05-25

Available Online: 2021-08-20

Publish Date: 2021-12-31

Abstract

Abstract

Using the direct observation data of the MSS90L turbulence profiler obtained in the summer cruise of the Changjiang River Estuary scientific investigation and experimental study (NORC2019-03-02) in July 2019, in this paper, the distribution of the turbulent kinetic energy dissipation rate ε and the vertical turbulent diffusion coefficient Kz are calculated and analyzed. The turbulent kinetic energy dissipation rate is 1.72×10⁻¹⁰W/kg to 2.95×10⁻⁵ W/kg, and the vertical turbulent diffusion coefficient is 3.24×10⁻⁷m²/s to 4.55×10⁻² m²/s. The distribution of the turbulent kinetic energy dissipation rate and the vertical turbulent diffusion coefficient are similar, both of which are the strongest in the upper layer, the next in the bottom layer and the weakest in the middle layer. In the upper layer, due to wind stress, the turbulent kinetic energy dissipation rate and vertical turbulent diffusion coefficient are larger; the stratification is stronger at the thermocline, which suppresses the dissipation of turbulent kinetic energy and vertical turbulent mixing. The secondary circulation of the salinity front will promote the separation of the low salt water mass, and the vertical circulation caused by the front will enhance the turbulent mixing of the ocean. The energy exchange between the low salt water mass and the outside world is less, and the turbulent kinetic energy dissipation rate is weaker. There are obvious upwelling and downwelling in the Changjiang River Estuary, which are produced by the secondary circulation of the front; the existence of upwelling and downwelling promotes the dissipation of turbulent kinetic energy and turbulent mixing.
- Changjiang River Estuary,
- thermocline,
- turbulent kinetic energy dissipation rate,
- vertical turbulent diffusion coefficient,
- salinity front

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References(33)

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