大亚湾的潮汐动力学研究——I.潮波系统的观测分析与数值模拟*

doi:10.11978/2016078

摘要/Abstract

摘要：

文章作为大亚湾潮汐动力学系列研究的第一部分, 展现了大亚湾水动力的最新观测结果, 并借助于不规则三角网格海洋模式建立了高时空分辨率的三维潮汐潮流数值模型, 重现大亚湾潮位和潮流变化状况。结合实测资料与模拟结果, 得到了较以往更为精细的大亚湾潮波系统特征。浅水分潮, 尤其是六分之一日分潮在大亚湾内快速增长, 成为大亚湾潮波系统的显著特征。在大亚湾范和港M₆分潮振幅达到与M₄、S₂分潮相同的量级。大亚湾外开阔海域的潮流以旋转流为主, 但进入湾内后潮流椭圆迅速扁平化, 往复流占据主导。在湾内主要潮流通道内, M₆潮流椭圆主轴流速超过了M₄和K₁分潮。潮能通量分析揭示了大亚湾内高频分潮的强耗散, M₆分潮的能量耗散率和半日周期内耗散的总能量均超过了M₄、M₂和K₁分潮。观测到的欧拉余流表现出其湾内不一致的大小潮变化以及湾外所受沿岸流的影响。模拟出的欧拉余流则揭示了大亚湾内的余流多涡旋结构和水体弱交换能力。

关键词: 大亚湾, 潮波系统, 浅水分潮, 六分之一日分潮, 数值模拟

Abstract:

This paper is the first part of our studies on the tidal dynamics in Daya Bay (DYB), China. It illustrates the recent field work results. We establish a three-dimensional, fine resolution, unstructured grid, coastal ocean model to reproduce the tides in DYB. The combination of observation and simulation in this paper gives a better description on the tidal dynamic system in DYB than previous studies. Shallow water tides, especially the sexta-diurnal tides increase fast in DYB, which become the most notable characteristic of DYB tidal dynamic system. In the Fanhe Harbour at the northeastern DYB, the amplitude of M₆ tide reaches the maximum, at the same order as M₄ and S₂ tides. In the open sea outside DYB, the tidal current is dominated by a rotating shape; but once the current enters the bay, it turns to rectilinear quickly. In the main tidal channels, the magnitude of M₆ tidal current is even larger than those of M₄ and K₁ tides. The distribution of tidal energy flux indicates larger tidal energy dissipation for higher frequency tides. In DYB, both the tidal energy dissipation rate and the net tidal energy dissipated in a semi-diurnal period are much larger by M₆tide than by M₄, M₂ and K₁ tides. The observed Euler residual currents show different spring-neap variation in magnitude inside DYB, and reveal the influence of the coastal current outside the bay. The numerical simulation shows a multi-vortex of residual current, and indicates poor water exchange in the bay.

Key words: Daya Bay, tidal dynamic system, shallow water tide, sexta-diurnal tide, numerical simulation

武文, 严聿晗, 宋德海. 大亚湾的潮汐动力学研究——I.潮波系统的观测分析与数值模拟^*[J]. 热带海洋学报, 2017, 36(3): 34-45.

Wen WU, Yuhan YAN, Dehai SONG. Study on the tidal dynamics in Daya Bay, China — Part I. Observation and numerical simulation of tidal dynamic system[J]. Journal of Tropical Oceanography, 2017, 36(3): 34-45.

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参考文献 18

[1]	王聪, 林军, 陈丕茂, 等, 2008. 大亚湾水交换的数值模拟研究[J]. 南方水产, 4(4): 8-15.
	WANG CONG, LIN JUN, CHEN PIMAO, et al, 2008. Numerical simulation on water exchange in Daya Bay[J]. South China Fisheries Science, 4(4): 8-15 (in Chinese).
[2]	王雪辉, 杜飞雁, 邱永松, 等, 2010. 1980—2007年大亚湾鱼类物种多样性、区系特征和数量变化[J]. 应用生态学报, 21(9): 2403-2410.
	WANG XUEHUI, DU FEIYAN, QIU YONGSONG, et al, 2010. Variations of fish species diversity, faunal assemblage, and abundances in Daya Bay in 1980-2007[J]. Chinese Journal of Applied Ecology, 21(9): 2403-2410 (in Chinese).
[3]	吴玲玲, 易斌, 林瑞, 等, 2009. 大亚湾生态监控区生态环境问题及管理对策研究[J]. 海洋开发与管理, 26(1): 14-20.
[4]	吴仁豪, 蔡树群, 王盛安, 等, 2007. 大亚湾海域潮流和余流的三维数值模拟[J]. 热带海洋学报, 26(3): 18-23.
	WU RENHAO, CAI SHUQUN, WANG SHENG’AN, et al, 2007. Three-dimensional numerical simulation of tidal current and residual current at Daya Bay[J]. Journal of Tropical Oceanography, 26(3): 18-23(in Chinese).
[5]	吴岩, 陶建华, 1998. 大亚湾潮流数学模型的校准及验证[J]. 港工技术, (1): 6-11.
	WU YAN, TAO JIANHUA, 1998. The calibration and verification of tide current model of Daya Bay[J]. Port Engineering Technology, (1): 6-11(in Chinese).
[6]	杨国标, 2001. 大亚湾海区潮流运动特征[J]. 人民珠江, (1): 30-32.
[7]	BLANTON J O, LIN GUOQING, ELSTON S A, 2002. Tidal current asymmetry in shallow estuaries and tidal creeks[J]. Continental Shelf Research, 22(11/13): 1731-1743.
[8]	CHEN CHANGSHENG, LIU HEDONG, BEARDSLEY R C, 2003. An unstructured grid, finite-volume, three-dimensional, primitive equations ocean model: Application to coastal ocean and estuaries[J]. Journal of Atmospheric and Oceanic Technology, 20(1): 159-186.
[9]	CHEN CHANGSHENG, BEARDSLEY R C, COWLES G, 2006. An unstructured grid, finite-volume coastal ocean model (FVCOM) system[J]. Oceanography, 19(1): 78-89.
[10]	DRONKERS J, 1986. Tidal asymmetry and estuarine morphology[J]. Netherlands Journal of Sea Research, 20(2/3): 117-131.
[11]	FOREMAN M G G, HENRY R F, WALTERS R A, et al, 1993. A finite element model for tides and resonance along the north coast of British Columbia[J]. Journal of Geophysical Research, 98(C2): 2509-2531.
[12]	GUO WENYUN, SONG DEHAI, WANG XIAOHUA, et al, 2016. Contributions of different tidal interactions to fortnightly variation in tidal duration asymmetry[J]. Journal of Geophysical Research, 121(8): 5980-5994.
[13]	LEFFLER K E, JAY D A, 2009. Enhancing tidal harmonic analysis: robust (hybrid L1/L2) solutions[J]. Continental Shelf Research, 29(1): 78-88.
[14]	PAWLOWICZ R, BEARDSLEY B, LENTZ S, 2002. Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE[J]. Computers & Geosciences, 28(8): 929-937.
[15]	SONG XINGYU, HUANG LIANGMIN, ZHANG JIANLIN, et al, 2009. Harmful algal blooms (HABs) in Daya Bay, China: an in situ study of primary production and environmental impacts[J]. Marine Pollution Bulletin, 58(9): 1310-1318.
[16]	SONG DEHAI, WANG XIAOHUA, ZHU XUEMING, et al, 2013. Modeling studies of the far-field effects of tidal flat reclamation on tidal dynamics in the East China Seas[J]. Estuarine, Coastal and Shelf Science, 133: 147-160.
[17]	SONG DEHAI, YAN YUHAN, WU WEN, et al, 2016. Tidal distortion caused by the resonance of sexta-diurnal tides in a micromesotidal embayment[J]. Journal of Geophysical Research, 121(10): 7599-7618.
[18]	YU JING, TANG DANLING, WANG SUFEN, et al, 2007. Changes of water temperature and harmful algal bloom in the Daya Bay in the Northern South China Sea[J]. Marine Science Bulletin, 9(2): 25-33.

分潮	T1		T2
分潮	振幅 /cm	迟角/º	振幅/cm	迟角/º
O₁	27.62	245.4	27.28	244.1
K₁	33.46	296.4	32.93	294.0
M₂	36.71	257.0	33.58	254.0
S₂	14.79	286.2	13.77	283.7
M₄	13.17	288.5	8.98	280.1
MS₄	10.81	341.7	7.22	333.3
M₆	10.80	107.0	3.83	89.9
2MS₆	10.69	175.2	3.78	159.2

分潮	T1			T2
分潮	振幅/cm	迟角/º	Diff/cm	振幅/cm	迟角/º	Diff/cm
O₁	-0.11	0.10	0.11	0.12	0.30	0.17
K₁	-0.78	0.80	0.93	-0.25	-0.20	0.26
M₂	-0.22	0.20	0.24	0.11	0.20	0.17
S₂	-0.29	-0.70	0.35	0.08	0.60	0.16
M₄	0.09	-0.20	0.10	-0.01	0.40	0.07
MS₄	0.10	-0.50	0.13	-0.02	0.90	0.12
M₆	-0.01	0.40	0.09	-0.02	-0.90	0.06
2MS₆	-0.25	-0.50	0.27	-0.02	-0.10	0.02