南海东沙岛西南大陆坡内潮特征  

Characteristics of the internal tide at the continental slope southwest of Dongsha Island,the South China Sea

作　　者：李俊德[1] 梁楚进[1] 金魏芳[1] 周蓓锋[1] 丁涛[1] 

机构地区：[1]卫星海洋环境动力学国家重点实验室,国家海洋局第二海洋研究所,浙江杭州310012

出　　处：《海洋学研究》2011年第1期1-8,共8页Journal of Marine Sciences

基　　金：国家海洋局青年海洋科学基金资助项目(2009422);国家海洋局第二海洋研究所基本科研业务费专项资助项目(JT0905、JG200811)

摘　　要：2008年4月—10月,在南海东沙岛西南大陆坡底部布放了1套全剖面锚系,同时沿大陆坡底部布放了3套近底锚系,应用谱分析和调和分析方法分析温度和海流连续观测资料,进而研究该海域的内潮特征。结果表明,东沙岛西南大陆坡存在强内潮现象,大陆坡底部温度变化受到内潮波的影响,上层海洋存在强日潮周期的内潮波振动;正压潮和斜压潮均以O1、K1全日分潮和M2、S2半日分潮为主,且全日潮强于半日潮;观测海域斜压潮强于正压潮,正压潮O1日分潮潮流振幅最大为4.34cm/s,斜压潮K1日分潮潮流振幅最大为8.70 cm/s。斜压潮潮流椭圆要素随深度变化特征表明斜压潮潮流矢量做顺时针旋转。内潮波水平传播方向基本与观测海域等深线相互垂直,垂直方向具有向下传播的相速度和向上传播的群速度,内潮波能量由深海向海表传播。From April,2008 to October,2008,a full profile mooring from the surface to the bottom and three bottom current moorings were deployed at the continental slope southwest of Dongsha Island,the South China Sea.The characteristics of the internal tide are studied by analyzing the temperature and current data with the methods of power spectrum and harmonic analysis.The results show that strong internal tide existed along the continental slope southwest of Dongsha Island.Temperature at the bottom of the slope was influenced by the internal tide and there was a strong diurnal internal tide oscillation in the upper ocean.The barotropic tide and baroclinic tide were dominated by O1 and K1 diurnal tides and M2 and S2 semidiurnal tides,and the diurnal tides were stronger than the semidiurnal tides.The baroclinic tides were much stronger than the barotropic tides,and the maximum amplitude of the O1 diunal barotropic tidal component was 4.34 cm/s,while that of the K1 diunal baroclinic tidal current component was 8.70 cm/s.Variations of the ellipse elements of the baroclinic tidal components with depth show that the internal tide current vectors made clockwise rotation.The horizontal propagation directions of the internal tide in the observed area were perpendicular to the isobaths.The internal tidal wave had a downward phase velocity and an the upward group velocity in vertical direction,implying an upward propagation of the energy from the sea bottom to the surface.

关 键 词：东沙岛 正压潮 内潮 潮流 南海 

分 类 号：P731.2[天文地球—海洋科学]