摘要
20-day in-situ ADCP current and CTD data are used to investigate the characteristics and energy of the internal tides in the northern South China Sea (NSCS). The results show that the O1, K1, M2 and S2 constituents of internal tides are energetic and diurnal constituents (O1 and K1) are dominating. In the observational period, the current vectors of these four constituents all rotate clockwise and the maximum semi-major axe of internal tidal ellipses is more than 14 cm/s. The variation of ocean temperature shows that the internal tides present obvious quasi-diurnal oscillation and the average amplitude reaches 50 m. Furthermore, these internal tides carry high energy and appear to be intermittent. The maximum values of KE (PE) during the observational period are up to 2 (3.5) k J/m^2 for diurnal internal tides, and up to 1 (1.5) k J/m^2 for semidiurnal internal tides.
对1998年6月南海北部20天的海流和温度定点连续观测资料进行分析,得到该海域内潮的特征及其能量分布。分析结果显示内潮的主要成分为O1,K1,M2与S2分量,其中全日内潮(O1与K1)的能量占主要部分。在观测期间,此四个分量的海流失量均为顺时针旋转,其潮流椭圆半长轴的最大值超过14cm/s。海水温度的变化显示出内潮存在准日周期振动,平均垂向振幅达到50m。观测到的内潮携带高能量且其活动存在不连续性,在观测范围内,全日内潮的动能及势能密度的最大值分别达到2kJ/m2及3.5kJ/m2,半日内潮的动能及势能密度的最大值分别达到1kJ/m2及1.5kJ/m2。
基金
supported by the National Natural Science Foundation of China (No.41176025, 40876008)
the SCSMEX project