南海西沙群岛陆架区的潮流特征分析

Analyses of the tidal current characteristics on the continental shelf of the Xisha Islands in the South China Sea

本文通过利用在南海西沙群岛陆架海区于2010年7月期间观测到的流速定点数据,分析了该海区的潮流特征。通过计算正压潮流和内潮流椭圆要素、海流能量谱及动能等参数,结果表明,通过观测点海流流向主要偏东方向,正压潮流显著,而内潮流并不明显;正压潮流以K1分潮为主,O1分潮次之;海流全日潮频率能量较大,台风过境后海流近惯性震荡显著增大;深度20m处内潮流平均动能与实测海流平均动能比值较小。

In this paper, the tidal current characteristics on the continental shelf of the Xisha Islands in the South China Sea are analyzed by using the current data, which are observed at a mooring site near the Xisha Islands in July, 2010. The parameters, such as the elliptical elements of the barotropic and baroclinic tidal current, the current energy spectra and the kinetic energy are calculated. The results show that the current mainly flows to the east and the barotropic tidal current is significant in this area while the baroclinic tidal current is not obvious. K1 is the main component barotropic tidal current, and then O1. The current energy of diurnal frequency is very strong and the near-inertial oscillation increases significantly after the passage of typhoon. The ratio of the mean kinetic energy of the baroclinic tidal current to the observational current is very small at the depth of 20m.