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为了了解潮流从西北太平洋经吕宋海峡进入南海内的变化及其垂向结构,本文利用在吕宋海峡附近沿东西方向布放的多套潜标同步获得的高分辨率ADCP长时间连续观测上层海流资料,使用调和分析方法将实测海流分解成3部分:不随时间变化的定常流、周期性潮流和剩余流,并将潮流分解为正压潮流和斜压潮流。通过对实测海流中各组分的分析,得到以下结论:该区域潮流类型在不同深度上有明显变化;M2潮自吕宋海峡传入南海后强度显著减弱75%左右,K1、O1分潮在上层强度减弱约三分之一。从垂向变化来看,在潮流强度上,各站点垂直方向上潮流强度均发生变化。从方向上看,各分潮潮流椭圆东西向特征明显,长轴变化较大,短轴(南北向特征)垂向变化不显著;潮流运动主要沿逆时针方向,垂直方向上潮流明显减弱或增强时会发生转向。斜压潮流主要集中在上表层,100m左右以下随深度逐渐减弱。东西方向斜压潮流能量比正压潮流强,而南北向的流比较稳定,且斜压潮流能量远小于正压潮流。定常流强度在各站点呈现相似的变化趋势,随深度变化减弱。
In order to know the trend and the vertical structure of the trend from the Northwest Pacific to the South China Sea via the Luzon Strait, this paper uses the high-resolution ADCP, which is obtained synchronously from multiple submersibles along the east-west direction near the Luzon Strait, The current data are decomposed into three parts by using harmonic analysis: steady flow, periodic flow and residual flow that do not change with time, and the flow is decomposed into positive pressure flow and baroclinic flow. Through the analysis of each component in the measured ocean currents, the following conclusions are drawn: the tidal current types in this area have significant changes at different depths; the intensity of M2 waves significantly weakened by about 75% since the passage of the Luzon Strait into the South China Sea; the tide of K1 and O1 The upper strength is reduced by about one third. From the vertical change point of view, in the tide intensity, the tidal current intensity changes in the vertical direction of each site. From the direction of view, the characteristics of the elliptical east-west trend of each tide tidal flow are obvious, the major axis changes a lot, but the vertical variation of the minor axis (north-south direction) is insignificant; the tidal current obviously weakens or strengthens in the anticlockwise direction and the vertical direction When will happen turn. Baroclinic currents are mainly concentrated in the upper surface, with the depth of about 100m or so gradually weakened. The baroclinic tidal current energy in east-west direction is stronger than the positive tidal current, while the south-north direction is relatively stable, and the energy of baroclinic tidal current is far less than the positive tidal current. The steady flow intensity showed a similar trend at all sites, with the change of depth weakened.