【摘要】 根据黑潮源区吕宋岛附近(18°N,122.5°E)投放的ADCP测得的流速,发现次表层流动与海表黑潮(Kuroshio,KC)流动并不一致,除了流动方向不同外,次表层吕宋潜流(Luzon Undercurrent, LUC)在500～1 000 m深度存在一个低频季节内周期变化(120 d),这一变化并非由海表黑潮的季节性变化引起。针对这一现象,结合混合坐标海洋模式(Hybrid Coordinate Ocean Model,HYCOM)数据,使用涡动能(Eddy Kinetic Energy, EKE)分析并追踪100～200 d周期温盐和流速变化异常,最终得出结论:吕宋潜流季节内变化存在两个频率的周期,较高频季节内变化(80 d)是由表层黑潮区的中尺度涡传递到次表层产生的,而低频季节内变化(100 d以上)由136°E附近的中尺度涡旋经过6～7个月的运动到达吕宋岛沿岸产生的。更多还原

【Abstract】 Two groups of buoys were set at 18°N off Luzon Island and the ycontinuously measure velocity for about two years. According to the data, we find that two kinds of seasonal variation sexisting in the subsurface flow(Luzon Undercurrent, LUC). One of them has a period of 80 days, caused by the surface flow(Kuroshio Current, KC). Another has a period of 120 days, only exist in the subsurface flow(500～1 000 m). It is not caused by KC. We find eddy activities are more intense in subsurface flow than seasurface according to the distribution of Eddy Kinetic Energy(EKE).The Hybird Coordinate Ocean Model(HYCOM) data was used in our study.We make a 100～200 d band pass filter of velocity to calculate EKE. We found that compared with the result of 200 d high pass filter, less eddy appeared along the Luzon Island. The eddies with longer periods appeard in the Northeast of Luzon. By tracking the velocity and temperature anomaly we found mesoscale subthermorcline eddies are produced along the island chain at 136°E,20°N.The eddy have a period of about 4 months consistent with the LUC.Then it spread from the east to the west and finaly arrived in the coast of Luzon Island. The path is mainly affected by water depth.更多还原