采用1993年1月到2008年12月16a融合海面高度距平数据,追踪吕宋海峡附近海域(18°~23°N,116°~126°E)中尺度涡的移动轨迹,结果表明:时间分辨率为7d的卫星高度计资料难以观测到中尺度涡从西北太平洋通过吕宋海峡传进南海的过程,但对1994年吕宋海峡中部观测到的一个气旋涡及其附近中尺度涡的运动轨迹进行分析可见,西北太平洋海面高度变化会与吕宋海峡内部海面高度耦合后向南海传播。海面高度距平数据的时间-经度图表明,西北太平洋海面高度变化信号在西传至吕宋海峡附近(121°~122°E)时出现信号不连续。对21°N,116°~140°E断面的海面高度距平数据按周期分别为1~3月、3~6月、330~390d(年信号)进行分段带通滤波,发现不同周期的西北太平洋信号穿过吕宋海峡传入南海受到的阻隔作用、向西传播的速度以及它们所受的强迫机制均不同。
16 years(1993-2008) of merged sea level anomaly(MSLA) data obtained from Archiving,Validation and Interpretation of Satellite Oceanographic data(AVISO) are used to track the trajectories of meso-scale eddies near the Luzon Strait(LS)(18°-23°N,116°-126°E),and the results indicate that it is difficult to observe meso-scale eddies from the northwestern Pacific propagating into the South China Sea(SCS) through the LS based on the data with the temporal resolution of 7 d.The analysis on one cyclonic eddy observed in the middle of the LS in 1994,suggests that the sea level anomaly from the Northwestern Pacific propagates into the SCS through the LS after coupling with the original signal in the LS.The time-longitude diagram implies that the sea level anomaly signals become discontinuous near the LS(121°-122°E) when they propagate westward.After applying the band-pass filter to the sea level anomaly data in the section 21°N,116°-140°E with the periods of 1-3 month,3-6 month and 330-390 d,one can conclude that the signals from the Northwestern Pacific propagating into the SCS through the LS get different blocked,have different westward propagation velocity and have different forcing mechanisms for different period bands.