多时间尺度环流对热带气旋海棠(0505)路径的影响

利用滤波方法将NCEP/NCAR提供的FNL风场资料分离出天气尺度和低频环流场，研究不同时间尺度环流对台风海棠（0505）路径的影响。热带气旋海棠路径的特征可以分两个主要阶段，在第一阶段，海棠西侧的天气尺度反气旋和低频流场副高南侧气流共同引导海棠向西南运动；第二阶段初期，天气尺度环流抑制海棠向北转向，但海棠西侧的QBW气旋和MJO尺度的气流共同引导海棠向北运动。海棠运动后期，海棠与低频气旋的相互作用导致了天气尺度流场中波列的产生和发展，形成了热带气旋的传播分量，令海棠产生了向东北转向的趋势，但是由于MJO环流场中副高的北抬和QBW气旋的引导，最终导致海棠向西运动。

Analysis of the multi-time scale circulation influences on the track of tropical cyclone Haitang(0505)

The influences of different time-scale circulations on the westward-moving tropical cyclone Haitang(2005) are analyzed by filtering the synoptic-scale and low-frequency-scale circulations from FNL data. In the first stage, the anti-cyclone west to Haitang in synoptic-scale circulation and subtropical high in low-frequency scale circulation lead the cyclone to a southwestward moving, while in the beginning of second stage, the northward deflection of Haitang is inhibited by synoptic-scale circulation but co-steered by cyclone west of cyclone in QBW circulation and subtropical high in MJO circulation. In the later stage of movement, the genesis and development of wave train are resulted from the interaction between Haitang and low-frequency cyclone and lead to the propagation of tropical cyclone. It also causes the tendency of Haitang to move to the northeast. But, finally, the TC moves westward due to the northward migration of subtropical high in the MJO fields and QBW-scale cyclone.