SPECTRUM期间目标台风移动的数值试验

在目标台风Ｙａｎｃｙ的移动过程中，选择４个时段进行预报数值试验。模式初始场系根据ＳＰＥＣＴＲＵＭ和ＴＣＭ－９０加强观测资料确定。结果表明：实际大气中目标台风移动的若干特征在模式大气中能够显示出来，如Ｙａｎｃｙ在１９９０年８月２０日００时移向的转折现象等；台风非对称结构的低频振荡是产生移向转折现象的一个重要原因。

NUMERICAL EXPERIMENTS ON THE MOVEMENT OF THE TYPHOON YANCY DURING THE SPECTRUM

Four stages are selected from the movement of the typhoon Yancy and four numerical experiments whose integration times correspond to the four stages by using a quasigeostrophic barotropical model.The gridpoint data of the initial fields are obtained from the intensive observations in the SPECTRUM and TCM-90 Field Experiment.Some main characteristics of the unusual motions of typhoon Yancy such as the unexpected turns in its tracks can be well simulated.The oscillation of asymmetric structure of the typhoon whose period is about 42 model hours can be also exhibited obvioursly.which may be responsible to the turns.