利用宽频带速度记录的频域特征研究台风

Research on typhoon using frequence character of broadband velocity record

利用福建省地震台网宽频带速度记录，以1h为移动窗长，研究了台风生成、发展、消亡整个过程的波谱特征，提出了以Fourier波谱的卓越周期作为刻画台风特征的一种尺度，并以台风“海棠”和“泰利”为例，统计了在登陆台湾之前，其卓越周期与台风参数的对应关系。研究表明，在台风初始形成阶段，其卓越周期由平常噪声的2～4s跃升为7～8s，随着台风向陆地的移动，卓越周期缓慢降低，经过台湾海峡时卓越周期显著降低，随着台风登陆，卓越周期又逐步恢复为噪声水平。

Using the broadband velocity records from the Fujian seismic network and taking l h as the time window, this article studed the spectrum characteristic during the entire process of typhoon＇ s formation, development and decline. It is suggested to adopt the predominant period of the Fourier spectrum as a dimension to describe the characteristic of the typhoon. Taking typhoons ＂Haitang＂and ＂Tailim＂ as examples,the relationship between predominant period and parameters of the typhoon was found statistically for the typhoon being prelanding Taiwan. The research shows that at initial formation stage,the predominant period increases from 2 -4s for normal noise to 7 -8s; along with typhoon＇ s movement to land, the predominant period decreases gradually and has a remarkable decrease at passing through Taiwan Strait;until the Typhoon＇s loading the predominat period returns to the noise level.