近百年西北太洋热带气旋频数变化特征与ENSO的关系

Study on the variation characteristics of annual frequency for tropical cyclones in western north pacific during the last hundred years and relationship with enso

本文根据西北太平洋近106年(1899～2004年)热带气旋系列资料,分析了热带气旋年频数多年变化的统计特征。结果表明:西北太平洋台风频数既存在明显的短周期的年际变化也存在明显长周期的年代际变化,是一种短周期与长周期相互作用的多时间尺度的变化。年际变化与ENSO有明显关系,ENSO事件的当年9月到次年8月冷事件年相对与暖事件年会有更多的台风生成和登陆。在年代际尺度上,106年的台风活动可以分为几个明显的活跃期和不活跃期,这种年代际的变化可能与海气耦合的经向模态调制有关系。

In this paper, we concluded the characteristics of Tropical Cyclones （TCs） activity over the western north Pacific from 1899 to 2004 by using data of serially numbered TCs in northwestern Pacific. The results show that, Firstly, TCs activity variation in northwestern Pacific show clearly interannuai and interdecadai periods cycle. It＇s the interactionai result of interannuai and interdecadai periods cycle. Secondly, interannuai periods cycle has relationship with ENSO. El Nino has more TCs frequency than La Nina from September to next August. Thirdly, interdecadai periods cycle can be composed of several active and fallow phases. It＇s possible caused by Pacific Meridionai Mode.