西北太平洋超强台风活动特征及其与ENSO的关系

Characteristics of Super Typhoon Activity over Western North Pacific and Its Relationship with ENSO

利用1965～2005年西北太平洋热带气旋(TC)资料,对发生在西北太平洋的超强台风(STY)进行统计,总结了超强台风的活动范围及季节演变特征。结合海表面温度(SST)分析了超强台风活动与ENSO现象的关系以及ENSO现象对超强台风活动的影响机制。结果表明:超强台风的数量占全部热带气旋总数的1/5,在7～11月间活动最为频繁,且11月达到超强台风的比例最高,出现频率最高的区域是菲律宾以东洋面上。在El Nio年,由于海温和季风槽的共同作用,热带气旋生成的位置比较偏东,再加上弱垂直风切变的影响,超强台风数量会比较多,La Nia年热带气旋生成的位置比较偏西,超强台风活动区域垂直风切变比较强,超强台风数量会比较少。

This paper analyzed the statistical features of super typhoon （STY） over Western North Pacific （WNP） from 1965 to 2005 and described the seasonal variability of STY activity. The relation between STY activity and ENSO as well as the mechanism of ENSO affecting on STY activity were also investigated. Results showed that one fifth tropical cyclones could reach the rank of STY. The most of STY appeared from July to November while there was a grate STY rate in November. On geographical distribution, the maximum was at the east of Philippine Sea. In El Nino years, affected by sea surface temperature （SST） , monsoon trough and weak vertical wind shear, TC formation location drift eastward and there were more STY, and vice versa during La Nina years.