近60年西北太平洋台风年代际变化特征及成因的初步分析

利用60年台风资料,对西北太平洋台风的频数、路径和强度变化做统计分析。结果表明:西北太平洋的台风活动在20世纪60年代是高峰期,70年代则是低谷期,从20世纪90年代后期开始,台风活动总体处于低谷期;台风路径主要以转向为主,在20世纪60、70年代平均路径比较偏南,而进入21世纪后平均路径比较偏北;强度在20世纪50、60年代总体较强,后25年总体较弱;西北太平洋台风异常偏多时,西北太平洋副高弱且位置偏东,太平洋海温分布呈"拉尼娜"特征;台风异常偏少时,副高强且位置偏西,太平洋海温分布呈"厄尔尼诺"特征。

Preliminary analysis on interdecadal variation characteristics of typhoon over the Northwestern Pacific in the past sixty years

Using typhoon data over the NorthWestern Pacific(NWP) in 60 years(1950-2009),the interdecadal variations of typhoon frequency,track and intensity are statistically analyzed.The results show that the frequency of typhoon over the NWP is high in 1960s and low in 1970s.From the late 1990s,the frequency is low again.The track of typhoon is mainly shifting,the average track is at the southern NWP in 1960s and 1970s,but in recent 10 years,the track is at the northern NWP.The intensity of typhoon is strong in 1950s and 1960s,but becomes weak in recent 25 years.In high frequency periods of typhoon,the subtropical high of NWP is weak and its position appears easternly.The distribution of Sea Surface Temperature(SST) shows characteristics of "La Nina"event.In low frequency periods of typhoon,the subtropical high of NWP is strong and and its position appears westernly.The distribution of SST shows characteristics of "El Nino" event.