华南登陆台风频数的变化及其与ENSO事件的关系

利用 18 90～ 1999年登陆于我国的台风资料 (指热带风暴、强热带风暴及台风 ) ,主要采用小波分析方法研究华南登陆台风多时间尺度特征 ,并探讨台风与 ENSO事件的关系。结果表明 ,华南登陆台风占全国的 6 3%,平均每年 5个 (最多 10个、最少 1个 ) ,主要周期有 15、5、80年 ,在 2 0世纪 6 0年代以前 15年周期显著 ,6 0年代及以后5年周期明显。台风频数与 ENSO事件的类型及其季节有密切的关系 ,华南台风在拉尼娜年始于夏季的当年明显偏多 (比厄尔尼诺年平均多 1.8个 ) ,台风偏多年 (年频数≥ 7) ,也是拉尼娜年数多于厄尔尼诺年数。影响台风活动的因素非常复杂 ,对拉尼娜年一般可考虑当年台风可能偏多 ,但厄尔尼诺年台风偏多的可能性亦不容忽视。

Variations of Annual Frequency of Landfall Typhoons in South China and Its Relation with ENSO

Data of tropical storms and severe tropical storms and typhoons making l andfall on China from 1890 to 1999 were used. With the technique of wavelet ana lysis, multi-time-scale features and links between the typhoon and ENSO were d iscussed.The result shows that typhoons making landfall in this part of the coun try take up 63% of the national total, being an average of 5 per year (10 at mos t and 1 at least). The landfall occurs mostly at periods of 15, 5 and 80 years, in which the 15-year period is the most prominent before the 1960's while the 5 -year period is the main tone in the 1960s and afterwards. There is a close li nk between the frequency of typhoon appearance and the ENSO event and time of th e year. There are much more typhoons in South China in resent years in which the La Nina phenomena first appear in summer, being generally 1.8 typhoons more tha n in the El Nino years. For years with anomalous more typhoons (defined so when the annual frequency ≥7), the La Nina year is also favored against the El Nino year by a margin of about 1/3.