影响广东的热带气旋与ENSO的关系

Impact of ENSO on the Tropical Cyclones Affecting Guangdong

为探讨ENSO对影响广东的热带气旋的影响,利用统计方法对1950-2003年期间进入广东防区的热带气旋的累计气旋能量ACE变量和其他变量与ENSO的关系进行了分析,发现在年的尺度上进入广东防区的热带气旋对ENSO的响应很弱,且表现出明显的季节差异,在6—8月表现出与Ni灳o3.4指数的正相关,而在10月份表现出明显的负相关。热带气旋的强度、数量、时间等在10月份都与Ni灳o3.4指数表现出较明显的负相关,即在拉尼娜出现当年的10月份热带气旋趋向于数量增多,强风暴的生命史增长,影响时间较长,强风暴强度也趋向更强,破坏力增大;而在厄尔尼诺年,热带气旋趋向于数量减少,强风暴的生命史缩短,影响时间较短,强风暴会趋向减弱,破坏力会减低。分析可知,ACE指数很好地反映热带气旋对ENSO响应的特性。

In order to discuss the effect of ENSO on the cyclone which endanger Guangdong, the relationships between Accumulated Cyclone Energy （ACE） and other variables of the tropical cyclones entering the Guangdong Area and ENSO are analyzed during the period of 1950-2003 by using statistical method. It is found that the response of the tropical cyclones affecting Guangdong to ENSO is very weak in year, and it shows significant seasonal differences. During the months from June to August, positive correlation can be found between the cyclones and Nino3. 4 indices, but negative correlation is obvious in October. Besides, the intensity, number and lifetime of the tropical cyclones occurring in October indicates greater negative correlation with ENSO. In other words, more cyclones are expected in La Nina years with longer life cycles, greater storm strengths and greater destructiveness, but fewer cyclones in El Nino years with shorter life cycles and less destructiveness. The result also shows that ACE index has a good clue to forecast the tropical cyclones affecting Guangdong.