利用NCEP/NCAR再分析资料、中国气象局热带气旋年鉴资料,对1949—2013年中国近海突然增强台风进行了统计分析,表明近海台风突然增强是一个小概率事件,占近海台风总数的10.1 9%。近海突增台风存在年代际变化,在20世纪50—70年代出现一个高峰,60年代达最高值,2000年以后明显减少;近海突增台风存在明显的时空分布特征,发生在4-10月,以8、9月最多;多数出现在南海,在黄海也有发生。对近海突增台风的大尺度环流特征作动态合成分析表明,突增台风通常处于副热带高压脊西南部;温度场上被暖脊包围;水汽输送上有持续的水汽输入台风环流;海温场上处高海温海域,同时,处于弱风垂直切变环境中,有利于台风突然增强。统计结果进一步表明,高海温、弱风垂直切变环境下,台风强度突增明显,其比例占所有突增台风总数的71.4%;当仅处于低海温环境下或仅处于强风垂直切变环境下,突然增强台风现象极少,比例都是所有突增台风总数的2.9%;但当高海温、强风垂直切变环境下,台风仍会出现突然增强现象,占所有突增台风总数的2.9%,在低海温、弱风垂直切变极端环境下,不出现突然增强台风。
Based on NCEP/NCAR Reanalysis data and CMA tropical cyclone Yearbook information(1949-2013),rapid intensification of typhoons over coastal water of China are statistical analyzed.The statistical results suggest that the rapid intensification of coastal typhoons are small probability events which with 10.07%for rapid intensification.It also has distinct temporal and spatial characteristics.Composite data analysis and dynamic diagnosis are employed to reveal the circulation characteristics of the phenomena.The results of height field analysis show that the rapid intensification of typhoon is related with the subtropical high situated to the north of it.In the temperature field,there are always warm ridges encompassing the typhoons during their rapid intensification.In terms of water vapor transportation,the moisture supply to the typhoon of rapid intensification is abundant.As to the sea temperature field,the rapid intensification occurs over warm sea surface temperature(SST)region.At the same time,the low VWS will make a contribution to rapid intensification of tropical cyclones.Statistics showed that high SST configuration,low vertical wind shear and typhoon strength spurt,71.4%of the total accounted for all the rapid intensification in typhoons.But when high SST configuration,high vertical wind shear and low SST,middle vertical wind shear configuration,these two typhoons still appear rapid intensification,accounted for 2.9%of all rapid intensification in total number of typhoons over coastal water of China.