台风珍珠和鲇鱼北折路径对比分析  

A Comparative Analysis on Sharp Recurving Tracks of Typhoons Chanchu and Megi

作　　者：曹晓岗[1] 王慧[1] 漆梁波[1] 

机构地区：[1]上海中心气象台,上海200030

出　　处：《气象》2012年第7期841-847,共7页Meteorological Monthly

基　　金：公益性行业(气象)科研专项(GYHY201006008);WMO登陆台风预报示范项目共同资助

摘　　要："珍珠"(0601,Chanchu)和"鲇鱼"(1013,Megi)都是发生北折路径的台风,通过分析发现导致台风珍珠和鲇鱼路径北折的天气形势变化有一些相同点:都发生在环境场的调整中,有西风槽影响华南的副热带高压,使之减弱东退、台风移速减慢,然后副热带高压加强并从台风南部向西南伸展、与赤道高压打通,其西侧的偏南气流与越赤道气流会合引导台风向北移动;同时有弱冷空气南侵。上述环境场的突然变化导致引导气流方向发生突然变化,是这两个台风西行北折的重要原因。引导气流分析还发现,秋台风鲇鱼最佳引导气流所在高度低于初夏台风珍珠。另外,不同的路径预报方法、不同的模式和超级集合预报提供了各种台风路径预报信息,在应用这些信息时要密切结合实况天气形势的变化,进行路径预报订正。Typhoons Chanchu （0601） and Megi （1013） make similar abrupt northward recurving move ments after they enter the South China Sea from the Philippine Sea. This analysis is performed to probe the main environmental factors responsible for TCs suddenly turning. The results show that both typhoons experience similar environmental adjustment periods, which can explain TCs movement. In the first stage, a westerly trough moves eastward, forcing the subtropical high to weaken and recede from South China, making the TC moving slow down. In the second stage, the subtropical high reinforces and extends south westward, passing by the south area to TC; when it is connected with the equatorial high, the crossequa torial flow joins the southerly wind west of the subtropical high, leading TC to move northward. Mean while, at higher latitudes, rather weak cold air flow intrudes southward. The further calculation confirms that steering flows change abruptly with the environmental situation, from easterly to southerly, which is principal for both Chanchu and Megi making northward turns. For autumn typhoon, Megi, the best steer ing flow is at lower levels than that of early summer typhoon Chanchu. In operational practice, there are many kinds of forecast information provided by different methods, models and super ensemble models, the realtime modifications are necessary in accordance with environmental circulation changes.

关 键 词：台风 北折路径 副热带高压 引导气流 

分 类 号：P457.8[天文地球—大气科学及气象学]