1010号台风“莫兰蒂”对福建近海风场的影响及其成因分析

Analysis of characteristics and formation of offshore wind field in Fujian influenced by 1010 typhoon Meranti

分析福建沿岸区域气象自动站、近海气象浮标站等有关风的精细观测资料以及NCEP再分析、雷达反演风场等资料,研究了2010年第10号台风"莫兰蒂"影响福建期间,福建近海风场分布的特点及其成因,以寻找台风影响时福建近海风场预报的着眼点.结果表明:受到环境场及台湾海峡狭管效应,气流与中央山脉之间绕流、阻挡等共同作用,1010号台风"莫兰蒂"影响福建期间,大风在海区上主要集中分布在台风环流东部和福建北部海区;福建中部沿海最早出现大风;而大部分台风影响时间中,中部沿海风力大于北部、南部沿海风力,呈现中间大两头小的布局.特别是1010号台风"莫兰蒂",进入台湾海峡后发展成微型台风,靠近台风的测站在台风临近时才大风突起.而这种微型台风,大风天气突发性强,在风的精细预报中要特别注意短时临近的监控监测.对比各种资料的应用效果表明:NCEP再分析资料反映的主要是海区的大风分布;雷达反演风场,必须结合实况资料验证,具有一定的参考价值;近海浮标站资料,能较早反映台风影响时风场的演变特点,但近海浮标站所观测的海区风力不一定大于相近的沿岸区域气象自动站所观测的沿海风力,二者所观测到的风力、风向的变化与台风位置密切相关.在业务预报中,对近海浮标站资料的应用,还需深入研究,具体情况具体分析.

In this paper,the characteristics of wind field over offshore Fujian and its formation associated with typhoon Meranti（1010）is investigated to provide some clues for prediction with data from automatic meteorological observation,buoy weather observation,NCEP reanalysis data,radar retrieved data and etc.Results show that,during the period,because of the channelization,flow distributing and blocking effect of central mountain range of Taiwan Island,strong wind mainly occurs in the east of typhoon and the north of offshore region,and the gale appear in the middle of costal area at first,at most of the impacting period,wind evolution displays one apex structure.In particular,for micro-typhoon,such as Meranti（1010） which developed in Taiwan strait when it approached monitoring stations and enhance abruptly,it indicate that nowcasting and short-time monitoring is very important for wind fine forecasting.Data verifications display that NCEP reanalysis data can display the gale over the sea and radar retrieved wind verifying with observation can also provide some useful reference.Buoy observation can monitor early wind evolution.However,its wind speed is not always stronger than the nearest automatic meteorological observation,which may be closer to the typhoon position.Therefore,the application of buoy observation still needs to be further analyzed.