台风“巨爵”近海急剧加强的特征及成因分析  

Characteristics of Rapid Offshore Intensification of Typhoon Koppu and Analysis of the Causation

作　　者：邓文剑[1] 吴振鹏 吴乃庚[1] 林良勋[1] 

机构地区：[1]广东省气象台,广东广州510080 [2]广州市气象信息网络中心,广东广州510080

出　　处：《广东气象》2014年第3期9-14,共6页Guangdong Meteorology

基　　金：广东省气象局科技研究项目"华南近海加强台风的成因分析"(2013B04);广东省科技计划项目(2011A03210006);中国气象局预报员专项项目(CMAYBY2014-048)共同资助

摘　　要：源自东风波动的0915号台风“巨爵”在自东向西靠近广东沿海时出现了近海急剧加强的异常现象.利用热带气旋定位资料、NCEP全球同化分析资料、卫星云图以及海上平台自动站探测资料等对“巨爵”近海加强特征和成因进行了诊断分析.结果表明：“巨爵”形成源自于西太副高南侧的东风波动,副高演变及引起的“北高南低”和“东高西低”的形势与“巨爵”环流增强发展密切相关;弱的垂直风切变、高空明显的辐散出流以及台风中心正涡度增大并向对流层中上层拓展有利于“巨爵”强度增强;低层弱冷空气南下,一方面从增加气压梯度和温度梯度来加强台风环流和暖心结构,另一方面通过触发外围对流云团发展并往台风中心输送进而对“巨爵”近海加强产生重要的触发作用;孟加拉湾西南季风气流、105°～110°E附近越赤道气流和西太副高西侧东南气流3支气流汇合为“巨爵”近海加强提供了充沛水汽条件.When approaching westward to the coast of Guangdong province, Typhoon Koppu （0915）, a storm that originated from easterly waves, intensified rapidly over offshore waters, a phenomenon that is abnormal. Using the location data of tropical cyclones, NCEP global assimilation analysis data, satellite imagery and measurements from automatic weather stations onboard maritime rigs, this work studied diagnostically the characteristics and causation of the rapid offshore intensification of Koppu. Koppu originated from the easterly waves to the south of the subtropical high and the evolution of the subtropical high in western Pacific resulted in patterns of higher pressure in the north （east） than in the south （ west）, which is closely linked with the intensification of Koppu＇s circulation. Vertical wind shear was weak, divergent outflow was significant at upper levels and positive vorticity was increasing in the eye of the typhoon and expanding to the midand upper-troposphere, causing Koppu to intensify. Weak cold air came south to enhance the pressure and temperature gradients to strengthen the circulation and the warm core of Koppu on the one hand, and to trigger the rapid intensification by initiating the development of convective cloud clusters at the periphery and transporting them towards the eye on the other. A southwesterly airflow from the Bay of Bengal, a cross-equatorial flow in 105 to 110°E and a southeasterly flow on the western side of the subtropical high merged to supply abundant amount of water vapor to Koppu.

关 键 词：天气预报 台风“巨爵” 台风近海加强 副热带高压 弱冷空气 

分 类 号：P45[天文地球—大气科学及气象学]