华南登陆热带气旋“珍珠”和“派比安”的对流非对称分布观测分析

OBSERVATIONAL ANALYSIS OF ASYMMETRIC DISTRIBUTION OF CONVECTION ASSOCIATED WITH TROPICAL CYCLONE "CHANCHU" AND "PRAPIROON" MAKING LANDFALL ALONG THE SOUTH CHINA COAST

采用广东省中尺度地面气象站和天气雷达的观测资料,对2006年登陆华南的热带气旋(TC)"珍珠"和"派比安"的对流非对称分布进行了分析。结果表明:在登陆TC"珍珠"和"派比安"从登陆前12小时到登陆后6小时期间,强对流主要位于TC中心的"东"、"北"象限,即TC移动路径的右侧和前方;同时TC对流在垂直方向也存在明显的差异。分析还发现,虽然登陆TC"珍珠"和"派比安"都有相同的对流非对称分布,但是引起这种对流非对称分布的原因并不完全相同,登陆TC"珍珠"的对流非对称分布主要与强的环境垂直风切变、低层水平风场切变、低层辐合和辐散的影响有关,而登陆TC"派比安"的对流非对称分布主要与低层辐合和辐散的影响有关。

Observational data of Mesoscale meteorological surface stations and weather radars of Guangdong province are employed, and the asymmetric distribution of convection from tropical cyclone（TC） prior to, during to after landfall associated with TC Chanchu and Prapiroon making landfall along the south China coast in 2006 has been analyzed. The results show that the stronger convection locates in the eastern and northern sectors for making landfall TC Chanchu and Prapiroon from 12 h prior to landfall to after 6 h landfall, namely the stronger convection locates in the front and left of TC track. And the convection of TC also exists distinct difference in vertical direction. Through analyzing it is found that although making landfall TC Chanchu and Prapiroon have same asymmetric distribution of convection, the reasons of causing this asymmetric distribution of convection are not completely same. The asymmetric distribution of convection for the case of Chanchu is majorly associated with the influences of a strong environmental vertical wind shear, low-level horizontal wind shear, low-level convergence and divergence. But for the case of Prapiroon, the asymmetric distribution of convection is majofly associated with the influences of low-level convergence and divergence.