登陆的0915号热带气旋“巨爵”降水分布及其中尺度结构的分析

AN ANALYSIS OF DISTRIBUTION AND MESOSCALE STRUCTURE OF PRECIPITATION ABOUT LANDFALLING TROPICAL CYCLONE No.0915-“KOPPU”

利用自动气象站、雷达和TRMM卫星的观测资料,对2009年广东登陆热带气旋(TC)"巨爵"(0915)的降水分布进行了分析。结果表明:登陆TC"巨爵"的降水具有明显的非对称性和中尺度特征,TC降水主要位于移动路径的左侧。通过对海表温度(SST)、水汽通量、Q矢量和环境风垂直切变等分析发现,SST分布、水汽辐合、低层对流上升运动和垂直切变都有利于在TC移动路径的左侧产生降水。通过Barnes带通滤波对中尺度结构进行分离发现,登陆TC"巨爵"的降水存在明显的围绕TC中心的中尺度螺旋结构,呈带状或块状形式;登陆TC"巨爵"的局地强降水主要与中尺度螺旋结构的降水有关。

Observational data from automatic weather stations,radars and TRMM satellites are employed to analyze the distribution of precipitation for tropical cyclone （TC） KOPPU （0915） that made landfall on Guangdong province in 2009.The results show that the precipitation of landfalling KOPPU has significant asymmetry and mesoscale features,and TC precipitation is mainly located to the left of the TC moving path.Through an analysis of sea surface temperature （SST）,water vapor flux,Q vector,vertical wind shear of environment etc.,it is found that the distribution of SST,water vapor convergence,low-level convection and ascending motion and vertical wind shear are conducive to TC precipitation to the left of the TC moving path.The Barnes band-pass filter is used to separate the mesoscale structure.It is found that the precipitation of landfalling KOPPU has some clear mesoscale spiral structures around the TC center,and these mesoscale structures take on the form of belts or blocks.The heavy local rainfall of landfalling KOPPU is mainly associated with the rainfall of mesoscale spiral structure.