台风登陆后非对称降水的非地转湿Q矢量研究  

Ageostrophic wet Q-vector study on asymmetric precipitation after typhoon landing

作　　者：张亚洲[1] 梅华[1] 邓文彬[1] 杨爱玲[1] 

机构地区：[1]中国人民解放军61936部队

出　　处：《气象科学》2011年第6期710-717,共8页Journal of the Meteorological Sciences

摘　　要：利用NCEP再分析资料和热带降水测量卫星资料,采用改进后考虑非绝热加热的非地转湿Q矢量理论,对"0907"号热带风暴"天鹅"登陆后非对称降水特征进行研究。结果表明:(1)台风登陆后雨带出现断裂,降水呈现明显非对称性特征,强降水主要位于第二象限;(2)非地转湿Q矢量散度分布较好描述了台风登陆后降水的非对称性,与降水的分布有较好的对应关系,强降水主要位于湿Q矢量散度梯度的大值区;(3)沿台风移动方向上,非地转湿Q矢量辐合、辐散交替分布构成雨区内的垂直环流结构,其中倾斜上升支的非对称结构,造成了降水的非对称性;(4)经过台风中心存在纬向的次级环流,对降水起抑制作用,其东西向的不对称结构有利于降水的非对称性发展;(5)非绝热加热项有利于加强降水的非对称性特征。Based on the improved ageostrophic wet Q-vector theory taking into account the role of di- abatic heating, asymmetric precipitation after landing of typhoon Koni （0907） was studied by using the NCEP reanalysis data and tropical rainfall measuring mission （TRMM） satellite data. The results indicate as follows ： （ 1 ） The rainband breaking occurred after typhoon landing. The precipitation distribution wasasymmetric and the heavy rain occurred at the second quadrant. （2） The ageostrophic wet Q-vector di- vergence can be used to describe the asymmetry of precipitation and its relation to precipitation. Heavy rain mainly occurred in the area of the high divergence gradient of ageostrophic wet Q-vector. （3） Along the direction of typhoon movement, the vertical circulation existed in rain area due to alternating of con- vergence and divergence of ageostrophic wet Q-vector. The asymmetric precipitation occurred due to the asymmetric structure of tilt upward current which existed in the vertical circulation. （4） There was a lati- tudinal secondary circulation across the typhoon center which had played a role in inhibiting precipitati- on. The transmeridional asymmetric structure in the latitudinal secondary circulation was in favor of the development of the asymmetric precipitation. （5） Diabatic heating was in favor of enhancing the asym- mety of precipitation.

关 键 词：台风 非对称降水 非地转湿Q矢量 垂直环流 次级环流 

分 类 号：P458.124[天文地球—大气科学及气象学]