强台风“纳沙”暴雨中尺度特征分析

Mesoscale characteristic analysis of rainstorm of violent typhoon “Neast”

利用海口多普勒天气雷达、闪电定位和日本静止卫星0.05°×0.05°TBB资料,对1117号强台风"纳沙"造成的海南岛暴雨的中尺度特征进行了分析。结果表明:台风暴雨分布特征与TC环流和地形增幅密切相关;明显的辐合性暖平流和"列车效应"有利于暴雨的持续;最大回波强度和小时雨量间有很好的对应关系,建议了海口多普勒雷达TC估测降水产品使用公式Z=230R1.25;海南岛强降水时段TBB值普遍小于-70℃,但仍属于降水效率高的弱对流;西半部地区强降水出现时间与中尺度对流云团对应较好,而东半部地区中尺度对流云团的发展则超前于强降水出现时间。

Based on data of Haikou Doppler Radar,Hainan lightning locating system and 0. 05° × 0. 05°TBB data of Japanese stationary satellite,the mesoscale characteristic of rainstorm caused by violent typhoon ' Neast' in Hainan Island was analyzed in this paper. The results show that,the distribution features of typhoon rainstorm are closely related with TC circulation and terrain enhancement; the remarkable convergence warm advection and ' the train effect' both are beneficial to the lasting rainstorm; the strongest echo intensity and hourly rainfall match well; the function Z = 230R1. 25 is suggested to be used for TC estimating precipitation production of Haikou Doppler Radar;though the TBB of heavy rainfall in Hainan Island is normally less than- 70 ℃,the heavy rainfall still belongs to weak convection with high rainfall efficiency; the occurring time of heavy rainfall in west half area matches well with mesoscale convective clouds,while the mesoscale convective clouds develop earlier than heavy rainfall in east half area.