2018年登陆上海两个台风暴雨结构特征综合对比分析

利用常规天气资料、雷达资料及NCEP(1°×1°)再分析资料,对1812号台风"云雀"和1818号台风"温比亚"在上海和浙江产生的暴雨过程进行对比分析,结果表明:①"云雀"受副高南侧偏东气流引导,降水集中在台风南侧,"温比亚"受大陆高压南侧偏东气流引导,降水在台风两侧分布均匀,暴雨范围比"云雀"广,但暴雨中心强度比"云雀"弱。②"云雀"后期南侧杭州湾一带有弱冷空气侵入,大气对流不稳性增强,降水再次增强,"温比亚"后期大气为弱对流不稳定状态,降水逐渐减弱。③"温比亚"两侧水汽分布均匀,水汽通量大值区范围和强度比"云雀"大,但垂直方向上"云雀"辐合高度到达了对流层中上层。④"云雀"暴雨中心正好位于南亚高压主体南侧偏东气流中,更有利于高层辐散加强,产生强降水。

Comparative Analysis of Structural Characteritics of Two Typhoons Landing in Shanghai in 2018

Based on the regular weather data, radar data and NCEP 1°×1° reanalysis data, the rainstorms occurred in Shanghai and Zhejiang Coast produced by typhoon Jongdari (1812) and typhoon Rumbia (1818) are comparatively analyzed. The results show: (1) Jongdari was guided by the easterly wind of the south subtropical high and the precipitation is concentrated on the south side. Rumbia was guided by the easterly wind of the south continental high and the precipitation evenly distributes on both sides. The rainstorm of Rumbia was wider than that of Jongdari, but the center is weaker. (2) At the late period of Jongdari, cold air intruded from the Hangzhou Bay which increased atmospheric convective instability and made precipitation increase again. The atmosphere was in a weak convective instability state at the late period of Rumbia, whose precipitation weakened gradually. (3) The water vapor distribution on both sides of Rumbia was even, and the water vapor flux was greater in range and more intensive than that of Jongdari, whose convergence height in vertical direction reached up to the upper troposphere. (4) The rainstorm center of Jongdari was located in the east wind of the southern South Asian high, which was conducive to the strengthening of high level divergence and strong precipitation.