利用2007—2013年福建省区域自动站和基本气象站小时降水观测资料,确定精细时空尺度上热带气旋暴雨突然增幅的阈值标准,分析暴雨突然增幅的时空分布特征及其与同期热带气旋之间的关系。结果表明:满足1 h、3 h和6 h暴雨突然增幅的热带气旋个例数随时间分辨率的降低而明显减少;3 h突增个例数主要出现在6—10月,且个例数和突增次数年分布总体呈上升趋势,突增次数日变化呈现"三峰型",高值区位于17—20时;暴雨突然增幅的热带气旋大多数在福建中南部沿海登陆,且不同的热带气旋中,强度较弱时发生突增次数较多,极值最大;暴雨突然增幅大多数发生在热带气旋登陆后24 h、距中心400 km内、西南方向,与登陆路径有关。对比分析了热带气旋登陆福建前后暴雨突然增幅的特征,发现登陆中部的热带气旋个数最多、暴雨突增次数也最多;热带气旋登陆后暴雨突增次数明显比登陆前多。
Threshold standard for abrupt intensification of tropical cyclone rainstorms was given, and the temporal and spatial distributions of abruptly intensifying rainstorms and their relationship to tropical cyclones were analyzed, using hourly precipitation data from regional auto- matic weather stations and basic weather stations in Fujian province from 2007 to 2013. The results showed that the number of tropical cy- clones that produce abruptly intensifying rainstorms as defined for 1 h, 3 h, and 6 h decreases as the time resolution reduces. The tropical cyclones that had abrupt intensification of rainstorms for 3 h mainly occurred from June to October, and both the number of cases and the times of abrupt intensification of rainstorms have increased year by year. The diurnal variation of the times of abrupt intensification of rain- storms showed a triple-peaked pattern, and the high values occurred from 17:00 to 20:00. Most of the tropical cyclones that had abrupt in- tensification of rainstorms made a landfall on the middle and south coast of Fujian province. Among the various tropical cyclones, the weak- er the intensity was, the more times of abrupt rainfall intensification and the higher amplification of rainfall intensity occurred. The abrupt intensification of heavy rainfall mainly occurred within 24h after the tropical cyclones" landfall, in the southwest direction, and within 400 km of the center, relative to the landing track of the tropical cyclone. Characteristics of abrupt intensification of heavy rainfall were analyzed comparatively before and after the tropical cyclones" landfall in Fujian province. The results showed that the most tropical cyclones land at the middle coast, and they have the highest number of times of abrupt intensification of heavy rainfall. The times of abrupt intensification of heavy rainfall after landfall were clearly higher than that before landfall of the tropical cyclones.