2010年8月19日阜新暴雨过程的多普勒雷达回波特征

利用营口多普勒雷达资料,对2010年8月19日出现在阜新南部的暴雨过程进行分析。结果表明：义县生成的强回波单体在东北上的过程中不断发展加强,最终形成从义县到彰武哈尔套的强回波带东移是造成此次暴雨到大暴雨过程的主要原因。同时通过对其回波强度、影响时间以及实况雨量的跟踪、对比和分析,得出小时降水量与回波强度关系：回波强度在35—45 dBz之间,小时降水量为25 mm;回波强度在45—50 dBz之间,小时降水量为40 mm;回波强度超过50 dBz,虽回波影响时间较短,不超过3个体扫,但小时降水量仍可达50 mm。低空急流的出现和加强为强降水的发展维持,提供了充足的水汽及不稳定能量,并促使雨带中的中尺度系统的生成和发展,是造成短时暴雨出现的关键因子。

Radar echo characteristics of a heavy rain process on August 19,2010 in Fuxin

Based on the Doppler radar data in Yingkou,a heavy rain process in the south of Fuxin on August 19,2010 was analyzed.The results indicate that a strong echo cell generated in Yixian county moves to the northeast and develops continually and strengthens,which forms a strong echo belt from Yixian county to Haertao of Zhangwu areas.The eastward movement of the strong echo belt is the main reason causing this process.The echo intensity,influencing duration and real precipitation are compared and analyzed.The relationship between the hourly precipitation and echo intensity is discussed.It shows that the hourly precipitation reaches 25 mm and 40 mm when echo intensity is between 35-45 dBz and between 45-50 dBz,respectively.The hourly precipitation can reach 50 mm when echo intensity exceeds 50 dBz,although echo influencing duration is short and less than 3 volume scanning periods.The occurrence and reinforcement of low-level jet provide sufficient water vapor and instability energy for this process and it makes the mesoscale system generation and development,which is the key factor causing the short time rainfall.