临安一次梅雨锋暴雨过程的风廓线雷达

Analysis on Wind Profiling Radar Data of a Rainstorm at Lin’an

作者：

何妤斐杭州市余杭区气象局杭州 310000
高祝宇浙江省气象信息网络中心杭州 310000

中文摘要：

利用临安CFL-03型边界层风廓线雷达探测资料对2017年6月23—24日的一次梅雨锋暴雨过程进行了详细分析，结果表明风廓线雷达能够揭示江淮梅雨系统中的中尺度切变线特征，低空切变线是这次暴雨过程的降水主要集中在降水前段和后段的主要原因，高空西风急流使降水得以维持发展。由功率谱数据估算的回波强度反映了此次暴雨过程的发展变化细节，降水集中区的降水云体发展深厚，达到5km以上。垂直速度和大气折射率结构常数（Cn²）与降水的变化趋势一致，10mm的降水量对应的垂直速度接近7m/s，Cn²对数值接近-11。由于与降水的良好对应关系，风廓线雷达产品可以应用于强降水灾害天气的监测业务。

中文关键词：

风廓线雷达，暴雨，切变线，急流，回波强度，垂直速度，大气折射率结构常数

KeyWords：

wind profiling radar, rainstorm, shear line, jet, echo intensity, vertical velocity, Cn²

Abstract：

A Meiyu front rainstorm process from June 23, 2017 to June 24, 2017 is analyzed in detail by using CFL-03 boundary-layer wind profiling radar at Lin’an, and the results show that wind profiling radar observations are able to reflect characteristics of mesoscale shear line during the Meiyu front system. The main reason why precipitation is relatively concentrated at the beginning and end of this process is that low-level wind shear happens to move over Lin’an during those periods. Thanks to upper level jet, this rainstorm lasts a long time. Except wind profiles, radar echo intensity is estimated by power spectrum data to analyze the details of developments of the rainstorm, and it is found that precipitation cloud develops vigorously with height over 5 km. Other wind profiling radar products, such as vertical velocity and atmospheric refractive index structure constant (Cn²), change in an identical way comparing with the precipitation. When the precipitation is above 10 mm, vertical velocity is around 7 m/s and log of Cn² is around -11. Consequently, wind profiling radar products can be used to monitor rainstorm operationally.