风廓线雷达在一次短时暴雨过程中的应用

Application of Wind Profiler Radar in a Short Period Heavy Rain Process

利用2014年8月24日天津地区一次短时暴雨天气的3部风廓线雷达资料和降水实况资料,对比分析降水发生、维持和消亡期间风廓线雷达资料的变化特征,以探讨风廓线雷达对降水天气的监测能力。结果表明:1)风廓线雷达不仅能够反映大气层结上冷下暖的结构,并且能够探测到切变线的存在,对风的垂直结构有较强的探测能力。2)当降水出现时,垂直速度和大气折射率结构常数明显增大。4 m·s^(-1)的垂直速度出现和消失时刻,对应降水的开始和结束时刻;降水期间,4000 m高度以下的垂直速度越大降水越强。西青、静海站的折射率结构常数与降水强度之间有很好的对应关系,但不同地区的大气折射率结构常数值对降水强度的指示标准并不一致。3)在降水最强阶段,风廓线雷达数据获取率明显下降,因此低的数据获取率对强降水有一定的指示意义。

Base on data obtained from 3 wind profiler radars and conventional observational data during a short period heavy rain process on 24th August 2014 in Tianjin,the variation characteristics of wind profiler radar data at the different stages of rainfall including formation,development and dissipation are analyzed to study the monitor ability of wind profiler radar on precipitation.The results show are as follows.1)The wind profiler radar can not only reflect the unstable atmospheric structure with cold lower and warm upper,but also has capable of detecting the presence of shear line,which has a strong ability to detect the vertical structure of wind.2)The vertical velocity and refractive index structure constant increase obviously when precipitation appears.The appearing and disappearing time of 4 m·s-1 vertical velocity reflect the start and end of the rainfall and the greater the vertical velocity below 4000 m,the stronger the precipitation.There is a perfect correlation between the refractive index structure constant and the precipitation intensity in Xiqing and Jinghai stations.Although the refractive index structure constant as the indicator of precipitation intensity is not identical in different regions.3)The acquired rate of the wind profiler radar data would decrease significantly in heavy precipitation period.So the low acquired rate of data has certain indicative significance for strong precipitation.