基于多源探测资料对四川一次冰雹天气的分析

利用多普勒雷达、地基微波辐射计、激光雨滴谱仪等资料,分析了宜宾2017年4月13日一次降雹过程,探讨新型探测资料在冰雹监测预警中的应用。研究结果表明:(1)阶梯槽是冰雹天气过程重要的环流形势,短波北槽触发了大气不稳定能量的爆发释放。0~6km存在较深厚的垂直风切变,0℃高度出现在约3.5km处。(2)此次降雹过程的回波特征为多单体强风暴,垂直结构上有回波悬垂和弱回波特征区,VIL有四次明显的跃增,20:44VIL密度值> 4g·m-3。(3)降雹前,0~10km相对湿度垂直分布存在“上下干,中间湿”的3层结构,K指数为40℃,降雹开始后相对湿度垂直分布存在“上干下湿”的2层结构,K指数波动较大;大气水汽总含量、大气液态水总量急剧增长,降雹发生在二者的波峰上。(4)雨滴谱仪观测到的降雹时段为20:56~21:19,最大冰雹直径为8.5mm;降水粒子的直径较小,大多数粒子直径只有0.2~1mm,雨滴谱呈双峰型分布特点,双峰上雨滴谱谱宽加大,雨强增大。 

Analysis of A Hailstorm Event in Sichuan Based on Multi-Source Data

Based on documents from Doppler radar,Ground-Based Microwave Radiometer and Laser Disdrometer,we analyze a hailstorm process on April 13th,2017,Yibin,and discuss the applications of the new detection data in the hail monitoring and warning.(1) The step trough is an important circulation pattern in hailstorm process,and the short wave north trough triggers the explosive release of instability energy.The deep of vertical section exists between 0~6km,and attitude of 0℃ exists in about 3.5km.(2) The radar echo character of this hailstorm process is:the appearance of bow's multi-cell convective storm,BEWR and suspension echo exists in vertical structures,VIL jumped evidently by four times,the density of VIL is greater than 4 g·m-3.(3) Before the hailstorm,the relative humidity manifests a 3-layer structure of vertical division,the K index is 40℃;in the process,the relative humidity manifests a 2-layer structure of vertical division,the K index fluctuates obviously;Total atmospheric water vapor content and total amount of atmospheric liquid water increases dramatically and hailstorm happens in the crest of wave.(4) The hailstorm interval observed by Laser Disdrometer is 20:56~21:19,the hail maximum diameter is 8.5mm;the diameter of precipitation particle is small,most of which are only 0.2~1mm,raindrop size distribution manifests a bimodal distribution,raindrop size widens and hailstorm increases on double front.