超级单体冰雹回波特征分析

Analysis on echo characteristics of supercell hail

本文使用MICAPS天气图、闪电数据、雷达回波等资料,采用天气学、雷达气象学的原理和方法,对2018—2022年江西4次超级单体冰雹回波特征进行分析。结果表明:(1)超级单体发生在500 hPa低槽东移过程和“上干下湿”的重叠地区。超级单体垂直速度区比较明显,正负速度梯度密集、分布零散,对应雷达回波上是典型的雷暴回波群超级单体结构。(2)赣州市石城观音坑超级单体冰雹直径≥2 cm,回波强度为65 dBZ,强回波面积为119 km^(2);南昌超级单体冰雹直径≥10 cm,回波强度≥70 dBZ,强回波面积为750 km^(2),并具有“盾”形回波结构;新余罗坊镇超级单体冰雹直径≥2 cm,回波强度为65 dBZ,强回波面积为280 km^(2);浮梁县经公桥镇、西湖乡微型超级单体冰雹直径≤2 cm,回波强度≤60 dBZ,强回波面积为119 km^(2)。(3)超级单体垂直积分液态水含量VIL≥60 kg·m^(-2),反射率因子垂直剖面RCS上回波强度≥65 dBZ,有回波核与倾斜;60 dBZ回波顶高在10 km以上。(4)超级单体“盾”形回波结构在底层1000~2000 m比较明显,层次越高有所分散,甚至形成多个回波中心。超级单体风暴中1000~4000 m高度风场变化比较杂乱,可见辐散、辐合等多种矢量流线,5000 m以上风场趋于一致。

Based on MICAPS weather maps,lightning data,radar echoes,and other data,the echo characteristics of four supercell hail events in Jiangxi from 2018 to 2022 were analyzed by using the principles and methods of meteorology and radar meteorology.Results show that:(1)super monomers occur in the overlapping area of the 500 hPa trough eastward migration process and“upper dry and lower wet”.The vertical velocity zone of the supercell is relatively obvious,with dense and scattered positive and negative velocity gradients,corresponding to a typical thunderstorm echo group supercell structure on the radar echo.(2)The diameter of the supercell hail in Guanyinkeng,Shicheng,Ganzhou City is≥2 cm,with an echo intensity of 65 dBZ and a strong echo area of 119 km^(2);the diameter of the supercell hail in Nanchang is≥10 cm,the echo intensity is≥70 dBZ,the strong echo area is 750 km^(2),and it has a shield shaped echo structure;super single hail occurred in Luofang Town,Xinyu,with a diameter of≥2 cm,an echo intensity of 65 dBZ,and a strong echo area of 280 km^(2);the diameter of micro supercell hail in Jinggongqiao Town and Xihu Township of Fuliang County is≤2 cm,the echo intensity is≤60 dBZ,and the strong echo area is 119 km^(2).(3)The vertical integrated liquid water content VIL of super monomers is≥60 kg·m^(-2),and the reflectivity factor on the vertical profile RCS has an echo intensity of≥65 dBZ,with echo nuclei and tilt;The top height of the 60 dBZ echo is above 10 km.(4)The super monomer“shield”shaped echo structure is more obvious at the bottom layer of 1000-2000 meters,and the higher the level,the more dispersed it is,and even multiple echo centers are formed.In supercell storms,the wind field changes at heights of 1000-4000 meters are relatively chaotic,with various vector streamlines such as divergence and convergence visible.Wind fields above 5000 meters tend to be consistent.