鄂东春季两次极端雷暴大风过程环境及雷达回波特征对比分析  

Comparative analysis of the environment and radar echo characteristics of two extreme thunderstorm gales in eastern Hubei in spring

作　　者：汤兴芝[1] 黄治勇[1] 王文玉[1] 姚望玲 顾永刚 TANG Xingzhi;HUANG Zhiyong;WANG Wenyu;YAO Wangling;GU Yonggang(Hubei Branch of China Meteorological Administration Training Centre,Wuhan 430074,China;Bureau of Meteorology of Wuhan Municipality,Wuhan 430074,China)

机构地区：[1]中国气象局气象干部培训学院湖北分院,武汉430074 [2]武汉市气象局,武汉430074

出　　处：《气象科学》2024年第5期961-973,共13页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(41975058)。

摘　　要：2021年5月10日和2022年3月16日,湖北省东部分别发生14级和12级的极端雷暴大风天气过程(简称“5·10”和“3·16”过程)。本文利用地面加密气象站的观测资料和ERA5逐小时0.25°×0.25°再分析资料及多普勒天气雷达等资料,对比分析了两次过程产生的环境背景和雷达回波特征。结果表明:(1)两次过程均受川东低槽和中低层低涡东部暖切变的影响,呈现上干冷下暖湿、低层辐合高层辐散的特征,表征雷暴大风的物理量如对流有效位能、下沉对流有效位能等极端异常,环境场有利于极端雷暴大风发生。(2)两次过程均由冷池出流形成阵风锋触发雷暴大风,但“5·10”过程还受其他地面中尺度辐合影响。(3)两次过程强风暴均由多个单体合并发展而成,“5·10”风暴高度更高,而“3·16”则强度更强,“5·10”表现出小弓状回波及其后侧弱回波通道特征;“3·16”弱回波区清晰,表现出类超级单体特征。(4)速度图上均表现出低仰角大风区和小尺度的辐散特征。“5·10”过程以低仰角大风区为主,大风由超低空急流叠加下击暴流造成;“3·16”过程则以中层径向辐合和最大反射率因子的快速下降特征为主,为下击暴流大风。Two thunderstorm gale processes with the Beaufort scale 14 and 12 occurred in estern Hubei on May 10,2021 and March 16,2022,respectively(called“5·10”and“3·16”processes).The environmental conditions and radar echo characteristics of the two processes were compared and analyzed by using the observation data of the ground encryption weather station,the 0.25°×0.25°hourly ERA5 datasets and the data of doppler weather radar.Results show:(1)The two processes are both affected by the eastern Sichuan trough and the warm shear in the eastern part of the low vortex in the middle and low levels,showing the characteristics of dry and cold in the upper layer,warm and wet in the lower layer,convergence in the lower layer and divergence in the upper layer.The physical quantities of thunderstorm gale,such as Convective Available Potential Energy(CAPE),the Down Convective Available Potential Energy(DCAPE),are extremely abnormal.The environmental field is conducive to the occurrence of extreme thunderstorm gale.(2)The two thunderstorm gales are both triggered by the the gust front formed by the outflow of the cold pool.But the“5·10”process is also affected by other mesoscale convergence on the ground.(3)The two strong storms are developed by the merger of several monomers,while the storm height of“5·10”is higher,while the strength of“3·16”is stronger.The“5·10”showes the characteristics of small bow echo and the weak echo channel in postero-lateral.The weak echo area of“3·16”is clear,showing the characteristics of supercell.(4)The velocity map shows the characteristics of low elevation gale area and small scale divergence.The“5·10”process is dominated by high wind areas at low elevations,which is caused by the superposition of ultra-low-level jets and downbursts.The“3·16”is caused by downburst gale with mid-altitude radial convergence and rapid decrease of maximum reflectivity factor as the main characteristics.

关 键 词：极端 雷暴大风 阵风锋 大风速区 小尺度辐散 

分 类 号：P458.123[天文地球—大气科学及气象学]