本文利用欧洲中期天气预报中心第五代再分析资料、S波段多普勒雷达数据、"葵花8号"卫星云图、地面常规和区域自动站资料,对浙东南沿海2023年8月17日12级和8月22日10级雷暴大风过程进行对比研究.结果表明:2次雷暴大风过程时大气都有较好的静力不稳定条件及较大的大气可降水量,但两者发生的天气形势、环境参数和大风产生的机理等却截然不同.8月17日过程系下击暴流导致的雷暴大风天气过程,具有整层大气"上干下湿"、近地面温度层结呈现干绝热递减的典型雷暴大风层结结构,下沉有效位能DCAPE(downward con-vective available potential energy)大等特点;12级大风出现在单体弓形回波中,具有中层径向辐合、低层径向速度大值区等回波特征.8月22日过程系阵风锋导致的雷暴大风天气过程,在中等强度垂直风切变环境下,10级大风出现在弓形回波复合体前端的阵风锋里.阵风锋具有弧状弱窄带雷达回波特征,可见光云图上有弧状云线特征.
Comparative Study of Environmental Parameters and Radar Characteristics of Two Thunderstorms Gale Events in the Southeast Coast of Zhejiang
Using data from the fifth generation ECMWF reanalysis for global climate(ERA5),S-band Doppler radar,"Himawari 8"satellite and automatic surface weather observation stations,a comparative analysis of two cases of thunderstorm gale events in southeast coast of Zhejiang province on August 17th and 22nd,2023 was performed.The results showed:both events were characterized by favorable static instability conditions and a considerable amount of atmospheric precipitable water,however,the circulation background,environmental parameters and mechanisms of gale for each event differed significantly.The thunderstorm gale on August 17th was caused by downburst,displaying a classic thunderstorm wind structure characterized by"dryness above and wetness below",a dry adiabatic lapse rate near the surface and significant downward convective available potential energy(DCAPE);The wind force reached up to 12 occurred within a single-cell bow echo that was characterized by Mid-altitude radial convergence and significant low-level radial velocity.The event on August 22nd was induced by gust fronts.Under a medium-strength vertical wind shear environment,the gale appeared at the forefront of a gust front within a bow echo complex.The gust front was characterized by arc-shaped weak narrow band radar echoes,and there was an arc-shaped cloud line on the visible satellite cloud images.
万方数据
维普
