陇东黄土高原一次超级单体降雹演化机制研究

Evolution Mechanism of a Supercell Hailstorm in Eastern Gansu Loess Plateau

利用西峰CD雷达资料,结合云图、探空及常规观测资料,对2021年10月1日傍晚发生在庆阳的一次超级单体风暴发生发展机制、环境背景、云物理特征及演变过程进行详细分析。结果表明,受500 hPa强西北气流及高低空冷暖平流影响,触发了此次强对流天气。探空图显示,对流发生前期有较大的位势不稳定能量,并且存在一定的对流抑制能量,0℃层高度及-20℃层的高度利于冰雹的产生及增长;云图分析显示,超级单体降雹主要由局地产生的对流云团发展移动而引发的,可见光云图上对流云团有明显的暗影存在;从雷达分析得出,此次风暴天气受超级单体影响,超级单体持续时间较长,钩状回波、前侧入流槽口及垂直积分液态水含量(VIL)跃变特征明显。

Using Xifeng CD radar data,combined with cloud images,soundings and conventional observation data,the environmental back-ground,cloud physical characteristics and evolution process of a supercell storm that occurred in the evening in Qingyang on 1 October 2021 were analyzed in detail.The results showed that the strong convective weather was triggered by the strong northwest airflow of 500 hPa and the advection of cold and warm at high and low altitudes.The sounding map showed that there was a large amount of geopotential instability energy in the early stage of convection,and there was a certain amount of convective inhibition energy.The height of the 0℃layer and the height of the-20℃layer were conducive to the generation and growth of hail.The analysis of cloud images showed that the hail fall of supercell was mainly caused by the development and movement of convective clouds generated locally,there were obvious shadows of convective clouds in visible light images.According to the radar analysis,the storm weather was influenced by the supercell,and the supercell lasted for a long time.The hook echo,the front inlet notch and the vertical cumulative liquid water content(VIL)value had obvious jump characteristics.