摘要
利用常规观测资料、ERA5再分析资料、多普勒天气雷达和双线偏振雷达以及自动站分钟级数据,通过诊断分析和风场反演,对2021年4月30日17—19时淮安地区发生的极端风雹天气的两个超级单体结构特征、维持机制和极端大风进行原因分析。结果表明:在500~700 hPa偏北急流背景下,地面强辐合中心和辐合区促使对流单体增强为超级单体风暴。淮安基准站的极端大风由超级单体A产生的下击暴流事件引发,表现为明显的风暴质心高度、最强回波高度和中气旋底高的下降,近地面层辐散风场等特征。产生强降雹的超级单体B最大反射率因子高度、风暴质心高度以及中气旋最强切变高度均达到湿球温度-20℃层高度以上。极端大风产生的原因包括强冰雹和大降水粒子下落过程中的重力拖曳和融化蒸发冷却,以及负浮力和低层强中气旋产生的垂直扰动气压梯度力。
In view of the extreme wind and hail weather in Huaian area from 17∶00 BST to 19∶00 BST on April 30,2021,by using conventional observation data,ERA5 reanalysis data,Doppler weather radar,dual polarization radar and automatic station minute data,through diagnosis analysis and wind field inversion,the structural characteristics,maintenance mechanism of two supercells and the causes of extreme gales caused by strong convective weather were analyzed.Results show that in the context of the 500-700 hPa northerly jet,the strong convergence center and convergence area on the ground promote the convective cell to become a supercell storm.The extreme gale at Huaian reference station is caused by the downburst event generated by supercell A,which is characterized by the obvious decline of storm centroid height,strongest echo height and mesocyclone bottom height,and the divergent wind field near the surface layer.The maximum reflectivity factor height,storm centroid height and the strongest shear height of mesocyclone of supercell B producing strong hail all reach above the height of wet bulb temperature-20℃.The causes of extreme gales include gravity drag and melting evaporative cooling in the falling process of heavy hail and heavy precipitation particles,negative buoyancy and vertical disturbance pressure gradient force generated by low-level strong mesocyclones.
作者
夏网萍
汤洁
庄潇然
慕瑞琪
安礼政
XIA Wangping;TANG Jie;ZHUANG Xiaorang;MU Ruiqi;AN Lizheng(Huaian Meteorological Bureau,Jiangsu Huaian 223000,China;Jiangsu Meteorological Observatory,Nanjing 210041,China;Key Laboratory of Transportation Meteorology,China Meteoroloical Administation,Nanjing 210041,China)
出处
《气象科学》
北大核心
2022年第6期835-843,共9页
Journal of the Meteorological Sciences
基金
南京气象科技创新研究院北极阁开放研究基金(BJG202103,BJG202208)
江苏省气象局青年基金资助项目(QK202014)。
