河南省一次暴雪伴雷电天气的形成机理  

Formation Mechanism of a Case of Snowstorm with Lightning in Henan

作　　者：宋清芝 孙景兰[2] 吕晓娜 

机构地区：[1]河南省气象台,郑州450003 [2]河南省气象局,郑州450003

出　　处：《气象》2011年第5期583-589,共7页Meteorological Monthly

摘　　要：为探讨河南冬季暴雪伴雷电天气的成因,利用常规观测资料、雷达资料和NCEP的1°×1°的每6小时分析资料,分析此过程的天气形势特点、高低空急流的作用、雷达回波结构特征及反映动力、热力和水汽条件的相关物理量场的特征。结果发现,强降雪伴雷电现象发生时,逆温层的高度达到600 hPa以上;对流不稳定区出现在对流层中层,有利于上升运动向高层发展,促使云体高度的增高、雷电的产生;强降雪伴雷电现象发生在高低空急流的强盛时段,第一次雷电现象发生时,其中尺度不稳定中心在800 hPa附近;第二次雷电现象发生时,其中尺度不稳定中心在700～650 hPa之间;强降雪出现在高能舌的前部和锋区南侧的对流不稳定的叠加区;源源不断的水汽输送、两路强冷空气在低层聚集和对峙、强的对称性不稳定是暴雪维持的条件。To explore the causes for snowstorm with lightning in Henan,the weather situation,effects of upper and low level jets and related quantities which reflect dynamic,thermal and water vapor conditions have been analyzed based on the conventional observations,radar data and NCEP 1°×1°reanalysis data per 6 hours.Results show that the height of inversion layer can reach to higher levels than 600 hPa when a snowstorm with lightning happens.When a frontal zone of instability energy appears at the middle layer of troposphere,it is helpful to the development of ascending motion,which makes the height of cloud increase and the lightning occur.Snowstorm with lightning appears in the vigorous period of upper and lower level jets.The center of mesoscale instability is near 800 hPa when lightning happens firstly,while it is between 700 and 650 hPa at the second time.Snowstorm appears at the front of high energy tongue and superimposed area of convective instability.Sustained water vapor transport,the accumulation and confrontation at lower layer of two strong cold air currents and the strong symmetrical instability are the causes for the keep of snowstorm.

关 键 词：强降雪伴雷电现象 雷达风廓线 强冷空气 逆温层 中尺度不稳定 对称不稳定 

分 类 号：P458.121.1[天文地球—大气科学及气象学]