摘要
利用地面观测资料、NCEP1°×1°再分析资料和雷达探测资料,从能量、动力和触发机制等角度,对2009年6月3日发生在河南东部地区的一次飑线过程进行综合分析。结果表明:东北冷涡是此次飑线过程的主要影响系统,涡后冷空气南下与低层暖湿空气叠加造成对流不稳定,高层的干冷空气侵入增强了对流不稳定;低层辐合、高层辐散为飑线强对流天气的发生发展提供了强烈上升运动的动力条件,地面维持并加强的干线所激发的次级环流可能是这次飑线系统发生发展的重要机制之一;中低层的垂直风切变稳定维持、加强、迅速减小与飑线强对流天气发生发展前后对应较好,其演变特征对此次飑线过程有很好的指示意义。
Using observation data,NCEP 1°×1°reanalysis data,automatic weather stations and radar data,a squall line event occurred in the east of Henan on 3 June 2009 was analyzed.The results showed that this squall line event was mainly affected by the northeastern cold vortex.Cold air which in the rear of the vortex flowed southward and overlaid the moist and warm air in the boundary layer which brought about the convective instability,and intrusion of dry and cold air down from the upper troposphere strengthened this instability.The construction of lower-level convergence and upper-level divergence provided dynamic condition for vertical ascending motion.Secondary circulation forced by dry line which maintained and became stronger before and during this squall line event may be an important mechanism of this convective system.The change of mid-lower level vertical wind shear maintenance,intensification and rapid reduction corresponded to every stage of squall line,therefore,its evolution characteristic had well indicative meaning for this squall line event.
出处
《气象与减灾研究》
2010年第1期31-39,共9页
Meteorology and Disaster Reduction Research
基金
国家科技支撑计划课题(编号:2007BAC29B06)
淮河流域气象开放基金项目(编号:20080170)
关键词
飑线
干侵入
干线
垂直风切变
Squall line
Dry intrusion
Dry line
Vertical wind shear.
