飑线传播与发展及其引发地面强风过程个例分析

Propagation and Development of a Squall Line and Its Induced Server Wind

针对2006年4月28日发生在江苏境内的一次飑线过程,分析了过程期间的边界层特征、垂直结构和飑线的传播演变特征,讨论了飑线造成地面强风的物理原因。结果表明,在近地面层中,飑线首先在地面辐合线上激发并发展起来,当它向前传播时,边界层水平风场产生扰动,使飑线在近地面层的传播过程中表现出明显的波动特征,飑线后部降水区中降水质点的拖曳和下沉气流的共同作用是地面强风产生的关键。

For the squall line process occurred on 28 April 2006 in Jiangsu Province, the main characteristics, including its boundary layer, vertical structure, propagation evolution, and development, are analyzed. The physical causes of the surface strong wind caused by the squall line are also discussed. The results show that the squall line was activated and developed along a surface convergence line, when the squall line propagated downstream; it generated perturbation in horizontal wind field in the boundary layer, resulting in obvious disturbance features accompanying the squall line propagation. In addition, the drag effect of rain particles, in cooperation with the down stream at the back of squall line, played a crucial role in generating the surface strong wind.