边界层辐合线发展成飑线的数值试验

利用高分辨率η坐标模式，以一个实际飑线个例的常规资料为初值，通过嵌入一定强度的边界中层尺度辐合线，进行了边界层辐合线型飑线激发的数值试验，结果表明，飑线实例的大尺度环境场提供了累积的有效浮力能，小尺度积云对流则通过对流翻腾提供高层水汽凝结潜热加热和低层降温冷却，而中尺度幅合线通过提供带状辐合上升运动，起着胚胎和组织积云对流的作用，这样大、中、小三种尺度相互作用导致了边界层中尺度辐合线发展成为飑线。

NUMERICAL TRIAL OF PBL CONVERGENCE LINE DEVELOPING TO SQUALL LINE

Based on the conventional data of a actual case of squall line and inserted certain intensity PBL convergence line,numerical trial of motivation of squall line of PBL convergence line type is made by using improved high resolution ETA model.The result shows that macro scale cumulus convection field provides condensation heating in upper layer and temperature dropping in lower layer by convecting and churning,meso scale convergence line plays roles of embryo and organization effect by means of providing banded convergence ascending motion.Such an interaction among macro scale,meso scale and micro scale results in meso scale convergence line developing to squall line.