【摘要】 利用FY-2G卫星云顶相当黑体温度(Black-Body Temperature,TBB)资料和NCEP(National Centers for Environmental Prediction)的1°×1°再分析资料,对2015年6月16—17日江淮流域中尺度涡旋引发的一次持续性梅雨期暴雨过程进行分析。结果表明:2015年江淮流域此次暴雨过程降水强度与MCV的增强和减弱及西南急流的强度一致,降水主要与MCV有关,MCV的形成与对流系统的发展密切联系,对流系统有组织的发展、大量潜热释放及低层辐合高层辐散的配置触发了MCV。由此次暴雨过程MCV与MCS的关系和结构特征可知:MCV从对流层低层一直伸展至对流层高层250 hPa,涡度最强中心位于对流层中低层。MCS有利于激发上升气流,湿Q矢量辐合与正涡度中心对应,有利于热量和水汽的垂直输送,加速MCV发展。MCV从产生至成熟阶段,中低层的水平平流项基本为负贡献,水平辐合辐散项决定MCV的形成和发展。此外,垂直运动直接影响涡度垂直输送项,从而影响MCV在垂直方向上的发展。更多还原

【Abstract】 Based on the equivalent black body temperature at the cloud top derived from FY-2 G and the NCEP( National Centers for Environmental Prediction) reanalysis data with resolutions of 1° × 1°,a sustained heavy rain in Yangtze-Huaihe river basin on June 16-17,2015 was analyzed. The results show that the intensity of this precipitation is essentially consistent with the evolution of mesoscale convective vortex( MCV) and the southwest jet.The MCV is triggered together by the latent heat release induced by the organized development of convection and the low-level convergence and upper-level divergence. The MCV extends from the lower troposphere to 250 hPa,and the strongest center for vorticity is at the middle-low level of the troposphere. During the mature stage,mesoscale convective system( MCS) can help to stimulate updraft and is a benefit to transport heat and water vapor because the convergence zone of wet Q vector corresponded to the center of positive vorticity,which promoted the development of MCV. The horizontal advection at the middle-lower level contributes negatively to the vorticity during the whole MCV stage. The formation and development of MCV is determined by the horizontal convergence and divergence. Ascending motion of the vortex has a direct impact on the vertical transportation of vorticity and further influences on the development of the vortex in the vertical.更多还原