多源探测资料在一次非线状MCS分析中的综合应用

用多种加密观测资料和NCEP日再分析资料分析了2010年7月14日强降水期间咸宁地区一次非线状MCS活动造成短时强降水的发生发展机制.结果表明,14日13-18时非线状MCS回波结构组织性差,强对流单体散乱地分布在大片层状回波中,准静止地维持在湖北咸宁地区大约5h,造成了短时强降水.该MCS发生在梅雨锋锋面附近的地面涡旋环流中,高空冷空气侵入和锋前抬升运动是对流的主要触发机制,切变线南侧不稳定的暖湿气流在长江中游地区辐合集中、局地的地面气流辐合和边界层有利的风切变是该非线状MCS发展维持在成宁地区的有利条件.高时空分辨率探测资料对MCS演变过程有较好的分析能力.

Synthetic Application of Multiple Intensified Observation Data in the Analysis of Nonlinear Mesoscale Convective System

Using multiple intensified observation data and NCEP daily reanalysis data, the development mechanism of a nonlinear mesoscale convective system (MCS) that caused a short time severe rainfall in Xianning City on 14 July 2010 is analyzed. The results show that the organization of nonlinear MCS is poor during 13:00-18:00 BT 14 July 2010. The strong convective cells are disorderly distributed in big stratiform echoes, keeping the quasi stationary front staying over Xianning about 5 h, and thus leading to the short time severe precipitation in Xianning. The nonlinear MCS generates in a surface vortex circulation near Meiyu front, and the convections are triggered primarily by upper cold air and lifting motion in front of the front. The favorite ambient conditions for the nonlinear MCS to maintain and develop are the convergence and concentration of unstable warm moist airflow on the southern side of the shear line over the middle reaches of Yangtze River, the mesosacle convergence of surface local airflow and the favorable wind shear of boundary layer. In general, the high spatial temporal resolution observation data can be well applied in analyzing the MCS evolution process.