【摘要】 为了提高对MCC致洪暴雨的预报和预警能力,利用卫星云图、MICAPS系统提供的资料以及多普勒雷达资料,对2006年7月2日黄河中游发生的一次中尺度对流复合体(MCC)和黄河中游暴雨天气过程进行了大尺度环境场和物理量的诊断分析以及三维流场结构分析。结果表明:MCC是造成暴雨的直接影响系统;对流层中低层深厚暖湿切变辐合的形成,配合对流层高层急流分支出口处生成中-α尺度强辐散、对流层低层华北冷空气南下倒灌锋生产生的动力抬升作用,形成有利于MCC生成发展的环流背景;MCC发生在高能、弱对流不稳定区;700hPa西南低空急流、850hPa分支南风气流为MCC的生成发展提供了充足的水汽和能量;涡度场和散度场的耦合、强烈上升运动的形成,成为MCC发生发展和维持的动力机制;多普勒雷达径向速度场显示,东南低空急流、配合西南低空急流的生成和稳定,西南低空急流左侧有气旋性辐合的维持、配合对流层中高层径向强辐散,构成MCC致洪暴雨的三维流场结构。更多还原

【Abstract】 In order to improve the capability of forecasting and warning of rainstorm-causing MCC,the diagnostic analysis was made on the synoptic cause and the 3-dimensional flow struc- ture of MCC on 2 July 2006 on the Middle Yellow River by using the satellite image,MICAPS and NCEP and Doppler radar data.The result shows that the MCC was the direct influence sys- tem,the formation of warm and wet shear convergence in the middle-low level,the a-scale diver- gence in the higher level,and the lifting force from low level caused by the cold air mass frontoge- nesis,all these circulation background are favorable to the MCC.The MCC occurred on high en- ergy and weak convective instability zone,where the southwest jet on 700hPa and south flow on 850 hPa provide plenty of water vapor and energy for MCC.The coupling of divergence field and vorticity field and the formation of updraft is the driving mechanism of MCC.The velocity images of Doppler radar show that the low southeast jet develops and maintains,the low jet to flow into the convergence line maintains and the bow-like a-scale divergence belt on middle high level de- velops and maintains,all these constitute the 3-dimensional flow structure of the MCC.更多还原