by using the routine observation data,the satellite cloud images,the synoptics analysis and the physical quantity field diagnosis analysis,the heavy snowstorm process which happened in Northeast China during March 3 -5 in 2007 was analyzed. The results showed that the main influence systems in the process were the eastward shift and up north of southern cyclone ,the combination of south and north high-altitude trough in 500 hPa. The dynamic mechanisms of heavy snowstorm formation were the strong ascending movement which was caused by the configuration of high-layer divergence and low-layer convergence,the generation and maintenance of deep positive vorticity in the middle and low layers. The sufficient water vapor in East China Sea and South China Sea which was brought by 700 hPa low-altitude by south jet stream reached Northeast China.The falling zones of strong precipitation were consistent with the big value zones of 850 hPa positive vorticity and 200 hPa positive divergence.Meanwhile,the intensity of temperature advection and the position of cold warm transition zone could reflect well the intensity and falling zone of precipitation.%利用常规观测资料、卫星云图等资料,运用天气学分析和物理量场诊断分析,对2007年3月3～5日东北特大暴风雪过程进行分析.结果表明,此次过程的主要影响系统是南方气旋东移北上和500 hPa南北两支高空槽的合并.强暴雪形成的动力机制是高层辐散与低层辐合相配置导致的强上升运动,以及中低层深厚的正涡度的产生和维持.水汽来源是由700 hPa偏南低空急流携带东海和南海2个源地的充沛水汽抵达东北地区.强降水落区与850 hPa正涡度和200 hPa正散度大值区相一致,同时温度平流的强弱及冷暖过渡带位置能够很好地反映降水的强度及落区.
展开▼
