东北地区MCC雷达回波特征分析

2005年7月16日在黑龙江省北部地区出现中尺度对流辐合体(MCC),产生了雷暴、冰雹、龙卷、暴雨等强对流天气,尤其是齐齐哈尔北部间隔1小时10分钟发生了2个龙卷。利用雷达、FY-2卫星云图和相关资料,对这次MCC过程进行了分析,并对比高纬度MCC和非MCC强降雨的区别。结果表明:高纬度MCC雷达回波速度场上有明显中气旋,龙卷发生在MCC的发展阶段。物理量分析发现高纬度MCC比非MCC强降雨在水汽条件和动力因子上要求更高。地形在高纬度MCC的形成过程中起到很重要的作用,相同的背景条件下,在山脉的背风坡系统明显加强。

Analysis on MCC Echo Characters of Dopple Radar in Northeast China

At the night of July 16, 2005, the synoptic process of mesoscale convective complex (MCC) occurred in the north part of Heilongjiang Province. The severe convective weather phenomena including thunderstorm, tornado, hailstone, gust and heavy rainfall were observed. Two tornados occurred in the north part of Qiqihar within 70 minutes. The MCC is analyzed by using the Dopple radar data, the satellite data of FY 2 and other relevant data. The difference is analyzed between MCC and other general heavy rainfall processes in high latitudes. The result shows that the obvious mesocyclone can be found in the radar echoes of velocity for MCC. The tornado is generated in the developing stage of MCC. The characteristics of physical quantities show that the conditons for vapor and dynamical factors are required to be more critical for MCC than others. The terrain commonly plays an important role in the generation process of MCC in high latitudes. At the same synoptic situation, the system evolution occurs at the lee side of the mountains.