弱冰雹云雷达回波结构特征分析

Analysis on the Structure and Characteristic of Weak Hail Cloud Radar Echo

综合多种观测资料,对黑龙江省2005年初春产生的历史上少见的大范围冰雹天气进行了分析。讨论了雷达反射率因子与径向速度场的特征,着重分析回波演变过程中结构的变化。初春较低的温度,使得对流发展高度较低、强度较弱,不能使用通常的标准进行强天气判断。由于回波强度较弱,冰雹天气未出现典型特征回波,但径向速度特征表现的较为明显,在春季中尺度辐合辐散特征仍是较明显。对初春与其他季节产生冰雹的不同变化特征进行了分析和研究,对深入认识不同季节产生冰雹的雷达回波特征具有重要意义。

A big area hail weather occurred in Heilongjiang province in the early spring of 2005, which has been seldom seen in the history, is studied with radar and other observation data. The analysis is emphasized on the change in structure of the echo during the cloud developing, and also the discussion is laid on the relationship between radar reflectivity factor and radial velocity field. With relative low temperature in the spring the convective cloud did not develop high and strong, so the usual standards, with which we judge severe weather, do not work well in this case. Though the weak echo and no typical hail echo feature have been observed, the characteristic of radial velocity and meso-scale convergence and divergence in spring can be found quite clearly. The analysis and study of different characteristics between hail weathers taking place in early spring and other seasons, are highly significant for better understanding of the hail echo characteristics in different season.