2006年夏季祁连山北坡雨滴谱特征

Raindrop-size distribution characteristics of the northern face of Qilian Mountains in the summer of 2006

利用2006年夏季在祁连山北坡进行人工影响天气综合科学试验期问的激光雨滴谱仪观测资料,对该地区夏季不同云系降水的雨滴谱特征进行分析.结果表明:按照降水云系的结构,分别对对流云系、层状云系和混合云系降水情况下降水雨滴的直径分布进行比较,雨滴各种平均粒径由大到小排序依次是对流云系、混合云系和层状云系.降雨强度和雨滴粒子数密度变化趋势一致.雨滴粒径和降落速度之间有很好的对数关系.3类云系的降水强度和雷达回波强度之间也满足对数关系.通过这些分析为祁连山实施人工增雨(雪)提供一定的科学依据.

Using the data observed by a laser optical disdrometer in the northern face of Qilian Mountains in the summer of 2006, the raindrop-size distribution characteristics of precipitation of Qilian Mountain in summer were analyzed. The structure of precipitation cloud was classified into three main types based on the precipitation cloud system： convective cloud, stratiform cloud and mixed cloud. The results showed that there are differences of raindrop size distribution among the three kinds of cloud system. The mean value of diameters in convective cloud precipitation is larger than that in other two cloud systems, and the value in mixed cloud precipitation is bigger than that in stratiform clouds. There are good logarithmic relationships between the particle size and falling velocity of raindrops, as well as rain intensity and radar reflectivity. The temporal-spatial variation tendency of precipitation intensity is consistent with the density of raindrops.