黄山不同高度雨滴谱的演变特征

选取2011年6月黄山地区一次降水过程,利用测得的雨滴谱资料对不同高度上降水微物理量及雨滴谱分布特征进行分析,并讨论其中的差异。结果表明:此次降水较强,各直径微物理量在山腰最大、山底次之、山顶最小;山腰的雨强最大,而山顶数浓度最大。在雨滴谱分布中,小于1mm的雨滴数密度是山顶大于山腰大于山底,这与小雨滴的蒸发和碰并有关;大于1.5 mm的雨滴数密度则是山腰大于山顶和山底,这可能与地形抬升使得云系加强有关。由各微物理量的时间序列可将降水过程分为两个阶段,第一阶段各微物理量值明显大于第二阶段,其中第一阶段的降水量约为第二阶段的3倍。雨强与雷达反射率、数浓度、最大直径近似成幂函数关系,其中雨强与雷达反射率相关性最好。

Raindrop size distribution at different altitudes in Mt. Huang

Based on the raindrop size distribution data observed in a precipitation process in Mt. Huang in June 2011,this paper studies the characteristics of raindrop size distribution and microphysical parameters at different altitudes as well as the discrepancy.It shows that all of the microphysical diameter parameters are the highest in the mountainside and the lowest in the mountaintop.The rainfall intensity is the highest in the mountainside,while the number concentration is the highest in the mountaintop.On the one hand,it is the highest in the mountaintop and the lowest in the mountain bottom that the number density of raindrops with diameter less than 1 mm,which is related to evaporation and collision coalescence of small raindrops,on the other hand,the number density of raindrops with diameter larger than 1.5 mm in the mountainside is lager than that in the mountaintop or the mountain bottom,which may be due to the topographic forcing.The precipitation process can be divided to two stages based on the time series of each microphysical parameter.The values of each microphysical parameter in the first stage are obviously higher than those in the second stage.The rainfall intensity in the first stage is about three times larger than that in the second stage.There are approximate power function relationships between rainfall intensity and radar reflectivity,number concentration and maximum diameter,and the correlation between rainfall intensity and radar reflectivity is the best.