一次积雨云降水过程的宏微观物理特征和雨水酸度的综合观测

1984年7月27日晚,在北京西郊北京大学综合观测了一场积雨云降水的全过程。包括两个降水过程:第一个降水过程持续时间短(33min),平均雨强大(12.9)mm/h),雨滴谱宽且出现多峰,降水pH值7.0左右;第二个降水过程的持续时间长(126min),平均雨强较弱(1.6mm/h),随降水的强烈冲刷,云下空气愈来愈干净,pH值连续下降至6.6,电导率也大大减小。

A comprehensive observation on macroscop and microscop physics and acidity of a Cb precipitation

In the evening of July 27th, 1984, a whole process of a cumulonimbers precipitation was observed in Peking University, which had two developing processes and two declining processes. The first process of precipitation lasted a short time(33min) and had a high average rainfall density (12.9mm/hr). The pH value of the first precipitation was about 7.0.The second process of precipitation kept a long time(126min) had a low average rainfall density 1.6mm/hr, With the strong washout of precipitation, the atmosphere under the cloud became cleaner. The pH value of the second precipitation dropped 6.6 continually and the conductance became down markebly.