西北地区云和降水微物理特征个例分析

Case Study of Cloud and Precipitation Micro-physics Structure over Northwest China

为了提高人工催化的效果和成功率，准确地选择催化作业时机和最佳作业部位，利用装有粒子测量系统（PMS）的飞机对2001年5月28日中国西北地区春季层状云系进行了探测飞行。将所取得的微物理资料结合卫星云图、天气实况等资料进行了分析，发现：（1）该地区过冷水分布的温度区间较大，这为人工增雨提供了有利条件。（2）在该个例中：粒子平均直径主要在10～20μm之间；平均粒子浓度为18．3个·cm^-3；平均含水量为0．036g·m^-3，与新疆、河北、山东等省的含水量值相当。（3）二维图像分析表明，聚并和凝华过程是冰晶增长的主要过程。

In order to improve the effect of artificial rain enhancement, an aircraft equipped with the Particle Measuring System （PMS） probed the spring precipitable stratiform clouds over Northwest China on May 28, 2001. The micro-structure characteristics of thecloud system are analyzed by means of micro-physical data from the aircraft measurement, satellite cloud picture and synoptic background data, etc. The main results are as follows： （1） The super-cooled water occurred in a wide temperature range, which is favorable for artificial rain enhancement. （2） In this case, the average particle diameter is about 10～20μm, the average particle concentration is 18. 3cm^-3, and the average liquid water content is 0. 036 g· m^-3 ,which is similar to the value of Xinjiang, Hebei, and Shandong Provience, etc. （3） From the 2D image we can see that the coagulation and sublimation are the main processes for ice crystal growing.