摘要:基于历史航测数据，对Holroyd云粒子形状分类方法的阈值进行了改进，使得改进阈值后的Holroyd云粒子形状分类方法更适合机载云粒子成像仪（Cloud Imaging Probe, CIP）在我国华北地区所测冰晶粒子形状识别。将改进阈值后的方法应用于山西一次降水性层状云的飞机观测资料分析发现，此次降水性层云中无论在水平分布还是垂直分布上，出现频率在15%以上的冰晶粒子形状有4种，其中有3种较为固定，分别是霰、线形状和不规则状，另外一种形状则与具体的云内环境有关，垂直方向上不同温度区间内为枝状（?8～0°C）和微小状（?12～?8°C），不同高度的水平方向上则是枝状（5200 m）、微小状（5500 m）和板状（5800 m）；云中冰晶粒子数浓度在水平和垂直方向上波动较大，最小值小于1 L?1，最大值则大于20 L?1，垂直方向上的最大值分别位于每层云中的下部；云中冰水含量值在水平方向和垂直方向上波动范围也很大，其在垂直方向上的云中最大值区域与冰晶粒子数浓度的最大值区域基本一致。
关键词:冰晶粒子/
形状分类/
降水性层状云/
机载云粒子成像仪
Abstract:To apply Holroyd’s proposed cloud particle habit classification method to the ice particle measured by airborne cloud imaging probe (CIP) in northern China, this article improves the thresholds in the Holroyd’s cloud particle habit classification based on historical airborne measurement data, which makes the habit classification method more suitable for the ice particle measured by CIP in northern China. The improved threshold method is used to process and analyze the airborne measurement data from a precipitation stratus cloud in Shanxi Province. It is found that there are four types of ice particles with a frequency of occurrence greater than 15% in the vertical and horizontal distribution in this stratiform precipitation cloud; three among them are relatively fixed, namely, graupel, line shape, and irregular type. The fourth type is related to the specific cloud environment. In the vertical direction, it is dendrite (?8 to 0°C) or tiny (?12 to 8°C), and in the horizontal direction of different heights it is dendrite (5200 m) or tiny (5500 m) or plate (5800 m). The concentration of ice particles fluctuates widely in the horizontal and vertical distribution, with a minimum of less than 1 L?1 and a maximum of more than 25 L?1. The maximum values in the vertical distribution are located in the central and lower parts of the cloud. The ice water content in the cloud also fluctuates a lot in the horizontal and vertical direction. The maximum vertical value area in the cloud is basically consistent with the number concentration of ice particles.
Key words:Ice particle/
Habit classification/
Precipitation stratus cloud/
Airborne cloud image probe
PDF全文下载地址:
http://www.iapjournals.ac.cn/qhhj/article/exportPdf?id=20200407
