基于 MODIS 和 CloudSat 的京津冀降水冰云季节分布特征

利用 2008 年 9 月~2016 年 8 月 Aqua MODIS 和 CloudSat 卫星数据，筛选出京津冀地区的降水 冰云，同时将其分为 4 个区域讨论，得到关于该地区降水冰云 4 个季节的分布特征，为该地区的人 工影响天气提供依据。结果表明：京津冀整个地区的降水冰云在夏季的发生率都较高，且发生率 有上升的趋势。从整个地区看来，京津冀地区的降水冰云的云顶高度在冬季最低、夏季最高，云顶 温度的最小值在冬季最高、夏季最低；京津冀地区的降水冰云在春夏秋 3 季均以单层云为主，而在 冬季则以双层云为主；京津冀地区的降水冰云的类型按春夏秋冬分别为 7 种、7 种、6 种和 5 种，且在 夏季该地区的降水冰云以深对流云为主（占 48.3%），而其他季节以雨层云为主；京津冀地区降水冰 云微物理量（包括冰水含量、粒子数浓度、粒子有效半径）主要分布高度分别为 0~13.5 km（春季）、 3.5~17.0 km（夏季）、1.0~14.0 km（秋季）、0~11.0 km（冬季）。冰水含量、粒子有效半径和粒子数浓度 的分布高度和最大值均在夏季最高，但粒子有效半径在秋季最低，冰水含量和粒子数浓度在冬季 最低。这 3 种微物理量随高度的分布特征夏季在京津冀各分区较为一致，都呈单峰结构，在其他季 节差异较大。

Seasonal distribution characteristics of precipitating ice clouds in Beijing- Tianjin-Hebei region based on MODIS and CloudSat

Beijing-Tianjin-Hebei is a region where water resources are scarce. Studying nonprecipitating and precipitating ice clouds is helpful for understanding the artificial precipitation enhancement potential and precipitation mechanism. Using the cloud product of CloudSat and Aqua MODIS from September 2008 to August 2016, the Beijing- Tianjin- Hebei region was divided into four sub- areas to study the distribution of precipitating ice clouds, including the occurrence probability, cloud top height and cloud top temperature, the number of cloud layers, cloud type, ice water content, particle concentration, and particle effective radius in the Beijing- Tianjin- Hebei region. Results show that the occurrence probability of precipitating ice clouds in Beijing-Tianjin-Hebei region is higher in summer with increasing incidence rate. The occurrence probability of precipitating ice clouds in 2012 is observed to be the highest, while the occurrence probability of precipitating ice clouds after 2012 is higher than that of the precipitating ice clouds before 2012. The cloud top height of the precipitating ice clouds cloud top in Beijing- Tianjin- Hebei is lowest in winter and the highest in summer. The minimum clout top temperature of the precipitating ice clouds in Beijing- Tianjin- Hebei is the highest in winter and the lowest in summer. The types of precipitation ice clouds in the Beijing-Tianjin-Hebei area are 7, 6, 6, and 5 in spring, summer, autumn, and winter, respectively. The precipitating ice clouds in this area are mainly deep convective clouds in summer (48.3%), while others are dominanted by nimbostratus. The main distribution height of the precipitating ice clouds’microphysical quantities (including ice water content, particle concentration, and particle effective radius) are 0- 13.5 km, 3.5- 17.0 km, 1.0- 14.0 km, and 0- 11.0 km according to the four seasons. The distribution height and the maximum value of ice water content and particle concentration are the lowest in winter and the highest in summer. The maximum height is the lowest in winter and highest in summer, and the maximum particle effective radius is the lowest in autumn and the highest in summer. In addition, in summer, the distribution characteristics of these three microphysical quantities with height are relatively consistent in Beijing-Tianjin-Hebei in summer with all having a single-peak structure.