利用CALIPSO和CloudSat协同反演产品DARDAR四年数据，分析了中国地区各种光学厚度冰云的发生概率，水平和垂直方向的分布规律，季节变化及微物理特性差异。结果表明：我国冰云特性不仅有明显区域和季节变化特征，还与不同光学厚度所定义的冰云类型有关。中国区域主要发生薄冰云（0.03 < τ < 0.3）和不透明冰云（0.3 < τ < 3）较多，发生率高值区均在青藏高原地区。除不可见冰云（τ < 0.03）外，其余类型冰云的主要发生高度会随着光学厚度的增加而降低。不同类型冰云的季节变化并不明显，但是夏季更容易出现有利于光学较厚（τ>3）冰云发生的条件。微物理特性方面，冰水含量明显随冰云类型的变化而变化，而冰云有效粒子半径与高度的关系比与光学厚度的关系更为密切。全国冰云特征的平均数值并不能代表区域内的冰云特性，由光学厚度定义的不同种类冰云的具体分析极为重要。
Ice clouds are crucial to the Earth's radiation balance. Two active sensors, the CloudSat radar and the CALIPSO lidar, provide the opportunity to detect ice clouds over the global region. Data DARDAR (liDAR/raDAR) combines these two active sensors advantages to derive ice cloud products, which make obtain optical thin and thick ice cloud vertical properties possible. Based on the data product DARDAR from January 2013 to December 2016, the ice cloud occurrence frequency, horizontal and vertical distribution, seasonal variation and microphysical properties of various optical depth ice clouds in China were analyzed. The results show that the occurrence frequency of ice clouds is 52% over the last four years, which is higher in spring and summer than in autumn and winter and the occurrence height is mainly between 5 and 10 km. The mean ice cloud optical depth, ice water path, and effective radius of China are approximately 4, 157 g·m-2 and 51 μm, respectively. The properties of ice cloud in China not only have obvious regional and seasonal variation characteristics, but also related to the type of ice cloud defined by different optical depth τ values. Optically thin ice clouds (0.03 < τ < 0.3) and opaque ice clouds (0.3 < τ < 3) are the most frequently observed in China which account for approximately 65% of all ice cloud samples and the high concentration area is in the Qinghai-Tibet Plateau. Except for the subvisual ice clouds (τ < 0.03), the main occurrence height of other types of ice clouds decreases with the increase of optical depth. Seasonal changes of different types of ice clouds are not obvious except for thicker ice clouds (τ>20). The more thick ice clouds with τ>3 are more occurred in summer while the thin ice cloud with τ < 3 are more occurred in winter. In terms of microphysical properties, the ice water content (IWC) are changing with the variation of optical depth. The Probability Distribution Function (PDF) of subvisual ice clouds accumulate with the IWC distribution. However, the range of PDF increases with optical depth increasing and both of the IWC distribution range and mode value increase. The relationship between the effective particle radius and height of the ice cloud is more closely related to the optical depth. According to the vertical frequency distribution analysis, all types of ice cloud effective radius increases with height decreasing significantly, optically thinner ones (τ < 3) frequency distribution almost unanimously, while thicker ones (τ>3) effective radius is generally larger.
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