新疆层状云冰粒子属性的垂直分布特征

Vertical Distribution of Ice Particle Property in Sheet Cloud over Xinjiang

摘要: 层状云是新疆主要的降水云系，是开展人工增水作业的主要对象。利用2009~2010年CloudSat卫星2B-CLDCLASS和2B-CWC-RVOD数据集提供的云分类产品和冰粒子等效半径(IER)、冰粒子数浓度(INC)、冰水含量(IWC)三种微物理量，对新疆层状云季节变化的分析表明，层状云冬季云层厚度较薄为7 km，其他季节云层较厚为10 km。IER低(0~50 μm)、中(50~80 μm)、高(≥80 μm)三种值段年出现频率分别为18.0%、72.9%、9.2%，INC低(0~50 L⁻¹)、中(50~100 L⁻¹)、高(≥100 L⁻¹)三种值段年出现频率分别为85.7%、12.7%、1.5%，IWC低(0~50 mg•m⁻³)、中(50~100 mg•m⁻³)、高(≥100 mg•m⁻³)三种值段年出现频率分别为92.4%、6.5%、1.3%。在垂直高度上三种微物理量低、中值段出现频率随高度呈单峰分布，在云层中部出现较多。

Abstract: Sheet cloud is the main precipitation cloud system and the main target of artificially enhancing precipi-tation in Xinjiang. By use of the data from 2009 to 2010 of cloud classification product, ice particles equivalent radius (IER), ice particle number concentration (INC) and ice water content (IWC) obtained from CloudSat satellite, 2B-CLDCLASS dataset and 2B-CWC-RVOD dataset, meanwhile the analysis for seasonal change of sheet cloud in Xinjiang, it shows that the thickness of sheet cloud (7 km) in winter is thinner than that (10 km) in other seasons in Xinjiang. The occurrence frequency of low IER (0 - 50 μm), moderate IER (50 - 80 μm) and high IER (≥ 80μm) are respectively 18.0%, 72.9% and 9.2%; that of low INC (0 - 50 L⁻¹), moderate INC (50 - 100 L⁻¹) and high INC (≥ 100 L⁻¹) are respectively 85.7%, 12.7% and 1.5%; and that of low IWC (0 - 50 mg•m⁻³), moderate IWC (50 - 100 mg•m⁻³) and high IWC (≥ 100 mg•m⁻³) are respectively 92.4%, 6.5% and 1.3%. The occurrence frequency of low and moderate value section of IER, INC and IWC shows single-peak distribution in vertical height, and is much higher in the middle of the cloud.