Abstract:

By using altostratus, nimbostratus, stratocumulus and stratus liquid cloud water data in southwest China (Yunnan, Guizhou, Sichuan and Chongqing) from NASA/CERES L3 cloud data, the temporal-spatial distribution and change trend of liquid cloud water of four types clouds were analyzed from the annual and seasonal variation. The results show that the annual and seasonal liquid cloud water of four types clouds at low latitude region was greater than that at high latitude region, and liquid cloud water in Chongqing and Guizhou was greater than that in Yunnan and Sichuan. The annual and seasonal mean liquid cloud water of nimbostratus was the most, followed by stratus, altostratus and stratocumulus in turn. In southwest China, the annual mean liquid cloud water of four types clouds from 2001 to 2010 presented decreasing trend, and in autumn liquid cloud water of four types clouds was greater than that in spring. In spring, there were both decreasing and increasing trends in liquid cloud water of medium clouds (altostratus and nimbostratus), and there was decreasing trend in liquid cloud water of low clouds (stratocumulus and stratus). In autumn, there was decreasing trend in liquid cloud water of both medium and low clouds. The annual and seasonal mean liquid cloud water in nimbostratus and stratus decreased significantly.

Key words: cloud water, temporal-spatial distribution, change trend, types of cloud, southwest China

摘要：

利用NASA/CERES发布的L3级云资料，选取西南地区（云南、贵州、四川、重庆）2001～2010年水高层云、水雨层云、水层积云、水层云的云水含量数据，研究了该区域4种类型云的年和季节云水含量时空分布特征和变化趋势。结果表明：（1）4种类型云的年和季节云水含量均在海拔低的地方偏多，海拔高的地方偏少。重庆、贵州云水含量高于云南、四川；（2）水雨层云年和季节云水含量最大，其次为水层云和水高层云，水层积云云水含量最少；（3）近10 a来，整个西南地区4种类型云的年平均云水含量均呈递减趋势；（4）4种类型云的云水含量秋季高于春季；（5）春季，中云（水高层云、水雨层云）云水含量既有增加区域，也有减少区域，低云（水层积云、水层云）云水含量呈递减趋势；秋季，中云、低云云水含量均为递减趋势；水雨层云和水层云年和季节云水含量的递减趋势最显著。

关键词: 云水含量, 时空分布, 变化趋势, 云类型, 西南地区