摘要
利用2006年7月—2009年4月的CloudSat2B-CLDCLASS云分类资料,针对中国及周边地区(0°—60°N,70°—140°E)各类云量和垂直结构参数的地理分布及季节变化进行了统计分析,并根据气候特征的地域差异从该区域选出8个子区域,逐区统计了各类云的垂直结构特征。结果表明,各类云量的分布存在较明显的区域差异和季节变化;青藏高原和帕米尔高原地区卷云、高层云和高积云等中高云的高度和厚度相对较小,陆上深对流云的云底高度大于海上,而热带、副热带地区云顶高度大于中纬度地区;除积云、层积云和雨层云外,中国南方地区其他各类云的云层厚度均大于北方地区;除了层积云外,其他各类云的云顶高度在各区域都存在比较明显的季节变化,低云云底高度的季节变化和区域差异都很小,而中高云的云底高度除了在印度洋季风区、南海和西太平洋地区季节差异较小外,其他地区季节差异较明显,各个地区在任何季节内,深对流云厚度最大,层积云最小;各类云出现频率随高度的分布具有较明显的区域差异;卷云与高积云的相关性比较强,经常相伴出现,夏季更加明显,而雨层云和深对流云之间相互排斥,两者几乎不可能同时出现。此外,统计中国及周边地区各类云的水平均一性发现,中高云的云底高度水平均一性较低云差,各类云中深对流云的云顶高度水平均一性最差,除了卷云和高积云的云顶高度水平均一性同其云底高度相当外,其他各类云的云顶高度水平均一性均比云底高度均一性差。
Based on the CloudSat 2B-CLDCLASS data from July 2006 to April 2009,the geographic distribution and seasonal characteristics of cloud amounts and the cloud vertical structure（CVS） for the particular cloud types over China and its neighborhood were analyzed.Also analyses of the CVS over 8 regions of China and its neighborhood were performed respectively.The results show that cloud amounts of different cloud types vary with territories and seasons apparently.The mean height and thickness of cirrus,altostratus and altocumulus clouds over the areas of the Tibetan Plateau and the Pamir Plateau are smaller than those over other areas.The cloud base height of deep convective cloud appears to be higher over lands,and there are higher average top heights of deep convective clouds in the tropics and subtropics than in the mid-latitude.For all cloud types except for cumulus,stratocumulus and nimbostratus,the mean thicknesses are larger over the south of China than those over the north.From the analysis of seasonal variation of cloud heights,we find that the cloud top heights of all cloud types except for stratocumulus have remarkable seasonal variation,and the cloud base heights of low clouds almost do not vary with territories and seasons.However,the cloud base heights of middle and high clouds appear to have obvious season variation over all regions except for the Indian Ocean monsoons zone,the South China Sea and the western Pacific.In any regions and seasons,the average thickness of deep convective clouds is the thickest and that of stratocumulus is the thinnest.The occurrence frequencies of cloud types at different heights vary with areas.As far as the simultaneous occurrence of different cloud types is concerned,cirrus and altocumulus tend to occur together,especially in summer,but nimbostratus and deep convective clouds do not.In deed,nimbostratus and deep convective clouds show a tendency to be somewhat mutually exclusive.Moreover,the statistics and analysis data on the homogeneity of cloud horizontal boundaries show that the cloud base heights of low clouds are more homogeneous than that of middle and high clouds,and cloud base heights of all cloud types except for cirrus and altocumulus whose cloud top and bottom homogeneities are comparable,are more homogeneous than cloud top heights.
出处
《气象学报》
CAS
CSCD
北大核心
2011年第5期883-899,共17页
Acta Meteorologica Sinica
关键词
CLOUDSAT
云类型
宏观特征
云垂直结构
CloudSat
Cloud type
Macroscopic characteristics
Cloud vertical structure
